Research Projects
1. My principal research project has emerged into: "Forecasting stream ecosystem responses to a regional landscape disturbance: indirect ecological consequences of the removal of eastern hemlock from New England forests". This research aims to understand how the ecology, biogeochemistry, and hydrology of the region's stream ecosystems will be altered as many riparian or stream-side forests change from eastern hemlock to black birch following the invasion of an exotic pest that attacks eastern hemlock.
Eastern hemlock (Tsuga canadensis) is one of the most abundant species in many of New England's riparian forests. Regional declines in eastern hemlock have been documented and attributed to the invasion of the hemlock woolly adelgid. The hemlock woolly adelgid is an aphid-like forest pest that was first introduced to the eastern U.S. in the 1950s in Virginia. The woolly adelgid's range has expanded to span much of southern New England and the range is ultimately expected to include most of New England.Hemlock-woolly adelgid invasions inevitably cause hemlock stand mortality within four years following consumption of hemlock needles and buds. Further, hemlock-woolly adelgid have no natural enemies and high dispersal rates via wind and animals. The northern expansion of the hemlock-woolly adelgid's range is a potential major landscape disturbance since eastern hemlock is such an important species in northern forests. While terrestrial ecologists are now recognizing the ecological consequences of the loss of eastern hemlock, there has not been an explicit attempt to forecast subsequent impacts on New Englandžs headwater streams and downstream ecosystems.
2. I continue to be interested in the limnology and restoration of Worcester's Blackstone River and have initiated a comparative study of the Blackstone River's headwaters and post-urban reaches. The Blackstone River Gateway Park adjacent to campus provides many research opportunities for Freshwater Ecology and research students.
3. I continue to collaborate with colleagues at the USGS in Menlo Park, CA on the "Ecological importance of detritus and phytoplankton in stream, riverine and estuarine food webs." This research is connected to the restoration of San Francisco Bay's inland freshwater delta, but is relevant to an array of freshwater and marine ecosystems.
Publications (most available as pdf)
Sobczak, W. V., J. E. Cloern, A. D. Jassby, B. E. Cole, T. S. Schraga, and A. Arnsburg. 2005. Detritus fuels metabolism but not metazoan food web in San Francisco Estuary's freshwater Delta. Estuaries 28: 124-137. (PDF)
Sobczak, W. V. 2005. Lindeman's trophic-dynamic aspect of ecology: Will you still need me when I'm 64? Bulletin of the American Society of Limnology and Oceanography 14: 53-57. (PDF)
Aaron M. Ellison, Michael S. Bank, Barton D. Clinton, Elizabeth A. Colburn, Katherine Elliott, Chelcy R. Ford, David R. Foster, Brian D. Kloeppel, Jennifer D. Knoepp, Gary M. Lovett, Jacqueline Mohan, David A. Orwig, Nicholas L. Rodenhouse, William V. Sobczak, Kristina A. Stinson, Pam Snow, Jeffrey K. Stone, Christopher M. Swan, Jill Thompson, Betsy Von Holle, and Jackson R. Webster. 2005.
Loss of foundation species: consequences for the structure and dynamics of forested ecosystems. Frontiers in Ecology and the Environment. 9: 479-486. (PDF)
Findlay, S.E. G., R. L. Sinsabaugh, W. V. Sobczak, and M. Hoostal. 2003. Metabolic and structural response of hyporheic microbial communities to variations in supply of dissolved organic matter. Limnology and Oceanography, 48:1608–1617. (PDF)
Sobczak, W. V., J. E. Cloern, A. D. Jassby, and A. Mueller-Solger. 2002.
Bioavailability of organic matter in a highly disturbed estuary: The role of detrital and algal resources. Proceedings of the National Academy of Sciences USA 99: 8101-8105. PDF
Sobczak, W. V. and S. Findlay. 2002. Variation in bioavailability of dissolved organic carbon among stream hyporheic flowpaths. Ecology: 83: 3194-3209. PDF
Sobczak, W. V., S. Findlay, and S. Dye. 2002. Relationships between DOC bioavailability and nitrate removal in an upland stream: An experimental approach. Biogeochemistry 62: 309-327 PDF
Lovett, G. L., K. W. Weathers, and W. V. Sobczak. 2000. Nitrogen saturation and retention in forested watersheds of the Catskill Mountains, New York. Ecological Applications 10:73-84. PDF
Findlay, S. and W. V. Sobczak. 2000. Microbial communities in hyporheic sediments. IN: Streams and Ground Waters. Jones, J. & P. Mulholland (Eds.). Academic Press, New York.
Sobczak, W. V., L. O. Hedin, and M. J. Klug. 1998. Relationships between bacterial productivity and organic carbon at a soil-stream interface. Hydrobiologia 386: 45-53. PDF
Findlay, S., R. O. Hall, and W. V. Sobczak. 1998. Book Review: Methods in Stream Ecology (R. Hauer & G. Lamberti eds.). Limnology and Oceanography 43: 1021-1022.
Sobczak, W. V. 1996. Epilithic bacterial responses to variations in algal biomass and labile DOC during biofilm colonization. Journal of the North American Benthological Society 15:143-154. PDF
Findlay, S. and W. V. Sobczak. 1996. Variability in removal of dissolved organic
carbon in hyporheic sediments. Journal of the North American Benthological Society 15:35-41. PDF
Sobczak, W. V. and T. M. Burton. 1996. Epilithic bacterial and algal colonization among a stream run, riffle, and pool: a test of co-variation. Hydrobiologia 332:159-166. PDF
