Postdoctoral Position Available (Fall 2023): Warming Winters & Watershed Nutrient Loss
We seek a field- and lab-oriented postdoctoral fellow to join our cutting-edge, transdisciplinary
research aimed at using high frequency soil and stream sensor data to identify how warm winters, with increasingly common rain, snowmelt, and rain-on-snow events, impact the timing and magnitude of watershed nutrient export and alter critical source areas and flowpaths for nitrogen and phosphorous.
The project’s goals are to test the hypotheses that winter floods have substantially different nutrient sources, sinks, and flowpaths than similar events during other seasons and that increasingly frequent winter floods alter watershed function to reduce nutrient retention.
With a somewhat flexible late summer to fall start date, this will be a 2-year position. Salary range: $56,500 to $65,000 plus excellent benefits (https://www.uvm.edu/human-resources/postdoctoral-associates-fellows-overview).
Please contact Carol Adair ([email protected]) or Andrew Schroth ([email protected]).
To apply: please send CV, names and contact information for three references, and a cover letter outlining research interests, expertise, and availability to [email protected]. Applications will be considered until the position is filled.
More information here.
research aimed at using high frequency soil and stream sensor data to identify how warm winters, with increasingly common rain, snowmelt, and rain-on-snow events, impact the timing and magnitude of watershed nutrient export and alter critical source areas and flowpaths for nitrogen and phosphorous.
The project’s goals are to test the hypotheses that winter floods have substantially different nutrient sources, sinks, and flowpaths than similar events during other seasons and that increasingly frequent winter floods alter watershed function to reduce nutrient retention.
With a somewhat flexible late summer to fall start date, this will be a 2-year position. Salary range: $56,500 to $65,000 plus excellent benefits (https://www.uvm.edu/human-resources/postdoctoral-associates-fellows-overview).
Please contact Carol Adair ([email protected]) or Andrew Schroth ([email protected]).
To apply: please send CV, names and contact information for three references, and a cover letter outlining research interests, expertise, and availability to [email protected]. Applications will be considered until the position is filled.
More information here.
Ecosystem modification is an unavoidable consequence of human activity. The proliferation of direct (e.g., land use change) and indirect (e.g., nitrogen, N, deposition) anthropogenic modifiers requires understanding the drivers and effects of these modifiers in virtually all ecosystems.
Our research focuses on the responses of ecosystem properties and processes to natural and anthropogenic changes and how such changes may feed back to further influence global, ecosystem, or community level changes. Because predicting and managing the effects of natural and anthropogenic changes depends on accurately depicting basic ecosystem processes, we combine field and laboratory experimental approaches with quantitative methods to better understand fundamental processes like decomposition.
We are committed to creating a safe and collaborative environment for conducting research. See our lab code of conduct here.
Our research focuses on the responses of ecosystem properties and processes to natural and anthropogenic changes and how such changes may feed back to further influence global, ecosystem, or community level changes. Because predicting and managing the effects of natural and anthropogenic changes depends on accurately depicting basic ecosystem processes, we combine field and laboratory experimental approaches with quantitative methods to better understand fundamental processes like decomposition.
We are committed to creating a safe and collaborative environment for conducting research. See our lab code of conduct here.
RESEARCH PROJECTS
What drives decomposition at large scales?
Global decomposition data set
This project uses large data sets and model selection techniques to discover the level of complexity that is needed to model decomposition at large spatial and temporal scales. Are simple, microbially implicit models sufficient to explain decomposition at a global scale (e.g., Adair et al. 2008)? Or will incorporating microbial populations and/or processes improve the ability of models to predict carbon and nitrogen losses?
We have compiled a large-scale, long-term litter decomposition database (figure below), to compare models that vary only in how microbial activity is modeled. A model comparison using this extensive data set will allow us to evaluate how much of this complex process must be explicitly modeled to accurately describe and predict decomposition at global and regional scales.
Combining experimental approaches to understanding the biogeochemical effects of abiotic or biotic global changes with data assimilation, analysis, and model comparison techniques will provide information on some major, unresolved issues in ecosystem ecology including the fate of litter and soil C in the face of global change. Such an approach will advance not only basic science, but also provide crucial information for management and policy formation.
We have compiled a large-scale, long-term litter decomposition database (figure below), to compare models that vary only in how microbial activity is modeled. A model comparison using this extensive data set will allow us to evaluate how much of this complex process must be explicitly modeled to accurately describe and predict decomposition at global and regional scales.
Combining experimental approaches to understanding the biogeochemical effects of abiotic or biotic global changes with data assimilation, analysis, and model comparison techniques will provide information on some major, unresolved issues in ecosystem ecology including the fate of litter and soil C in the face of global change. Such an approach will advance not only basic science, but also provide crucial information for management and policy formation.
Winter watershed nutrient fluxes and sources
Winter dynamics are changing across the U.S. and in Vermont. Events that produce substantial winter runoff are increasing with unknown cascading impacts on water quality and ecosystem health. Mid-winter melts and rain-on-snow events (ROS) are becoming more frequent, but we have little understanding of howthey impact the hydrologic and biogeochemical processes that govern the storage, release, and transformation of nutrients – especially across land uses. Preliminary data suggest that winter runoff events are disproportionately important contributors to annual nutrient loads, transporting as much as 24% of annual nitrate (NO3) loads, with loads enriched in reactive metal and phosphorus (P) species.
This project focuses on identifying how changing winters, with increasingly common snowmelt and rain-on-snow events, impact the timing and magnitude of watershed nutrient export and alter critical source areas and flowpaths for water, nitrogen, and phosphorous.
Research leverages a heavily instrumented suite of watersheds in Vermont of different landcover and focuses on geochemical pathways and processes that drive nutrient export, with particular emphasis on how export pathways and processes vary between winter events (thaws and rain on snow) and growing season events.
This project focuses on identifying how changing winters, with increasingly common snowmelt and rain-on-snow events, impact the timing and magnitude of watershed nutrient export and alter critical source areas and flowpaths for water, nitrogen, and phosphorous.
Research leverages a heavily instrumented suite of watersheds in Vermont of different landcover and focuses on geochemical pathways and processes that drive nutrient export, with particular emphasis on how export pathways and processes vary between winter events (thaws and rain on snow) and growing season events.
Research on Adaptation to Climate Change - terrestrial ecosystem responses and watershed connectivity
The increased persistence and magnitude of weather patterns have contributed to repeated flooding in Vermont, with unclear consequences for water quality. This research seeks to address the fundamental research questions: What properties within the Lake Champlain Basin drive hydrologic and nutrient responses to extreme events, and what are strategies for increasing resilience to protect water quality in the social ecological system? Within this large interdisciplinary project, our focus is on the riparian areas that link watersheds to surface waters. Do some riparian areas have properties or processes that are critical to maintaining water quality, especially during extreme events? More information on BREE here. You can also see our work featured on the PBS special "Saving Our Waters".
What controls forest carbon storage across scales?
What controls the capacity for forests to store carbon from stand to regional and global scales? For example, biodiversity clearly has impacts on productivity in small-scale experiments, but what impact does it have across large scales in forests? We are conducting research to understand the relative impact of forest composition and structure among the known drivers of carbon storage in forests. We've found that, in Quebec temperate and boreal forests, tree diversity has its largest impact on aboveground carbon storage (Adair et al. 2018). Increasing tree diversity can increase the average amount of carbon stored in live trees up to 30%. But, it's impacts on belowground storage are much smaller. We are therefore using a multi-scale approach - small in-lab experimentation to large data sets and regional studies - to determine the role of diversity and other variables, such as microbial community composition and mineralogy, on determining belowground forest carbon storage.
The Agriculture-Climate Change connection
Measuring GHG emissions on Borderview Farm
As climate changes increasingly affect agriculture, farmers and policy makers are challenged by how to best address climate change mitigation and adaptation. Central to this challenge is developing agroecosystems that improve soil health, increase soil carbon storage and mitigate agriculture’s contribution to greenhouse gas (GHG) emissions, all while remaining economically viable.
Most agricultural soils are currently a source of CO2 and N2O (a powerful GHG). The conversion of natural systems to agriculture and traditional cultivation methods has led to the loss of 40% to 75% of original soil organic carbon as CO2, and severe depletion of soil organic carbon degrades soil quality and reduces productivity. However, changing tillage practices to no till or low till and incorporating cover crops have the potential to increase soil carbon storage. An important co-benefit of these practices may be reducing emissions of CO2 and N2O. An additional concern is the emissions associated with the application of manure or fertilizer. Can we change the method or timing of application to reduce GHG emissions? This project focuses on the capacity for different tillage practices, cover crops, and nutrient application methods to mitigate climate change by reducing GHG emissions and increasing soil carbon storage.
Most agricultural soils are currently a source of CO2 and N2O (a powerful GHG). The conversion of natural systems to agriculture and traditional cultivation methods has led to the loss of 40% to 75% of original soil organic carbon as CO2, and severe depletion of soil organic carbon degrades soil quality and reduces productivity. However, changing tillage practices to no till or low till and incorporating cover crops have the potential to increase soil carbon storage. An important co-benefit of these practices may be reducing emissions of CO2 and N2O. An additional concern is the emissions associated with the application of manure or fertilizer. Can we change the method or timing of application to reduce GHG emissions? This project focuses on the capacity for different tillage practices, cover crops, and nutrient application methods to mitigate climate change by reducing GHG emissions and increasing soil carbon storage.
Agricultural resilience in a changing climate
This long-term, collaborative project seeks to work with farmers, agricultural service providers, researchers, and community organizations to address the impacts of climate change on agriculture in Vermont. The project focuses on evaluating and implementing on-farm climate change adaptation and mitigation practices. In partnership with farmers, we are identifying "best management practices" for dealing with climate change, and will evaluate the economic and environmental impacts of these strategies. Our work also seeks to involve and inform state and federal policymakers.
Within this collaborative project, our lab's focus is on evaluating the potential of agricultural practices to increase carbon storage, reduce greenhouse gas emissions (CO2, N2O and CH4) and improve regional water quality.
For more information on our current project investigating the impacts of best management practices in the dominant agroecosystems of the Northeast, check out this USDA 360 project: project page, virtual tour, and YouTube playlist.
Within this collaborative project, our lab's focus is on evaluating the potential of agricultural practices to increase carbon storage, reduce greenhouse gas emissions (CO2, N2O and CH4) and improve regional water quality.
For more information on our current project investigating the impacts of best management practices in the dominant agroecosystems of the Northeast, check out this USDA 360 project: project page, virtual tour, and YouTube playlist.