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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Emergency fire rehabilitation of BLM lands in the Great Basin : revegetation & monitoring

McArthur, Ted O. 20 February 2004 (has links)
The Bureau of Land Managements (BLM) Emergency Fire Rehabilitation (EFR) policy was developed in 1985 to encourage protection of sites from soil erosion and to minimize potential changes in vegetation communities that may result from the dominance of weedy species. To achieve the goals of EFR policy, managers often used introduced perennial grasses that established quicker and competed better with introduced annuals than did native plants. However, the change of sagebrush-grass communities to communities dominated by introduced forage grasses has led to concerns for wildlife habitat. This concern contributed to a policy change encouraging the use of native species, when available, for rehabilitation projects. This study attempts to assess the effectiveness of BLM EFR projects in meeting the stated goals of the BLM EFR policy in the Great Basin. To do this, two field offices per state were randomly selected from an inclusive list of all Great Basin field offices. In 2001, we randomly selected three EFR projects per field office from those projects that used native species. On each project site, we used a common monitoring technique in association with monitoring techniques implemented by the BLM to assess if national EFR objectives were being met. A semi-structured survey was developed to determine the potential reasons why native and introduced plants were either used or not used, why monitoring was and was not proposed, and whether monitoring was implemented in rehabilitation projects. BLM monitoring techniques did not adequately evaluate EFR goal achievement. The time it took to implement any of the BLM methods did not differ significantly from the time needed to implement the common protocol on the two projects where BLM had implemented monitoring and used native plants (F[subscript 3,12]=1.63, P=0.23). Cost to implement the common monitoring technique was minimal and it directly measured aspects of stated EFR policy goals. Vegetative cover of all natives, seeded and volunteers, contributed half of the overall cover on EFR projects and was significantly higher than sown introduced species. Invasive species were intermediate and did not differ significantly from either the natives or the introduced. The seeded species were a subset of the native or introduced classes. Composition by cover between sown native, sown introduced, and invasive species did not differ significantly. Vegetation cover increased the surface soil stability 39% of the time and subsurface stability 56% beneath the vegetation. Respondents of the survey stated that they generally use more natives and more complex seed mixtures than they did historically. Many also stated that they prefer to use native over introduced species. However, most felt that introduced species are more effective in meeting EFR goals on the degraded sites than native species. All respondents would like to access a summarized report of other rehabilitation projects. The respondents were split between accessing it through the World Wide Web or through a written report. We believe that a common database could be created and maintained on the World Wide Web if a common sampling protocol was implemented. / Graduation date: 2004

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