Ecohydrology and forest community change

Biological Sciences: Jesse Bellemare (Smith College)
Engineering: Andrew Guswa (Smith College)

In the face of climate change, land-use modification, and exotic species invasions, gaining a clear understanding of the connections and interactions between hydrology and ecology is vital for effective environmental planning and decision-making.This project, led by a plant ecologist and a hydrologist, will engage students in the measurement and modeling of plant-water interactions from the scale of individual trees to whole forest communities and landscapes.Of particular interest are the divergent ecological and hydrological impacts of coniferous hemlock (Tsuga canadensis) vs. deciduous forest canopies on key ecosystem-level processes in southern New England.This study system is currently in flux, as hemlock faces imminent decline due to attack by the invasive insect hemlock wooly adelgid (Adelges tsugae), while other substantial changes are expected due to rapid climate change in coming decades.Field investigations will be carried out at the Ada and Archibald MacLeish Field Station, a two-hundred acre property managed by Smith College’s Center for the Environment, Ecological Design and Sustainability, that supports environmental research and education.Field projects for students will range from measurement of sap-flux on individual trees, to quantification of forest community structure and dynamics, to assessment of stand-level throughfall, and snow sampling in hemlock and deciduous forest areas.To complement these field studies, students will also employ mathematical models to explore the effects of species, functional type, spatial variability, hydraulic lift, and other factors on plant-water relations and hydrologic processes in the landscape.Using these techniques, students will explore how the hydrologic cycle may change due to changes in forest composition (for example, loss of dominant hemlock), or, conversely, how forest composition may change as a result of modifications in the hydrologic cycle (for example, via climate change), along with consideration of the inherent feedbacks in these processes.