The Study Of The Grasshopper Diversity On The Songhua Lake

In this paper, the author investigated the community of grasshopper in Songhua lake Nature Reserve from June to September, 2004, and referred to the data investigated on 2002. The paper mainly studied the diversity of grasshopper, including the community structure of grasshopper, the distribution laws, the diversity of grasshopper in different habitats, the change of the community of grasshopper in different seasons and the diversity of grasshopper in island habitat etc. According to the character of vegetations and geography, Songhua lake Nature Reserve was divided into five kinds of habitats, artificial larch tree, cutting blank, lakefront wetland, farmland region, crude redeposit broad leaf weed tree forest. With the methods of systematic and random sampling, the 39 grasshopper species and more than 3000 specimens had been collected in 5 kinds of habitats, belonging to 5 families, 26 genera. Of the collected specimens, Catantopidae has most genera and Arcypferidae has most species, the form accounts for 38.5% of total species, and the latter accounts for 33.3%. By comparing the similarity of grasshoppers' community in different habitat regions and clustering and PCA analyzing, the different habitat regions could be divided into 3 types: far off lake region including cutting blank and farmland region; near Lake Region including artificial larch tree and lakefront wetland; mountain site including crude redeposit broad-leaf weed-tree forest. The species relative abundance distribution could be well described by the model of log normal distribution. The grasshoppers' species are very abundant and the distribution is very homogeny. Using a variety of diversity indexes to study the diversity of grasshopper in different habitat region, the results showed that diversity index (H′)of 5 kinds of habitats has the order: crude redeposit broad-leaf weed-tree forest>farmland region>artificial larch tree>lakefront wetland>cutting blank. The variety of evenness index(E) is similar to H′. Correlation coefficient is 0.918, achieving to significance level. Studying the variety of season about the community of grasshopper in songhua lake Natural Reserve shows that the diversity index of grasshopper is the maximum in July and the species are abundant. Simpson dominance is the maximum in September. The author studied the morphology construction of three kinds of grasshopper in island habitat and land habitat by single factor analysis. The results showed that the wing length of Calliptamus abbreviatus has notable significant difference and the tibia length of Oedaleus infernalis has significant difference. The mainly reason is the geography insulation and division. The relation of island area and species abundance was studied and the result showed that there is positive correlation between them. But the author pointed out the island area is not only influential factor. In summary, the studies of above aspects were attempted to offer some scientific foundations for protection of insect diversity, effective guard-against harmful grasshopper. Moreover, it can provide rationable proposal to construct Natural reserve.