Abstract
Long-term studies are essential to understanding the effects of urbanization on wetlands and the effectiveness of management actions. Using data from the National Wetlands Inventory (NWI) in combination with GIS analyses and field surveys, we tracked changes over 16 years (1982 –1998) in small (<-2 ha), palustrine emergent/open water wetlands (PEM/POW) in Portland, Oregon, USA. Wetlands identified on NWI maps and that had not been converted to other land uses at the time of the 1992 survey were surveyed in 1998. Data were collected on 164 of the 171 wetlands in the target population. Despite development pressure throughout the 1990s, loss of small PEM/POW wetlands slowed between 1992 and 1998, with only 6% of the sites being destroyed as compared to 40% between 1982 and 1992. Of 11 sites that were not identifiable due to drought in 1992, eight had recovered with the return of typical rainfall, three had been destroyed. Most of the wetlands existing in 1998 were in hydrogeomorphic (HGM) classes atypical to the region due to human manipulation. Hydrologic modifications were observed on 60% of the sites, but on-site disturbances like mowing, dumping, and trail building had decreased since the 1992 survey. Over the time period studied, land uses adjacent to the study sites shifted from undeveloped and agricultural to urban and residential use. Reflecting the common occurrence of on- and off-site stressors and modifications, we rated the condition of only 11% of the sites as good, with 46% fair and 43% poor. Our results demonstrate the utility of combining field surveys with GIS analyses to track the status of wetland resources over time. The next challenge is to use such data to develop strategies to manage urban wetlands in ways that maintain and ultimately improve the condition of the resource.
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Literature cited
Abbruzzese, B., A. B. Allen, S. Henderson, and M. E. Kentula. 1987. Selecting Sites For Comparison With Created Wetlands. p. 291–297. In C. D. A. Rubec and R. P. Overend (eds.) Proceedings of Symposium ’87—Wetlands/Peatlands. Environment Canada, Ottawa, Ontario, Canada.
Adams, M. J. 1999. Correlated factors in amphibian decline: exotic species and habitat change in western Washington. Wildlife Management 63:1162–1171.
Adams, M. J., C. A. Pearl, and R. B. Bury. 2003. Indirect facilitation of an anuran invasion by non-native fishes. Ecology Letters 6: 343–351.
Alig, R. J. and R. G. Healy. 1987. Urban and built-up land area changes in the United States: an empirical investigation of determinants. Land Economics 63:215–226.
Anderson, J. R., E. E. Hardy, J. T. Roach, and R. E. Witmer. 1976. A land-use and land-cover classification for use with remote sensor data. U.S. Geological Survey, Reston, VA, USA. Professional Paper 964.
Azous, A. L. and R. R. Horner (eds.). 2001. Wetlands and Urbanization: Implications for the Future. Lewis Publishers, Boca Raton, FL, USA.
Brinson, M. M. 1993. A Hydrogeomorphic Classification for Wetlands. U.S. Army Corps of Engineers, Waterways Experiment Station, Vicksburg, MS, USA. Technical Report WRP-DE-4.
Clarke, S. E., D. White, and A. L. Schaedel. 1991. Oregon ecological regions and subregions for water quality management. Environmental Management 15:847–856.
Cowardin, L. M., V. Carter, F. C. Golet, and E. T. LaRoe. 1979. Classification of Wetlands and Deepwater Habitats of the United States. U.S. Fish and Wildlife Service, Washington, DC, USA. FWS/OBS-79/31.
Craft, C. B., S. W. Broome, and E. D. Seneca. 1988. Nitrogen, phosphorus and organic carbon pools in natural and transplanted marsh soils. Estuaries 11:255–264.
Davis, M. M. 1995. Endemic wetlands of the Willamette Valley, Oregon. p. 1–8. In Studies of Plant Establishment Limitations in Wetlands of the Willamette Valley, Oregon. U.S. Army Corps of Engineers, Waterways Experiment Station, Vicksburg, MS, USA. WRP-RE-13.
Edgar, B. 1994. Wild about Portland: Mike Houck, the protector of place. Pacific Discovery Spring: 14–19.
Forstall, R. L. (ed.). 1995. Population of Counties by Decennial Census: 1900 to 1990. Population Division, U.S. Bureau of the Census, Washington, DC, USA.
Gibson, K. D., J. B. Zedler, and R. Langis. 1994. Limited response of cordgrass (Spartina foliosa) to soil amendments in a constructed marsh. Ecological Applications 4:757–767.
Groffman, P. M., G. C. Hanson, E. Kiviat, and G. Stevens. 1996. Variation in microbial biomass of activity in four different wetland types. Soil Science Society of America Journal 60:622–629.
Guard, J. B. 1995. Wetland Plants of Oregon and Washington. Lone Pine Publishing, Vancouver, BC, Canada.
Gwin, S. E., M. E. Kentula, and P. W. Shaffer. 1999. Evaluating the effects of wetland regulation through hydrogeomorphic classification and landscape profiles. Wetlands 19:477–489.
Hall, R. S. 1988. Urban wetlands: are 404(b)(1) guidelines effective? p. 231–233. In J. A. Kusler, S. Daly, and G. Brooks (eds.) Proceedings of the National Wetland Symposium: Urban Wetlands. Association of State Wetland Managers, Berne, NY, USA.
Holland, C. C., J. Honea, S. E. Gwin, and M. E. Kentula. 1995. Wetland degradation and loss in the rapidly urbanizing area of Portland, Oregon. Wetlands 15:336–345.
Horner, R. R., A. L. Azous, K. O. Richter, S. S. Cooke, L. E. Reinelt, and K. Ewing. 2001. Wetlands and stormwater management guidelines. p. 299–324. In A. L. Azous and R. R. Horner (eds.) Wetlands and Urbanization: Implications for the Future. Lewis Publisher, Boca Raton, FL, USA.
Hurn, J. 1989. GPS: a Guide to the Next Utility. Trimble Navigation LTD., Sunnyvale, CA, USA.
Kentula, M. E., J. C. Sifneos, J. W. Good, M. Rylko, and K. Kunz. 1992a. Trends and patterns in Section 404 permitting requiring compensatory mitigation in Oregon and Washington, USA. Environmental Management 16:109–119.
Kentula, M. E., R. P. Brooks, S. E. Gwin, C. C. Holland, A. D. Sherman, and J. C. Sifneos. 1992b. An Approach to Improving Decision Making in Wetland Restoration and Creation. Island Press, Washington, DC, USA.
Kiesecker, J. M. and A. R. Blaustein. 1997. Population difference in responses of red-legged frogs (Rana aurora) to introduced bull-frogs. Ecology 78:1752–1760.
Kiesecker, J. M., A. R. Blaustein, and C. L. Miller. 2001. Potential mechanisms underlying the displacement of native red-legged frogs by introduced bullfrogs. Ecology 82:1964–1970.
Kupferberg, S. J. 1997. Bullforg (Rana catesbeiana) invasion of a California river: the role of larval competition. Ecology 78:1736–1751.
Langis, R., M. Zalejko, and J. B. Zedler. 1991. Nitrogen assessments in a constructed and a natural salt marsh of San Diego Bay. Ecological Applications 1:40–51.
Lathwell, D. J., H. F. Mullign, and D. R. Bouldin. 1969. Chemical properties, physical properties, and plant growth in twenty artificial wildlife marshes. New York Fish and Game Journal 16:158–183.
Leonard, W. P., H. A. Brown, L. L. C. Jones, K. R. McAllister, and R. M. Storm. 1993. Amphibians of Washington and Oregon. Seattle Audubon Society, Seattle, WA, USA.
Magee, T. K., T. L. Ernst, M. E. Kentula, and K. A. Dwire. 1999. Floristic comparison of freshwater wetlands in an urbanizing environment. Wetlands 19:517–534.
Magee, T. K., S. E. Gwin, R. G. Gibson, P. W. Shaffer, J. C. Sifneos, and M. E. Kentula. 1993. Research Plan and Methods Manual for the Oregon Wetlands Study. U.S. Environmental Protection Agency, Environmental Research Laboratory, Corvallis, Oregon, USA. EPA/600/R-93/ 072.
McDonnell, M. J. and S. T. A. Pickett. 1990. Ecosystem structure and function along urban-rural gradients: an unexploited opportunity for ecology. Ecology 71:1232–1237.
Minello, T. J. and J. W. Webb. 1997. Use of natural and created Spartina alterniflora salt marshes by fishery species and other aquatic fauna in Galveston Bay, Texas, USA. Marine Ecology Progress Series 151:165–179.
Morris, J. T. and W. B. Bowden. 1986. A mechanistic, numerical model of sedimentation, mineralization, and decomposition for marsh sediments. Soil Science Society of America Journal 50:96–105.
Moy, L. D. and L. A. Levin. 1991. Are Spartina marshes a replaceable resource? A functional approach to evaluation of marsh creation efforts. Estuaries 14:1–16.
National Research Council. 2001. Compensating for Wetland Losses Under the Clean Water Act. National Academy Press, Washington, DC, USA.
Nussbaum, R. A., E. D. Brodie, Jr., and R. M. Storm. 1983. Amphibians and Reptiles of the Pacific Northwest. University of Idaho Press, Moscow, ID, USA.
ODLCD. 1992. What is an urban growth boundary? Oregon Department of Land Conservation and Development, Salem, OR, USA.
Population Research Center. 2000. Components of Population Change for Oregon’s Counties: April 1, 1990 to April 1, 2000. Portland State University, Portland, OR, USA.
Reinelt, L. E. and B. L. Taylor. 2001. Effects of watershed development on hydrology. p. 221–236. In A. L. Azous and R. R. Horner (eds.) Wetlands and Urbanization: Implications for the Future. Lewis Publishers, Boca Raton, FL, USA.
Richter, B. D., D. P. Braun, M. A. Mendelson, and L. L. Master. 1997. Threats to imperiled freshwater fauna. Conservation Biology 11:1081–1093.
Sacco, J. N., E. D. Seneca, and T. R. Wentworth. 1994. Infaunal community development of artificially established salt marshes in North Carolina. Estuaries 17:489–500.
Scatolini, S. R. and J. B. Zedler. 1996. Epibenthic invertebrates of natural and constructed marshes of San Diego Bay. Wetlands 16: 24–37.
Schueler, T. 1994. The importance of imperviousness. Watershed Protection Techniques 1:100–110.
Shaffer, P. W., C. A. Cole, M. E. Kentula, and R. P. Brooks. 2000. Effects of measurement frequency on water-level summary statistics. Wetlands 20:148–161.
Shaffer, P. W. and T. L. Ernst. 1999. Distribution of soil organic matter in freshwater emergent/open water wetlands in the Portland, Oregon metropolitan area. Wetlands 19:505–516.
Shaffer, P. W., M. E. Kentula, and S. E. Gwin. 1999. Characterization of wetland hydrology using hydrogeomorphic classification. Wetlands 19:490–504.
Smith, R., A. Ammann, C. Bartlodus, and M. M. Brinson. 1995. An Approach for Assessing Wetland Functions Using Hydrogeomorphic Classification, Reference Wetlands, and Functional Indices. U.S. Army Corps of Engineers, Waterways Experiment Station, Vicksburg, MS, USA. Technical Report WRP-DE-9.
Zedler, J. B. and R. Langis. 1991. Comparisons of constructed and natural salt marshes of San Diego Bay. Restoration and Management Notes 9:21–25.
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Kentula, M.E., Gwin, S.E. & Pierson, S.M. Tracking changes in wetlands with urbanization: Sixteen years of experience in Portland, Oregon, USA. Wetlands 24, 734–743 (2004). https://doi.org/10.1672/0277-5212(2004)024[0734:TCIWWU]2.0.CO;2
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DOI: https://doi.org/10.1672/0277-5212(2004)024[0734:TCIWWU]2.0.CO;2