Doctor of Philosophy, University of Tennessee Knoxville (2017)
PhD, University of Tennessee, Ecology and Evolutionary Biology (2017)
Bachelor of Science, Seattle University (2011)
- Symbiotic niche mapping reveals functional specialization by two ectomycorrhizal fungi that expands the host plant niche FUNGAL ECOLOGY 2020; 46
Intraspecific trait variation across elevation predicts a widespread tree species' climate niche and range limits
ECOLOGY AND EVOLUTION
2020; 10 (9): 3856–67
Global change is widely altering environmental conditions which makes accurately predicting species range limits across natural landscapes critical for conservation and management decisions. If climate pressures along elevation gradients influence the distribution of phenotypic and genetic variation of plant functional traits, then such trait variation may be informative of the selective mechanisms and adaptations that help define climatic niche limits. Using extensive field surveys along 16 elevation transects and a large common garden experiment, we tested whether functional trait variation could predict the climatic niche of a widespread tree species (Populus angustifolia) with a double quantile regression approach. We show that intraspecific variation in plant size, growth, and leaf morphology corresponds with the species' total climate range and certain climatic limits related to temperature and moisture extremes. Moreover, we find evidence of genetic clines and phenotypic plasticity at environmental boundaries, which we use to create geographic predictions of trait variation and maximum values due to climatic constraints across the western US. Overall, our findings show the utility of double quantile regressions for connecting species distributions and climate gradients through trait-based mechanisms. We highlight how new approaches like ours that incorporate genetic variation in functional traits and their response to climate gradients will lead to a better understanding of plant distributions as well as identifying populations anticipated to be maladapted to future environments.
View details for DOI 10.1002/ece3.5969
View details for Web of Science ID 000534741200003
View details for PubMedID 32489616
View details for PubMedCentralID PMC7244802
Warming and disturbance alter soil microbiome diversity and function in a northern forest ecotone.
FEMS microbiology ecology
The response to global change by soil microbes is set to affect important ecosystem processes. These impacts could be most immediate in transitional zones, such as the temperate-boreal forest ecotone, yet previous work in these forests has primarily focused on specific subsets of microbial taxa. Here, we examined how bacterial and fungal communities respond to simulated above- and belowground warming under realistic field conditions in closed and open canopy treatments in Minnesota, USA. Our results show that warming and canopy disturbance shifted bacterial and fungal community structure as dominant bacterial and fungal groups differed in the direction and intensity of their responses. Ectomycorrhizal and saprotrophic fungal communities with greater connectivity (higher prevalence of strongly interconnected taxa based on pairwise co-occurrence relationships) were more resistant to compositional change. Warming effects on soil enzymes involved in the hydrolytic and oxidative liberation of carbon from plant cell walls and nutrients from organic matter were most strongly linked to fungal community responses, although community structure-function relationships differed between fungal guilds. Collectively, these findings indicate that warming and disturbance will influence the composition and function of microbial communities in the temperate-boreal ecotone, and fungal responses are particularly important to understand for predicting future ecosystem functioning.
View details for DOI 10.1093/femsec/fiaa108
View details for PubMedID 32472932
- Climate-driven reduction of genetic variation in plant phenology alters soil communities and nutrient pools GLOBAL CHANGE BIOLOGY 2019; 25 (4): 1514–28
- Bringing Plants & Soils to Life through a Simple Role-Playing Activity AMERICAN BIOLOGY TEACHER 2019; 81 (4): 287–90
Climate-driven reduction of genetic variation in plant phenology alters soil communities and nutrient pools.
Global change biology
We examined the hypothesis that climate-driven evolution of plant traits will influence associated soil microbiomes and ecosystem function across the landscape. Using a foundation tree species, Populus angustifolia, observational and common garden approaches, and a base population genetic collection that spans 17 river systems in the western United States, from AZ to MT, we show that (a) as mean annual temperature (MAT) increases, genetic and phenotypic variation for bud break phenology decline; (b) soil microbiomes, soil nitrogen (N), and soil carbon (C) vary in response to MAT and conditioning by trees; and (c) with losses of genetic variation due to warming, population-level regulation of community and ecosystem functions strengthen. These results demonstrate a relationship between the potential evolutionary response of populations and subsequent shifts in ecosystem function along a large temperature gradient.
View details for PubMedID 30659721
- Feedbacks link ecosystem ecology and evolution across spatial and temporal scales: Empirical evidence and future directions FUNCTIONAL ECOLOGY 2019; 33 (1): 31–42
- Ecosystem feedbacks contribute to geographic variation in plant-soil eco-evolutionary dynamics across a fertility gradient FUNCTIONAL ECOLOGY 2019; 33 (1): 95–106
- Soil fungi underlie a phylogenetic pattern in plant growth responses to nitrogen enrichment JOURNAL OF ECOLOGY 2018; 106 (6): 2161–75