Abstract:

This experiment was conducted to study densities and spatial distribution of seed rain and soil seed bank of endangered plant Amygdalus mongolica at different altitudes between 2008 and 2009 in Baotou, Inner Mongolia. Self-renewal abilities and effect of changes in the micro-habitats on A. mongolica populations were analyzed. The purpose is to provide reference information for protection and reconstruction of A. mongolica populations. The results showed that the seed rain density changed obviously, while the soil seed bank density did not change significantly in the inter-annual. Seed rain mainly distributed around the shrub crown within 2 m, and the horizontal distribution was relatively narrow. The soil seed bank mainly distributed in the litter layer of 1.50 m circumference section around the parent tree, in which it was not conducive to seed germination. There existed more significant differences in the seed rain and soil seed bank at different altitude zone (P＜0.05), which showed a decreasing trend with the elevation increased. The correlation analysis showed that, seed rain densities had a significant negative correlation (P＜0.05) and soil seed bank densities had even a more significant negative correlation (P＜0.01) with altitude gradient. Therefore, altitude would be the most important factor that determines the seed rain and soil seed banks.

Key words: Amygdalus mongolica, seed rain, soil seed bank, elevation gradient