Study on interspecific association of springautumn pasture under enclosure and recovering conditions in Yili River valley

The interspecific association in the major population of grazing communities and enclosed communities for 1, 5 and 6 years (springautumn pasture) in Yili River valley were studied and the results showed that the species in the communities enclosed for 5 and 6 years unassociated, and those enclosed for 1 year and unenclosed slightly associated. Along with the vegetation restoration, the species with positive association remarkably increased and those with negative association remarkably reduced. The positive and negative association rate performed a decreasing and then increasing pattern. The distribution of dominant species showed a relatively stable status and neutrally associated with other populations, the other populations were easily affected by environmental factors. The association coefficient reflected the relationships among species and with the environmental factors to a certain degree and it was strongly affected by environmental factors at the beginning of enclosure and the biological affection gradually reduced along with the improvement of habitat.