Changes in Soil Seed Banks and Biodiversity along an Altitude Gradient in Taibai Mt.
太白山土壤种子库储量与物种多样性的垂直格局

Soil seed bank is the pool for species composition of a plant community. It plays a critical role in succession of the community and maintenance of the community structures and functions. In this paper, we studied the distribution of soil seed banks along an altitudinal gradient (1500-3500 m asl) on the southern slope of the Taibai Mountain. The main results are summarized as follows: (1) Reserves of the soil seed bank increased with an increase of elevation, reached its maximum at an altitude of about 2600 m, and then decreased with increasing altitude. Above the altitude of 2000 m, the distribution of seed reserves in the soil profile can be generally characterized by the fact that most of soil seeds occurred in litter-fall layer, and smallest reserves were in the subsurface soil layer. Below the altitude of 2000 m, most of soil seeds occurred in humus layer. (2) A total of 172 plant species from the soil seed banks were accounted in 21 plots. The number of species was reduced along an altitudinal gradient. The community characteristic of soil seed banks varied obviously in two altitudinal ranges, 1500-2500 m and 2500-3500 m. (3) The reserves and density of seed banks showed a similar pattern along the altitudinal gradient. It was better to use reserves to indicate the size of soil seed banks. In this study, the soil samples were divided into three layers: litter-fall layer, humus layer and subsurface soil layer.