Spelling suggestions: "subject:"restoration ecology -- great basin"" "subject:"restoration ecology -- great yasin""
1 |
Emergency fire rehabilitation of BLM lands in the Great Basin : revegetation & monitoringMcArthur, 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
|
Page generated in 0.1802 seconds