古尔班通古特沙漠地区短命植物土壤种子库研究

采用野外定点取样和室内萌发相结合的试验方法,研究了短命植物在沙丘不同部位的空间分布、萌发状况、密度、物种多样性及土壤种子库生物多样性与地上植物多样性的关系。结果表明:短命植物种子主要集中分布于地表0~5 cm土壤中,5 cm以下土壤中极少存在有活力的种子;沙丘间及沙丘不同部位的种子库密度大小不同,密度自坡底随高度增加逐渐减少,坡底、坡中部及坡顶部密度分别为124粒/m2、91粒/m2、66粒/m2。迎风坡种子库密度比背风坡面少,迎风坡种子库平均密度为81粒/m2,而背风坡种子库平均密度为100粒/m2;短命植物种子在4月上旬达到萌发高峰,沙丘不同部位物种多样性存在差异,土壤种子库和地上植被存在较高的相似性,此外短命植物在沙丘不同部位的分布存在较高的空间异质性。

Soil seed banks of ephemerals in the Gurbantunggut Desert Area

This study selected the ephemerals which grow in the Gurbantunggut Desert Area as the object of the study, which is based on the field sampling and the bourgeoning experiment in laboratory, The distributing , bourgeoning status,density, diversity of the soil seed banks and its relationship with vegetation showed in this area sand dunes were studied. The results showed the seeds of ephemerals mainly distributes in 0- 5 cm soil and there are few seeds under the 5 cm soil. The density of the seed banks is different among the different parts of the sand dune. The density decreases gradually from the foot to the top. The density of the foot , middle part and top are 124grain/m^2,91 grain/m^2,66 grain/m^2, the seeds is more little windward than the leeward. The density of seed banks in windward is 81grain/m^2 and the leeward density is 100grain/m^2. The seed of ephemerals bourgeoning reaches the pinnacle on April and May. The diversity of different parts sand dune is different, but the differences do not reach the marked level. The similarity is high between the seed banks and the vegetation.