HR: 1340h
AN: B23A-1034    [Abstracts]
TI: Growth and recession of tamarisk in response to a regulated hydrograph in Grand Canyon National Park.
AU: * Kearsley, M J
EM: mike.kearsley@nau.ed
AF: Northern Arizona University, Department of Biological Sciences NAU Box 5640, Flagstaff, AZ 86011 United States
AB: The imposition of flow regulation in large rivers of the Western U.S.A. not only permitted the invasion by tamarisk into riparian habitats, it continues to contribute to invasion through the effects of elements of the regulated hydrograph. Data from four years of surveys which were part of a larger riparian ecosystem monitoring project show several important elements of the response of tamarisk (Tamarix sp.) to regulated flows. In the spring, the density of Tamarix foliage in post-dam (low elevation) riparian habitats is positively related to both the top end of fluctuations regulated by Glen Canyon Dam and the abundance of precipitation, although the latter has less of an effect. In pre-dam habitats, directly above the low elevation ones, precipitation is the primary driver of tamarisk abundance. These patterns mirror those of native species of Salix and Baccharis, but are more pronounced. Simultaneously collected data from surveys of breeding birds and arthropods show these impacts cascade up through the riparian food web.
DE: 0439 Ecosystems, structure and dynamics (4815)
DE: 0476 Plant ecology (1851)
DE: 0481 Restoration
DE: 0483 Riparian systems (0744, 1856)
SC: Biogeosciences [B]
MN: Fall Meeting 2005