藏北高原高寒草甸地上生物量与气候因子的关系

摘要

采用收获法测量了藏北不同海拔高度(4300～4700m) 2010年(6～8月)嵩草草甸群落地上总生物量,通过相关分析和多重同归分析法探讨了地上生物量与土壤温度、土壤含水量、空气温度、相对湿度、饱和水汽压亏缺以及比湿的关系.结果表明:总体而言,随着海拔高度的升高地上生物量逐渐增加,地上生物量与相对湿度、比湿以及土壤含水量分别呈极显著的正相关关系,与饱和水汽压亏缺呈极显著的负相关关系,而与土壤温度、空气温度呈不显著的负相关关系；相对湿度和饱和水汽压亏缺共同解释了地上生物量94%的变异,其中相对湿度的贡献较大.相对湿度是决定高寒嵩草草甸沿海拔分布的主导因子.%The relationships between aboveground biomass and climate factors on alpine meadow along the altitudinal gradient (4300~4700m) in northern Tibet were analyzed using correlation analysis and multiple stepwise linear regression analysis. Overall, aboveground biomass increased gradually with increasing altitude. The positive correlations between aboveground biomass and relative humidity, specific humidity and soil water content" were significant, respectively. The negative correlation between aboveground biomass and vapor pressure deficit was also significant. Nevertheless, the negative correlations between aboveground biomass and soil temperature and air temperature were not significant, respectively. Relative humidity and vapor pressure deficit could together explain 94% variations of aboveground biomass and the contribution of relative humidity was larger than that of vapor pressure deficit. Therefore, relative humidity was the dominant factor to determine the distribution of Kobresia myosuroides meadow along the altitudinal gradient .