Analysis of soil seed bank level structure in degenerated Seriphidium transiliense desert grassland.

The objective of the study was carried out to analyze soil seed bank of Seriphidium transiliense desert with seed - germination method in three different degraded stages.The result shows that three stages of the total amount of seed germination are concentrated in the former 15 days,the peak of germination was on the 10 th days in the first around,the end of the germination was on 50 th day;medial - heavy and extreme stage of the soil seed bank have little change in number of species,13 species,11 species and 11 species,which are quantity in a dominant position are as follows:Seriphidium transiliense,Petrosimonia sibirica and Ceratocarpus arenarius,Petrosimonia sibirica;With the growing in intensity of degeneration,grassland vegetation gradually was developed into annual plant.The soil seed bank of Seriphidium transiliense gradually degenerate until disappear.