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Efectos del Pastoreo Histórico de Ganado sobre la Vegetación en el Parque Histórico Nacional Cultura Chaco, Nuevo México
Author(s) -
FLOYD M. LISA,
FLEISCHNER THOMAS L.,
HANNA DAVID,
WHITEFIELD PAUL
Publication year - 2003
Publication title -
conservation biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.2
H-Index - 222
eISSN - 1523-1739
pISSN - 0888-8892
DOI - 10.1111/j.1523-1739.2003.00227.x
Subject(s) - grazing , shrub , species richness , vegetation (pathology) , geography , edaphic , national park , conservation grazing , ecology , livestock , grazing pressure , agroforestry , forestry , environmental science , biology , soil water , medicine , pathology
Livestock grazing is the most ubiquitous land use in western North America, yet it rarely has been studied in a controlled manner because of the lack of large areas free of grazing. We compared the ecological effects of three grazing treatments—long‐term protection, short‐term protection, and currently grazed—at Chaco Culture National Historic Park in northern New Mexico. Chaco has a long history of human habitation and is now one of the largest grazing exclosures in the American West. We studied the effects of livestock grazing on the cover of plants, soil crusts, and plant species richness at six sites with different potential natural vegetation. Species richness was higher under long‐term protection than under current grazing at all six sites. Trends in shrub and grass response varied significantly across the six sites. Shrub cover increased with long‐term protection at four upland sites, and grass cover increased with protection at four sites. The response of Chaco vegetation to release from grazing varied significantly according to each site's ecological potential, determined in part by edaphic and topographic characteristics. These nuances in vegetation response represent natural ecological variation and contrast with the notions of widespread shrub “invasion” often inferred in the past.