The capacity of soil systems to transform organic matter and nutrients impacts global climate, water quality, and ecosystem productivity. These functions arise from complex interactions among microbes, plants, minerals, and physical components. Unpacking these interactions is an exciting challenge with key implications for understanding and managing the impacts of land use and climate change.

We are a biogeochemistry lab, and our research necessarily spans the domains of both the biological and Earth sciences. We take an interdisciplinary approach to understanding patterns and processes of organic matter decomposition, greenhouse gas production, and nutrient cycling across broad range of spatial and temporal scales. We pursue basic and applied research questions across a diverse suite of ecosystems, including tropical rainforests, intensive agricultural landscapes, urban watersheds, and boreal peatlands. We are particularly interested in the impacts of fluctuating redox dynamics on the microbial and geochemical processes that mediate carbon and nutrient cycling in terrestrial and freshwater wetland ecosystems.

I am seeking motivated and enthusiastic graduate and undergraduates students! Please contact Steven at stevenjh [at] iastate.edu for more information.

Research themes

• Impacts of climate and land-use change on soil organic matter dynamics
• The competing and contentious roles of iron in soil carbon and nutrient cycling
• Nitrogen cycling in human-dominated landscapes
• Exploring new methods and applications of stable isotopes in biogeochemistry