2010 - Impact of the Hemlock Woolly Adelgid on the Water Cycle in New England: Differences in Hydrologic Fluxes Between Hemlock and Deciduous Forest Stands

Grant Award Year: 
Principal Investigator: 
Dr. Andrew Guswa
Research Description: 
In the northeastern United States, the hemlock woolly adelgid (HWA) poses a significant threat to eastern hemlock (Tsuga canadensis). Replacement of hemlock forests by other species, such as birch, maple, and oak, may alter the hydrologic cycle and impact water resources. Changes to hydrologic fluxes include both the input of water, which is affected by canopy interception, and the uptake of water for transpiration. This proposal seeks to build upon and complement earlier findings to better understand differences in hydrologic fluxes between hemlock and deciduous forests. The objectives of this project are to quantify the difference in average interception between hemlock and deciduous stands, quantify the spatial variability of throughfall in hemlock and deciduous stands, quantify differences in summertime water use for hemlock and deciduous stands. To achieve these objectives, this project will engage a cohort of three undergraduates in a two-month field campaign to measure and characterize hydrologic fluxes in hemlock and deciduous forest stands. The field work will be carried out at the Ada and Archibald MacLeish Field Station, a 200-acre site maintained by Smith College. We will establish two hemlock sites and two deciduous sites and instrument them to measure throughfall and sap flux. Achievement of the project objectives will address a variety of water resources research needs of regional importance. This project will also engage undergraduates in scientific research, which has the potential to advance science, enhance education, strengthen the research community, and raise general awareness of the importance and impact of scientific understanding.