Work in our lab is aimed at understanding how the health of rivers and streams can be maintained in the face of global change. There are several factors that currently negatively affect rivers and streams – which are called ‘stressors’. Some examples of stressors are factors associated with climate change, land use change and changes in species composition, such as stream warming, increased nutrient inputs, altered hydrology, increases in toxins, and the effects of overharvesting or species invasions on native biodiversity.
We are working to understand the mechanistic effects of many watershed-derived stressors in order to inform best management practices. Because excess nutrients are a leading source of impairment to streams, we have focused much of our work on understanding their effects on stream ecosystems. We have particularly focused on food web and carbon pathways based on terrestrially-derived (detrital) carbon because these pathways support the majority of ecosystem functions in many streams and have been understudied relative to the effects of nutrients on algal pathways. To understand how nutrients affect ecosystem functions in streams, we use a stoichiometric perspective, which gives us a view of how the balance of carbon and nutrients in an ecosystem is altered with anthropogenic nutrient loading or loss of important species that recycle nutrients in ecosystems.
We are also working with other scientists and stakeholders to determine how multiple stressors associated with land use and climate change affect stream ecosystems. Land use and management decisions associated with urbanization result in multiple stressors to streams. We are working to find out how multiple stressors affect the biotic integrity of streams and how biotic integrity can be maintained. We are also working with other ecologists and hydrologists to quantify the effects of stressors and assess changes in ecosystem functions at appropriate scales. We are contributing to these efforts by conducting measurements at large and small scales and determining important drivers of ecosystem function at both scales. Our collaborators are helping scale these measurements so that appropriate estimations of ecosystem functions at river network scales can be made. Please see the sections below for more details of our studies!