Author
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Tartowski, Sandy |
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Submitted to: Popular Publication
Publication Type: Popular Publication Publication Acceptance Date: 3/16/2005 Publication Date: 5/30/2005 Citation: Tartowski, S.L. 2005. Browsing the Bosque. LTER Network News: Newsletter of the Long Term Ecological Research Network. 18(1):7. Interpretive Summary: No interpretive summary required. Technical Abstract: Invasive Salt Cedar (Tamarix spp.) occupies riparian zones throughout the Western United States and has been reported to increase evapotranspiration, increase fire frequency, reduce habitat values, and replace native plant species. Herbicides and mechanical clearing are the main methods used to remove salt cedar. We are conducting the first study of the use of goats to control salt cedar. Goats readily browsed salt cedar and Russian olive in replicated 1-3 acre plots along the Rio Grande, while maintaining weight and health. Nearly every salt cedar plant was damaged by browsing, breaking branches or stripping bark. Goats had an especially severe impact on resprouts, removing about half of the vegetation in the first year of browsing. Goats had much less impact on large dense salt cedar , but cleared out the understory, reducing laddering fuels, improving access for recreation and reducing costs for mechanical or manual clearing. After two years of goat treatment, the width of salt cedars was reduced by about 35%, but only about 4% of the large salt cedars were killed. It may take five years of goat browsing to deplete the root reserves of salt cedar sufficiently to increase tree mortality. Goats browsed desirable native plants as well as salt cedar, but most of the understory vegetation recovered during the following growing season. Large cottonwoods were not damaged and browsed willows resprouted vigorously. Grass cover, especially native grama grasses (Bouteloua barbatus and B. aristoides), increased from less than 1% immediately before goat browsing to about 20% one year after goat browsing. |
