Cycling of Carbon and Nutrients

This project integrates soil and ecosystem data to impute important soil properties for hydric soils and wetlands. The work hopes to answer the questions: How have historical changes in biogeochemical processes affected present-day and potential future interactions among land, water, and ecosystem resources? How can improved understanding of historical and present-day biogeochemical interactions...

Wetlands accumulate organic-rich sediment or peat stratigraphically, making them great archives of past environmental change. Wetlands also act as hydrologic buffers on the landscape and are important to global biogeochemical cycling. This project uses wetland archives from a range of environments to better understand how vegetation, hydrology, and hydroclimate has changed on decadal to multi...

While research into eutrophication has been a cornerstone of limnology for more than 100 years, only recently has it become a topic for the remote alpine lakes that are icons of protected national parks and wilderness areas. National park lakes in the western U.S. are threatened by global change, specifically air pollution, warming, and their interactions, and the problem is quickly worsening...

Land cover and land use (LC/LU), climate, and biogeochemical processing are significant drivers of water quality in streams and rivers over broad scales of space and time. As LC/LU and climate continue to change we can expect changes in water quality. This project seeks to understand the drivers of spatial and temporal variability in water quality across scales using new and existing data to...

Stream transport (lateral transfer) of carbon remains a poorly understood flux within the global carbon budget. This research addresses the need to refine our knowledge of both provenance and transformations of Dissolved Organic Matter (DOM) as it moves from mountains to sea. Interpreting shifts in carbon quality with increasing stream order, and how these patterns change with variation in...

Changes in snowpack accumulation, distribution, and melt in high-elevation catchments are likely to have important impacts on water, carbon, and nitrogen cycles, which are tightly coupled through exchanges of energy and biogeochemical compounds between atmospheric, terrestrial, and aquatic environments. Our research helps to better understand how changes in climate will affect water availability...

The ecological foundation of thousands of acres of wetland habitat is being impacted by changes in land cover, land use, climate, and invasive species. This project utilizes USGS remotely-sensed products, along with experimental and observational field data to develop spatially-explicit, landscape-scale models of invasive cattails and soil biogeochemical processes. These models will assist...

Significant change to the Arctic and sub-arctic water cycle is underway, impacting hydrologic and biogeochemical fluxes. In southcentral Alaska, glacier mass loss, changes to precipitation (including the rain/snow fraction), thawing ground ice, and vegetation encroachment will change both magnitude and timing of water and solute fluxes downstream. Although altered fluxes of limiting nutrients are...

The Prairie Pothole Region (PPR) of North America is one of the most important breeding areas for continental waterfowl populations, a Department of Interior (DOI) trust resource. Land use and climate both influence the functioning of the region’s wetland ecosystems, with effects not just on the waterfowl that depend on these wetlands, but also on the services they provide to society, such as...

Changing temperature, precipitation, and land use intensification has resulted in global soil degradation. The accompanying loss of soil organic matter (SOM) decreases important soil health services. Soil organic matter is a major global pool of carbon; if SOM can be increased, soils can mitigate elevated atmospheric CO2. However, there are major knowledge gaps in SOM persistence. This project...

This project investigates the links between terrestrial and marine carbon cycling and fluvial transport of freshwater and dissolved organic carbon (DOC) to the near-coastal ocean. The project analyzes DOC export that integrates complex interacting processes in natural and human-impacted terrestrial and aquatic environments. Changes in DOC export may indicate changes in terrestrial ecosystem carbon...

More than a third of the United States population lives in counties directly on the shoreline, making them vulnerable to hazards associated with changing sea level and storm surges associated with hurricanes and severe storms. The geologic record contains many examples of past intervals of warm climate and high sea level. "Geological Investigation of the Neogene" is examining proxy records of...