关键词: 土壤种子库, 植被恢复, 生物多样性, 物种相似度

Abstract: A major characteristic of desert ecosystems is that the number of seeds per unit area in the soil seed bank varies among different habitats. Soil seed bank is an important element affecting both ecosystem resistance and resilience. By sampling a number of soil samples in the field, surveying seedlings in sampling sites, and observing seedlings emergence in laboratory, an investigation was done on the soil seed banks in artificially re-vegetated region (ARR) and naturally stabilized sandy land (NSSL) in the southeast edge of the Tengger Desert. The results showed that: (1) There were 21 species in ARR which belonged to 7 families, and 33 species in NSSL which belonged to 11 families. Among these families, Gramineae, Compositae and Chenopodiaceae were the main components in both regions. In addition, the main species and life forms were different in ARR and NSSL. Annuals were the main species in ARR, while perennials dominated in NSSL. (2) There were less seeds in ARR than in NSSL. The seed density between the two regions varied with certain species. For example, there was not significant difference for seed density of Eragrostis minor, Chloris virgata and Cornulaca alaschanica, while there was significant difference for Bassia dasyphylla, Cleistogenes songorica, Artemisia frigida, Tragus bertesonianus and Setaria viridis. (3) The species richness was lower in ARR than in NSSL as well as diversity index. (4) The species similarity index between the soil seed banks and above ground plants in ARR was 0.73, and 0.71 in NSSL. According to the study, it is a long time for the restoration of species diversity in ARR.

Key words: soil seed banks, plant restoration, biodiversity, species similarity