Title: | Vegetation change in northern Chihuahuan Desert grasslands. |
Author: | Yanoff, S. and Muldivan, E. |
Abstract: | There is evidence that northern Chihuahuan Desert grasslands have declined in extent and condition as a result of intensified human activities over the past 200 years. We reconstructed historical vegetation and compared results for two large study sites with similar soils, climate and other environmental features. Both sites were grazed by livestock during the last part of the 19th century and well into the 20th century. One site was excluded from livestock grazing 55 years ago while the adjacent site has been continuously grazed to the present. The recently ungrazed site is a military holding and the continuously grazed site is managed as public lands. Vegetation was reconstructed by processing and analyzing historical General Land Office surveys in a GIS (Geographic Information System). The analysis reveals a large continuous historical grassland that has radically diminished and become fragmented over time. Declines are greatest on the continuously grazed site. If the calculated rate of grassland area lost per year is extrapolated into the future it is possible to predict imminent loss of the remaining portions of the historical grassland. Though such predictions are simplistic they should alert land managers and researchers to step up monitoring and conservation efforts. This study also documents the role that military lands can play as ad-hoc preserves for declining ecosystems. |
URI: | http://bva.colech.edu.mx/xmlui/handle/123456789/HASH38b8e2628e98869b1a3d7d |
Date: | 2012-03-09 |
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Observatorio Ambiental de El Colegio de Chihuahua (COLECH)
Biblioteca Virtual Ambiental del Estado de Chihuahua (BVA)
Correo electrónico: bva@colech.edu.mx