Comparative Study On Belowground Biomass Of Different Degradation Degree The Stipa Krylovii Grassland Community

Inner Mongolia Stipa krylovii grassland was fourth largest Stipa grandis grassland of China. It had extremely Significance on the ecological, economic construction and geographical distribution. This paper is compared the belowground biomass of community in different degradation degree of stipa krylovii grassland and the main factor that affecting on belowground biomass of community. The result indicated as following.Because of different degree of grassland degradation, the constructive species of the Stipa grandis community had produced an alternative substitution effect. Stipa krylovii, Artemisia frigida, Convolvuls ammanii, Peganum nigellastrum was the constructive species of the Standard Lot, moderating degradation Lot, Strength degradation Lot, and extreme degradation Lot respectively.The construction of root type in the lots of different degradation had clear differentiation. The root type of the standard lot was mainly tuft type grass. The root type of the moderate degradation lot and the strength degradation lot was mainly taproot type grass. The root type of the extreme degradation lot was predominated by the plant of creeping-root type. The plant components and root type construction of community was tending to simplicity with the increasing degradation degree.From the entire series of the degradation, the depth of Belowground Biomass distribution extended downward with the increasing degradation degree.The spatial distribution shape of the belowground biomass of the standard Lot and the moderate degradation lot was mainly"T"; the spatial distribution shape of the belowground biomass of the strength degradation lot and the extreme degradation lot was predominately"Inverted Pyramid". The seasonal distribution of the belowground biomass as following: The seasonal distribution of the standard Lot and the moderate degradation lot was bimodal peak. The seasonal distribution of the strength degradation and the extreme degradation lot was single peak.Belowground biomass and aboveground biomass of the standard lot showed significantly phenology changes, but didn't have significantly phenology changes in the moderate degradation lot, the strength degradation lot and the extreme degradation lot.Asexual reproduction capacity of plant enhanced gradually and distribution of photosynthate significantly shifted to underground part, with the increasing degradation degree of grassland.