锡林河流域草原群落植物多样性和初级生产力沿水热梯度变化的样带研究

CHANGES IN PLANT SPECIES DIVERSITY AND PRODUCTIVITY ALONG GRADIENTS OF PRECIPITATION AND ELEVATION IN THE XILIN RIVER BASIN, INNER MONGOLIA

用样带法研究了草原群落植物多样性和初级生产力沿海拔和水分梯度的变化 ,结果表明 :在样带梯度上 ,物种丰富度、多样性和群落初级生产力与海拔高度、年降水量和土壤有机 C及全 N含量呈正相关 ,而与年平均气温和干燥度呈负相关。随着海拔高度的降低 ,降水量的减少 ,热量和干燥度的增加 ,以及土壤有机 C和全 N含量的降低 ,草原群落的物种丰富度、多样性和初级生产力逐渐降低。典型相关分析的结果揭示出 ,土壤有机 C含量和干燥度是对草原群落物种丰富度和初级生产力具有更大的影响。同时 。

Changes in plant species diversity and productivity along gradients of precipitation and elevation were studied in the Xilin River Basin,Inner Mongolia using a transect approach.Species richness,diversity,productivity were negatively correlated with mean annual temperature, ≥10°C cumulative temperature,and aridity. Inverse relationships were also found between species richness,diversity, productivity and precipitation, elevation, soil organic carbon and total nitrogen content.The species richness,Shannon Wiener diversity index,and productivity of the communities declined with a decreasing elevation,precipitation,soil organic carbon and total nitrogen content,and with increasing mean annual temperature and aridity.The effects of the land use type and intensity were also very strong.