The Diversity Of Grasshopper Communities In Northern Shaanxi And Habitat Fragmentation And The Effects Research

Shaanei lied in North Shaanxi, with arid weather complicated terrain and more grass.The plague of locusts is one of the most serious factor the hinder the development ofagriculture and enimal husbandry. The paper mainly studied the composition,Structure,diversity of grass-hopper community.According to character of geography and vegetaion, Shaanbei was divided into 7different habitat regions: desert prairie region, desert region typical steppe, meadowprairie,bottomland meadow, farmland region, river marshland region. The compositionof grasshoppers community and the distribution laws were studied, Which based on the largearea investigation in different habitat region. The grasshoppers species, which had beencollected from this region, were examied inculde 7 families, 2l genera and 37species. Theybelong to Tetrigidae, Pyrgomorphidae, Pamphagidae, Catantopidae, Arcypteridae,Oedipodidae and Acrididae. The grasshopper species composition and abundance aredifferent in different habitat regions. By comparing the resemblance of grasshoperscommunity in different habitat regions and dendorgram and PCA analysis, the differenthabitat region can be divided into 3 types; the Water abundance type include farmlandregion, bottomland river marshland, the damp and better vegetation type include typicalsteppe and meadow praise. The arid and worse vegetation type include desert prairie regionand desert region.Based on the sampling investigation, the patterns of species-area relationship modelwas ehablished S_q=2.957lq^0.2983[r=0.9534 r_8,0.01=0.632]and the species-abundancerelationship model was established N(R)=l0exp[-0.097(r-5)²] [X²=20.43 X²_0.01=2l.63]According to the data obtained from the investigation in different habitat region, thediversity index of shannon-wiener (H'), pielou's evenness(E), simpson's dominance (D)were computed the relationship of diversity and evenness. Abundance was disussed too.The results as fO1lows; the diversity index of different habitat region from high to low wastdesert Prairie region>yPical stCPPe>meadow prairie>desert region> Bottomland meadoW>driland region>river marshland region, By the analyses, the community diversity was thefimction of evenness and abundance but not equal in value.Stuopng the graSshOPPer coInInunity in oases, the SPecies in oases are fewer thanYulin. It is obviously related with the grasshopper SPecies' in oases and soil hUmidityweatheT, vegeaion and other factors, but it is not obviously related with the oasis area anddiStance to the contrast land.EffeCt of fragmented forest on grasshoppers is not different in forest edge grass. Thechange of interior forest grass is sligh. Whn the forest area is not small and the tree wasnOt badiy cul,bu grasshoPPer species and number in foreSt imerior grass don't riseviolenty When the forest area is small, and was cut badly, the grasshopper sPecies andWer in forest interior rise obviously It showed by PCA and stePwise regression analsis,the comPlicated comPosition of grass in fOrest is the mainly faCtor on affecting thegrasshoPPer sPecies and ntnnber...