|Mealor, B -|
Submitted to: Society for Range Management Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: September 9, 2009
Publication Date: N/A
Technical Abstract: The invasive annual, cheatgrass (Bromus tectorum), has become the most ubiquitous weed in sagebrush systems of Western North America. The center of invasion has largely been the Great Basin region, but an increase in abundance and distribution has been occurring in the Rocky Mountain States. We used repeat, very large scale aerial (VLSA) imagery and ground-based digital photography, to document changes in vegetation composition immediately after, and five years after, prescribed fires and a wildfire in the southern Wind River Mountain Range of Wyoming over an elevation range from 1700m to over 2500m. We also examined average spring (April, May, June) temperatures recorded at the Lander airport. VLSA imagery and ground imagery were both effective at detecting canopy cover of cheatgrass. Total vegetation cover increased across all burned sites from 2002-2008 (post-fire). Cheatgrass canopy cover increased across the entire burned area from 2002 (1.77% ± 0.72 SE) to 2008 (10.39% ± 1.98 SE; p < 0.0001), whereas cheatgrass cover remained unchanged in the unburned reference area (p > 0.54). Temperature data indicate a long-term warming trend with the decade before the 2008 survey being 1.7oC warmer than the decade 1948 to 1957. Our results indicate that VLSA and ground-based digital imagery are useful tools for documenting invasion of cheatgrass in relatively complex rangeland ecosystems, and confirms the expansion of cheatgrass into higher elevations in Wyoming.