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  • Field Studies
    Recent Field Studies
    Completed Field Studies
    Wijayrante, U.C. and D. A. Pyke. 2007. Investigating seed longevity of Mountain and Wyoming Big Sagebrush. Forest and Rangeland ecosystem Science Center, USGS. Corvallis, OR.

    Abstract: The Intermountain West is dominated by big sagebrush communities (Artemisia tridentata ssp.) that provide invaluable habitat and forage for wildlife species, prevent erosion, and are important economically, both in terms of recreation and the livestock industry. The two most prominent subspecies of big sagebrush in this region are Wyoming big sagebrush (ssp. wyomingensis) and mountain big sagebrush (ssp. vaseyana). Wise management of these lands is crucial for the persistence of sagebrush communities and will benefit from increased understanding of the seed bank dynamics. For example, ssp. vaseyana is subjected to shorter fire return intervals and prescribed fire is a tool used often to rejuvenate stands and reduce tree (Juniperus sp. or Pinus sp.) encroachment. A persistent seed bank for mountain big sagebrush would be advantageous.

    The lack of seed dormancy in ssp. wyomingensis support seed bank studies of big sagebrush which conclude that its seed banks are transient, with little or no seed carry-over (Hassan and West, 1986). However, seed dormancy appears prominent in the life cycle of ssp. vaseyana. Germination studies of ssp. vaseyana in the lab have shown that seeds had increased germination after being stratified and seeds from cold winter sites were nearly 100% light-requiring. Unexplained seedling emergence after fires suggests the possibility of acquired seed dormancy. Although lab studies suggest dormancy in big sagebrush is habitat-specific, there are few field studies verifying these relationships.

    The goal of this study was to confirm lab-identified seed dormancy of ssp. vaseyana by tracking added seeds, which has never been done, and sampling for seeds in situ. We will compare this to the predicted non-dormancy of ssp. wyomingensis. The seed addition experiment will consist of placing a known quantity of seeds in the environment and evaluating how many of the seeds germinate or die at key times during the year (after snowmelt, late spring, and autumn before seed dispersal). We will determine whether ungerminated seeds are viable and we will investigate three seed position treatments to determine whether dormancy is affected by continued darkness or environmental conditions.

    Recent Field Studies

    Ecological Assessments and Research Supported by the Lava Lake Institute:

    Bradley, B. 2007. Short term impacts of changing grazing regime in central Idaho detected with remote sensing. Princeton University. Princeton, NJ.
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    Bunting, S. and E. Strand. 2008 Enhancing spatial heterogeneity of grazed landscapes: implications to the fire fuel matrix. University of Idaho. Moscow, ID.
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    Carlisle, J. 2007. Analysis of riparian bird population changes in the Pioneer Mountain Foothills at Lava Lake Ranch from 2001-2007. Boise, ID.
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    Caselton Lowe, C. 2008. An examination of insect communities and their response to changes in vegetation structure with emphasis on Coleoptera and Hymenoptera in a sagebrush steppe habitat in south-central Idaho. Master
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    Karl, J, K. Colson, A.R. Sands, and B. Unnasch. 2008. The Landscape Toolbox: Integrating Tools and Methods for Effective Rangeland Management at Multiple Spatial Scales. The Nature Conservancy, Boise, ID.
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    O'Sullivan, M.T., K. Murray, and S. Bergen. 2009. Maintaining Connectivity for Wide-Ranging Species: Pronghorn Migration Routes and Crucial Habitat in the Lost River Sinks Landscape. Hailey, ID.
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    Pollock, M. 2009.  Effects of sheep grazing and habitat composition on Brewer's sparrow and vesper sparrow habitat selection and breeding success in mountain big sagebrush steppe. Master
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    Strand, E., S. Bunting, and M.T. O'Sullivan. 2008. Change detection in quaking aspen using current and historical aerial photography. University of Idaho. Moscow, ID.
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    Wijayrante, U.C. and D. A. Pyke. 2007. Investigating seed longevity of Mountain and Wyoming Big Sagebrush. Forest and Rangeland ecosystem Science Center, USGS. Corvallis, OR.
    Read abstract >

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    Zaroban, D. 2008. Distribution, habitat use, ranging behavior, and disturbances influencing the Wood River sculpin. Department of Environmental Quality. Boise, ID.
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    P. O. Box 2249 • Hailey, Idaho 83333 • Phone 208.788.1378 • Fax 208.788.1264 • info@lavalakeinstitute.org
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