祁连山东麓高寒草甸不同退化程度草地土壤种子库特征研究

通过野外调查和种子萌发法对东祁连山高寒草甸4种不同退化程度草地(未退化,ND;轻度退化,LD;中度退化,MD;重度退化,HD)土壤种子库进行了比较研究。结果表明:4种退化程度草地种子密度大小为:轻度退化草地>未退化草地>中度退化草地>重度退化草地;未退化草地共发现了6种植物,主要为十字花科(Cruciferae)和毛茛科(Ranunculaceae)植物;轻度退化草地共发现了9种植物,主要为禾本科(Gramineae)、菊科(Compositae)和豆科(Leguminosae)植物;中度退化草地共发现了5种植物,主要为车前科(Plantaginaceae)植物;重度退化草地共发现了5种植物,主要为禾本科(Gramineae)植物;对于土壤种子库的物种多样性,轻度退化草地最有利于维持和保护该地区物种多样性,未退化草地和轻度退化草地显著优于中度退化草地和重度退化草地;总体来看,4种退化程度草地种子库种子与地面植被物种相似性均较低。

Characteristics of Soil Seed Banks of Alpine Meadow under Different Degradation Degrees in Eastern Qilian Mountains

The comparative studies of soil seed banks of four different degradation degrees grassland(Non-degraded, ND; light degraded, LD; moderate degraded, MD; heavy degraded, HD) in the eastern Qilian Mountains were carried out through field investigation and seed germination test. The results showed that the soil seed densities of 4 different degradation degrees grassland were ordered as LD >ND >MD >HD. Six plant species were discovered in ND grassland and main species belonged to Cruciferae and Ranunculaceae; Nine plant species were discovered in LD grassland and main species belonged to Gramineae, Compositae and Leguminosae; Five plant species were discovered in MD grassland and main species belonged to Plantaginaceae; Five plant species were discovered in HD grassland and main species belonged to Gramineae. The species diversities of soil seed banks in ND and LD grasslands were richer than that in MD and HD grasslands. LD grassland was the most beneficial to maintain and protect the species diversity of the region. In general, the species of soil seed banks were not similar to that of vegetation.