Abstract
The Chesapeake Bay Watershed, located in the Mid-Atlantic Region of the United States, is experiencing rapid habitat loss and fragmentation from sprawling low-density development. The bay itself is heavily stressed by excess sediment and nutrient runoff. Three states, the District of Columbia, and the federal government signed an agreement in 2000 to address these problems. The commitments included an assessment of the watershed's resource lands, and targeting the most valued lands for protection. As part of this task, the Resource Lands Assessment identified an ecological network comprised of large contiguous blocks (hubs) of forests, wetlands, and streams, interconnected by corridors to allow animal and plant propagule dispersal and migration. Hubs were prioritized by ecoregion, by analyzing a variety of ecological parameters, including: rare species presence, rarity and population viability; vegetation and vertebrate richness; habitat area, condition, and diversity; intactness and remoteness; connectivity potential; and the nature of the surrounding landscape. I found that much of the watershed was still fairly intact, although this varied dramatically by ecoregion. Current protection also varied, and an assessment of vulnerability will help focus protection efforts among the most valuable hubs and corridors.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
American Forests: 1999, 'Regional ecosystem analysis: Chesapeake Bay region and the Baltimore-Washington corridor', American Forests, Washington, DC, USA.
Anderson, G.S. and Danielson, B.J.: 1997, 'The effects of landscape composition and physiognomy on metapopulation size: the role of corridors', Landscape Ecol. 12, 261-271.
Beier, P. and Noss, R.F.: 1998, 'Do habitat corridors provide connectivity?', Conserv. Biol. 12 (6), 1241-1252.
Bennett, A.F.: 1998, Linkages in the landscape: the role of corridors and sensitivity in wildlife conservation, IUCN, Gland, Switzerland and Cambridge, UK.
Bockstael, N.E.: 1996, 'Modeling economics and ecology: the importance of a spatial perspective', Amer. J. Agr. Econ. 78, 1168-1180.
Brown, M.T., Schaefer, J.M. and Brandt, K.H.: 1990, 'Buffer zones for water, wetlands and wildlife in East Central Florida', Center for Wetlands, University of Florida, Gainesville, FL, USA.
Bushman, E.S. and Therres, G.D.: 1988, 'Habitat management guidelines for forest interior breeding birds of coastal Maryland', Wildlife Tech. Pub. 88-1 Maryland Department of Nation Resources, Annapolis, MD, USA.
Conservation Fund, The: 2000, “Welcome to the GreenInfrastructure.” Net Website: Providing a Strategic Framework for Smart Conservation (2000). 10 Febuary 2001. <http:// greeninfrastructure.net/ >
Costanza, R. et al.: 1997, 'The value of the world's ecosystem services and natural capital', Nature. 387, 252-259.
Donovan, T.M., Thompson, F.R. III, Faaborg, J. and Probst, J.R.: 1995, 'Reproductive success of migratory birds in habitat sources and sinks', Conserv. Biol. 9, 1380-1395.
Dramstad, W. E., Olson, J.D. and Forman R.T.T.: 1996, Landscape ecology principles in landscape architecture and land-use planning Island Press, Washington, DC, USA.
Dunning, J.B., Danielson, B.J. and Pulliam, H.R.: 1992, 'Ecological processes that affect populations in complex landscapes', Oikos. 65, 169-175.
Forman, R.T.T.: 1995, Land mosaics: the ecology of landscapes and regions, Cambridge University Press, Cambridge, UK.
Forman, R.T.T., and Godron, M.: 1986, Landscape Ecology, John Wiley and Sons, New York, NY, USA.
Hansen, J.H. and Urban, D.L.: 1992, 'Avian response to landscape pattern: the role of species' life histories', Landscape Ecol. 7, 163-180.
Hanski, I.: 1997, 'Predictive and practical metapopulation models: the incidence function approach', in D. Tilman and P. Kareiva (eds), Spatial ecology, Princeton University Press, Princeton, NJ, USA.
Harris, L.D.: 1984, The Fragmented Forest University of Chicago Press, Chicago, IL, USA.
Harris, L.D.: 1988, 'Landscape linkages: the dispersal corridor approach to wildlife conservation', Trans. 53rd N. A. Wildl. & Nat. Res. Conf., 595-607.
Harris, L.D.: 1989, 'Isolation of nature reserves in north Florida: measuring linkage exposure', Trans. 54th N. A. Wildl. & Nat. Res. Conf., 113-120.
Hintze, J.L.: 2001, NCSS User's Guide, Number Cruncher Statistical Systems, Kaysville, UT, USA.
MacArthur, R.H., and Wilson, E.O.: 1967, The theory of island biogeography, Princeton University Press, Princeton, NJ, USA.
maryland.htm>
Odum, H.T.: 1983, Systems ecology, John Wiley & Sons, New York, NY, USA.
Omernik, J.M.: 1987, 'Ecoregions of the conterminous United States', Annals of the Association of American Geographers. 77 (1), 118-125.
Omernik, J.M.: 1995, 'Ecoregions: A spatial framework for environmental management', in W.S. Davis and T.P. Simon (eds.), Biological Assessment and Criteria: Tools for Water Resource Planning and Decision Making, Lewis Publishers, Boca Raton, FL, USA.
Robichaud, I., Villard, M.A. and Machtans, C.S.: 2002, 'Effects of forest regeneration on songbird movements in a managed forest landscape of Alberta, Canada', Landscape Ecol. 17, 247-262.
Robinson, S.K.: 1988, 'Reappraisal of the costs and benefits of habitat heterogeneity for nongame wildlife', Trans. Amer. Wildl. Nat. Resour. Conf. 53, 145-155.
Robinson, S.K., Thompson, F.R. III, Donovan, T.M., Whitehead, D.R. and Faaborg, J.: 1995, 'Regional forest fragmentation and the nesting success of migratory birds', Science. 267, 1987-1990.
Scheuler, T.: 2002, Personal communication, 14 February 2002.
Söndgerath, D. and Schröder, B.: 2002, 'Population dynamics and habitat connectivity affecting the spatial spread of populations-a simulation study', Landscape Ecol. 17, 57-70.
Sorrell, J.: “Using geographic information systems to evaluate forest fragmentation and identify wildlife corridor opportunities in the Cataraqui watershed.” (1997). 10 February 2001. <http://www.nhb.com/sorrell/index.htm>
Tewksbury, J., Levey, D., Haddad, N., Sargent, S., Orrock, J.L., Weldon, A., Danielson, B., Brinkerhoff, J., Damschen, E. and Townsend, P.: 2002, 'Corridors affect plants, animals, and their interactions in fragemented landscapes', PNAS. 99 (20), 12923-12926.
Tilman, D. and Lehman, C.L.: 1997, 'Habitat destruction and species extinctions', in D. Tilman and P. Kareiva (eds), Spatial ecology, Princeton University Press, Princeton, NJ, USA.
Tilman, D., Lehman, C.L. and Kareiva, P.: 1997, 'Population dynamics in spatial habitats'extinctions', D. Tilman and P. Kareiva (eds.), Spatial ecology, Princeton University Press, Princeton, NJ, USA.
USEPA: 1995, 'Level III Ecoregions of the Continental United States', Map M-1 (revision of Omernik, 1987), U.S. Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, Corvallis, OR, USA.
Van Dorp, D., Schipners, P. and van Groenendael, J.M.: 1997, 'Migration rates of grassland plants along corridors in fragmented landscapes assessed with a cellular automation model', Landscape Ecol. 12, 39-50
Weber, T.: 2003, Maryland's Green Infrastructure Assessment: A Comprehensive Strategy for Land Conservation and Restoration, Maryland Department of Natural Resources, Annapolis, MD, USA.
Weber, T. and Aviram, R.: 2002, Forest and Green Infrastructure loss in Maryland 1997-2000, and implications for the future, Maryland Department of Natural Resources, Annapolis, MD, USA.
Weber, T. and Wolf, J.: 2000, 'Maryland's green infrastructure: using landscape assessment tools to identify a regional conservation strategy', Environ. Monit. and Assess. 63, 265-277.
Wiken, E.: 1986, 'Terrestrial ecozones of Canada', Ecological Land Classification Series No. 19 Environment Canada, Ottawa, Canada.
With, K. A. and King, A.W.: 1999, 'Dispersal success on fractal landscapes: a consequence of lacunarity thresholds', Landscape Ecol. 14, 73-82.
Woods, A.J., Omernik, J.O., Brown, D.D., and Kiilsgaard, C.W.: 1996, 'Level IV ecoregions of EPA', Metadata U.S. Environmental Protection Agency, Region 3, Philadelphia, PA, USA.
Woods, A.J., Omernik, J.O., and Brown, D.D.: 1999, 'Level III and IV ecoregions of Delaware, Maryland, Pennsylvania, Virginia, and West Virginia', U.S. Environmental Protection Agency, National Health and Environmental Effects Research Laboratory, Corvallis, OR, USA.
Yahner, R.H.: 1988, 'Changes in wildlife communities near edges', Conserv. Biol. 2, 333-339.
Rights and permissions
About this article
Cite this article
Weber, T. Landscape Ecological Assessment of the Chesapeake Bay Watershed. Environ Monit Assess 94, 39–53 (2004). https://doi.org/10.1023/B:EMAS.0000016878.15260.52
Issue Date:
DOI: https://doi.org/10.1023/B:EMAS.0000016878.15260.52