Several important research themes in my lab include:
The biology of biogeochemical cycling.
Plants and microbes have direct and indirect influences on ecosystem processes. Plant-microbial interactions govern several important aspects of soil nutrient cycling. In northern regions, our research investigates changing community structure along disturbance gradients and how functional traits assemble to influence decomposition and exchange of carbon between the biosphere and the atmosphere. I am broadly interested in plant and microbial communities that thrive in permafrost and wetland systems and how they adapt to stressful environments (cold, wet soils). Lastly, wetlands are particularly vulnerable to biological invasions due to their hydrologic function and I am interested in the role of invasive species on biogeochemical processes in the Great Lakes basin and other wetland-rich regions.
Climate change and disturbance in boreal and taiga regions.
In many regions, climate change has caused pronounced shifts in the frequency and severity of disturbances such as wildfire, permafrost degradation, and insect outbreaks. Fire has strong controls over carbon sequestration across boreal landscapes, and we are examining the influence of burning on aspects of water and air quality such as nitrogen and mercury cycling. While the short-term influence of fires includes these biogeochemical alterations, we also study how burning influences long-term ecosystem behavior through vegetation composition and by potentially triggering permafrost thaw.
I am interested in using a variety of scientific approaches - including descriptive studies, gradient studies, paleoecology, modeling, and experiments – to understand how ecosystems and ecosystem services are responding to changing climatic and disturbance regimes. More than 15 years ago, I initiated a series of water table drawdown and soil warming experiments in fens in interior Alaska (the APEX experiment), and we remain committed to using this experimental design to collect long term data. This work is affiliated with the Bonanza Creek LTER site. We also are conducting research in Alaska and Canada following up on the immediate and long-term consequences of major fire seasons, such as the 2004 fires in Alaska and the 2014 fires in the Northwest Territories.
Carbon cycle research to address northern food and water security.
My northern research program is now posing a variety of research questions linking ecosystem services and carbon cycle science to water and food security. Indigenous households experience far more food insecurity than other households, and this is intimately connected to water. For example, we study how permafrost thaw affects water quality and the ability of subsistence harvesters to travel and access traditional foods. We are working with communities to identify how thermokarst is affecting culturally important lands.
Many models also show that northern Canada will become more suitable for certain crops under future climate change. This makes the north one of the most important agricultural frontiers. Productivity on northern soils will require drainage, which causes large carbon emissions. We are using a number of approaches to help build capacity in northern communities to better adjust to this shifting agricultural landscape and embrace climate-smart food production and agriculture.