Analysis on grasshopper spatial heterogeneity and pattern of natural grass in upper reaches of Heihe

Abstract

Grasshopper species spatial distribution pattern is the result of natural long鄄term adaptation, and a reflection of the relationship between grasshoppers and the environment. The spatial heterogeneity is an important theory basis to recognize the dynamic characteristics of the population development. To study the spatial distribution pattern of grasshoppers in natural grassland of heihe upstream in a quantitative research method, to analyze the spatial distribution characteristics of dominant species, then to determine the spatial structure features of grasshopper population and the spatial autocorrelation, all of what provided the theory basis to understand the ecological explanation of grasshoppers occurrence and distribution. On July 25, August 5, August 15, 2009, in the Baidaban, which locates at the south side of theater circles river鄄 Heihe branch of north Qilian Mountain, a north鄄south investigation area with length of 3500m, width of 900m was set up along altitudinal gradients, combined with the survey data of wild vegetation communities, then 3-8 investigation plots were set in each type of grassland, and finally 36 representative kinds were chose out with each kind of 100 伊 100 m 2 , extracting three 50 m 伊 50 m rectangle sample point in double diagonal method from each standard plots, a total of 108 sample points. To take samples 3 times with no returns, each time with the insect net (net diameter 30cm) which were used to sweep 200 nets like parallel lines, each net with radian 180毅, then collected grasshopper's abundance, density, many degrees in each type place according to each sample point's three statistical average. We tested the data using the statistical software SPSS (16. 0) of the P鄄P normal probability graph method, and analyzed the grasshoppers regionalized variables space structure,