Rangeland Ecology & Management

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LONG-TERM VEGETATION TRENDS OF GRAZED AND UNGRAZED RANGELANDS IN NEVADA
Author
Mahlberg, Melissa M.
Spahan, Kaci B.
Shane, Tracy L.
Perryman, Barry
Publisher
Society for Range Management
Publication Year
2014
Body

Prior to 1934, cattle grazing on Nevada rangelands went largely unregulated which resulted in severely degraded ecosystems. After enactment of the Taylor Grazing Act in 1934, 28 Nevada Plot exclosures were erected to monitor secondary plant succession between grazed and non-grazed areas. The exclusion of livestock from nine intact sites remaining in 2013 provided 76 years of ungrazed vegetation to compare with today's managed grazing lands. This study focused on determining if a difference could be detected in vegetation cover and density between the vegetation inside and outside of the exclosures.  Density and percent cover of perennial vegetation was collected from five 50 meter transects from inside and outside the exclosure to assess the vegetation composition. The 2013 study found a difference in percent cover at only one site and a difference in density at two sites. The Pyramid Lake #2 site showed a greater percentage of vegetation cover inside (20±5) as compared to outside (8±2) the exclosure. Density was found to be greater outside the exclosure at both the Connors Station [inside (8±1) vs. outside (17±1)] and Wellington [inside (4±0.4) vs. outside (19±5)] sites. Courtois et al. (2004) showed similar findings for density at the Connors Station and Wellington sites, but the difference in percent cover at Pyramid Lake #2 was not detected previously. Courtois et al. had also found differences at other sites that were not detectable in the 2013 study. The changes in density and percent cover from the 2004 study to the 2013 study may be due to variation in precipitation or a response to intermediate grazing disturbances. The long-term vegetation trends may bring to light the positive or negative impacts of managed livestock grazing and assist land managers in rangeland grazing practices.

Language
English
Resource Type
Text
Document Type
Conference Proceedings
Conference Name
SRM Orlando, FL