放牧强度对荒漠草原植物种群高度的季节性影响

The Seasonal Effect of Grazing Intensity on Population Height in Desert Steppe

荒漠草原是处于草原和荒漠之间的过渡草原和缓冲地带,其植物种群高度易受自然因素和人为因素的制约。研究了人为因素中的放牧对3种植物种群高度的季节性影响,分别为建群种短花针茅(Stipa breviflora),优势种冷蒿(Artemisia frigida)和无芒隐子草(Cleistogenes songorica)。结果表明,在6—9月,3种植物种群高度均随放牧强度的增加而降低。其中,短花针茅种群高度从6月初—9月呈现逐月降低的趋势;冷蒿和无芒隐子草种群高度从5—9月表现为先增加后降低的趋势,8月达到最大值。

Desert steppe is a type of transition form of steppe and the buffer zone between desert and typical steppe where the population height is sensitive to natural and human factors. The present study assessed the seasonal effect of grazing intensity, one of the human factors, on population height of three constructive species in desert steppe, including Stipa breviflora, Artemisia frigida and Cleistogenes songorica. We found that during the period from June to September, population height of the three constructive species was reduced with the increase of grazing intensity. During the period from early June to September, the population height of Stipa breviflora was gradually reduced. For Artemisia frigida and Cleistogenes songorica, their population height was increased at first and then decreasedfrom May to September, and the maximum was observed in August.