All Publications


  • Soil drying induces widespread productivity loss but unequal climate vulnerability among ecotypes of a foundational Arctic sedge FUNCTIONAL ECOLOGY Gewirtzman, J., Fetcher, N. 2026; 40 (7): 2301-2317
  • Compounded effects on wetland greenhouse gas fluxes from climate change and water management along a saline to freshwater gradient PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA Doughty, C. L., Ying, Q., Ward, E., Delaria, E., Wolfe, G. M., Malone, S. L., Reed, D. E., Troxler, T., Kominoski, J. S., Castaneda-Moyae, E., Shoemaker, W., Yannick, D., Starr, G., Oberbauer, S. F., Barenblitt, A., Campbell, A., Charles, S., Fatoyinbo, L., Gewirtzman, J., Hanisco, T., Hannun, R., Kawa, S., Lagomasino, D., Lait, L., Lindquist, A., Newman, P., Raymond, P., Rosentreter, J., Thornhill, K., Vaughn, D., Poulter, B. 2026; 123 (8)
  • Compounded effects on wetland greenhouse gas fluxes from climate change and water management along a saline to freshwater gradient. Proceedings of the National Academy of Sciences of the United States of America Doughty, C. L., Ying, Q., Ward, E., Delaria, E., Wolfe, G. M., Malone, S. L., Reed, D. E., Troxler, T., Kominoski, J. S., Castañeda-Moya, E., Shoemaker, W. B., Yannick, D., Starr, G., Oberbauer, S. F., Barenblitt, A., Campbell, A., Charles, S., Fatoyinbo, L., Gewirtzman, J., Hanisco, T., Hannun, R., Kawa, S., Lagomasino, D., Lait, L., Lindquist, A., Newman, P., Raymond, P., Rosentreter, J., Thornhill, K., Vaughn, D., Poulter, B. 2026; 123 (8): e2513685123

    Abstract

    Saline and freshwater wetlands store large amounts of carbon, which has driven interest in their role as nature-based climate solutions. Because these ecosystems can be both sinks and sources of carbon to the atmosphere as environmental conditions and human influence change, the net climate mitigation potential of wetlands at regional to global scales remains uncertain. We used a data-driven approach to measure ground-based and airborne fluxes to upscale carbon dioxide (CO2) and methane (CH4) fluxes using satellite-based surface reflectances at 500-m resolution across a gradient of saline to freshwater wetlands in Southern Florida, USA. Daily time series of CO2 and CH4 fluxes from 2000 to 2024 integrated surface properties related to vegetation productivity, flooding, and disturbance, and captured 80% and 91% of the variability in annual fluxes of CO2 and CH4, respectively. Long-term (23-y) patterns in the fluxes of CH4, CO2, and their CO2-equivalent (CO2eq) are represented as Global Warming Potential 100 (GWP100) and were shown to vary spatially with wetland management, revealing higher carbon uptake in mangroves susceptible to hurricane damage and coastal hydrology, and greater carbon emissions in freshwater sawgrass marshes where freshwater hydrology is managed for restoration. Regional net annual CO2eq uptake in coastal and freshwater wetlands increased by 18% from -7.0 ± 3.3 MMT CO2eq y-1 in ~2003 to -8.4 ± 3.8 MMT CO2eq y-1 in ~2020 at an uptake rate of -0.06 ± 0.01 MMT CO2eq y-2. Annually, roughly 43% of CO2 uptake was offset by CH4 emissions from all wetlands in the region (from 16% in mangroves to 82% in freshwater marshes).

    View details for DOI 10.1073/pnas.2513685123

    View details for PubMedID 41701819

    View details for PubMedCentralID PMC12933060

  • The Global Woody Surface: A Planetary Interface for Biodiversity, Ecosystem Function, and Climate GLOBAL CHANGE BIOLOGY Gewirtzman, J. 2026; 32 (1): e70699

    View details for DOI 10.1111/gcb.70699

    View details for Web of Science ID 001659618400001

    View details for PubMedID 41517910

  • Impacts and Legacies of Extreme Precipitation on Temperate Forests During Critical Ecological Windows ANNUAL REVIEW OF ECOLOGY EVOLUTION AND SYSTEMATICS Matthes, J., Reinmann, A., Naughton, H., Gewirtzman, J., Pederson, N. 2025; 56 (1): 315-335
  • Methane flux from living tree stems in a northern conifer forest BIOGEOCHEMISTRY Hettwer, C., Savage, K., Gewirtzman, J., Ruzol, R., Wason, J., Cadillo-Quiroz, H., Fraver, S. 2025; 168 (4)
  • A diverse and distinct microbiome inside living trees NATURE Arnold, W., Gewirtzman, J., Raymond, P. A., Duguid, M. C., Brodersen, C. R., Brown, C., Norbraten, N., Wood, Q., Bradford, M. A., Peccia, J. 2025; 644 (8078): 1039-+

    Abstract

    Despite significant advances in microbiome research across various environments1, the microbiome of Earth's largest biomass reservoir-the wood of living trees2-remains largely unexplored. Here, we illuminate the microbiome inhabiting and adapted to wood and further specialized to individual host tree species, revealing that wood is a harbour of biodiversity and potential key players in tree health and forest ecosystem functions. We demonstrate that a single tree hosts approximately one trillion bacteria in its woody tissues, with microbial communities distinctly partitioned between heartwood and sapwood, each maintaining unique microbiomes with minimal similarity to other plant tissues or ecosystem components. The heartwood microbiome emerges as a particularly unique ecological niche, distinguished by specialized archaea and anaerobic bacteria driving consequential biogeochemical processes. Our findings support the concept of plants as 'holobionts'3,4-integrated ecological units of host and associated microorganisms-with implications for tree health, disease and functionality. By characterizing the composition, structure and functions of tree internal microbiomes, our work opens up pathways for understanding tree physiology and forest ecology and establishes a new frontier in environmental microbiology.

    View details for DOI 10.1038/s41586-025-09316-0

    View details for Web of Science ID 001545403700001

    View details for PubMedID 40770104

    View details for PubMedCentralID 6192678

  • Low-Cost CO<sub>2</sub> NDIR Sensors: Performance Evaluation and Calibration Using Machine Learning Techniques SENSORS Dubey, R., Telles, A., Nikkel, J., Cao, C., Gewirtzman, J., Raymond, P. A., Lee, X. 2024; 24 (17)

    View details for DOI 10.3390/s24175675

    View details for Web of Science ID 001312989000001

  • Low-Cost CO2 NDIR Sensors: Performance Evaluation and Calibration Using Machine Learning Techniques. Sensors (Basel, Switzerland) Dubey, R., Telles, A., Nikkel, J., Cao, C., Gewirtzman, J., Raymond, P. A., Lee, X. 2024; 24 (17)

    Abstract

    The study comprehensively evaluates low-cost CO2 sensors from different price tiers, assessing their performance against a reference-grade instrument and exploring the possibility of calibration using different machine learning techniques. Three sensors (Sunrise AB by Senseair, K30 CO2 by Senseair, and GMP 343 by Vaisala) were tested alongside a reference instrument (Los Gatos precision greenhouse gas analyzer). The results revealed differences in sensor performance, with the higher cost Vaisala sensors exhibiting superior accuracy. Despite its lower price, the Sunrise sensors still demonstrated reasonable accuracy. Meanwhile, the K30 sensor measurements displayed higher variability and noise. Machine learning models, including linear regression, gradient boosting regression, and random forest regression, were employed for sensor calibration. In general, linear regression models performed best for extrapolating data, whereas decision tree-based models were generally more useful in handling non-linear datasets. Notably, a stack ensemble model combining these techniques outperformed the individual models and significantly improved sensor accuracy by approximately 65%. Overall, this study contributes to filling the gap in intercomparing CO2 sensors across different price categories and underscores the potential of machine learning for enhancing sensor accuracy, particularly in low-cost sensor applications.

    View details for DOI 10.3390/s24175675

    View details for PubMedID 39275586

    View details for PubMedCentralID PMC11397870

  • A method for sampling the living wood microbiome METHODS IN ECOLOGY AND EVOLUTION Arnold, W., Gewirtzman, J., Raymond, P. A., Bradford, M. A., Butler, C., Peccia, J. 2024; 15 (6): 1084-1096
  • Fluxbot: The Next Generation - Design and Validation of a Wireless, Open-Source Mechatronic CO<sub>2</sub> Flux Sensing Chamber Pan, C., Patel, V., Gewirtzman, J., Richardson, I., Dubey, R., Caylor, K., Dollar, A., Forbes, E., Assoc Computing Machinery ASSOC COMPUTING MACHINERY. 2024: 85-96
  • Effects of Urbanization and Forest Fragmentation on Atmospheric Nitrogen Inputs and Ambient Nitrogen Oxide and Ozone Concentrations in Mixed Temperate Forests JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES Rindy, J. E., Pierce, E. A., Geddes, J., Garvey, S. M., Gewirtzman, J., Driscoll, C. T., Hutyra, L. R., Templer, P. H. 2023; 128 (12)
  • Multi-scale observations of mangrove blue carbon ecosystem fluxes: The NASA Carbon Monitoring System BlueFlux field campaign ENVIRONMENTAL RESEARCH LETTERS Poulter, B., Adams-Metayer, F. M., Amaral, C., Barenblitt, A., Campbell, A., Charles, S. P., Roman-Cuesta, R., D'Ascanio, R., Delaria, E. R., Doughty, C., Fatoyinbo, T., Gewirtzman, J., Hanisco, T. F., Hull, M., Kawa, S., Hannun, R., Lagomasino, D., Lait, L., Malone, S. L., Newman, P. A., Raymond, P., Rosentreter, J. A., Thomas, N., Vaughn, D., Wolfe, G. M., Xiong, L., Ying, Q., Zhang, Z. 2023; 18 (7)
  • Tree Species Effects on Soil CO<sub>2</sub> and CH<sub>4</sub> Fluxes in a Mixed Temperate Forest ECOSYSTEMS Jevon, F. V., Gewirtzman, J., Lang, A. K., Ayres, M. P., Matthes, J. 2023; 26 (7): 1587-1602
  • Atmospheric wet deposition in urban and suburban sites across the United States ATMOSPHERIC ENVIRONMENT Conrad-Rooney, E., Gewirtzman, J., Pappas, Y., Pasquarella, V. J., Hutyra, L. R., Templer, P. H. 2023; 305
  • Urbanization and fragmentation have opposing effects on soil nitrogen availability in temperate forest ecosystems GLOBAL CHANGE BIOLOGY Caron, S., Garvey, S. M. M., Gewirtzman, J., Schultz, K., Bhatnagar, J. M. M., Driscoll, C., Hutyra, L. R. R., Templer, P. H. H. 2023; 29 (8): 2156-2171

    Abstract

    Nitrogen (N) availability relative to plant demand has been declining in recent years in terrestrial ecosystems throughout the world, a phenomenon known as N oligotrophication. The temperate forests of the northeastern U.S. have experienced a particularly steep decline in bioavailable N, which is expected to be exacerbated by climate change. This region has also experienced rapid urban expansion in recent decades that leads to forest fragmentation, and it is unknown whether and how these changes affect N availability and uptake by forest trees. Many studies have examined the impact of either urbanization or forest fragmentation on nitrogen (N) cycling, but none to our knowledge have focused on the combined effects of these co-occurring environmental changes. We examined the effects of urbanization and fragmentation on oak-dominated (Quercus spp.) forests along an urban to rural gradient from Boston to central Massachusetts (MA). At eight study sites along the urbanization gradient, plant and soil measurements were made along a 90 m transect from a developed edge to an intact forest interior. Rates of net ammonification, net mineralization, and foliar N concentrations were significantly higher in urban than rural sites, while net nitrification and foliar C:N were not different between urban and rural forests. At urban sites, foliar N and net ammonification and mineralization were higher at forest interiors compared to edges, while net nitrification and foliar C:N were higher at rural forest edges than interiors. These results indicate that urban forests in the northeastern U.S. have greater soil N availability and N uptake by trees compared to rural forests, counteracting the trend for widespread N oligotrophication in temperate forests around the globe. Such increases in available N are diminished at forest edges, however, demonstrating that forest fragmentation has the opposite effect of urbanization on coupled N availability and demand by trees.

    View details for DOI 10.1111/gcb.16611

    View details for Web of Science ID 000925625400001

    View details for PubMedID 36682025

  • Leaf and root phenology and biomass of Eriophorum vaginatum in response to warming in the Arctic JOURNAL OF PLANT ECOLOGY Ma, T., Parker, T., Fetcher, N., Unger, S. L., Gewirtzman, J., Moody, M. L., Tang, J. 2022; 15 (5): 1091-1105
  • Responses of root phenology in ecotypes of<i> Eriophorum</i><i> vaginatum</i> to transplantation and warming in the Arctic SCIENCE OF THE TOTAL ENVIRONMENT Ma, T., Parker, T., Unger, S., Gewirtzman, J., Fetcher, N., Moody, M. L., Tang, J. 2022; 805: 149926

    Abstract

    The effect of climate change on phenology and growth is less understood for belowground plant tissues than for aboveground plant tissues, particularly in high-latitude regions. Ecotypes within a species adapted to a locality may display different responses to climate change. We established two common garden plots in the Arctic tundra north of the Brooks Range in northern Alaska. Three ecotypes of Eriophorum vaginatum along a latitudinal gradient were transplanted into common gardens, and half of the transplants were warmed using open-top chambers (OTCs). Minirhizotrons were used to track the root phenology during the growing seasons of 2016 and 2017. Warming with OTCs (approximately +1 °C in air) did not affect the root biomass, root production or root phenology. The southern ecotype (from 67°16'N) of Eriophorum vaginatum transplanted northward experienced delayed startup and root production compared to two northern ecotypes (from 68°38'N and 69°25'N), although significant differences were not observed in the three ecotypes in terms of root production, root biomass and growth duration at the two sites. Our results suggest that as the climate warms, ecotypes of Eriophorum vaginatum may be able to adjust their duration of root growth and root productivity by phenotypic plasticity, although the degree of plasticity controlling the root startup time may vary between southern and northern ecotypes.

    View details for DOI 10.1016/j.scitotenv.2021.149926

    View details for Web of Science ID 000704385400013

    View details for PubMedID 34543789

  • Controls on Riverine Dissolved Organic Matter Composition Across an Arctic-Boreal Latitudinal Gradient JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES Johnston, S., Carey, J. C., Kellerman, A., Podgorski, D. C., Gewirtzman, J., Spencer, R. G. M. 2021; 126 (9)
  • Arctic River Dissolved and Biogenic Silicon Exports-Current Conditions and Future Changes With Warming GLOBAL BIOGEOCHEMICAL CYCLES Carey, J. C., Gewirtzman, J., Johnston, S., Kurtz, A., Tang, J., Vieillard, A. M., Spencer, R. G. M. 2020; 34 (3)
  • Soil Warming Accelerates Biogeochemical Silica Cycling in a Temperate Forest FRONTIERS IN PLANT SCIENCE Gewirtzman, J., Tang, J., Melillo, J. M., Werner, W. J., Kurtz, A. C., Fulweiler, R. W., Carey, J. C. 2019; 10
  • Financing loss and damage: reviewing options under the Warsaw International Mechanism CLIMATE POLICY Gewirtzman, J., Natson, S., Richards, J., Hoffmeister, V., Durand, A., Weikmans, R., Huq, S., Roberts, J. 2018; 18 (8): 1076-1086
  • How Will We Pay for Loss and Damage? ETHICS POLICY & ENVIRONMENT Roberts, J., Natson, S., Hoffmeister, V., Durand, A., Weikmans, R., Gewirtzman, J., Huq, S. 2017; 20 (2): 208-226