Study On The Distribution Features Of Population Of Orchardgrass(Dactylis Glomerata L.) At Different Altitude Of Wusun Mountain In Zhaosu, Yili

Orchardgrass is a cool-season grass species which has strong adaptability and high nutritive value and has been widely distributed in the world. Orchardgrass of Xinjiang mainly distributed in the altitude 1300~2800 m of Tianshan mountain and Altai mountain, which is the important component of montance meadow and meadow steppe. Studying on the population distribution rule, species diversity, interspecific relationship, distribution pattern and the relationship of distribution features and the altitude in the different altitude and exploring the variation law to adapt the environmental condition for the conservation and utilization of orchardgrass germplasm and for providing the information.In this research region, the result showed that the height, the density, the coverage and the biomass of orchardgrass community appeared obvious difference in the different altitude. The structure of orchardgrass community stays stable. And the maximum biomass(650.77 g/m2) is in the altitude 2000 m; therefore, the altitude is the main factor to the structure of orchardgrass community.The diversity index showed obvious difference in the different altitude. And the mindiversity is in the altitude 2000 m. The main cause is that the altitude 1800 m and 2200 m both are at the transition region of orchardgrass community. And the species number increase, result in the increase of species diversity.Because of the difference of moisture and temperature, the species pairs in the altitude 1800 m and 2000 m appear positively, nonsignificantly related and positively, significantly related respectively. And most pairs are in a tight relationship. It showed that the species can use resource jointly and stay a strong stable condition in this region. At the altitude 2200 m, the relationship of specie pairs showed passively, significantly. It showed that the orchardgrass community stays in instability relatively.This paper use the diffusion coefficient, aggregation degree and negative binomial parameter to study the distribution pattern of orchardgrass population in the different altitude. The result showed that the distribution pattern of orchardgrass was clumped distribution of different scale in the altitude 1800 m; while it was clumped distribution at the scale arranging from 400~12800 cm2 and was uniform distribution at the scale 25600 cm2 in the altitude 2000 m and 2200 m. Negative binomial parameter and aggregation degree showed that the minimum aggregation degree was in the altitude 2000 m; the clumped scale generally arrange from 400~12800 cm2.