青藏高原东缘典型草甸与沼泽化草甸中种子雨的差异

 种子雨是一种潜在群落，在多样性维持中起着重要作用。本研究以青藏高原东缘的典型草甸和沼泽化草甸为研究对象，研究了不同群落种子雨物种组成与季节动态，及其与地上植被间的关系。结果表明，１）典型草甸与沼泽化草甸植被中的物种丰富度、Ｓｈａｎｎｏｎ指数以及植株个体数虽无显著差异，但无度量多维度标定（ＮＭＤＳ）排序结果表明，２种群落物种组成有明显分离；２）典型草甸中种子雨密度显著高于沼泽化草甸；３）典型草甸与沼泽化草甸中种子雨密度的季节动态均呈双峰模式；４）典型草甸与沼泽化草甸中种子雨物种组成的相似性高于植被的相似性，该结果得到了ＮＭＤＳ排序结果的证实。

The differences of seed rain between typical and swamp meadows on the eastern Tibetan Plateau

Seed rain,as a potential community,plays important roles in maintenance of biodiversity.In both typical and swamped meadow of eastern Tibetan Plateau,we studied the relationship between seed rain and vegetation on their species composition and seasonal dynamics.The results showed that,1) There were no significant differences in species richness,Shannon index and individual density for vegetations between typical and swamp meadows,but NMDS(nonmetric multidimensional scaling)revealed that there was a clear separation of species composition between them;2) Seed rain density in typical meadow was significantly higher than that of swamp meadow;3) The seasonal dynamics of seed rain density both in typical and meadow exhibited bimodal patterns;4) The similarity of seed rain between typical and swamp meadows were higher than that of vegetations,which was confirmed by the NMDS ordination analysis.