Grazing intensity on vegetation dynamics of a typical steppe in Northeast Inner Mongolia

TitleGrazing intensity on vegetation dynamics of a typical steppe in Northeast Inner Mongolia
Publication TypeJournal Article
Year of Publication2009
AuthorsLiang Y., Han G., Zhou H., Zhao M., Snyman H.A., Shan D., Havstad K
JournalRangeland Ecology and Management
Volume62
Start Page328
Pagination328-336
Date Published07/2009
ARIS Log Number238831
Keywordsforage utilization, grazed ecosystem, Inner Mongolia grasslands, plant-herbivore interactions
Abstract

Vegetation features radiating from residential areas in response to livestock grazing were quantified for an arid steppe rangeland in the Keshiketeng Banner, Chifeng Prefecture in northeastern Inner Mongolia in 2004 and 2006. The aim of this study was to estimate grazing impacts on the vegetation dynamics of these historical grazed ecosystems. Grazing intensities were classified as reference area (RA), light (LG), moderate (MG) and heavy (HG) according to the vegetation utilization across the study area. Rangelands were studied along a grazing gradient, where characteristics of plant communities, heights of dominant species, above ground vertical structures and below ground biomass were investigated. Along this grazing gradient vegetation changed from the original plant dominant species Leymus chinensis (Trin.) Tzvel to a semi-subshrub species Artemisia frigida Willdin moving from the reference area (RA) to the region around the settlement. Canopy coverage, above ground productivity, and the number of perennial species declined moving towards the residential area. Heights of five dominant species, except for Stipa grandis P. Smirn, declined with increases in grazing intensity. Vertical structure above ground in the RA treatment showed a more resilient model than the other treatments. There were no difference in root biomass in the top 1 m of soil showed no difference (P > 0.05) between the RA treatment and the area immediately around settlement (HG treatment). Generally, we found that the intensity of grazing disturbance did not exceed the tolerance of the rangeland ecosystem within LG treatment. However, vegetative conditions in HG treatment became worse with increases in grazing pressure. Rangelands in this arid steppe are under tremendous threats due to excessive forage utilization that can not be considered as sustainable practices.

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