Distribution of organic matter、nitrogen and phosphorus along an altitude gradient and productivity change and their relationships with environmental factors in the Alpine meadow

The distribution gradient of soil organic matter, nitrogen and phosphorus, productivity changes, and their responses to environmental factors were analyzed in this study. The data analyzed in this study was collected from sites at 6 different altitudes ((3 840),3 856,3 927,3 988,4 232,4 435 m), in the alpine meadow. The results indicated that the amount of soil organic matter, soil total nitrogen, soil available nitrogen and soil total phosphorus were higher at the altitudes of 3 840 m and 4 435 m and lower at the mid-altitude gradients. Soil available phosphorus fluctuated. The effect of precipitation on soil organic matter, nitrogen and phosphorus decreased with soil total nitrogen, soil organic matter, soil total phosphorus, soil available nitrogen and soil available phosphorus. The effect of temperature on soil organic matter, nitrogen and phosphorus decreased with soil available nitrogen, soil organic matter, soil total nitrogen, soil total phosphorus, and soil available phosphorus. Based on the results from the study it was concluded that temperature was the major environmental factor that affected the primary productivity of the plant community in the alpine meadow. The stepwise regression equation with environmental factors was: Ya=-92.982+13.832X_3 (F=13.355,P0.05).