The Basic Characteristics Of Soil Seedbank In Qira Desert-oasis Transitional Zone

The soil seedbank of a plant community may be regarded as evolutional memory of the past conditions. Simultaneously it is also an important factor to reflect the present and future characteristic of the community. On the one hand, as a reservoir of the vegetative forms, the seedbank can reduce the probability for the population to exterminate. The existence of soil seedbank extremely has the possibility to provide vegetative forms after disturbance and destruction. On the other hand, the soil seedbank is the latent community, it can directly participate in the renewal of vegetation. The quantities, quality, composition and spatial pattern of seedbank have crucial influence on plant community, and it is the foundation for population to settle down, survive, multiply and diffuse.Especially in some serious degenerated ecosystem, soil seedbank is important seed source for vegetation to reconstruct, in great degree it decides the progress and direction of vegetation reconstruction. After ecosystem recover, the seedbank possibly reserve massive original and present groups, and species from other systems included. The soil seedbank preserves many and varied species, genes and phenotypes, which is an important foundation to maintain biodiversity; moreover it also has vital significance to miantain ecology diversity. Study by germination on soil seedbank in Qira desert-oasis transitional zone showed: The research area habitat condition particularity has accomplished distinctive quality of the experiment result.In intermediate belt soil seedbank reserve abundantly, each two landform groups have no remarkable difference between, because of distributes influence of Tamarix ramosessima, the quantity of each species are quite uneven, its individual quantity holds the very great proportion in the seedbanks, other species seed densities are extremely few. The special climate characteristic of transitional zone--harsh and changeable climate (sandstorm), causes low and short-life cycle herb (Perennials and Annuals) can compare other lives to survive, therefore it has formed seedbank species composition by the herbaceous. In the transitional zone, the lack of vegetation types and the quantity enlarge the possibility of appearing same types in the different seed banks, the similarity between every two different soil seedbanks also maintain a higher level. The seedbank type belongs to the persistent soil seedbank, and it is mainly consisted by dormancy seed. In the experiment the majority of seeds complete germination in 20 days, the time characteristic is one-summit pattern.The experiment proved this desert– oasis transitional belt already had basical factor (seed source) to carries on natural regeneration and expansion. Given correctly conditions and scientific management, it will be very beneficial to reconstruct. The seeds of all the species except Tamarix ramosessima reserves deficiently, once the natural vegetations are damaged, most of tree and herbaceous species (including constructive species) can't supply the new individual from seed bank, so it only can depend upon other forms to obtain the supplement. Therefore, we should pay more attention to the local vegetation protection , in particular to Populus euphratica forest, to strictly prohibits the over cutting and the overgrazing, so as to prevent further ecological deterioration due to the vegetation degenerates.