At the University of Wyoming, I work in the Collins Lab as a Postdoctoral Researcher

During my PhD. I was part of the NSF EPSCoR Track II project to create a database of stoichiometric traits of organisms in their chemical habitats (STOICH) and to conduct related research. This database will be the first of its kind and will enable current and future freshwater scientists to expand the field of ecological stoichiometry and to build upon our understanding of patterns that result from mismatches between available elements and requirements by communities of organisms. Learn more about the Ecological Stoichiometry Cooperative.

​A global perspective on divergence and commonality between lotic and lentic seston stoichiometry

Picture
We are currently working on the first global synthesis of freshwater seston stoichiometry that includes both lentic and lotic ecosystems, using a newly compiled, open-source dataset. Our findings reveal distinct stoichiometric patterns between ecosystem types and highlight how local- and broad-scale environmental gradients (e.g., trophic state, elevation, precipitation) interact to shape C:N:P ratios. These results empirically support the biogeochemical mosaic hypothesis and demonstrate that while nutrient concentrations are relatively predictable, stoichiometric ratios are more variable and context-dependent. This study provides a novel framework for understanding cross-scale nutrient dynamics in freshwater systems and offers important insights for predicting ecological responses to environmental change.

This work will appeal to aquatic ecologists, biogeochemists, and global change scientists interested in nutrient cycling, food web dynamics, and large-scale ecological synthesis. Limnology and Oceanography is the ideal outlet due to its broad readership and its legacy of publishing foundational work in aquatic stoichiometry and ecosystem science.

Nutrient and stoichiometry variability along a headwater lake-river network​

High-elevation, headwater aquatic networks are crucial for water provisioning and ecosystem services in the western United States (U.S.) due to their capacity for water storage and recharge, streamflow generation, and specialized habitat. Because headwaters serve as large sources of water, nutrients, and solutes, headwater quality can have serious implications on quality and quantity of downstream waters. In this study, we focused on nitrogen (N) and phosphorus (P) concentrations and N:P stoichiometry to examine how nutrient dynamics change along a headwater network in the Rocky Mountains in Colorado, U.S.  This study highlights the importance of freshwater network connectivity and the differential role of streams and lakes in modulating nutrients. 

​Nutrient budgets and influences on productivity in a critical Wyoming water source

Picture

​Reservoirs serve as critical human resources for drinking water, irrigation, navigation, flood control, hydropower, recreation, and fisheries. The Wyoming Department of Environmental Quality routinely lists Harmful Cyanobacterial Bloom Advisories for Boysen Reservoir. It a culturally significant waterbody that is used for recreation and drinking water supply, but harmful cyanobacterial blooms threaten the water quality and ecosystem services provided by the reservoir. Thus, Boysen is considered a high priority for implementation of proactive nutrient reduction as part of the Wyoming Nutrient Strategy. We are working to better understand nutrient dynamics in Boysen Reservoir to develop management targets and reduce harmful cyanobacterial blooms.

A Broad-Scale Look at Nutrient Limitation and a Shift toward Colimitation
in United States Lakes

Picture



https://doi.org/10.1021/acs.est.4c03135
There is a longstanding debate about the role of nitrogen (N) vs phosphorus (P) in limiting primary production in lakes and whether co-nutrient limitation should be considered for managing eutrophication. We evaluated nutrient limitation and eutrophication at a subcontinental scale. Using U.S. Environmental Protection Agency National Lakes Assessment data, we assessed broad-scale patterns in nutrient limitation and compared samples of all surveyed lakes and lakes resurveyed in multiple surveys. We found that N correlated more strongly with productivity in the western U.S., while P correlated more strongly in the eastern U.S. The aggregated subcontinental effect suggests the importance of factors like N-deposition, terrestrial vegetation, underlying geology, and land use for understanding drivers of nutrient dynamics in lakes. Our study showed how patterns can aggregate across subcontinental scales yet still demonstrate considerable variation when more deeply examined on an individual lake level. Overall, we found that nutrient limitation is dynamic over space and time, with most lakes being co-limited. The prevalence of co-limitation also increased from 2007 to 2017. Trophic states within each limitation category varied substantially. Our findings underscore the need for combined N and P reductions to mitigate accelerated eutrophication.

Examining climate change-induced disturbances in temperate montane ecosystesm via stream hydrology and water chemistry​

Picture
https://doi.org/10.1007/s10021-024-00942-9
At the University of Wyoming, a team of aquatic ecologists, terrestrial ecologists, and hydrologists are worked together to reveiw disturbances that have the potential to significantly alter temperate montane stream ecosystem health and services. Temperate montane ecosystems with complex drainage networks are especially vulnerable to ecosystem transformation due to their low fertility, heterogeneous landscape environments, and tight coupling between terrestrial and aquatic components. We focused on pulse and press disturbances that impact stream water quality and quantity. Pulse disturbances occur over short time periods and rapidly introduce changes to ecosystem processes and properties, while press disturbances alter ecosystems gradually; e.g., wildfire (pulse), bark beetle (pulse), changes to the hydrological cycle (press), and vegetation community shifts (press). As these four disturbance types increase in severity and frequency and pose a risk to temperate montane streams, it is critical that we develop our understanding of the downstream ramifications on both aquatic and human communities.  

​Conducting Communication, Research, and Education from Climate Change Perspectives

Picture
A group of five Ph.D. students and early career researchers, connected through the Association for the Sciences of Limnology and Oceanography (ASLO), joined together to discuss the challenges of communication, research, and education from climate change perspectives and develop ideas on how to foster diversity, equity, inclusion, and justice in the aquatic sciences community. Check out our pieces here: 

Lakes protect downstream riverine habitats from chloride toxicity

https://aslopubs.onlinelibrary.wiley.com/doi/10.1002/lno.12340 
Anthropogenic salt pollution has significantly contributed to the global problem of freshwater salinization, especially in areas where road salt is a commonly used during winter. Here, we examined salt export regimes along a river-lake continuum in a mixed urban and agricultural watershed in the Midwest United States that is experiencing rising salinity. We quantified chloride loads and fluxes through the watershed with the aim of understanding the role of lakes in downstream salt transport. We found that variations in salt export exist based on hydrological, anthropogenic, and seasonal controls in tributaries upstream of lakes and that the lakes diminish those controls on salinity through hydrological and biogeochemical processes.

 Annual patterns, drivers, and balance of chloride in the Upper Yahara River Watershed

Picture
In the Dugan Lab, I studied how chloride is changing freshwater and the impacts of these changes. If you are interested in ways to prevent your salt use from impacting our beautiful lakes and rivers, visit WI Salt Wise for information.
​
The goal of my salt research was to track the movement of chloride in the Upper Yahara Watershed and its potential to impact aquatic ecology. This study may also serve to inform management of water quality in the Yahara River Watershed. The Upper Yahara River Watershed is home to Lakes Mendota and Monona. Chloride concentrations have been steadily increasing in these lakes since the 1940s and in recent years, streams in the watershed have been added to the state’s impaired waters list for chloride. With continued urbanization, chloride contamination could quickly become a problem for Dane County’s freshwater ecosystem functions and services. Through my findings, I aimed to improve our understanding of the sources, pathways, and long-term trajectory of chloride in the Yahara River Watershed.