中文摘要：

通过野外调研和室内实验,研究了祁连山南坡灌丛草甸地上生物量的生长季变化,并对地上生物量与水热因子的关系进行了探讨。结果表明：在不同区域群落结构有所不同,覆盖度越低,上层和下层的植物高度越低,丰富度和多样性越小。但均匀度还受草场退化阶段的影响,群落结构相对稳定,植物的均匀度越高;地上生物量的年内变化是单峰曲线,乌鞘岭和门源的地上生物量在7月份最大,祁连和野牛沟的地上生物量在9月份最大;地上生物量的积累与前1月和前2月的气温和降水正相关,与前4月的气温也正相关,并且对气温变化的敏感性大于降水,但与地温和土壤水分的相关性不明显,前1月表层地温较高对地上生物量的积累有积极作用;对于地上生物量积累,日气温、日相对湿度、降水量有直接正向作用,而日最高气温、日最低气温、日水汽压有直接负向作用,5 cm、20 cm地温和0~10 cm、20~30 cm土壤水分也有直接正向作用,而10 cm地温和10~20 cm土壤水分也有直接负向作用。

英文摘要：

Based on field investigation and laboratory analysis, the biomass of shrubbery meadows and the relation with water and heat factors during growing season were studied in the southern slope of the Qilian Mountains. The result indicated that community structures of shrubbery meadows exhibited obviously regional differences. The plant height, community richness and species diversity are lower owing to the lower community coverage, whiles plant evenness degree is correlated with the different stages of degeneration. However, the higher plant evenness degree was owing to the steadier of community structure. The annual variations of above ground biomass for shrubbery meadow communities showed the hump line pattern, and its highest values in Wushaoling and Menyuan happened on July but this occured on September in Qilian and Yeniugou station.The above ground biomass increments of shrubbery meadow communities had the positive correlation with temperature and precipitation before one and two monthes as well as temperature before four monthes, and its sensitivity to temperature was larger than to precipitation. The correlations with soil humidity and temperature were not obvious, but topsoil temperature before one month is conductive to the increment of above ground biomass. Daily temperature, relative humidity and precipitation displayed the directly positive effect on above ground biomass, but this is contrary to daily maximum temperature, daily minimum temperature and water vapor pressure. Soil temperature underground 5 cm and 20 cm and soil humidity underground 0-10 cm and20-30 cm have directly positive effect on above ground biomass, whiles this is opposite to soil temperature underground 10 cm and soil humidity underground 10-20 cm.