Effects of Hemlock Decline on Streams
The potential loss of hemlock over a large landscape as a result of the spread of the hemlock woolly adelgid (HWA), an invasive insect that kills all ages of hemlock trees, has implications for water chemistry, physical habitat, vertebrate and invertebrate community composition, and trophic structure in large numbers of streams throughout New England. Changes in headwater streams due to hemlock decline are likely to be reflected in changes in downstream receiving waters including larger rivers, lakes, and water supply reservoirs. We are studying physical, chemical, and biological characteristics of streams in hemlock-dominated watersheds and comparing them with streams from catchments dominated by deciduous trees, in order to predict large-scale changes that are likely over time as HWA continues its northward advance.