高山草原放牧率与群落物种丰富度

Relationships between stocking rate and species richness on alpine steppe

选择甘肃省肃南裕固族自治县甘肃马鹿(Cervus elaphus kansuensis)养殖场冬季牧场不同牧压梯度的6个样地,采用巢式样方法调查草地植物群落的物种数,研究了甘肃马鹿山地草原放牧系统放牧率与草地群落物种丰富度的关系。结果表明,放牧强度梯度上,冬季牧场物种数随取样面积的增大而逐渐增加,放牧减轻导致物种增幅上升,放牧对物种丰富度的贡献率提高。高山草原的最小取样面积为0.71～1.54m2,各放牧率样地物种数的变化分别在0.16～0.32和0.32～0.64 m2范围内最剧烈。物种数随放牧增强呈下降趋势,在放牧率2.45AUM.hm-2出现拐点,拐点两侧放牧对物种多样性具有不同的作用规律,2.45AUM.hm-2为高山草原适宜的放牧率。在牧场尺度上,当面积超过2.56m2,改善放牧管理对物种丰富度的增加没有作用。

The research selected six plots of different grazing gradient of winter pasture in Sunan Deer Farm, and used nest-style methods to investigate the number of grassland plant communities＇ species. Focus on the relationship between stocking rate and species richness of grassland community in Gansu wapiti grazing system on mountain grassland. The results showed that：1）Species increased gradually with the expansion of sampling area in winter pasture, among the grazing intensity gradient, the trend of species richness resulted from grazing alleviate increased, and the contribution of grazing effected on species richness enhanced. 2）The minimum sampling area of alpine grassland was 0.71 - 1.54 m^2 , and the dramatic change of species richness happened in the range of 0.16 0.32 m^2and0.32-0.64 m^2 respectively in all stocking rates. 3）Species richness showed downward trend along with increasing of stock rate, and inflection point of stocking rates was 2.45 AUM · hm ^（-2）. The effect of stocking rate on species diversity was different on both sides of inflection point. That suggested 2. 45 AUM · hm^（-2） was the appropriate stocking rate on alpine grasslands. 4）The contribution of stocking rate on species richness does not work at the condition of an sampling area of more than 2.56 m^2 in the pasture scale.