Study on Reasonable Grazing Intensity in Nalati Mountain Meadow Steppe

【Objective】 To make clear the rational carrying capacity of poisonous grass in mountain meadow and study the characteristics of grassland vegetation and population of Aconitum leucostomum under different grazing intensities.【Method】The mountain meadow of Nalati was taken as the research object, and the unit weight gain of sheep, the characteristics of population of A. leucostomum and index of grassland quality under different grazing intensities (lightly grazing 13.5 sheep/hm², moderately grazing 20.3 sheep/hm², heavily grazing 26.3 sheep/hm², extremely grazing 33.0 sheep/hm²) were studied.【Result】(1) With the increase of grazing intensity, the biomass, height and coverage of edible forage grass gradually decreased, and the biomass of edible forage grass and the quality index of grassland in grazing plots were significantly reduced by 32.2%-70.2%, 23.6%-65.7% (P<0.01) compared CK plot. (2) The important value of A. leucostomum gradually decreased with the increase of grazing intensity, and the grazing plots was significantly higher than that (51.5%-114.7%) of the CK plot (P<0.01). (3) There was a significant (P<0.05) or very significant (P<0.01) negative correlation relationship between grazing intensity and unit weight gain of sheep, biomass of edible forage grass, index of grassland quality, but there was a significant positive correlation between the grazing intensity and the important value of A. leucostomum (P<0.01).【Conclusion】Considering the economic and ecological benefits, the reasonable grazing intensity of herbaceous meadow was 20.0 sheep / hm²