Peter Vitousek
Clifford G. Morrison Professor of Population and Resource Studies, Professor of Earth System Science, Senior Fellow at the Woods Institute for the Environment and Professor, by courtesy, of Biology
Academic Appointments
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Professor, Biology
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Professor, Earth System Science
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Senior Fellow, Stanford Woods Institute for the Environment
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Professor, Biology
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Senior Fellow, Stanford Woods Institute for the Environment
Program Affiliations
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Center for East Asian Studies
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Center for Latin American Studies
Current Research and Scholarly Interests
Please see 'Short research description.'
2024-25 Courses
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Independent Studies (6)
- Directed Individual Study in Earth Systems
EARTHSYS 297 (Aut, Win, Spr, Sum) - Directed Reading in Environment and Resources
ENVRES 398 (Aut, Win, Spr, Sum) - Directed Research
EARTHSYS 250 (Aut, Win, Spr, Sum) - Directed Research in Environment and Resources
ENVRES 399 (Aut, Win, Spr, Sum) - Honors Program in Earth Systems
EARTHSYS 199 (Aut, Win, Spr, Sum) - Teaching Practicum in Biology
BIO 290 (Aut, Win, Spr, Sum)
- Directed Individual Study in Earth Systems
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Prior Year Courses
2023-24 Courses
- Island Ecology
ESS 16N (Aut)
2022-23 Courses
- Biology and Global Change
BIO 117, EARTHSYS 111, EARTHSYS 217, ESS 111 (Win) - Ecology of the Hawaiian Islands
BIO 116, SUSTAIN 116 (Aut)
2021-22 Courses
- Biology and Global Change
BIO 117, EARTHSYS 111, EARTHSYS 217, ESS 111 (Win) - Ecosystem Ecology and Biogeochemistry
BIO 147, BIO 240, EARTHSYS 147, EARTHSYS 247 (Aut)
- Island Ecology
Graduate and Fellowship Programs
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Biology (School of Humanities and Sciences) (Phd Program)
All Publications
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Changes in belowground biodiversity during ecosystem development
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2019; 116 (14): 6891–96
View details for DOI 10.1073/pnas.1818400116
View details for Web of Science ID 000463069900064
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Changes in belowground biodiversity during ecosystem development.
Proceedings of the National Academy of Sciences of the United States of America
2019
Abstract
Belowground organisms play critical roles in maintaining multiple ecosystem processes, including plant productivity, decomposition, and nutrient cycling. Despite their importance, however, we have a limited understanding of how and why belowground biodiversity (bacteria, fungi, protists, and invertebrates) may change as soils develop over centuries to millennia (pedogenesis). Moreover, it is unclear whether belowground biodiversity changes during pedogenesis are similar to the patterns observed for aboveground plant diversity. Here we evaluated the roles of resource availability, nutrient stoichiometry, and soil abiotic factors in driving belowground biodiversity across 16 soil chronosequences (from centuries to millennia) spanning a wide range of globally distributed ecosystem types. Changes in belowground biodiversity during pedogenesis followed two main patterns. In lower-productivity ecosystems (i.e., drier and colder), increases in belowground biodiversity tracked increases in plant cover. In more productive ecosystems (i.e., wetter and warmer), increased acidification during pedogenesis was associated with declines in belowground biodiversity. Changes in the diversity of bacteria, fungi, protists, and invertebrates with pedogenesis were strongly and positively correlated worldwide, highlighting that belowground biodiversity shares similar ecological drivers as soils and ecosystems develop. In general, temporal changes in aboveground plant diversity and belowground biodiversity were not correlated, challenging the common perception that belowground biodiversity should follow similar patterns to those of plant diversity during ecosystem development. Taken together, our findings provide evidence that ecological patterns in belowground biodiversity are predictable across major globally distributed ecosystem types and suggest that shifts in plant cover and soil acidification during ecosystem development are associated with changes in belowground biodiversity over centuries to millennia.
View details for PubMedID 30877251
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Restoration of ' Aina Malo'o on Hawai 'i Island: Expanding Biocultural Relationships
SUSTAINABILITY
2018; 10 (11)
View details for DOI 10.3390/su10113985
View details for Web of Science ID 000451531700159
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Soil fertility response to Ulex europaeus invasion and restoration efforts
BIOLOGICAL INVASIONS
2018; 20 (10): 2777–91
View details for DOI 10.1007/s10530-018-1729-9
View details for Web of Science ID 000445069800010
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Combining spectroscopic and isotopic techniques gives a dynamic view of phosphorus cycling in soil
NATURE COMMUNICATIONS
2018; 9: 3226
Abstract
Current understanding of phosphorus (P) cycling in soils can be enhanced by integrating previously discrete findings concerning P speciation, exchange kinetics, and the underlying biological and geochemical processes. Here, we combine sequential extraction with P K-edge X-ray absorption spectroscopy and isotopic methods (33P and 18O in phosphate) to characterize P cycling on a climatic gradient in Hawaii. We link P pools to P species and estimate the turnover times for commonly considered P pools. Dissolved P turned over in seconds, resin-extractable P in minutes, NaOH-extractable inorganic P in weeks to months, and HCl-extractable P in years to millennia. Furthermore, we show that in arid-zone soils, some primary mineral P remains even after 150 ky of soil development, whereas in humid-zone soils of the same age, all P in all pools has been biologically cycled. The integrative information we provide makes possible a more dynamic, process-oriented conceptual model of P cycling in soils.
View details for PubMedID 30104647
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Policy distortions, farm size, and the overuse of agricultural chemicals in China
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2018; 115 (27): 7010–15
Abstract
Understanding the reasons for overuse of agricultural chemicals is critical to the sustainable development of Chinese agriculture. Using a nationally representative rural household survey from China, we found that farm size is a strong factor that affects the use intensity of agricultural chemicals across farms in China. Statistically, a 1% increase in farm size is associated with a 0.3% and 0.5% decrease in fertilizer and pesticide use per hectare (P < 0.001), respectively, and an almost 1% increase in agricultural labor productivity, while it only leads to a statistically insignificant 0.02% decrease in crop yields. The same pattern was also found using other independently collected data sources from China and an international panel analysis of 74 countries from the 1960s to the 2000s. While economic growth has been associated with increasing farm size in many other countries, in China this relationship has been distorted by land and migration policies, leading to the persistence of small farm size in China. Removing these distortions would decrease agricultural chemical use by 30-50% and the environmental impact of those chemicals by 50% while doubling the total income of all farmers including those who move to urban areas. Removing policy distortions is also likely to complement other remedies to the overuse problem, such as easing farmer's access to modern technologies and knowledge, and improving environmental regulation and enforcement.
View details for PubMedID 29915067
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Response: Commentary: Rain, Sun, Soil, and Sweat: A Consideration of Population Limits on Rapa Nui (Easter Island) before European Contact
FRONTIERS IN ECOLOGY AND EVOLUTION
2018; 6
View details for DOI 10.3389/fevo.2018.00072
View details for Web of Science ID 000451661200001
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Plant acclimation to long-term high nitrogen deposition in an N-rich tropical forest
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2018; 115 (20): 5187–92
Abstract
Anthropogenic nitrogen (N) deposition has accelerated terrestrial N cycling at regional and global scales, causing nutrient imbalance in many natural and seminatural ecosystems. How added N affects ecosystems where N is already abundant, and how plants acclimate to chronic N deposition in such circumstances, remains poorly understood. Here, we conducted an experiment employing a decade of N additions to examine ecosystem responses and plant acclimation to added N in an N-rich tropical forest. We found that N additions accelerated soil acidification and reduced biologically available cations (especially Ca and Mg) in soils, but plants maintained foliar nutrient supply at least in part by increasing transpiration while decreasing soil water leaching below the rooting zone. We suggest a hypothesis that cation-deficient plants can adjust to elevated N deposition by increasing transpiration and thereby maintaining nutrient balance. This result suggests that long-term elevated N deposition can alter hydrological cycling in N-rich forest ecosystems.
View details for PubMedID 29717039
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Soil nutrients and pre-European contact agriculture in the leeward Kohala field system, Island of Hawai"i
ARCHAEOLOGY IN OCEANIA
2018; 53 (1): 28–40
View details for DOI 10.1002/arco.5138
View details for Web of Science ID 000428871300003
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Convergence and contrast in the community structure of Bacteria, Fungi and Archaea along a tropical elevation-climate gradient.
FEMS microbiology ecology
2017; 93 (5)
Abstract
Changes in species richness along climatological gradients have been instrumental in developing theories about the general drivers of biodiversity. Previous studies on microbial communities along climate gradients on mountainsides have revealed positive, negative and neutral richness trends. We examined changes in richness and composition of Fungi, Bacteria and Archaea in soil along a 50-1000 m elevation, 280-3280 mm/yr precipitation gradient in Hawai'i. Soil properties and their drivers are exceptionally well understood along this gradient. All three microbial groups responded strongly to the gradient, with community ordinations being similar along axes of environmental conditions (pH, rainfall) and resource availability (nitrogen, phosphorus). However, the form of the richness-climate relationship varied between Fungi (positive linear), Bacteria (unimodal) and Archaea (negative linear). These differences were related to resource-ecology and limiting conditions for each group, with fungal richness increasing most strongly with soil carbon, ammonia-oxidizing Archaea increasing with nitrogen mineralization rate, and Bacteria increasing with both carbon and pH. Reponses to the gradient became increasingly variable at finer taxonomic scales and within any taxonomic group most individual OTUs occurred in narrow climate-elevation ranges. These results show that microbial responses to climate gradients are heterogeneous due to complexity of underlying environmental changes and the diverse ecologies of microbial taxa.
View details for DOI 10.1093/femsec/fix045
View details for PubMedID 28402397
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Controls of nitrogen cycling evaluated along a well-characterized climate gradient.
Ecology
2017
Abstract
The supply of nitrogen (N) constrains primary productivity in many ecosystems, raising the question "what controls the availability and cycling of N"? As a step toward answering this question, we evaluated N cycling processes and aspects of their regulation on a climate gradient on Kohala Volcano, Hawaii, USA. The gradient extends from sites receiving <300 mm/yr of rain to those receiving >3,000 mm/yr, and the pedology and dynamics of rock-derived nutrients in soils on the gradient are well understood. In particular, there is a soil process domain at intermediate rainfall within which ongoing weathering and biological uplift have enriched total and available pools of rock-derived nutrients substantially; sites at higher rainfall than this domain are acid and infertile as a consequence of depletion of rock-derived nutrients, while sites at lower rainfall are unproductive and subject to wind erosion. We found elevated rates of potential net N mineralization in the domain where rock-derived nutrients are enriched. Higher-rainfall sites have low rates of potential net N mineralization and high rates of microbial N immobilization, despite relatively high rates of gross N mineralization. Lower-rainfall sites have moderately low potential net N mineralization, relatively low rates of gross N mineralization, and rates of microbial N immobilization sufficient to sequester almost all the mineral N produced. Bulk soil δ(15) N also varied along the gradient, from +4‰ at high rainfall sites to +14‰ at low rainfall sites, indicating differences in the sources and dynamics of soil N. Our analysis shows that there is a strong association between N cycling and soil process domains that are defined using soil characteristics independent of N along this gradient, and that short-term controls of N cycling can be understood in terms of the supply of and demand for N.
View details for DOI 10.1002/ecy.1751
View details for PubMedID 28130777
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Parent material and pedogenic thresholds: observations and a simple model
BIOGEOCHEMISTRY
2016; 130 (1-2): 147-157
View details for DOI 10.1007/s10533-016-0249-x
View details for Web of Science ID 000387274300011
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Climate-driven thresholds for chemical weathering in postglacial soils of New Zealand
JOURNAL OF GEOPHYSICAL RESEARCH-EARTH SURFACE
2016; 121 (9): 1619-1634
View details for DOI 10.1002/2016JF003864
View details for Web of Science ID 000392827000003
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The soil and plant biogeochemistry sampling design for The National Ecological Observatory Network
ECOSPHERE
2016; 7 (3)
View details for DOI 10.1002/ecs2.1234
View details for Web of Science ID 000374896800011
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Evidence for a Historic Change Occurring in China.
Environmental science & technology
2016; 50 (2): 505-6
View details for DOI 10.1021/acs.est.5b05972
View details for PubMedID 26709065
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Nitrogen fixation during decomposition of sugarcane (Saccharum officinarum) is an important contribution to nutrient supply in traditional dryland agricultural systems of Hawai'i
INTERNATIONAL JOURNAL OF AGRICULTURAL SUSTAINABILITY
2016; 14 (2): 214-230
View details for DOI 10.1080/14735903.2015.1071547
View details for Web of Science ID 000375915500005
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Evidence for a historic change occurring in China
Environmental Science and Technology
2016; 50: 505-506
View details for DOI 10.1021/acs.est.5b05972
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Identification and evaluation of risk factors related to provincial food insecurity in China
JOURNAL OF RISK RESEARCH
2015; 18 (9): 1184-1202
View details for DOI 10.1080/13669877.2014.913667
View details for Web of Science ID 000362881500005
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Using plant functional traits to restore Hawaiian rainforest
JOURNAL OF APPLIED ECOLOGY
2015; 52 (4): 805-809
View details for DOI 10.1111/1365-2664.12413
View details for Web of Science ID 000358004300001
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Integrated reactive nitrogen budgets and future trends in China.
Proceedings of the National Academy of Sciences of the United States of America
2015; 112 (28): 8792-8797
Abstract
Reactive nitrogen (Nr) plays a central role in food production, and at the same time it can be an important pollutant with substantial effects on air and water quality, biological diversity, and human health. China now creates far more Nr than any other country. We developed a budget for Nr in China in 1980 and 2010, in which we evaluated the natural and anthropogenic creation of Nr, losses of Nr, and transfers among 14 subsystems within China. Our analyses demonstrated that a tripling of anthropogenic Nr creation was associated with an even more rapid increase in Nr fluxes to the atmosphere and hydrosphere, contributing to intense and increasing threats to human health, the sustainability of croplands, and the environment of China and its environs. Under a business as usual scenario, anthropogenic Nr creation in 2050 would more than double compared with 2010 levels, whereas a scenario that combined reasonable changes in diet, N use efficiency, and N recycling could reduce N losses and anthropogenic Nr creation in 2050 to 52% and 64% of 2010 levels, respectively. Achieving reductions in Nr creation (while simultaneously increasing food production and offsetting imports of animal feed) will require much more in addition to good science, but it is useful to know that there are pathways by which both food security and health/environmental protection could be enhanced simultaneously.
View details for DOI 10.1073/pnas.1510211112
View details for PubMedID 26124118
View details for PubMedCentralID PMC4507225
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Provincial food security in China: a quantitative risk assessment based on local food supply and demand trends
FOOD SECURITY
2015; 7 (3): 621-632
View details for DOI 10.1007/s12571-015-0458-5
View details for Web of Science ID 000355346400015
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Long-Term Effects of Compost and Cover Crops on Soil Phosphorus in Two California Agroecosystems
SOIL SCIENCE SOCIETY OF AMERICA JOURNAL
2015; 79 (2): 688-697
View details for DOI 10.2136/sssaj2014.09.0369
View details for Web of Science ID 000351640900036
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Variation in Rapa Nui (Easter Island) land use indicates production and population peaks prior to European contact
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2015; 112 (4): 1025-1030
Abstract
Many researchers believe that prehistoric Rapa Nui society collapsed because of centuries of unchecked population growth within a fragile environment. Recently, the notion of societal collapse has been questioned with the suggestion that extreme societal and demographic change occurred only after European contact in AD 1722. Establishing the veracity of demographic dynamics has been hindered by the lack of empirical evidence and the inability to establish a precise chronological framework. We use chronometric dates from hydrated obsidian artifacts recovered from habitation sites in regional study areas to evaluate regional land-use within Rapa Nui. The analysis suggests region-specific dynamics including precontact land use decline in some near-coastal and upland areas and postcontact increases and subsequent declines in other coastal locations. These temporal land-use patterns correlate with rainfall variation and soil quality, with poorer environmental locations declining earlier. This analysis confirms that the intensity of land use decreased substantially in some areas of the island before European contact.
View details for DOI 10.1073/pnas.1420712112
View details for Web of Science ID 000348417000032
View details for PubMedID 25561523
View details for PubMedCentralID PMC4313829
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Grassland ecology: Complexity of nutrient constraints.
Nature plants
2015; 1: 15098-?
View details for DOI 10.1038/nplants.2015.98
View details for PubMedID 27250262
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Producing more grain with lower environmental costs
NATURE
2014; 514 (7523): 486-?
Abstract
Agriculture faces great challenges to ensure global food security by increasing yields while reducing environmental costs. Here we address this challenge by conducting a total of 153 site-year field experiments covering the main agro-ecological areas for rice, wheat and maize production in China. A set of integrated soil-crop system management practices based on a modern understanding of crop ecophysiology and soil biogeochemistry increases average yields for rice, wheat and maize from 7.2 million grams per hectare (Mg ha(-1)), 7.2 Mg ha(-1) and 10.5 Mg ha(-1) to 8.5 Mg ha(-1), 8.9 Mg ha(-1) and 14.2 Mg ha(-1), respectively, without any increase in nitrogen fertilizer. Model simulation and life-cycle assessment show that reactive nitrogen losses and greenhouse gas emissions are reduced substantially by integrated soil-crop system management. If farmers in China could achieve average grain yields equivalent to 80% of this treatment by 2030, over the same planting area as in 2012, total production of rice, wheat and maize in China would be more than enough to meet the demand for direct human consumption and a substantially increased demand for animal feed, while decreasing the environmental costs of intensive agriculture.
View details for DOI 10.1038/nature13609
View details for Web of Science ID 000343775900039
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Producing more grain with lower environmental costs.
Nature
2014; 514 (7523): 486-9
Abstract
Agriculture faces great challenges to ensure global food security by increasing yields while reducing environmental costs. Here we address this challenge by conducting a total of 153 site-year field experiments covering the main agro-ecological areas for rice, wheat and maize production in China. A set of integrated soil-crop system management practices based on a modern understanding of crop ecophysiology and soil biogeochemistry increases average yields for rice, wheat and maize from 7.2 million grams per hectare (Mg ha(-1)), 7.2 Mg ha(-1) and 10.5 Mg ha(-1) to 8.5 Mg ha(-1), 8.9 Mg ha(-1) and 14.2 Mg ha(-1), respectively, without any increase in nitrogen fertilizer. Model simulation and life-cycle assessment show that reactive nitrogen losses and greenhouse gas emissions are reduced substantially by integrated soil-crop system management. If farmers in China could achieve average grain yields equivalent to 80% of this treatment by 2030, over the same planting area as in 2012, total production of rice, wheat and maize in China would be more than enough to meet the demand for direct human consumption and a substantially increased demand for animal feed, while decreasing the environmental costs of intensive agriculture.
View details for DOI 10.1038/nature13609
View details for PubMedID 25186728
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Fertilizer nitrogen recovery efficiencies in crop production systems of China with and without consideration of the residual effect of nitrogen
ENVIRONMENTAL RESEARCH LETTERS
2014; 9 (9)
View details for DOI 10.1088/1748-9326/9/9/095002
View details for Web of Science ID 000344963500018
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Resilience against exotic species invasion in a tropical montane forest
JOURNAL OF VEGETATION SCIENCE
2014; 25 (3): 734-749
View details for DOI 10.1111/jvs.12112
View details for Web of Science ID 000334184300013
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Indicators of soil fertility and opportunities for precontact agriculture in Kona, Hawai'i
ECOSPHERE
2014; 5 (4)
View details for DOI 10.1890/ES13-00328.1
View details for Web of Science ID 000335010800005
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Litter quality versus soil microbial community controls over decomposition: a quantitative analysis
OECOLOGIA
2014; 174 (1): 283-294
Abstract
The possible effects of soil microbial community structure on organic matter decomposition rates have been widely acknowledged, but are poorly understood. Understanding these relationships is complicated by the fact that microbial community structure and function are likely to both affect and be affected by organic matter quality and chemistry, thus it is difficult to draw mechanistic conclusions from field studies. We conducted a reciprocal soil inoculum × litter transplant laboratory incubation experiment using samples collected from a set of sites that have similar climate and plant species composition but vary significantly in bacterial community structure and litter quality. The results showed that litter quality explained the majority of variation in decomposition rates under controlled laboratory conditions: over the course of the 162-day incubation, litter quality explained nearly two-thirds (64%) of variation in decomposition rates, and a smaller proportion (25%) was explained by variation in the inoculum type. In addition, the relative importance of inoculum type on soil respiration increased over the course of the experiment, and was significantly higher in microcosms with lower litter quality relative to those with higher quality litter. We also used molecular phylogenetics to examine the relationships between bacterial community composition and soil respiration in samples through time. Pyrosequencing revealed that bacterial community composition explained 32 % of the variation in respiration rates. However, equal portions (i.e., 16%) of the variation in bacterial community composition were explained by inoculum type and litter quality, reflecting the importance of both the meta-community and the environment in bacterial assembly. Taken together, these results indicate that the effects of changing microbial community composition on decomposition are likely to be smaller than the potential effects of climate change and/or litter quality changes in response to increasing atmospheric CO2 concentrations or atmospheric nutrient deposition.
View details for DOI 10.1007/s00442-013-2758-9
View details for Web of Science ID 000329624300027
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Pedogenic Thresholds and Soil Process Domains in Basalt-Derived Soils
ECOSYSTEMS
2013; 16 (8): 1379-1395
View details for DOI 10.1007/s10021-013-9690-z
View details for Web of Science ID 000327096100001
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The global nitrogen cycle in the twenty-first century
PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY B-BIOLOGICAL SCIENCES
2013; 368 (1621)
Abstract
Global nitrogen fixation contributes 413 Tg of reactive nitrogen (Nr) to terrestrial and marine ecosystems annually of which anthropogenic activities are responsible for half, 210 Tg N. The majority of the transformations of anthropogenic Nr are on land (240 Tg N yr(-1)) within soils and vegetation where reduced Nr contributes most of the input through the use of fertilizer nitrogen in agriculture. Leakages from the use of fertilizer Nr contribute to nitrate (NO3(-)) in drainage waters from agricultural land and emissions of trace Nr compounds to the atmosphere. Emissions, mainly of ammonia (NH3) from land together with combustion related emissions of nitrogen oxides (NOx), contribute 100 Tg N yr(-1) to the atmosphere, which are transported between countries and processed within the atmosphere, generating secondary pollutants, including ozone and other photochemical oxidants and aerosols, especially ammonium nitrate (NH4NO3) and ammonium sulfate (NH4)2SO4. Leaching and riverine transport of NO3 contribute 40-70 Tg N yr(-1) to coastal waters and the open ocean, which together with the 30 Tg input to oceans from atmospheric deposition combine with marine biological nitrogen fixation (140 Tg N yr(-1)) to double the ocean processing of Nr. Some of the marine Nr is buried in sediments, the remainder being denitrified back to the atmosphere as N2 or N2O. The marine processing is of a similar magnitude to that in terrestrial soils and vegetation, but has a larger fraction of natural origin. The lifetime of Nr in the atmosphere, with the exception of N2O, is only a few weeks, while in terrestrial ecosystems, with the exception of peatlands (where it can be 10(2)-10(3) years), the lifetime is a few decades. In the ocean, the lifetime of Nr is less well known but seems to be longer than in terrestrial ecosystems and may represent an important long-term source of N2O that will respond very slowly to control measures on the sources of Nr from which it is produced.
View details for DOI 10.1098/rstb.2013.0164
View details for Web of Science ID 000319502100013
View details for PubMedID 23713126
View details for PubMedCentralID PMC3682748
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Mahele: Sustaining Communities through Small-Scale Inshore Fishery Catch and Sharing Networks
PACIFIC SCIENCE
2013; 67 (3): 329-344
View details for DOI 10.2984/67.3.3
View details for Web of Science ID 000329260100003
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Long-term effects of agriculture on soil carbon pools and carbon chemistry along a Hawaiian environmental gradient
4th Conference on the Mechanisms of Organic Matter Stabilization and Destabilization (SOM) - Organic Matter Stabilization and Ecosystem Functions
SPRINGER. 2013: 229–43
View details for DOI 10.1007/s10533-012-9718-z
View details for Web of Science ID 000316018800017
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Irrigated taro (Colocasia esculenta) farming in North Kohala, Hawai'i sedimentology and soil nutrient analyses
JOURNAL OF ARCHAEOLOGICAL SCIENCE
2013; 40 (3): 1528-1538
View details for DOI 10.1016/j.jas.2012.08.028
View details for Web of Science ID 000315015000008
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Enhanced nitrogen deposition over China
NATURE
2013; 494 (7438): 459-462
Abstract
China is experiencing intense air pollution caused in large part by anthropogenic emissions of reactive nitrogen. These emissions result in the deposition of atmospheric nitrogen (N) in terrestrial and aquatic ecosystems, with implications for human and ecosystem health, greenhouse gas balances and biological diversity. However, information on the magnitude and environmental impact of N deposition in China is limited. Here we use nationwide data sets on bulk N deposition, plant foliar N and crop N uptake (from long-term unfertilized soils) to evaluate N deposition dynamics and their effect on ecosystems across China between 1980 and 2010. We find that the average annual bulk deposition of N increased by approximately 8 kilograms of nitrogen per hectare (P < 0.001) between the 1980s (13.2 kilograms of nitrogen per hectare) and the 2000s (21.1 kilograms of nitrogen per hectare). Nitrogen deposition rates in the industrialized and agriculturally intensified regions of China are as high as the peak levels of deposition in northwestern Europe in the 1980s, before the introduction of mitigation measures. Nitrogen from ammonium (NH4(+)) is the dominant form of N in bulk deposition, but the rate of increase is largest for deposition of N from nitrate (NO3(-)), in agreement with decreased ratios of NH3 to NOx emissions since 1980. We also find that the impact of N deposition on Chinese ecosystems includes significantly increased plant foliar N concentrations in natural and semi-natural (that is, non-agricultural) ecosystems and increased crop N uptake from long-term-unfertilized croplands. China and other economies are facing a continuing challenge to reduce emissions of reactive nitrogen, N deposition and their negative effects on human health and the environment.
View details for DOI 10.1038/nature11917
View details for Web of Science ID 000315661500034
View details for PubMedID 23426264
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Framing Sustainability in a Telecoupled World
ECOLOGY AND SOCIETY
2013; 18 (2)
View details for DOI 10.5751/ES-05873-180226
View details for Web of Science ID 000321257100044
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Traditional Ecological Values, Knowledge, and Practices in Twenty-First Century Hawai'i
14th Cary Conference on Linking Ecology and Ethics for a Changing World
SPRINGER. 2013: 63–70
View details for DOI 10.1007/978-94-007-7470-4_5
View details for Web of Science ID 000343412600005
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Biological nitrogen fixation: rates, patterns and ecological controls in terrestrial ecosystems.
Philosophical transactions of the Royal Society of London. Series B, Biological sciences
2013; 368 (1621): 20130119-?
Abstract
New techniques have identified a wide range of organisms with the capacity to carry out biological nitrogen fixation (BNF)-greatly expanding our appreciation of the diversity and ubiquity of N fixers-but our understanding of the rates and controls of BNF at ecosystem and global scales has not advanced at the same pace. Nevertheless, determining rates and controls of BNF is crucial to placing anthropogenic changes to the N cycle in context, and to understanding, predicting and managing many aspects of global environmental change. Here, we estimate terrestrial BNF for a pre-industrial world by combining information on N fluxes with (15)N relative abundance data for terrestrial ecosystems. Our estimate is that pre-industrial N fixation was 58 (range of 40-100) Tg N fixed yr(-1); adding conservative assumptions for geological N reduces our best estimate to 44 Tg N yr(-1). This approach yields substantially lower estimates than most recent calculations; it suggests that the magnitude of human alternation of the N cycle is substantially larger than has been assumed.
View details for DOI 10.1098/rstb.2013.0119
View details for PubMedID 23713117
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Fungal endophyte communities reflect environmental structuring across a Hawaiian landscape
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2012; 109 (32): 13022-13027
Abstract
We surveyed endophytic fungal communities in leaves of a single tree species (Metrosideros polymorpha) across wide environmental gradients (500-5,500 mm of rain/y; 10-22 °C mean annual temperature) spanning short geographic distances on Mauna Loa Volcano, Hawai'i. Using barcoded amplicon pyrosequencing at 13 sites (10 trees/site; 10 leaves/tree), we found very high levels of diversity within sites (a mean of 551 ± 134 taxonomic units per site). However, among-site diversity contributed even more than did within-site diversity to the overall richness of more than 4,200 taxonomic units observed in M. polymorpha, and this among-site variation in endophyte community composition correlated strongly with temperature and rainfall. These results are consistent with suggestions that foliar endophytic fungi are hyperdiverse. They further suggest that microbial diversity may be even greater than has been assumed and that broad-scale environmental controls such as temperature and rainfall can structure eukaryotic microbial diversity. Appropriately constrained study systems across strong environmental gradients present a useful means to understand the environmental factors that structure the diversity of microbial communities.
View details for DOI 10.1073/pnas.1209872109
View details for Web of Science ID 000307551700042
View details for PubMedID 22837398
View details for PubMedCentralID PMC3420199
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Long-term carbon storage through retention of dissolved aromatic acids by reactive particles in soil
GLOBAL CHANGE BIOLOGY
2012; 18 (8): 2594-2605
View details for DOI 10.1111/j.1365-2486.2012.02681.x
View details for Web of Science ID 000306228300020
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Mineralogical controls on soil black carbon preservation
GLOBAL BIOGEOCHEMICAL CYCLES
2012; 26
View details for DOI 10.1029/2011GB004109
View details for Web of Science ID 000304263400002
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Introduced Canopy Tree Species Effect on the Soil Microbial Community in a Montane Tropical Forest
PACIFIC SCIENCE
2012; 66 (2): 141-150
View details for DOI 10.2984/66.2.4
View details for Web of Science ID 000303625400004
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The Ahupua'a of Puanui: A Resource for Understanding Hawaiian Rain-Fed Agriculture
PACIFIC SCIENCE
2012; 66 (2): 161-172
View details for DOI 10.2984/66.2.6
View details for Web of Science ID 000303625400006
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The Climate Benefits of Better Nitrogen and Phosphorus Management
ISSUES IN SCIENCE AND TECHNOLOGY
2012; 28 (2): 85-91
View details for Web of Science ID 000307915400027
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Cyanolichens: a link between the phosphorus and nitrogen cycles in a Hawaiian montane forest
JOURNAL OF TROPICAL ECOLOGY
2012; 28: 73-81
View details for DOI 10.1017/S0266467411000605
View details for Web of Science ID 000299668700008
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Agricultural potential and actualized development in Hawai'i: an airborne LiDAR survey of the leeward Kohala field system (Hawai'i Island)
JOURNAL OF ARCHAEOLOGICAL SCIENCE
2011; 38 (12): 3605-3619
View details for DOI 10.1016/j.jas.2011.08.031
View details for Web of Science ID 000297384300043
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Are patterns in nutrient limitation belowground consistent with those aboveground: results from a 4 million year chronosequence
BIOGEOCHEMISTRY
2011; 106 (3): 323-336
View details for DOI 10.1007/s10533-010-9522-6
View details for Web of Science ID 000297360300003
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Dependence of Forest Structure and Dynamics on Substrate Age and Ecosystem Development
ECOSYSTEMS
2011; 14 (7): 1156-1167
View details for DOI 10.1007/s10021-011-9472-4
View details for Web of Science ID 000300144100009
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Integrated soil-crop system management for food security
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2011; 108 (16): 6399-6404
Abstract
China and other rapidly developing economies face the dual challenge of substantially increasing yields of cereal grains while at the same time reducing the very substantial environmental impacts of intensive agriculture. We used a model-driven integrated soil-crop system management approach to develop a maize production system that achieved mean maize yields of 13.0 t ha(-1) on 66 on-farm experimental plots--nearly twice the yield of current farmers' practices--with no increase in N fertilizer use. Such integrated soil-crop system management systems represent a priority for agricultural research and implementation, especially in rapidly growing economies.
View details for DOI 10.1073/pnas.1101419108
View details for Web of Science ID 000289680400020
View details for PubMedID 21444818
View details for PubMedCentralID PMC3080987
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Vegetation Effects on Soil Organic Matter Chemistry of Aggregate Fractions in a Hawaiian Forest
ECOSYSTEMS
2011; 14 (3): 382-397
View details for DOI 10.1007/s10021-011-9417-y
View details for Web of Science ID 000290492700004
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Cellulose delta O-18 is an index of leaf-to-air vapor pressure difference (VPD) in tropical plants
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2011; 108 (5): 1981-1986
Abstract
Cellulose in plants contains oxygen that derives in most cases from precipitation. Because the stable oxygen isotope composition, δ(18)O, of precipitation is associated with environmental conditions, cellulose δ(18)O should be as well. However, plant physiological models using δ(18)O suggest that cellulose δ(18)O is influenced by a complex mix of both climatic and physiological drivers. This influence complicates the interpretation of cellulose δ(18)O values in a paleo-context. Here, we combined empirical data analyses with mechanistic model simulations to i) quantify the impacts that the primary climatic drivers humidity (e(a)) and air temperature (T(air)) have on cellulose δ(18)O values in different tropical ecosystems and ii) determine which environmental signal is dominating cellulose δ(18)O values. Our results revealed that e(a) and T(air) equally influence cellulose δ(18)O values and that distinguishing which of these factors dominates the δ(18)O values of cellulose cannot be accomplished in the absence of additional environmental information. However, the individual impacts of e(a) and T(air) on the δ(18)O values of cellulose can be integrated into a single index of plant-experienced atmospheric vapor demand: the leaf-to-air vapor pressure difference (VPD). We found a robust relationship between VPD and cellulose δ(18)O values in both empirical and modeled data in all ecosystems that we investigated. Our analysis revealed therefore that δ(18)O values in plant cellulose can be used as a proxy for VPD in tropical ecosystems. As VPD is an essential variable that determines the biogeochemical dynamics of ecosystems, our study has applications in ecological-, climate-, or forensic-sciences.
View details for DOI 10.1073/pnas.1018906108
View details for Web of Science ID 000286804700045
View details for PubMedID 21245322
View details for PubMedCentralID PMC3033288
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Agriculture in Brazil: impacts, costs, and opportunities for a sustainable future
CURRENT OPINION IN ENVIRONMENTAL SUSTAINABILITY
2010; 2 (5-6): 431-438
View details for DOI 10.1016/j.cosust.2010.09.008
View details for Web of Science ID 000286088700015
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Understanding ecosystem retrogression
ECOLOGICAL MONOGRAPHS
2010; 80 (4): 509-529
View details for Web of Science ID 000283478800001
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Erosion, Geological History, and Indigenous Agriculture: A Tale of Two Valleys
ECOSYSTEMS
2010; 13 (5): 782-793
View details for DOI 10.1007/s10021-010-9354-1
View details for Web of Science ID 000280260100012
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Soil nutrient analysis of Rapa Nui gardening
ARCHAEOLOGY IN OCEANIA
2010; 45 (2): 80-85
View details for Web of Science ID 000280970200004
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Top-Down Analysis of Forest Structure and Biogeochemistry across Hawaiian Landscapes
PACIFIC SCIENCE
2010; 64 (3): 359-366
View details for Web of Science ID 000279480500001
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Significant Acidification in Major Chinese Croplands
SCIENCE
2010; 327 (5968): 1008-1010
Abstract
Soil acidification is a major problem in soils of intensive Chinese agricultural systems. We used two nationwide surveys, paired comparisons in numerous individual sites, and several long-term monitoring-field data sets to evaluate changes in soil acidity. Soil pH declined significantly (P < 0.001) from the 1980s to the 2000s in the major Chinese crop-production areas. Processes related to nitrogen cycling released 20 to 221 kilomoles of hydrogen ion (H+) per hectare per year, and base cations uptake contributed a further 15 to 20 kilomoles of H+ per hectare per year to soil acidification in four widespread cropping systems. In comparison, acid deposition (0.4 to 2.0 kilomoles of H+ per hectare per year) made a small contribution to the acidification of agricultural soils across China.
View details for DOI 10.1126/science.1182570
View details for Web of Science ID 000274625800043
View details for PubMedID 20150447
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Terrestrial phosphorus limitation: mechanisms, implications, and nitrogen-phosphorus interactions
ECOLOGICAL APPLICATIONS
2010; 20 (1): 5-15
Abstract
Nutrient limitation to primary productivity and other biological processes is widespread in terrestrial ecosystems, and nitrogen (N) and phosphorus (P) are the most common limiting elements, both individually and in combination. Mechanisms that drive P limitation, and their interactions with the N cycle, have received less attention than mechanisms causing N limitation. We identify and discuss six mechanisms that could drive P limitation in terrestrial ecosystems. The best known of these is depletion-driven limitation, in which accumulated P losses during long-term soil and ecosystem development contribute to what Walker and Syers termed a "terminal steady state" of profound P depletion and limitation. The other mechanisms are soil barriers that prevent access to P; transactional limitation, in which weathering of P-containing minerals does not keep pace with the supply of other resources; low-P parent materials; P sinks; and anthropogenic changes that increase the supply of other resources (often N) relative to P. We distinguish proximate nutrient limitation (which occurs where additions of a nutrient stimulate biological processes, especially productivity) from ultimate nutrient limitation (where additions of a nutrient can transform ecosystems). Of the mechanisms that drive P limitation, we suggest that depletion, soil barriers, and low-P parent material often cause ultimate limitation because they control the ecosystem mass balance of P. Similarly, demand-independent losses and constraints to N fixation can control the ecosystem-level mass balance of N and cause it to be an ultimate limiting nutrient.
View details for Web of Science ID 000275358100002
View details for PubMedID 20349827
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Prevalence of Tree Regeneration by Sprouting and Seeding Along a Rainfall Gradient in Hawai'i
BIOTROPICA
2010; 42 (1): 80-86
View details for DOI 10.1111/j.1744-7429.2009.00540.x
View details for Web of Science ID 000273301100012
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Landscape-level variation in forest structure and biogeochemistry across a substrate age gradient in Hawaii
ECOLOGY
2009; 90 (11): 3074-3086
Abstract
We compared forest canopy heights and nitrogen concentrations in long-term research sites and in 2 x 2 km landscapes surrounding these sites along a substrate age gradient in the Hawaiian Islands. Both remote airborne and ground-based measurements were used to characterize processes that control landscape-level variation in canopy properties. We integrated a waveform light detection and ranging (LiDAR) system, a high-resolution imaging spectrometer, and a global positioning system/inertial measurement unit to provide highly resolved images of ground topography, canopy heights, and canopy nitrogen concentrations (1) within a circle 50 m in radius focused on a long-term study site in the center of each landscape; (2) for the entire 2 x 2 km landscape regardless of land cover; and (3) after stratification, for our target cover class, native-dominated vegetation on constructional geomorphic surfaces throughout each landscape. Remote measurements at all scales yielded the same overall patterns as did ground-based measurements in the long-term sites. The two younger landscapes supported taller trees than did older landscapes, while the two intermediate-aged landscapes had higher canopy nitrogen (N) concentrations than did either young or old landscapes. However, aircraft-based analyses detected substantial variability in canopy characteristics on the landscape level, even within the target cover class. Canopy heights were more heterogeneous on the older landscapes, with coefficients of variation increasing from 23-41% to 69-78% with increasing substrate age. This increasing heterogeneity was associated with a larger patch size of canopy turnover and with dominance of most secondary successional stands by the mat-forming fern Dicranopteris linearis in the older landscapes.
View details for Web of Science ID 000271457300011
View details for PubMedID 19967863
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Opportunities and constraints for intensive agriculture in the Hawaiian archipelago prior to European contact
JOURNAL OF ARCHAEOLOGICAL SCIENCE
2009; 36 (10): 2374-2383
View details for DOI 10.1016/j.jas.2009.06.030
View details for Web of Science ID 000270001900032
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Changing sources of strontium to soils and ecosystems across the Hawaiian Islands
Annual Fall American-Geophysical-Union Meeting
ELSEVIER SCIENCE BV. 2009: 64–76
View details for DOI 10.1016/j.chemgeo.2009.01.009
View details for Web of Science ID 000270631000007
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Sources of nutrients to windward agricultural systems in pre-contact Hawai'i
ECOLOGICAL APPLICATIONS
2009; 19 (6): 1444-1453
Abstract
Prior to European contact in 1778, Hawaiians developed intensive irrigated pondfield agricultural systems in windward Kohala, Hawai'i. We evaluated three potential sources of nutrients to windward systems that could have sustained intensive agriculture: (1) in situ weathering of primary and secondary minerals in upland soils; (2) rejuvenation of the supply of rock-derived nutrients on eroded slopes and in alluvium; and (3) transport of rock-derived nutrients to crops via irrigation water. Our results show that most windward soils are infertile and suggest that weathering of minerals within upland soils was insufficient to sustain intensive agriculture without substantial cultural inputs. Erosion enhances weathering and so increases nutrient supply, with soils of the largest alluvial valleys (>200 m deep) retaining 37% of calcium from parent material (compared to 2% in upland sites). However, soils of smaller valleys that also supported pre-contact agricultural systems are substantially less enriched. Isotopic 87Sr/86Sr analyses of stream water demonstrate that at low to moderate stream flow over 90% of dissolved strontium derives from weathering of basalt rather than deposition of atmospheric sources; most other dissolved cations also derive from basalt weathering. We calculate that irrigation water could have supplied approximately 200 kg ha(-1) yr(-1) of calcium to pondfield systems, nearly 100 times more than was supplied by weathering in soils on stable geomorphic surfaces. In effect, irrigation waters brought nutrients from rocks to the windward crops.
View details for Web of Science ID 000269075200007
View details for PubMedID 19769093
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Agriculture. Nutrient imbalances in agricultural development.
Science
2009; 324 (5934): 1519-1520
View details for DOI 10.1126/science.1170261
View details for PubMedID 19541981
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Contrasting Predictors of Fern versus Angiosperm Decomposition in a Common Garden
BIOTROPICA
2009; 41 (2): 154-161
View details for DOI 10.1111/j.1744-7429.2008.00470.x
View details for Web of Science ID 000263747000003
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Nitrogen in Agriculture: Balancing the Cost of an Essential Resource
ANNUAL REVIEW OF ENVIRONMENT AND RESOURCES
2009; 34: 97-125
View details for DOI 10.1146/annurev.environ.032108.105046
View details for Web of Science ID 000272082000006
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Stoichiometry of ferns in Hawaii: implications for nutrient cycling
OECOLOGIA
2008; 157 (4): 619-627
Abstract
We asked if element concentrations in ferns differ systematically from those in woody dicots in ways that could influence ecosystem properties and processes. Phylogenetically, ferns are deeply separated from angiosperms; for our analyses we additionally separated leptosporangiate ferns into polypod ferns, a monophyletic clade of ferns which radiated after the rise of angiosperms, and all other leptosporangiate (non-polypod) ferns. We sampled both non-polypod and polypod ferns on a natural fertility gradient and within fertilized and unfertilized plots in Hawaii, and compared our data with shrub and tree samples collected previously in the same plots. Non-polypod ferns in particular had low Ca concentrations under all conditions and less plasticity in their N and P stoichiometry than did polypod ferns or dicots. Polypod ferns were particularly rich in N and P, with low N:P ratios, and their stoichiometry varied substantially in response to differences in nutrient availability. Distinguishing between these two groups has the potential to be useful both in and out of Hawaii, as they have distinct properties which can affect ecosystem function. These differences could contribute to the widespread abundance of polypod ferns in an angiosperm-dominated world, and to patterns of nutrient cycling and limitation in sites where ferns are abundant.
View details for DOI 10.1007/s00442-008-1108-9
View details for Web of Science ID 000259191000007
View details for PubMedID 18649088
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A unifying framework for dinitrogen fixation in the terrestrial biosphere
NATURE
2008; 454 (7202): 327-U34
Abstract
Dinitrogen (N(2)) fixation is widely recognized as an important process in controlling ecosystem responses to global environmental change, both today and in the past; however, significant discrepancies exist between theory and observations of patterns of N(2) fixation across major sectors of the land biosphere. A question remains as to why symbiotic N(2)-fixing plants are more abundant in vast areas of the tropics than in many of the mature forests that seem to be nitrogen-limited in the temperate and boreal zones. Here we present a unifying framework for terrestrial N(2) fixation that can explain the geographic occurrence of N(2) fixers across diverse biomes and at the global scale. By examining trade-offs inherent in plant carbon, nitrogen and phosphorus capture, we find a clear advantage to symbiotic N(2) fixers in phosphorus-limited tropical savannas and lowland tropical forests. The ability of N(2) fixers to invest nitrogen into phosphorus acquisition seems vital to sustained N(2) fixation in phosphorus-limited tropical ecosystems. In contrast, modern-day temperatures seem to constrain N(2) fixation rates and N(2)-fixing species from mature forests in the high latitudes. We propose that an analysis that couples biogeochemical cycling and biophysical mechanisms is sufficient to explain the principal geographical patterns of symbiotic N(2) fixation on land, thus providing a basis for predicting the response of nutrient-limited ecosystems to climate change and increasing atmospheric CO(2).
View details for DOI 10.1038/nature07028
View details for Web of Science ID 000257665300037
View details for PubMedID 18563086
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Invasive plants transform the three-dimensional structure of rain forests
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2008; 105 (11): 4519-4523
Abstract
Biological invasions contribute to global environmental change, but the dynamics and consequences of most invasions are difficult to assess at regional scales. We deployed an airborne remote sensing system that mapped the location and impacts of five highly invasive plant species across 221,875 ha of Hawaiian ecosystems, identifying four distinct ways that these species transform the three-dimensional (3D) structure of native rain forests. In lowland to montane forests, three invasive tree species replace native midcanopy and understory plants, whereas one understory invader excludes native species at the ground level. A fifth invasive nitrogen-fixing tree, in combination with a midcanopy alien tree, replaces native plants at all canopy levels in lowland forests. We conclude that this diverse array of alien plant species, each representing a different growth form or functional type, is changing the fundamental 3D structure of native Hawaiian rain forests. Our work also demonstrates how an airborne mapping strategy can identify and track the spread of certain invasive plant species, determine ecological consequences of their proliferation, and provide detailed geographic information to conservation and management efforts.
View details for DOI 10.1073/pnas.0710811105
View details for Web of Science ID 000254263300079
View details for PubMedID 18316720
View details for PubMedCentralID PMC2393775
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Amplified temperature dependence in ecosystems developing on the lava flows of Mauna Loa, Hawai'i
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2008; 105 (1): 228-233
Abstract
Through its effect on individual metabolism, temperature drives biologically controlled fluxes and transformations of energy and materials in ecological systems. Because primary succession involves feedbacks among multiple biological and abiotic processes, we expected it to exhibit complex dynamics and unusual temperature dependence. We present a model based on first principles of chemical kinetics to explain how biologically mediated temperature dependence of "reactant" concentrations can inflate the effective temperature dependence of such processes. We then apply this model to test the hypothesis that the temperature dependence of early primary succession is amplified due to more rapid accumulation of reactants at higher temperatures. Using previously published data from the lava flows of Mauna Loa, HI, we show that rates of vegetation and soil accumulation as well as rates of community compositional change all display amplified temperature dependence (Q(10) values of approximately 7-50, compared with typical Q(10) values of 1.5-3 for the constituent biological processes). Additionally, in young ecosystems, resource concentrations increase with temperature, resulting in inflated temperature responses of biogeochemical fluxes. Mauna Loa's developing ecosystems exemplify how temperature-driven, biologically mediated gradients in resource availability can alter the effective temperature dependence of ecological processes. This mechanistic theory should contribute to understanding the complex effects of temperature on the structure and dynamics of ecological systems in a world where regional and global temperatures are changing rapidly.
View details for DOI 10.1073/pnas.0710214104
View details for Web of Science ID 000252435300044
View details for PubMedID 18156366
View details for PubMedCentralID PMC2224191
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Morella cerifera invasion and nitrogen cycling on a lowland Hawaiian lava flow
BIOLOGICAL INVASIONS
2008; 10 (1): 19-24
View details for DOI 10.1007/s10530-007-9101-5
View details for Web of Science ID 000252473900003
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Precontact vegetation and soil nutrient status in the shadow of Kohala Volcano, Hawaii
26th Binghamton Geomorphology Symposium on Geomorphology and Ecosystems
ELSEVIER SCIENCE BV. 2007: 70–83
View details for DOI 10.1016/j.geomorph.2006.07.023
View details for Web of Science ID 000251894900006
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Development of a diverse epiphyte community in response to phosphorus fertilization
ECOLOGY LETTERS
2007; 10 (7): 628-636
Abstract
The role of terrestrial soil nutrient supply in determining the composition and productivity of epiphyte communities has been little investigated. In a montane Hawaiian rainforest, we documented dramatic increases in the abundance and species richness of canopy epiphytes in a forest that had been fertilized annually with phosphorus (P) for 15 years; there was no response in forest that had been fertilized with nitrogen (N) or other nutrients. The response of N-fixing lichens to P fertilization was particularly strong, although mosses and non-N-fixing lichens also increased in abundance and diversity. We show that enhancement of canopy P availability is the most likely factor driving the bloom in epiphytes. These results provide strong evidence that terrestrial soil fertility may structure epiphyte communities, and in particular that the abundance of N-fixing lichens--a functionally important epiphyte group--may be particularly sensitive to ecosystem P availability.
View details for DOI 10.1111/j.1461-0248.2007.01054.x
View details for Web of Science ID 000247123900009
View details for PubMedID 17542941
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Soil phosphorus and agricultural development in the leeward Kohala Field System, Island of Hawai'i
PACIFIC SCIENCE
2007; 61 (3): 347-353
View details for Web of Science ID 000246422000003
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Phosphorus fertilization increases the abundance and nitrogenase activity of the cyanolichen Pseudocyphellaria crocata in hawaiian montane forests
BIOTROPICA
2007; 39 (3): 400-405
View details for DOI 10.1111/j.1744-7429.2007.00267.x
View details for Web of Science ID 000245939300013
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Resource-use efficiency and plant invasion in low-resource systems
NATURE
2007; 446 (7139): 1079-1081
Abstract
No species can maximize growth, reproduction and competitive ability across all environments, so the success of invasive species is habitat-dependent. Nutrient-rich habitats often experience more invasion than resource-poor habitats, a pattern consistent with traits generally associated with successful invaders (high growth rates, early reproduction and many offspring). However, invaders do colonize resource-poor environments, and the mechanisms that allow their success in these systems are poorly understood. Traits associated with resource conservation are widespread among species adapted to resource-poor environments, and invasive species may succeed in low-resource environments by employing resource conservation traits such as high resource-use efficiency (RUE; carbon assimilation per unit of resource). We investigated RUE in invasive and native species from three habitats in Hawaii where light, water or nutrient availability was limiting to plant growth. Here we show that across multiple growth forms and broad taxonomic diversity invasive species were generally more efficient than native species at using limiting resources on short timescales and were similarly efficient when RUE measures were integrated over leaf lifespans. Our data challenge the idea that native species generally outperform invasive species under conditions of low resource availability, and suggest that managing resource levels is not always an effective strategy for invasive species control.
View details for DOI 10.1038/nature05719
View details for Web of Science ID 000245950400049
View details for PubMedID 17460672
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Uplift, erosion, and phosphorus limitation in terrestrial ecosystems
ECOSYSTEMS
2007; 10 (1): 158-170
View details for DOI 10.1007/s10021-006-9011-x
View details for Web of Science ID 000246766000014
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Risky business: Temporal and spatial variation in preindustrial dryland agriculture
HUMAN ECOLOGY
2006; 34 (6): 739-763
View details for DOI 10.1007/s10745-006-9037-x
View details for Web of Science ID 000241522400001
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Interactive effects of fire, elevated carbon dioxide, nitrogen deposition, and precipitation on a California annual grassland
ECOSYSTEMS
2006; 9 (7): 1066-1075
View details for DOI 10.1007/s10021-005-0077-7
View details for Web of Science ID 000242334600003
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Vegetation-climate interactions among native and invasive species in Hawaiian rainforest
ECOSYSTEMS
2006; 9 (7): 1106-1117
View details for DOI 10.1007/s10021-006-0124-z
View details for Web of Science ID 000242334600006
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Prehistoric agricultural depletion of soil nutrients in Hawai'i
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2006; 103 (29): 11092-11097
Abstract
We investigated the fate of soil nutrients after centuries of indigenous dryland agriculture in Hawai'i using a coupled geochemical and archaeological approach. Beginning approximately 500 years ago, farmers began growing dryland taro and sweet potato on the leeward slopes of East Maui. Their digging sticks pierced a subsurface layer of cinders, enhancing crop access to the soil water stored below the intact cinders. Cultivation also catalyzed nutrient losses, directly by facilitating leaching of mobile nutrients after disturbing a stratigraphic barrier to vertical water movement, and indirectly by increasing mineral weathering and subsequent uptake and harvest. As a result, centuries of cultivation lowered volumetric total calcium, magnesium, sodium, potassium, and phosphorus content by 49%, 28%, 75%, 37%, and 32%, respectively. In the absence of written records, we used the difference in soil phosphorus to estimate that prehistoric yields were sufficient to meet local demand over very long time frames, but the associated acceleration of nutrient losses could have compromised subsequent yields.
View details for DOI 10.1073/pnas.0604594103
View details for Web of Science ID 000239327200049
View details for PubMedID 16832047
View details for PubMedCentralID PMC1544177
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Business strategies for conservation on private lands: Koa forestry as a case study
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2006; 103 (26): 10140-10145
Abstract
Innovative financial instruments are being created to reward conservation on private, working lands. Major design challenges remain, however, to make investments in biodiversity and ecosystem services economically attractive and commonplace. From a business perspective, three key financial barriers for advancing conservation land uses must frequently be addressed: high up-front costs, long time periods with no revenue, and high project risk due to long time horizons and uncertainty. We explored ways of overcoming these barriers on grazing lands in Hawaii by realizing a suite of timber and conservation revenue streams associated with their (partial) reforestation. We calculated the financial implications of alternative strategies, focusing on Acacia koa ("koa") forestry because of its high conservation and economic potential. Koa's timber value alone creates a viable investment (mean net present value = $453/acre), but its long time horizon and poor initial cash flow pose formidable challenges for landowners. At present, subsidy payments from a government conservation program targeting benefits for biodiversity, water quality, and soil erosion have the greatest potential to move landowners beyond the tipping point in favor of investments in koa forestry, particularly when combined with future timber harvest (mean net present value = $1,661/acre). Creating financial mechanisms to capture diverse ecosystem service values through time will broaden opportunities for conservation land uses. Governments, nongovernmental organizations, and private investors have roles to play in catalyzing this transition by developing new revenue streams that can reach a broad spectrum of landowners.
View details for DOI 10.1073/pnas.0600391103
View details for Web of Science ID 000238872900070
View details for PubMedID 16782816
View details for PubMedCentralID PMC1502519
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Agricultural intensification: Will land spared from farming be land spared for nature?
CONSERVATION BIOLOGY
2006; 20 (3): 709-710
View details for DOI 10.1111/j.1523-1739.2006.00442.x
View details for Web of Science ID 000238313200028
View details for PubMedID 16909562
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Ecosystem science and human-environment interactions in the Hawaiian archipelago
Annual Meeting of the British-Ecological-Society
WILEY-BLACKWELL PUBLISHING, INC. 2006: 510–21
View details for DOI 10.1111/j.1365-2745.2006.01119.x
View details for Web of Science ID 000236717700001
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Persistence of rock-derived nutrients in the wet tropical forests of La Selva, Costa Rica
ECOLOGY
2006; 87 (3): 594-602
Abstract
We used strontium isotopes and analysis of foliar and soil nutrients to test whether erosion can rejuvenate the supply of rock-derived nutrients in the lowland tropical rain forest of La Selva, Costa Rica. We expected that these nutrients would be depleted from soils on stable surfaces, a result of over one million years of weathering in situ. In fact, trees and palms in all landscape positions derive a relatively high percentage (> or =40%) of their strontium from bedrock, rather than atmospheric, sources. The fraction that is rock-derived increases on slopes, but with no detectable effect on plant macronutrient concentrations. These results differ from those in a similar ecosystem on Kauai, Hawaii, where plants on uneroded surfaces derive almost all of their foliar Sr from atmospheric, rather than bedrock, sources. The results from La Selva challenge the assumption that tropical Oxisols in general have low nutrient inputs from bedrock, and support the hypothesis that erosion can increase the supply of these nutrients in lower landscape positions.
View details for Web of Science ID 000236289600008
View details for PubMedID 16602289
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Temperature influences carbon accumulation in moist tropical forests
ECOLOGY
2006; 87 (1): 76–87
Abstract
Evergreen broad-leaved tropical forests can have high rates of productivity and large accumulations of carbon in plant biomass and soils. They can therefore play an important role in the global carbon cycle, influencing atmospheric CO2 concentrations if climate warms. We applied meta-analyses to published data to evaluate the apparent effects of temperature on carbon fluxes and storages in mature, moist tropical evergreen forest ecosystems. Among forests, litter production, tree growth, and belowground carbon allocation all increased significantly with site mean annual temperature (MAT); total net primary productivity (NPP) increased by an estimated 0.2-0.7 Mg C x ha(-1) x yr(-1) x degrees C(-1). Temperature had no discernible effect on the turnover rate of aboveground forest biomass, which averaged 0.014 yr(-1) among sites. Consistent with these findings, forest biomass increased with site MAT at a rate of 5-13 Mg C x ha(-1) x degrees C(-1). Despite greater productivity in warmer forests, soil organic matter accumulations decreased with site MAT, with a slope of -8 Mg C x ha(-1) x degrees C(-1), indicating that decomposition rates of soil organic matter increased with MAT faster than did rates of NPP. Turnover rates of surface litter also increased with temperature among forests. We found no detectable effect of temperature on total carbon storage among moist-tropical evergreen forests, but rather a shift in ecosystem structure, from low-biomass forests with relatively large accumulations of detritus in cooler sites, to large-biomass forests with relatively smaller detrital stocks in warmer locations. These results imply that, in a warmer climate, conservation of forest biomass will be critical to the maintenance of carbon stocks in moist tropical forests.
View details for DOI 10.1890/05-0023
View details for Web of Science ID 000236020000009
View details for PubMedID 16634298
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Consensus on climate change
TRENDS IN ECOLOGY & EVOLUTION
2005; 20 (12): 648-649
View details for DOI 10.1016/j.tree.2005.10.008
View details for Web of Science ID 000233878700003
View details for PubMedID 16701450
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Interactive effects of elevated CO2, N deposition and climate change on extracellular enzyme activity and soil density fractionation in a California annual grassland
GLOBAL CHANGE BIOLOGY
2005; 11 (10): 1808-1815
View details for Web of Science ID 000232390200022
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Ground-based and remotely sensed nutrient availability across a tropical landscape
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2005; 102 (31): 10909-10912
Abstract
Tropical soils often are assumed to be highly weathered and thus nutrient-depleted, but this prediction applies primarily to geomorphically stable surfaces. Topography complicates the assumption of nutrient depletion, because erosion can enhance the supply of nutrients to tropical ecosystems. Consequently, understanding nutrient availability across landscapes requires a spatially explicit assessment of the relative strength of depletion and enhancement. We document the relationship between foliar nutrients and topographic position across a 20-km(2), 4- to 5-million-year-old eroded landscape in Kaua'i, Hawai'i, and use this relationship to build a bottom-up map of predicted nutrient availability across this landscape. Only approximately 17% of the landscape is nutrient-poor, mostly on stable uplands; nutrient availability on slopes and valley bottoms is much higher, in some cases similar to the most fertile montane forests in the Hawaiian Islands. This pattern was corroborated by top-down remote sensing of area-integrated canopy phosphorus concentrations.
View details for DOI 10.1073/pnas.0504929102
View details for Web of Science ID 000231102400033
View details for PubMedID 16040798
View details for PubMedCentralID PMC1182458
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Ca cycling and isotopic fluxes in forested ecosystems in Hawaii
GEOPHYSICAL RESEARCH LETTERS
2005; 32 (11)
View details for DOI 10.1029/2005GL022746
View details for Web of Science ID 000229985800003
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The influence of nutrient availability on soil organic matter turnover estimated by incubations and radiocarbon modeling
ECOSYSTEMS
2005; 8 (4): 352-372
View details for DOI 10.1007/s10021-004-0259-8
View details for Web of Science ID 000230804500002
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Responses of extracellular enzymes to simple and complex nutrient inputs
SOIL BIOLOGY & BIOCHEMISTRY
2005; 37 (5): 937-944
View details for DOI 10.1016/j.soilbio.2004.09.014
View details for Web of Science ID 000228242300014
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Short-term controls over inorganic phosphorus during soil and ecosystem development
SOIL BIOLOGY & BIOCHEMISTRY
2005; 37 (4): 651-659
View details for DOI 10.1016/j.soilbio.2004.08.022
View details for Web of Science ID 000226872900005
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Remote analysis of biological invasion and biogeochemical change
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2005; 102 (12): 4383-4386
Abstract
We used airborne imaging spectroscopy and photon transport modeling to determine how biological invasion altered the chemistry of forest canopies across a Hawaiian montane rain forest landscape. The nitrogen-fixing tree Myrica faya doubled canopy nitrogen concentrations and water content as it replaced native forest, whereas the understory herb Hedychium gardnerianum reduced nitrogen concentrations in the forest overstory and substantially increased aboveground water content. This remote sensing approach indicates the geographic extent, intensity, and biogeochemical impacts of two distinct invaders; its wider application could enhance the role of remote sensing in ecosystem analysis and management.
View details for DOI 10.1073/pnas.0500823102
View details for Web of Science ID 000227854800030
View details for PubMedID 15761055
View details for PubMedCentralID PMC554001
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Interactive effects of elevated CO2, N deposition and climate change on plant litter quality in a California annual grassland
OECOLOGIA
2005; 142 (3): 465-473
Abstract
Although global changes can alter ecosystem nutrient dynamics indirectly as a result of their effects on plant litter quality, the interactive effects of global changes on plant litter remain largely unexplored in natural communities. We investigated the effects of elevated CO2, N deposition, warming and increased precipitation on the composition of organic compounds in plant litter in a fully-factorial experiment conducted in a California annual grassland. While lignin increased within functional groups under elevated CO2, this effect was attenuated by warming in grasses and by water additions in forbs. CO2-induced increases in lignin within functional groups also were counteracted by an increase in the relative biomass of forbs, which contained less lignin than grasses. Consequently, there was no net change in the overall lignin content of senesced tissue at the plot level under elevated CO2. Nitrate additions increased N in both grass and forb litter, although this effect was attenuated by water additions. Relative to changes in N within functional groups, changes in functional group dominance had a minor effect on overall litter N at the plot level. Nitrate additions had the strongest effect on decomposition, increasing lignin losses from Avena litter and interacting with water additions to increase decomposition of litter of other grasses. Increases in lignin that resulted from elevated CO2 had no effect on decomposition but elevated CO2 increased N losses from Avena litter. Overall, the interactions among elements of global change were as important as single-factor effects in influencing plant litter chemistry. However, with the exception of variation in N, litter quality had little influence on decomposition over the short term.
View details for DOI 10.1007/s00442-004-1713-1
View details for PubMedID 15558326
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Imaging spectroscopy studies of Hawaniian ecosystems, carbon properties, and disturbance
Conference on Image Processing and Pattern Recognition in Remote Sensing II
SPIE-INT SOC OPTICAL ENGINEERING. 2005: 1–8
View details for DOI 10.1117/12.588738
View details for Web of Science ID 000227661700001
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Erosion and landscape development affect plant nutrient status in the Hawaiian Islands
OECOLOGIA
2005; 142 (3): 440-449
Abstract
We quantified variation in plant nutrient concentrations and provenance along catenas in landscapes of three different ages (0.15, 1.4, and 4.1 ma) in the Hawaiian Islands. Strontium (Sr) isotopes demonstrate that erosion provides a renewed source of rock-derived nutrients to slopes in landscapes of all ages, in some cases reversing a million years of ecosystem development in a distance of 100 m. However the effects of this input vary with landscape age. Plants on uneroded surfaces in a 0.15-ma landscape derive approximately 20% of their Sr from local bedrock (foliar 87Sr/86Sr approximately 0.7085), while on adjacent slopes this increases to approximately 80% (foliar 87Sr/86Sr approximately 0.7045). Despite this shift in provenance, foliar N and P do not vary systematically with slope position. Conversely, eroded slopes in a 4.1-ma landscape show smaller increases in rock-derived cations relative to stable uplands (foliar 87Sr/86Sr approximately 0.7075 vs 0.7090), but have >50% higher foliar N and P. These results demonstrate both that erosion can greatly increase nutrient availability in older landscapes, and that the ecological effects of erosion vary with landscape age. In addition, there can be as much biogeochemical variation on fine spatial scales in eroding landscapes as there is across millions of years of ecosystem development on stable surfaces.
View details for DOI 10.1007/s00442-004-1743-8
View details for Web of Science ID 000226357400012
View details for PubMedID 15538635
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Rapid nutrient cycling in leaf litter from invasive plants in Hawai'i
OECOLOGIA
2004; 141 (4): 612-619
Abstract
Physiological traits that contribute to the establishment and spread of invasive plant species could also have impacts on ecosystem processes. The traits prevalent in many invasive plants, such as high specific leaf areas, rapid growth rates, and elevated leaf nutrient concentrations, improve litter quality and should increase rates of decomposition and nutrient cycling. To test for these ecosystem impacts, we measured initial leaf litter properties, decomposition rates, and nutrient dynamics in 11 understory plants from the Hawaiian islands in control and nitrogen + phosphorus fertilized plots. These included five common native species, four of which were ferns, and six aggressive invasive species, including five angiosperms and one fern. We found a 50-fold variation in leaf litter decay rates, with natives decaying at rates of 0.2-2.3 year(-1) and invaders at 1.4-9.3 year(-1). This difference was driven by very low decomposition rates in native fern litter. Fertilization significantly increased the decay rates of leaf litter from two native and two invasive species. Most invasive litter types lost nitrogen and phosphorus more rapidly and in larger quantities than comparable native litter types. All litter types except three native ferns lost nitrogen after 100 days of decomposition, and all litter types except the most recalcitrant native ferns lost >50% of initial phosphorus by the end of the experiment (204-735 days). If invasive understory plants displace native species, nutrient cycling rates could increase dramatically due to rapid decomposition and nutrient release from invasive litter. Such changes are likely to cause a positive feedback to invasion in Hawai'i because many invasive plants thrive on nutrient-rich soils.
View details for DOI 10.1007/s00442-004-1679-z
View details for Web of Science ID 000224999800007
View details for PubMedID 15549401
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An exotic tree alters decomposition and nutrient cycling in a Hawaiian montane forest
ECOSYSTEMS
2004; 7 (8): 805-814
View details for DOI 10.1007/s10021-004-0009-y
View details for Web of Science ID 000226163400003
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Extracellular enzyme activities and carbon chemistry as drivers of tropical plant litter decomposition
BIOTROPICA
2004; 36 (3): 285-296
View details for Web of Science ID 000223742800002
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Environment, agriculture, and settlement patterns in a marginal Polynesian landscape
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2004; 101 (26): 9936-9941
Abstract
Beginning ca. A.D. 1400, Polynesian farmers established permanent settlements along the arid southern flank of Haleakala Volcano, Maui, Hawaiian Islands; peak population density (43-57 persons per km(2)) was achieved by A.D. 1700-1800, and it was followed by the devastating effects of European contact. This settlement, based on dryland agriculture with sweet potato as a main crop, is represented by >3,000 archaeological features investigated to date. Geological and environmental factors are the most important influence on Polynesian farming and settlement practices in an agriculturally marginal landscape. Interactions between lava flows, whose ages range from 3,000 to 226,000 years, and differences in rainfall create an environmental mosaic that constrained precontact Polynesian farming practices to a zone defined by aridity at low elevation and depleted soil nutrients at high elevation. Within this productive zone, however, large-scale agriculture was concentrated on older, tephra-blanketed lava flows; younger flows were reserved for residential sites, small ritual gardens, and agricultural temples.
View details for DOI 10.1073/pnas.0403470101
View details for Web of Science ID 000222405600075
View details for PubMedID 15210963
View details for PubMedCentralID PMC470777
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Soils, agriculture, and society in precontact Hawai
SCIENCE
2004; 304 (5677): 1665-1669
Abstract
Before European contact, Hawai'i supported large human populations in complex societies that were based on multiple pathways of intensive agriculture. We show that soils within a long-abandoned 60-square-kilometer dryland agricultural complex are substantially richer in bases and phosphorus than are those just outside it, and that this enrichment predated the establishment of intensive agriculture. Climate and soil fertility combined to constrain large dryland agricultural systems and the societies they supported to well-defined portions of just the younger islands within the Hawaiian archipelago; societies on the older islands were based on irrigated wetland agriculture. Similar processes may have influenced the dynamics of agricultural intensification across the tropics.
View details for Web of Science ID 000221934300049
View details for PubMedID 15192228
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Biological and geochemical sinks for phosphorus in soil from a wet tropical forest
ECOSYSTEMS
2004; 7 (4): 404-419
View details for DOI 10.1007/s10021-004-0264-y
View details for Web of Science ID 000222319200009
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Erosion and the rejuvenation of weathering-derived nutrient supply in an old tropical landscape
ECOSYSTEMS
2003; 6 (8): 762-772
View details for DOI 10.1007/s10021-003-0199-8
View details for Web of Science ID 000187308500005
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Polyphenols in litter from tropical montane forests across a wide range in soil fertility
BIOGEOCHEMISTRY
2003; 64 (1): 129-148
View details for Web of Science ID 000184413200007
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Breaks in the cycle: dissolved organic nitrogen in terrestrial ecosystems
FRONTIERS IN ECOLOGY AND THE ENVIRONMENT
2003; 1 (4): 205-211
View details for Web of Science ID 000221789900023
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Landslides significantly alter land cover and the distribution of biomass: an example from the Ninole ridges of Hawai'i
PLANT ECOLOGY
2003; 166 (1): 131-143
View details for Web of Science ID 000182132400011
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Nitrogen fixation in bryophytes, lichens, and decaying wood along a soil-age gradient in Hawaiian montane rain forest
BIOTROPICA
2003; 35 (1): 12-19
View details for Web of Science ID 000182530700002
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An unexpected nitrate decline in New Hampshire streams
ECOSYSTEMS
2003; 6 (1): 75-86
View details for DOI 10.1007/s10021-002-0219-0
View details for Web of Science ID 000181088800007
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Stoichiometry and flexibility in the Hawaiian model system
Conference on Element Interactions
ISLAND PRESS. 2003: 117–133
View details for Web of Science ID 000221668200006
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Interactions of climate change with biological invasions and land use in the Hawaiian Islands: Modeling the fate of endemic birds using a geographic information system
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
2002; 99 (22): 14246-14249
Abstract
The Hawaiian honeycreepers (Drepanidae) represent a superb illustration of evolutionary radiation, with a single colonization event giving rise to 19 extant and at least 10 extinct species [Curnutt, J. & Pimm, S. (2001) Stud. Avian Biol. 22, 15-30]. They also represent a dramatic example of anthropogenic extinction. Crop and pasture land has replaced their forest habitat, and human introductions of predators and diseases, particularly of mosquitoes and avian malaria, has eliminated them from the remaining low- and mid-elevation forests. Landscape analyses of three high-elevation forest refuges show that anthropogenic climate change is likely to combine with past land-use changes and biological invasions to drive several of the remaining species to extinction, especially on the islands of Kauai and Hawaii.
View details for Web of Science ID 000178967400052
View details for PubMedID 12374870
View details for PubMedCentralID PMC137869
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Soil phosphorus fractions and symbiotic nitrogen fixation across a substrate-age gradient in Hawaii
ECOSYSTEMS
2002; 5 (6): 587-596
View details for DOI 10.1007/s10021-002-0172-y
View details for Web of Science ID 000178121000007
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Oceanic islands as model systems for ecological studies
JOURNAL OF BIOGEOGRAPHY
2002; 29 (5-6): 573-582
View details for Web of Science ID 000176652300002
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Towards an ecological understanding of biological nitrogen fixation
BIOGEOCHEMISTRY
2002; 57 (1): 1-45
View details for Web of Science ID 000176001500002
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Nitrogen and nature
2nd International Nitrogen Conference
ROYAL SWEDISH ACAD SCIENCES. 2002: 97–101
Abstract
Anthropogenic changes to the global N cycle are important in part because added N alters the composition, productivity, and other properties of many natural ecosystems substantially. Why does added N have such a large impact? Why is N in short supply in so many natural ecosystems? Processes that slow the cycling of N relative to other elements and processes that control ecosystem-level inputs and outputs of N could cause N supply to limit the dynamics of ecosystems. We discuss stoichiometric differences between terrestrial plants and other organisms, the abundance of protein-precipitating plant defenses, and the nature of the C-N bond in soil organic matter as factors that can slow N cycling. For inputs, the energetic costs of N fixation and their consequences, the supply of nutrients other than N, and preferential grazing on N-fixers all could constrain the abundance and/or activity of biological N-fixers. Together these processes drive and sustain N limitation in many natural terrestrial ecosystems.
View details for Web of Science ID 000175937500007
View details for PubMedID 12078015
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Production and resource use efficiencies in N- and P-limited tropical forests: A comparison of responses to long-term fertilization
ECOSYSTEMS
2001; 4 (7): 646-657
View details for Web of Science ID 000172503300003
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Stand dynamics, nitrogen accumulation, and symbiotic nitrogen fixation in regenerating stands of Acacia koa
ECOLOGICAL APPLICATIONS
2001; 11 (5): 1381-1394
View details for Web of Science ID 000171417700011
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Nitrogen fixation rates of Stereocaulon vulcani on young Hawaiian lava flows
BIOGEOCHEMISTRY
2001; 55 (2): 179-194
View details for Web of Science ID 000170160000003
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Landslides, alien species, and the diversity of a Hawaiian montane mesic ecosystem
BIOTROPICA
2001; 33 (3): 409-420
View details for Web of Science ID 000171709800004
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Resource optimization and symbiotic nitrogen fixation
ECOSYSTEMS
2001; 4 (4): 369-388
View details for Web of Science ID 000169413600010
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Effects of soil nutrient availability on investment in acquisition of N and P in Hawaiian rain forests
ECOLOGY
2001; 82 (4): 946-954
View details for Web of Science ID 000168135100004
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Organic matter and nitrogen accumulation and nitrogen fixation during early ecosystem development in Hawaii
BIOGEOCHEMISTRY
2001; 52 (3): 259-279
View details for Web of Science ID 000167397100002
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Potential ecosystem-level effects of genetic variation among populations of Metrosideros polymorpha from a soil fertility gradient in Hawaii
OECOLOGIA
2001; 126 (2): 266-275
Abstract
This study assessed intrinsic differences in tissue quality and growth rate among populations of Metrosideros polymorpha native to sites with a range of soil fertilities. We collected seedlings from three Hawaiian mesic forests that were either phosphorus-limited, nitrogen-limited, or relatively fertile. These individuals were grown in a common garden under a factorial high/low, N/P fertilization regime for 1.5 years and then harvested to determine genetic divergence; aboveground growth rate; and lignin, N, and P concentrations in leaves and roots. Allozyme analyses indicated that the three groups had genetically diverged to some degree (genetic distance = 0.036-0.053 among populations). Relative growth rate did not differ significantly among the populations. Senescent leaves from the fertile-site population had the highest N concentrations (due to low N resorption) and had lower lignin concentrations than plants from the N-limited site. Across treatments, P concentrations in senescent leaves were highest in plants from the fertile and P-limited site. Root tissue quality did not generally differ significantly among populations. Since decomposition rate of senescent leaves in this system is related positively to N concentration and negatively to lignin concentration, senescent leaves from the fertile-site population may have a genetic tendency toward faster decay than the others. The intrinsic qualities of the three populations may provide positive feedbacks on nutrient cycling at each site-nutrient availability may be raised to some degree at the fertile site, and reduced at the N- or P-limited sites. Our results suggest that even a small degree of genetic differentiation among groups can influence traits related to nutrient cycling.
View details for Web of Science ID 000166494800015
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Potential ecosystem-level effects of genetic variation among populations of Metrosideros polymorpha from a soil fertility gradient in Hawaii.
Oecologia
2001; 126 (2): 266-275
Abstract
This study assessed intrinsic differences in tissue quality and growth rate among populations of Metrosideros polymorpha native to sites with a range of soil fertilities. We collected seedlings from three Hawaiian mesic forests that were either phosphorus-limited, nitrogen-limited, or relatively fertile. These individuals were grown in a common garden under a factorial high/low, N/P fertilization regime for 1.5 years and then harvested to determine genetic divergence; aboveground growth rate; and lignin, N, and P concentrations in leaves and roots. Allozyme analyses indicated that the three groups had genetically diverged to some degree (genetic distance = 0.036-0.053 among populations). Relative growth rate did not differ significantly among the populations. Senescent leaves from the fertile-site population had the highest N concentrations (due to low N resorption) and had lower lignin concentrations than plants from the N-limited site. Across treatments, P concentrations in senescent leaves were highest in plants from the fertile and P-limited site. Root tissue quality did not generally differ significantly among populations. Since decomposition rate of senescent leaves in this system is related positively to N concentration and negatively to lignin concentration, senescent leaves from the fertile-site population may have a genetic tendency toward faster decay than the others. The intrinsic qualities of the three populations may provide positive feedbacks on nutrient cycling at each site-nutrient availability may be raised to some degree at the fertile site, and reduced at the N- or P-limited sites. Our results suggest that even a small degree of genetic differentiation among groups can influence traits related to nutrient cycling.
View details for DOI 10.1007/s004420000523
View details for PubMedID 28547626
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Morphological and physiological adjustment to N and P fertilization in nutrient-limited Metrosideros polymorpha canopy trees in Hawaii
TREE PHYSIOLOGY
2001; 21 (1): 43-50
Abstract
Leaf-level studies of Metrosideros polymorpha Gaud. (Myrtaceae) canopy trees at both ends of a substrate age gradient in the Hawaiian Islands pointed to differential patterns of adjustment to both nutrient limitation and removal of this limitation by long-term (8-14 years) nitrogen (N), phosphorus (P) and N + P fertilizations. The two study sites were located at the same elevation, had similar annual precipitation, and supported forests dominated by M. polymorpha, but differed in the age of the underlying volcanic substrate, and in soil nutrient availability, with relatively low N at the young site (300 years, Thurston, Hawaii) and relatively low P at the oldest site (4,100,000 years, Kokee, Kauai). Within each site, responses to N and P fertilization were similar, regardless of the difference in soil N and P availability between sites. At the young substrate site, nutrient addition led to a larger mean leaf size (about 7.4 versus 4.8 cm2), resulting in a larger canopy leaf surface area. Differences in foliar N and P content, chlorophyll concentrations and carboxylation capacity between the fertilized and control plots were small. At the old substrate site, nutrient addition led to an increase in photosynthetic rate per unit leaf surface area from 4.5 to 7.6 micromol m(-2) s(-1), without a concomitant change in leaf size. At this site, leaves had substantially greater nutrient concentrations, chlorophyll content and carboxylation capacity in the fertilized plots than in the control plots. These contrasting acclimation responses to fertilization at the young and old sites led to significant increases in total carbon gain of M. polymorpha canopy trees at both sites. At the young substrate site, acclimation to fertilization was morphological, resulting in larger leaves, whereas at the old substrate site, physiological acclimation resulted in higher leaf carboxylation capacity and chlorophyll content.
View details for Web of Science ID 000166771400006
View details for PubMedID 11260823
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Cattle grazing, forest loss, and fuel loading in a dry forest ecosystem at Pu'u Wa'aWa'a ranch, Hawai'i
BIOTROPICA
2000; 32 (4): 625-632
View details for Web of Science ID 000166540200005
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Nutrient and mineralogical control on dissolved organic C, N and P fluxes and stoichiometry in Hawaiian soils
BIOGEOCHEMISTRY
2000; 51 (3): 283-302
View details for Web of Science ID 000089142400003
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Hurricane effects on nitrogen trace gas emissions in Hawaiian montane rain forest
BIOTROPICA
2000; 32 (4): 751-756
View details for Web of Science ID 000166540200019
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Climate cycles, geomorphological change, and the interpretation of soil and ecosystem development
ECOSYSTEMS
2000; 3 (6): 522-533
View details for Web of Science ID 000166192700004
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Heterotrophic nitrogen fixation in decomposing litter: Patterns and regulation
ECOLOGY
2000; 81 (9): 2366-2376
View details for Web of Science ID 000089093500002
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Changes in asymbiotic, heterotrophic nitrogen fixation on leaf litter of Metrosideros polymorpha with long-term ecosystem development in Hawaii
ECOSYSTEMS
2000; 3 (4): 386-395
View details for Web of Science ID 000088984300006
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Nutrient limitation of decomposition in Hawaiian forests
ECOLOGY
2000; 81 (7): 1867-1877
View details for Web of Science ID 000088214400009
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The role of polyphenols in terrestrial ecosystem nutrient cycling
TRENDS IN ECOLOGY & EVOLUTION
2000; 15 (6): 238-243
Abstract
Interspecific variation in polyphenol production by plants has been interpreted in terms of defense against herbivores. Several recent lines of evidence suggest that polyphenols also influence the pools and fluxes of inorganic and organic soil nutrients. Such effects could have far-ranging consequences for nutrient competition among and between plants and microbes, and for ecosystem nutrient cycling and retention. The significance of polyphenols for nutrient cycling and plant productivity is still uncertain, but it could provide an alternative or complementary explanation for the variability in polyphenol production by plants.
View details for Web of Science ID 000087160800008
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Consequences of changing biodiversity
NATURE
2000; 405 (6783): 234-242
Abstract
Human alteration of the global environment has triggered the sixth major extinction event in the history of life and caused widespread changes in the global distribution of organisms. These changes in biodiversity alter ecosystem processes and change the resilience of ecosystems to environmental change. This has profound consequences for services that humans derive from ecosystems. The large ecological and societal consequences of changing biodiversity should be minimized to preserve options for future solutions to global environmental problems.
View details for Web of Science ID 000087080100061
View details for PubMedID 10821284
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Regulation of soil phosphatase and chitinase activity by N and P availability
BIOGEOCHEMISTRY
2000; 49 (2): 175-190
View details for Web of Science ID 000085422600004
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Precipitation, decomposition and litter decomposability of Metrosideros polymorpha in native forests on Hawai'i
JOURNAL OF ECOLOGY
2000; 88 (1): 129-138
View details for Web of Science ID 000085946700010
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Global change and wilderness science
Wilderness Science in a Time of Change Conference
US DEPT AGR, FOREST SERV ROCKY MT FOREST & RANGE EXPTL STN. 2000: 5–9
View details for Web of Science ID 000165332500002
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Decomposition of Metrosideros polymorpha leaf litter along elevational gradients in Hawaii
GLOBAL CHANGE BIOLOGY
2000; 6 (1): 73-85
View details for Web of Science ID 000086189700006
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Nutrient limitation to nitrogen fixation in young volcanic sites
ECOSYSTEMS
1999; 2 (6): 505-510
View details for Web of Science ID 000084534100004
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Weathering versus atmospheric sources of strontium in ecosystems on young volcanic soils.
Oecologia
1999; 121 (2): 255-259
Abstract
We used isotopes of Sr to quantify weathering versus atmospheric sources of foliar Sr in 34 Hawaiian forests on young volcanic soils. The forests varied widely in climate, and in lava flow age and texture. Weathering supplied most of the Sr in most of the sites, but atmospheric deposition contributed 30-50% of foliar Sr in the wettest rainforests. A stepwise multiple regression using annual precipitation, distance from the ocean, and texture of the underlying lava explained 76% of the variation in Sr isotope ratios across the sites. Substrate age did not contribute significantly to variation in Sr isotope ratios in the range of ages evaluated here (11-3000 years), although atmospheric sources eventually dominate pools of biologically available Sr in Hawaiian rainforests in older substrates (≥150,000 years).
View details for DOI 10.1007/s004420050927
View details for PubMedID 28308565
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Weathering versus atmospheric sources of strontium in ecosystems on young volcanic soils
OECOLOGIA
1999; 121 (2): 255-259
Abstract
We used isotopes of Sr to quantify weathering versus atmospheric sources of foliar Sr in 34 Hawaiian forests on young volcanic soils. The forests varied widely in climate, and in lava flow age and texture. Weathering supplied most of the Sr in most of the sites, but atmospheric deposition contributed 30-50% of foliar Sr in the wettest rainforests. A stepwise multiple regression using annual precipitation, distance from the ocean, and texture of the underlying lava explained 76% of the variation in Sr isotope ratios across the sites. Substrate age did not contribute significantly to variation in Sr isotope ratios in the range of ages evaluated here (11-3000 years), although atmospheric sources eventually dominate pools of biologically available Sr in Hawaiian rainforests in older substrates (≥150,000 years).
View details for Web of Science ID 000083846300012
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Controls over the accumulation and decline of a nitrogen-fixing lichen, Stereocaulon vulcani, on young Hawaiian lava flows
JOURNAL OF ECOLOGY
1999; 87 (5): 784-799
View details for Web of Science ID 000083683500005
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Volcano fixes nitrogen into plant-available forms
BIOGEOCHEMISTRY
1999; 47 (1): 111-118
View details for Web of Science ID 000081664600007
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Deliberate introductions of species: Research needs - Benefits can be reaped, but risks are high
BIOSCIENCE
1999; 49 (8): 619-630
View details for Web of Science ID 000081683500006
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The globalization of N deposition: ecosystem consequences in tropical environments
BIOGEOCHEMISTRY
1999; 46 (1-3): 67-83
View details for Web of Science ID 000080776300005
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Nitrogen stable isotopic composition of leaves and soil: Tropical versus temperate forests
BIOGEOCHEMISTRY
1999; 46 (1-3): 45-65
View details for Web of Science ID 000080776300004
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Ecosystem constraints to symbiotic nitrogen fixers: a simple model and its implications
BIOGEOCHEMISTRY
1999; 46 (1-3): 179-202
View details for Web of Science ID 000080776300010
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Hurricane damage to a Hawaiian forest: Nutrient supply rate affects resistance and resilience
ECOLOGY
1999; 80 (3): 908-920
View details for Web of Science ID 000082154300015
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Changing sources of nutrients during four million years of ecosystem development
NATURE
1999; 397 (6719): 491-497
View details for Web of Science ID 000078574900040
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Changing sources of base cations during ecosystem development, Hawaiian Islands
GEOLOGY
1998; 26 (11): 1015-1018
View details for Web of Science ID 000076807000014
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Foliar and litter nutrients, nutrient resorption, and decomposition in Hawaiian Metrosideros polymorpha
ECOSYSTEMS
1998; 1 (4): 401-407
View details for Web of Science ID 000075676400009
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Microclimate change and effect on fire following forest-grass conversion in seasonally dry tropical woodland
BIOTROPICA
1998; 30 (2): 286-297
View details for Web of Science ID 000074462000013
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Nutrient dynamics on a precipitation gradient in Hawai'i
OECOLOGIA
1998; 113 (4): 519-529
View details for Web of Science ID 000072196300009
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Ecosystem development on Hawaiian lava flows: biomass and species composition
JOURNAL OF VEGETATION SCIENCE
1998; 9 (1): 17-26
View details for Web of Science ID 000072873800002
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Within-system element cycles, input-output budgets, and nutrient limitation
7th Cary Conference
SPRINGER. 1998: 432–451
View details for Web of Science ID 000076391800018
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Experimental investigation of nutrient limitation of forest growth on wet tropical mountains
ECOLOGY
1998; 79 (1): 10-22
View details for Web of Science ID 000071525500003
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The effects of plant composition and diversity on ecosystem processes
SCIENCE
1997; 277 (5330): 1302-1305
View details for Web of Science ID A1997XT82700054
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Human domination of Earth's ecosystems
SCIENCE
1997; 277 (5325): 494-499
View details for Web of Science ID A1997XM86700030
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After the volcano
NATURAL HISTORY
1997; 106 (5): 48-53
View details for Web of Science ID A1997WZ76600020
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On regression and residuals: Response to Knops et al.
OECOLOGIA
1997; 110 (4): 557-559
View details for Web of Science ID A1997XD21000016
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On regression and residuals: response to Knops et al.
Oecologia
1997; 110 (4): 557-559
View details for DOI 10.1007/s004420050195
View details for PubMedID 28307250
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Introduced species: A significant component of human-caused global change
NEW ZEALAND JOURNAL OF ECOLOGY
1997; 21 (1): 1–16
View details for Web of Science ID A1997XP01200001
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Biological invasions as global environmental change
AMERICAN SCIENTIST
1996; 84 (5): 468-478
View details for Web of Science ID A1996VC02700013
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Process modeling of controls on nitrogen trace gas emissions from soils worldwide
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
1996; 101 (D1): 1361-1377
View details for Web of Science ID A1996TR61600003
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Terrestrial transects for global change research
KLUWER ACADEMIC PUBL. 1995: 53–65
View details for DOI 10.1007/BF00044672
View details for Web of Science ID A1995TQ95500007
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NUTRIENT DYNAMICS AND NITROGEN TRACE GAS FLUX DURING ECOSYSTEM DEVELOPMENT IN MONTANE RAIN-FOREST
ECOLOGY
1995; 76 (1): 292–304
View details for DOI 10.2307/1940650
View details for Web of Science ID A1995QC87200025
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POTENTIAL NITROGEN-FIXATION DURING PRIMARY SUCCESSION IN HAWAII VOLCANOS NATIONAL-PARK
BIOTROPICA
1994; 26 (3): 234-240
View details for Web of Science ID A1994PK38400001
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SUCCESSIONAL DEVELOPMENT OF A HAWAIIAN MONTANE GRASSLAND
BIOTROPICA
1994; 26 (1): 2-11
View details for Web of Science ID A1994NE09100001
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LITTER DECOMPOSITION ON THE MAUNA-LOA ENVIRONMENTAL MATRIX, HAWAII - PATTERNS, MECHANISMS, AND MODELS
ECOLOGY
1994; 75 (2): 418-429
View details for Web of Science ID A1994MZ45400013
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AN AGE ALTITUDE MATRIX ANALYSIS OF HAWAIIAN RAIN-FOREST SUCCESSION
JOURNAL OF ECOLOGY
1994; 82 (1): 137-147
View details for Web of Science ID A1994NL94400015
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LEAF MORPHOLOGY ALONG ENVIRONMENTAL GRADIENTS IN HAWAIIAN METROSIDEROS-POLYMORPHA
BIOTROPICA
1994; 26 (1): 17-22
View details for Web of Science ID A1994NE09100003
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FACTORS CONTROLLING ECOSYSTEM STRUCTURE AND FUNCTION
Symposium on Factors of Soil Formation: A 50th Anniversary Retrospective, held during the 1991 Annual Meeting of the Soil-Science-Society-of-America
SOIL SCIENCE SOC AMER. 1994: 87–97
View details for Web of Science ID A1994BA26Z00005
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TERRESTRIAL ECOSYSTEM PRODUCTION - A PROCESS MODEL-BASED ON GLOBAL SATELLITE AND SURFACE DATA
GLOBAL BIOGEOCHEMICAL CYCLES
1993; 7 (4): 811-841
View details for Web of Science ID A1993MM23400006
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BARRIERS TO SHRUB REESTABLISHMENT FOLLOWING FIRE IN THE SEASONAL SUBMONTANE ZONE OF HAWAII
OECOLOGIA
1993; 93 (4): 557-563
Abstract
Introduced grass species have invaded extensive areas of Hawaii Volcanoes National Park and increased the size and frequency of fire. Following fire, grass cover is enhanced while native shrub cover is reduced; the reduction in most shrubs persists for at least 20 years even in the absence of fire. Shrub seedlings were planted in burned and unburned plots with and without grass cover. Biomass of 14 month old shrub seedlings was generally highest in recently burned/grass removed plots, intermediate in old burn/grass removed plots, and lowest in unburned/grass removed plots. In contrast, shrub biomass in plots with grass cover was low and did not differ significantly among burn treatments. Light competition is likely to be responsible for differences in shrub growth rates; grass cover reduced light to 1-10% of background levels. In addition, pool sizes of available soil N were highest in recently burned, intermediate in old burn, and lowest in unburned areas.
View details for Web of Science ID A1993KW41400014
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Barriers to shrub reestablishment following fire in the seasonal submontane zone of Hawai'i.
Oecologia
1993; 93 (4): 557-563
Abstract
Introduced grass species have invaded extensive areas of Hawaii Volcanoes National Park and increased the size and frequency of fire. Following fire, grass cover is enhanced while native shrub cover is reduced; the reduction in most shrubs persists for at least 20 years even in the absence of fire. Shrub seedlings were planted in burned and unburned plots with and without grass cover. Biomass of 14 month old shrub seedlings was generally highest in recently burned/grass removed plots, intermediate in old burn/grass removed plots, and lowest in unburned/grass removed plots. In contrast, shrub biomass in plots with grass cover was low and did not differ significantly among burn treatments. Light competition is likely to be responsible for differences in shrub growth rates; grass cover reduced light to 1-10% of background levels. In addition, pool sizes of available soil N were highest in recently burned, intermediate in old burn, and lowest in unburned areas.
View details for DOI 10.1007/BF00328965
View details for PubMedID 28313825
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PROCESSES REGULATING SOIL EMISSIONS OF NO AND N2O IN A SEASONALLY DRY TROPICAL FOREST
ECOLOGY
1993; 74 (1): 130-139
View details for Web of Science ID A1993KF77500014
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BIOLOGICAL DIVERSITY AND TERRESTRIAL ECOSYSTEM BIOGEOCHEMISTRY
Symposium on Biodiversity and Ecosystem Function
SPRINGER-VERLAG BERLIN. 1993: 3–14
View details for Web of Science ID A1993BZ53F00001
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NUTRIENT LIMITATIONS TO PLANT-GROWTH DURING PRIMARY SUCCESSION IN HAWAII-VOLCANOS-NATIONAL-PARK
BIOGEOCHEMISTRY
1993; 23 (3): 197-215
View details for Web of Science ID A1993MV60300003
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TROPICAL SOILS COULD DOMINATE THE SHORT-TERM CARBON-CYCLE FEEDBACKS TO INCREASED GLOBAL TEMPERATURES
CLIMATIC CHANGE
1992; 22 (4): 293-303
View details for Web of Science ID A1992KB25800002
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TROPICAL FORESTS AND TRACE GASES - POTENTIAL INTERACTIONS BETWEEN TROPICAL BIOLOGY AND THE ATMOSPHERIC SCIENCES
BIOTROPICA
1992; 24 (2): 233-239
View details for Web of Science ID A1992JB55000003
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THE MAUNA-LOA ENVIRONMENTAL MATRIX - FOLIAR AND SOIL NUTRIENTS
OECOLOGIA
1992; 89 (3): 372-382
Abstract
The accumulation of total carbon, nitrogen, and phosphorus in soils, available soil nutrients, and foliar nutrients in the native dominant Metrosideros polymorpha were determined across a wide elevational range on 9 lava flows on Mauna Loa, Hawai'i. The flows included a young (<140 y) and an old (>2800 y) áá (rough surface texture) and pāhoehoe (smooth) flow on the wet east and dry northwest side of the mountain. Soil element pools and nutrient availability increased with flow age independent of climate. The dry sites accumulated organic matter and nutrients more slowly than comparable wet sites, but relative nutrient availability to plants (as indicated by soil assays and foliar nutrients) was greater in the dry sites. Accumulation of soil organic matter and nutrients occurred most rapidly in lowerelevation sites on the young flows, but the largest accumulations occurred at higher elevations on old flows. The range of sites sampled represents a complete and largely independent matrix of major factors governing ecosystem structure and function.
View details for Web of Science ID A1992HJ15300010
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The Mauna Loa environmental matrix: foliar and soil nutrients.
Oecologia
1992; 89 (3): 372-382
Abstract
The accumulation of total carbon, nitrogen, and phosphorus in soils, available soil nutrients, and foliar nutrients in the native dominant Metrosideros polymorpha were determined across a wide elevational range on 9 lava flows on Mauna Loa, Hawai'i. The flows included a young (<140 y) and an old (>2800 y) áá (rough surface texture) and pāhoehoe (smooth) flow on the wet east and dry northwest side of the mountain. Soil element pools and nutrient availability increased with flow age independent of climate. The dry sites accumulated organic matter and nutrients more slowly than comparable wet sites, but relative nutrient availability to plants (as indicated by soil assays and foliar nutrients) was greater in the dry sites. Accumulation of soil organic matter and nutrients occurred most rapidly in lowerelevation sites on the young flows, but the largest accumulations occurred at higher elevations on old flows. The range of sites sampled represents a complete and largely independent matrix of major factors governing ecosystem structure and function.
View details for DOI 10.1007/BF00317415
View details for PubMedID 28313086
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BIOLOGICAL INVASIONS BY EXOTIC GRASSES, THE GRASS FIRE CYCLE, AND GLOBAL CHANGE
ANNUAL REVIEW OF ECOLOGY AND SYSTEMATICS
1992; 23: 63-87
View details for Web of Science ID A1992JZ28100004
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Nitrogen transformations and nitrous oxide flux in a tropical deciduous forest in México.
Oecologia
1991; 88 (3): 362-366
Abstract
Emissions of nitrous oxide and soil nitrogen pools and transformations were measured over an annual cycle in two forests and one pasture in tropical deciduous forest near Chamela, México. Nitrous oxide flux was moderately high (0.5-2.5 ng cm-2 h-1) during the wet season and low (<0.3 ng cm-2 h-1) during the dry season. Annual emissions of nitrogen as nitrous oxide were calculated to be 0.5-0.7 kg ha-1 y-1, with no substantial difference between the forests and pasture. Wetting of dry soil caused a large but short-lived pulse of N2O flux that accounted for <2% of annual flux. Variation in soil water through the season was the primary controlling factor for pool sizes of ammonium and nitrate, nitrogen transformations, and N2O flux.
View details for DOI 10.1007/BF00317579
View details for PubMedID 28313797
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ECOLOGICAL SUCCESSION AND NUTRIENT BUDGETS - A CITATION-CLASSIC COMMENTARY ON ECOSYSTEM SUCCESSION AND NUTRIENT RETENTION - A HYPOTHESIS BY VITOUSEK,P.M. AND REINERS,W.A.
CURRENT CONTENTS/AGRICULTURE BIOLOGY & ENVIRONMENTAL SCIENCES
1991: 10-10
View details for Web of Science ID A1991GH39700001
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SOIL EMISSIONS OF NITRIC-OXIDE IN A SEASONALLY DRY TROPICAL FOREST OF MEXICO
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
1991; 96 (D8): 15439-15445
View details for Web of Science ID A1991GC31400015
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AN INVADER ALTERS GERMINATION AND GROWTH OF A NATIVE DOMINANT TREE IN HAWAII
ECOLOGY
1991; 72 (4): 1449-1455
View details for Web of Science ID A1991GB18500028
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CAN PLANTED FORESTS COUNTERACT INCREASING ATMOSPHERIC CARBON-DIOXIDE
JOURNAL OF ENVIRONMENTAL QUALITY
1991; 20 (2): 348-354
View details for Web of Science ID A1991FK17900003
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NITROGEN TRANSFORMATIONS AND NITROUS-OXIDE FLUX IN A TROPICAL DECIDUOUS FOREST IN MEXICO
OECOLOGIA
1991; 88 (3): 362-366
Abstract
Emissions of nitrous oxide and soil nitrogen pools and transformations were measured over an annual cycle in two forests and one pasture in tropical deciduous forest near Chamela, México. Nitrous oxide flux was moderately high (0.5-2.5 ng cm-2 h-1) during the wet season and low (<0.3 ng cm-2 h-1) during the dry season. Annual emissions of nitrogen as nitrous oxide were calculated to be 0.5-0.7 kg ha-1 y-1, with no substantial difference between the forests and pasture. Wetting of dry soil caused a large but short-lived pulse of N2O flux that accounted for <2% of annual flux. Variation in soil water through the season was the primary controlling factor for pool sizes of ammonium and nitrate, nitrogen transformations, and N2O flux.
View details for Web of Science ID A1991GP20700009
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NITROGEN LIMITATION ON LAND AND IN THE SEA - HOW CAN IT OCCUR
BIOGEOCHEMISTRY
1991; 13 (2): 87-115
View details for Web of Science ID A1991GH74100001
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ECOSYSTEM APPROACH TO A GLOBAL NITROUS-OXIDE BUDGET
BIOSCIENCE
1990; 40 (9): 667-671
View details for Web of Science ID A1990DZ70100009
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C in Hawaiian Metrosideros polymorpha: a case of internal resistance?
Oecologia
1990; 84 (3): 362-370
Abstract
Sun leaves of Metrosideros polymorpha were collected in 51 sites on 9 lava flows that represented gradients of elevation, precipitation, substrate age, and substrate texture on Mauna Loa volcano, Hawai'i. Leaf mass per unit leaf area increased with increasing elevation on all flows, while foliar nitrogen concentration decreased with increasing elevation and increased with increasing substrate age. Foliar δ(13)C became less negative with increasing elevation on the wet east-side lava flows, but not the dry northwest-side flows; it did not reflect patterns of precipitation or presumed water availability. δ(13)C was very strongly correlated with leaf mass per area across all of the sites. Limited gas-exchange information suggested that calculated ci/ca did not decrease with elevation in association with less-negative δ(13)C, and photosynthesis per unit of nitrogen was significantly reduced in high-elevation plants. These results are consistent with a substantial internal resistance to CO2 diffusion in the thick Metrosideros polymorpha leaves in high elevation sites.
View details for DOI 10.1007/BF00329760
View details for PubMedID 28313026
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SOURCES OF VARIATION IN NITROUS-OXIDE FLUX FROM AMAZONIAN ECOSYSTEMS
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
1990; 95 (D10): 16789-16798
View details for Web of Science ID A1990EB20200036
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EFFECTS OF SOIL RESOURCES ON PLANT INVASION AND COMMUNITY STRUCTURE IN CALIFORNIAN SERPENTINE GRASSLAND
ECOLOGY
1990; 71 (2): 478-491
View details for Web of Science ID A1990CV62800008
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BIOLOGICAL INVASIONS AND ECOSYSTEM PROCESSES - TOWARDS AN INTEGRATION OF POPULATION BIOLOGY AND ECOSYSTEM STUDIES
OIKOS
1990; 57 (1): 7-13
View details for Web of Science ID A1990CT25900004
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GROWTH-RESPONSES OF TROPICAL SHRUBS TO TREEFALL GAP ENVIRONMENTS
ECOLOGY
1990; 71 (1): 165-179
View details for Web of Science ID A1990CN23200017
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VARIATION IN FOLIAR DELTA-C-13 IN HAWAIIAN METROSIDEROS-POLYMORPHA - A CASE OF INTERNAL RESISTANCE
OECOLOGIA
1990; 84 (3): 362-370
Abstract
Sun leaves of Metrosideros polymorpha were collected in 51 sites on 9 lava flows that represented gradients of elevation, precipitation, substrate age, and substrate texture on Mauna Loa volcano, Hawai'i. Leaf mass per unit leaf area increased with increasing elevation on all flows, while foliar nitrogen concentration decreased with increasing elevation and increased with increasing substrate age. Foliar δ(13)C became less negative with increasing elevation on the wet east-side lava flows, but not the dry northwest-side flows; it did not reflect patterns of precipitation or presumed water availability. δ(13)C was very strongly correlated with leaf mass per area across all of the sites. Limited gas-exchange information suggested that calculated ci/ca did not decrease with elevation in association with less-negative δ(13)C, and photosynthesis per unit of nitrogen was significantly reduced in high-elevation plants. These results are consistent with a substantial internal resistance to CO2 diffusion in the thick Metrosideros polymorpha leaves in high elevation sites.
View details for Web of Science ID A1990EC00700009
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SEEDLING AND CLONAL RECRUITMENT OF THE INVASIVE TREE PSIDIUM-CATTLEIANUM - IMPLICATIONS FOR MANAGEMENT OF NATIVE HAWAIIAN FORESTS
BIOLOGICAL CONSERVATION
1990; 53 (3): 199-211
View details for Web of Science ID A1990DU06500004
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NITROUS OXIDE FLUX FROM DRY TROPICAL FORESTS
GLOBAL BIOGEOCHEMICAL CYCLES
1989; 3 (4): 375-382
View details for DOI 10.1029/GB003i004p00375
View details for Web of Science ID 000211480500007
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BIOLOGICAL INVASION BY MYRICA-FAYA IN HAWAII - PLANT DEMOGRAPHY, NITROGEN-FIXATION, ECOSYSTEM EFFECTS
ECOLOGICAL MONOGRAPHS
1989; 59 (3): 247-265
View details for Web of Science ID A1989AM64100003
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NITROGEN AVAILABILITY AND NITRIFICATION DURING SUCCESSION - PRIMARY, SECONDARY, AND OLD-FIELD SERES
PLANT AND SOIL
1989; 115 (2): 229-239
View details for Web of Science ID A1989AG59200008
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Foliar 15N natural abundance in Hawaiian rainforest: patterns and possible mechanisms.
Oecologia
1989; 78 (3): 383-388
Abstract
Foliar samples were obtained from symbiotic nitrogen-fixers and control plants (non-fixers) along elevational and primary successional gradients in volcanic sites in Hawai'i. Most control plants had negative δ15N values (range-10.1 to +0.7‰), while most nitrogen-fixers were near 0‰. Foliar 15N in the native tree Metrosideros polymorpha did not vary with elevation (from sea level to tree-line), but it did increase substantially towards 0‰ on older soils. The soil in an 197-yr-old site had a δ15N value of approximately-2‰, while in a ∼67000-yr-old site it was +3.6‰. We suggest that inputs of 15N-depleted nitrogen from precipitation coupled with very low nitrogen outputs cause the strongly negative δ15N values in non-nitrogen-fixing plants on early successional sites.
View details for DOI 10.1007/BF00379113
View details for PubMedID 28312585
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FOLIAR N-15 NATURAL ABUNDANCE IN HAWAIIAN RAINFOREST - PATTERNS AND POSSIBLE MECHANISMS
OECOLOGIA
1989; 78 (3): 383-388
Abstract
Foliar samples were obtained from symbiotic nitrogen-fixers and control plants (non-fixers) along elevational and primary successional gradients in volcanic sites in Hawai'i. Most control plants had negative δ15N values (range-10.1 to +0.7‰), while most nitrogen-fixers were near 0‰. Foliar 15N in the native tree Metrosideros polymorpha did not vary with elevation (from sea level to tree-line), but it did increase substantially towards 0‰ on older soils. The soil in an 197-yr-old site had a δ15N value of approximately-2‰, while in a ∼67000-yr-old site it was +3.6‰. We suggest that inputs of 15N-depleted nitrogen from precipitation coupled with very low nitrogen outputs cause the strongly negative δ15N values in non-nitrogen-fixing plants on early successional sites.
View details for Web of Science ID A1989T479200014
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Nitrous oxide flux following tropical land clearing
Global Biogeochemical Cycles
1989; 3: 281-285
View details for DOI 10.1029/gb003i003p00281
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Elevational and age gradients in hawaiian montane rainforest: foliar and soil nutrients.
Oecologia
1988; 77 (4): 565-570
Abstract
Soils and plants were sampled along an elevational gradient from 265-1675 m on a 133-and a 3100-year-old lava flow on Mauna Loa, Hawai'i. Soil organic matter and nutrients accumulated more rapidly at low elevation on the young flow, but reached higher levels at higher elevation on the old flow. Foliar nitrogen and phosphorus concentrations were less and specific leaf weight greater for Metrosideros polymorpha leaves collected at high versus low elevations and on the young versus the old flow. Foliar δ13C was strongly correlated with specific leaf weight across the range of sites sampled.
View details for DOI 10.1007/BF00377275
View details for PubMedID 28311279
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NITROUS-OXIDE FLUX AND NITROGEN TRANSFORMATIONS ACROSS A LANDSCAPE GRADIENT IN AMAZONIA
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES
1988; 93 (D2): 1593-1599
View details for Web of Science ID A1988M303000022
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NITROGEN TRANSFORMATIONS IN A RANGE OF TROPICAL FOREST SOILS
SOIL BIOLOGY & BIOCHEMISTRY
1988; 20 (3): 361-367
View details for Web of Science ID A1988P241000016
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SOIL-NITROGEN TURNOVER IS ALTERED BY HERBICIDE TREATMENT IN A NORTH-CAROLINA PIEDMONT FOREST SOIL
FOREST ECOLOGY AND MANAGEMENT
1988; 23 (1): 19-25
View details for Web of Science ID A1988M400500002
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ELEMENT INTERACTIONS IN FOREST ECOSYSTEMS - SUCCESSION, ALLOMETRY AND INPUT-OUTPUT BUDGETS
BIOGEOCHEMISTRY
1988; 5 (1): 7-34
View details for Web of Science ID A1988L992500003
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ELEVATIONAL AND AGE GRADIENTS IN HAWAIIAN MONTANE RAINFOREST - FOLIAR AND SOIL NUTRIENTS
OECOLOGIA
1988; 77 (4): 565-570
Abstract
Soils and plants were sampled along an elevational gradient from 265-1675 m on a 133-and a 3100-year-old lava flow on Mauna Loa, Hawai'i. Soil organic matter and nutrients accumulated more rapidly at low elevation on the young flow, but reached higher levels at higher elevation on the old flow. Foliar nitrogen and phosphorus concentrations were less and specific leaf weight greater for Metrosideros polymorpha leaves collected at high versus low elevations and on the young versus the old flow. Foliar δ13C was strongly correlated with specific leaf weight across the range of sites sampled.
View details for Web of Science ID A1988R443600019
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EXCHANGE OF MATERIALS BETWEEN TERRESTRIAL ECOSYSTEMS AND THE ATMOSPHERE
SCIENCE
1987; 238 (4829): 926-932
Abstract
Many biogenic trace gases are increasing in concentration or flux or both in the atmosphere as a consequence of human activities. Most of these gases have demonstrated or potential effects on atmospheric chemistry, climate, and the functioning of terrestrial ecosystems. Focused studies of the interactions between the atmosphere and the biosphere that regulate trace gases can improve both our understanding of terrestrial ecosystems and our ability to predict regional-and global-scale canges in atmospheric chemistry.
View details for Web of Science ID A1987K781000026
View details for PubMedID 17829357
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BIOLOGICAL INVASION BY MYRICA-FAYA ALTERS ECOSYSTEM DEVELOPMENT IN HAWAII
SCIENCE
1987; 238 (4828): 802-804
Abstract
The exotic nitrogen-fixing tree Myrica faya invades young volcanic sites where the growth of native plants is limited by a lack of nitrogen. Myrica quadruples the amount of nitrogen entering certain sites and increases the overall biological availability of nitrogen, thereby altering the nature of ecosystem development after volcanic eruptions.
View details for Web of Science ID A1987K681000034
View details for PubMedID 17814707
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INTRODUCED SPECIES IN HAWAII - BIOLOGICAL EFFECTS AND OPPORTUNITIES FOR ECOLOGICAL RESEARCH
TRENDS IN ECOLOGY & EVOLUTION
1987; 2 (7): 224-227
Abstract
The articles in this volume illustrate that the Hawaiian islands are perhaps the most extraordinary living museum of evolution on the planet. However, Hawaii's value as a museum has diminished as the products of millions of years of evolutionary radiation have been lost to habitat destruction and biological invasions by exotic species. Human-caused habitat destruction can largely be controlled in parks and preserves, but exotic species do not respect park boundaries and can degrade native communities within protected areas. On the other hand, invasions by exotic species provide a dynamic laboratory of ecological processes at the same time as they erode the value of the evolutionary museum.
View details for Web of Science ID A1987J338200012
View details for PubMedID 21227856
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NITROGEN TRANSFORMATIONS FOLLOWING TROPICAL FOREST FELLING AND BURNING ON A VOLCANIC SOIL
ECOLOGY
1987; 68 (3): 491-502
View details for Web of Science ID A1987H301400004
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DIFFERENCES IN EXTRACTABLE PHOSPHORUS AMONG SOILS OF THE LA SELVA BIOLOGICAL STATION, COSTA-RICA
BIOTROPICA
1987; 19 (2): 167-170
View details for Web of Science ID A1987J378900011
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BIOASSAYS OF NUTRIENT LIMITATION IN A TROPICAL RAIN-FOREST SOIL
OECOLOGIA
1987; 74 (3): 370-376
View details for Web of Science ID A1987L238200009
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Cross-system comparisons of soil nitrogen transformationas and nitrous oxide flux in tropical forest ecosystems
Global Biogeochemical Cycles
1987; 1: 163-170
View details for DOI 10.1029/gb001i002p00163
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NITROGEN AND PHOSPHORUS AVAILABILITY IN TREEFALL GAPS OF A LOWLAND TROPICAL RAIN-FOREST
JOURNAL OF ECOLOGY
1986; 74 (4): 1167-1178
View details for Web of Science ID A1986F492100019
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HUMAN APPROPRIATION OF THE PRODUCTS OF PHOTOSYNTHESIS
BIOSCIENCE
1986; 36 (6): 368-373
View details for Web of Science ID A1986C429000006
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Microbial transformations of labelled nitrogen in a clear-cut pine plantation.
Oecologia
1986; 68 (4): 601-605
Abstract
Labelled nitrogen was used to evaluate the effects of intensive forest management on soil nitrogen transformations. The total release of N into inorganic forms (ammonium plus nitrate) was much greater than net N mineralization in all treatments. Immobilization of N by microbes was greatest in minimally-treated harvested plots, while the turnover of N within soil microbes was greatest in intensively-treated plots. Ammonium was immobilized 2.4-3.2 times more rapidly than nitrate in havested plots; nitrification in disturbed sites could thus increase the availability of N to regrowing vegetation.
View details for DOI 10.1007/BF00378778
View details for PubMedID 28311719
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THE RESPONSE OF PLANTS TO ELEVATED CO2 .2. 2 DECIDUOUS-FOREST TREE COMMUNITIES
OECOLOGIA
1986; 69 (3): 454-459
View details for Web of Science ID A1986C708500018
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NUTRIENT CYCLING IN MOIST TROPICAL FOREST
ANNUAL REVIEW OF ECOLOGY AND SYSTEMATICS
1986; 17: 137-167
View details for Web of Science ID A1986F014300007
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THE NATURE OF NUTRIENT LIMITATION IN PLANT-COMMUNITIES
AMERICAN NATURALIST
1986; 127 (1): 48-58
View details for Web of Science ID A1986AYX2300004
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MICROBIAL TRANSFORMATIONS OF LABELED NITROGEN IN A CLEAR-CUT PINE PLANTATION
OECOLOGIA
1986; 68 (4): 601-605
Abstract
Labelled nitrogen was used to evaluate the effects of intensive forest management on soil nitrogen transformations. The total release of N into inorganic forms (ammonium plus nitrate) was much greater than net N mineralization in all treatments. Immobilization of N by microbes was greatest in minimally-treated harvested plots, while the turnover of N within soil microbes was greatest in intensively-treated plots. Ammonium was immobilized 2.4-3.2 times more rapidly than nitrate in havested plots; nitrification in disturbed sites could thus increase the availability of N to regrowing vegetation.
View details for Web of Science ID A1986A436700020
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DISTURBANCE, NITROGEN AVAILABILITY, AND NITROGEN LOSSES IN AN INTENSIVELY MANAGED LOBLOLLY-PINE PLANTATION
ECOLOGY
1985; 66 (4): 1360-1376
View details for Web of Science ID A1985ANN8200029
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FINE-ROOT BIOMASS AND NUTRIENT CYCLING IN ARISTIDA-STRICTA IN A NORTH-CAROLINA COASTAL-PLAIN SAVANNA
CANADIAN JOURNAL OF BOTANY-REVUE CANADIENNE DE BOTANIQUE
1984; 62 (4): 823-829
View details for Web of Science ID A1984SR97400029
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MECHANISMS OF NITROGEN-RETENTION IN FOREST ECOSYSTEMS - A FIELD EXPERIMENT
SCIENCE
1984; 225 (4657): 51-52
Abstract
Intensive forest management led to elevated losses of nitrogen from a recently harvested loblolly pine plantation in North Carolina. Measurements of nitrogen-15 retention in the field demonstrated that microbial uptake of nitrogen during the decomposition of residual organic material was the most important process retaining nitrogen. Management practices that remove this material cause increased losses of nitrogen to aquatic ecosystems and the atmosphere.
View details for Web of Science ID A1984SX61000030
View details for PubMedID 17775660
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SOIL DEVELOPMENT AND NITROGEN TURNOVER IN MONTANE RAINFOREST SOILS ON HAWAII
BIOTROPICA
1983; 15 (4): 268-274
View details for Web of Science ID A1983SX19800004