乌兰布和沙漠沿黄河段植物群落特征及空间分异

Characteristics and spatial differentiation of plant communities along the Yellow River in the Ulan Buh Desert

乌兰布和沙漠是黄河流域风沙最活跃的区域。本文以乌兰布和沙漠沿黄河段植物为研究对象,分析了植物群落特征的空间差异性及地上和地下植物含水率和生物量的分异规律。结果表明:乌兰布和沙漠沿黄河段典型植物物种组成单一,植物多样性低,Shannon-Wiener多样性指数最高为0.80。靠近黄河沿岸草本植物更具优势,平均植物含水率最高(最大值为80.6%);靠近沙漠腹地,灌木植物更具优势,灌木含水率高于黄河沿岸处。从黄河沿岸至沙漠腹地,草本生物量逐渐减少,但地上部分含水率增大。造成植物特征空间分异的关键影响因子是土壤含水量和含盐量,较高的土壤含水量对植物生长有促进作用,高盐分土壤环境对草本植物生长有抑制作用,对灌木植物影响较小。

The Ulan Buh Desert is one of the most decertified areas in China,as well as the most active area of wind and sand in the Yellow River Basin.In this paper,the plants from the beach of Yellow River to the hinterland of the desert were taken as the research object,and the spatial differences of the plant communities and the differentiation of plant water content and biomass were analyzed.The results showed that the plant composition along the Yellow River was simple,and the plant diversity was low with the highest Shannon-Wiener diversity index of 0.624.Herbaceous plants were more dominant near the beach of Yellow River,with the highest average plant water content(the maximum value was 80.6%).Close to the hinterland of the desert,shrubs were more dominant,and the water content of the shrubs was higher than that along the Yellow River.From the coast of the Yellow River to the hinterland of the desert,the herbaceous biomass gradually decreased,but the water content of the above-ground parts increased.The key factors which caused the spatial differentiation of plant characteristics were soil water content and salinity.Soil water content can promote plant growth,and high-salt environment would inhibit the growth of herbaceous plants while have little effect on shrubs.