Changes in riparian vegetation buffers in response to development in three Oregon cities

dc.contributor.authorYeakley, J. A.
dc.contributor.authorOzawa, C. P.
dc.contributor.authorHook, A. M.
dc.date.accessioned2020-06-19T17:44:25Z
dc.date.available2020-06-19T17:44:25Z
dc.description.abstractRiparian vegetation buffer loss was investigated for three cities with contrasting local regulatory controls in urbanizing northwest Oregon. The cities examined were Hillsboro, Oregon City and Portland, all having experienced high rates of population increase in the 1990s. All cities are covered under Oregon’s land use law that provides goals for the protection of open space and natural resources. On the municipality level, regulatory controls in Portland included a system of environmental zoning for riparian area protection, while regulatory controls on development in riparian areas in Hillsboro and Oregon City were less stringent. Digital aerial photographs covering buffer areas within 200 m of all permanent streams for these cities were digitized for the years 1990 and 1997 using criteria including minimum inter-patch distance of 5 m for adjacent classes and minimum patch area of 20 m2. Cover classes were divided into vegetation areas adjacent to stream and total, as well as woody and unmanaged vegetation areas. Banding analysis was performed for these vegetation coverages for several buffer widths out to 100 m from streams. Results for the 1990 to 1997 period showed larger losses for unmanaged adjacent vegetation 100 m from stream for Hillsboro and Oregon City (≥1.5 percent/year) than for Portland (<1 percent/year). For adjacent tree vegetation within a 100 m buffer width, again Hillsboro and Oregon City had higher rates of loss (>1 percent/year), while Portland lost trees in the 100 m buffer at a lower rate (<1 percent/ year). Factors explaining these lower rates of riparian buffer loss for Portland may include both a higher amount of riparian area in public ownership and more stringent local regulatory controls on development in riparian buffers. These results also demonstrate that vegetated riparian buffers continue to be lost due to development in growing Oregon municipalities regardless of the level of regulatory protection.en_US
dc.description.sponsorshipFunding for this research was provided by a grant from Portland State University. Research assistants on the project have included Shannon Axtell, Richard Friday, Jennifer (Shively) Hughes, Melanie Sharp, and Jessica Sladek.en_US
dc.description.urihttps://www.fs.usda.gov/treesearch/pubs/26423en_US
dc.format.extent7 pagesen_US
dc.genreconference papers and proceedingsen_US
dc.identifierdoi:10.13016/m2iuwi-hayn
dc.identifier.citationYeakley, J. A.; Ozawa, C. P.; Hook, A. M. 2006. Changes in riparian vegetation buffers in response to development in three Oregon cities. In: Aguirre-Bravo, C.; Pellicane, Patrick J.; Burns, Denver P.; and Draggan, Sidney, Eds. 2006. Monitoring Science and Technology Symposium: Unifying Knowledge for Sustainability in the Western Hemisphere Proceedings RMRS-P-42CD. Fort Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. p. 296-302, https://www.fs.usda.gov/treesearch/pubs/26423en_US
dc.identifier.urihttp://hdl.handle.net/11603/18940
dc.language.isoen_USen_US
dc.relation.isAvailableAtThe University of Maryland, Baltimore County (UMBC)
dc.relation.ispartofUMBC Geography and Environmental Systems Department Collection
dc.rightsThis item is likely protected under Title 17 of the U.S. Copyright Law. Unless on a Creative Commons license, for uses protected by Copyright Law, contact the copyright holder or the author.
dc.rightsPublic Domain Mark 1.0*
dc.rightsThis is a work of the United States Government. In accordance with 17 U.S.C. 105, no copyright protection is available for such works under U.S. Law.
dc.rights.urihttp://creativecommons.org/publicdomain/mark/1.0/*
dc.titleChanges in riparian vegetation buffers in response to development in three Oregon citiesen_US
dc.typeTexten_US

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