Niche Of Grasshoppers In Ecological Restoration In The Hilly And Gully Area Of Loess Plateau Of Yan'an

The aim of this study was to know the structure of grasshoppers' communities and niche were compared and analyzed in ecological restoration in the hilly and gully area of Loess Plateau of Yan'an.An investigation of grasshoppers communities was carried out using niche breadth index and niche overlap index analysis in four habitats,seven county and four restored years in July to Ooctober,2013-2014.The results are as follows:This investigation has collected 3396 grasshoppers,subject to 6 families 15 genera and 30 species.Among them,1 genera,1 species of Pamphagidae,1 genera,1 species of Pyrgomorphidae,2 genera,5 species of Cantantopidae,6 genera,7 species of Oedipodidae,4 genera,13 species of Arcypteridae,1genera,3 species of Acididae.The number of Atractomorpha sinensis species is the most and this is the dominant species.Niche of grasshopper populations in different locations : four species of Trilophidia annulata,Chorthippus albonemus,Acrida cinerea and Atractomorpha sinensis are the biggest of thirty niche breadth index in this area.The highest and lowest level is 1 and 0 of 435 niche overlap,overlap index > 0.5 accounting for 25.75% of totality and overlap index<0.5 accounting for 74.25 % of totality.Niche of grasshopper populations in different artificial restoration types:Chorthippus albonemus is the biggest of 17 niche breadth index in this area,four species of Celes skalozubovi,Chorthippus aethalinus,Euchorthippus cheui and Euchorthippus unicolor are the smallest of 17 niche breadth index.The highest and lowest level is 1 and 0 of 136 niche overlap,verlap index > 0.5 accounting for 33.09 % of totality and overlap index<0.5 accounting for 8.82% of totality.Niche of grasshopper populations in different restoration stage:four species of Sphingonotus mongolicus,Trilophidia annulata,Oedaleus infernalis and Atractomorpha sinensis are the biggest of 30 niche breadth index in this area,four species of Callitamus barbarus,Arcyptera coreana,Chorthippus hammarstroemi and Chorthippus intermedius are the smallest of 30 niche breadth index.The highest and lowest level is 1 and 0 of 435 niche overlap,overlap index > 0.5 accounting for 47.59% of totality and overlap index<0.5 accounting for 52.41% of totality.Six species of Trilophidia annulata,Chorthippus albonemus,Acrida cinerea,Atractomorpha sinensis,Sphingonotus mongolicus and Oedaleus infernalis are the generalization of competitive species with the biggest of niche breadth index in this area.Niche overlap existed at all levels which mainly are the lower and higher levels,indicating that the grasshopper competitive exclusion is not strong,and the resource utilization competition is relatively weak.