Diversity Of Ground-dwelling Beetles And Their Value As Bioindicators In Desert Landscape In Lingwu Baijitan Of Ningxia

The Baijitan National Nature Reserve of Ningxia is one of the typical nature reserve with desert ecosystem as its main protected object of Caragam korshimkii, Oxytropisaciphylla etc.psammophyte. Because of the continuous artificial desertification control, it had a unique ecological landscape. With the continuing evolution of natural and artificial psammophyte and the desert insects of advantage groups has been changed. The study selected this nature reserve as the experimental area during the period from 2014 to 2015 in April to October, using pitfull trap method to investigate the ground-dwelling beetles in the typical habitat, using community diversity indices, the indicator value and other indices, through researching community the ground-dwelling beetles diversity, preliminary screening of ground-dwelling beetles as bioindicators of different habitat types in desert ecosystem, exploring the desert landscape pattern and the ground-dwelling beetle diversity changes, habitat indicator species and the relationship between the habitat of characteristics. This study has a certain guiding significance for the research and conservation of biodiversity in this nature reserve, guidance reasonable desertification control, as well as maintaining ecological balance of the desert landscape etc. In this paper the main research results are as follows:(1) Selected arid desert steppe and artificial sand fixation of 2 habitats 14 plots, using pitfull trap method to collect the ground-dwelling beetles, researching the spatial distribution and its pattern of activity in different habitats. A total of 3389 beetles were collected, belonging to 16 families,57 genera and 80 species. Tenebrionidae was the absolute dominant group (accounting for 78.49% of the total individuals). Followed by Melolonthidae (accounting for 12.32%).These were the dominant families in this area. Carabidae (accounting for 4.07%), Curculionidae (accounting for 2.24%) and Elateridae (accounting for 1.12%) were common families. Anatolica mucronata (accounting for 26.78% of the number of individuals)and Microdera kraatz alasharticaand(accounting for 24.37%)were the dominant species. The number species of ground-dwelling beetles had reached its peak period in May. Within the investigation period existed significant difference among species (F(6.91)=3.0560,P=0.0091<0.01), (in April and May, in June and July). Between in April, May, June and July had no significant difference. Between in June, August, September and October had no significant difference. Within the investigation period, the number of individuals of the ground-dwelling beetles appeared two peaks (in April and May, in July and August).(2) Collected 3 habitats 9 plots of Reaumuria soongarica, Caragam korshimkii etc. as constructive species of arid desert steppe in this reserve to research the community composition of ground-dwelling beetles as bioindicators of its habitat. A total of 3885 beetles were collected, belonging to 16 families, 42 genera and 54 species. Tenebrionidae was the absolute dominant group, accounting for 82.29% of the total individuals. Followed by Carabidea, accounting for 12.27% of the total individuals. Species richness index was in turn, Reaumuria soongarica-Stipa glareosa community habitat> Caragam korshimkii-Ammopiptanthus monglicus community habitat> Reaumuria soongarica-Stipa breviflora community habitat. According to the indicator value of more than 50% as the characteristics of the indicator species selection standard, Aphodiidae, Calerucidae and Eumolpidae, Blaps femoralis, Anutolica ningxiana etc. of the Tenebrionidae can be used as the characteristics of the indicator species of Reaumuria soongarica-Stipa glareosa community habitat. Geotrupidae, Carabidae, Curculionidae and Silphidae had the choice tendency of Reaumuria soongarica-Stipa breviflora community habitat. Pterocoma reitteri, Pterocoma vittata hedini, Trigonocnera pseudopimelia, Harpalus calceatus, Harpalus sinicus, Conorrhynchus conirostris, Lethrus potaniri etc. can be used as the characteristics of the indicator species of Reaumuria soongarica-Stipa breviflora community habitat. Histeridae, Elateridae, Melolonthidae and Scarabaeidae had the obvious tendency of Caragam korshimkii-Ammopiptanthus monglicus community habitat. Blaps femoralis, Anatolica potanini, Anatolica mucronata, Mantichorula semenowi, Platyope mongolica, Sternoplax setosa setosa, Pseudotaphoxenus brevipennis, Trematodes tenebrioides, Chrysolina aerichalcea etc. had the obvious tendency of this habitat.(3) Collected 5 habitats 15 plots of artificial sand fixation in this reserve to research the community composition of ground-dwelling beetles as bioindicators of its habitat. A total of 3434 beetles were collected, belonging to 15 families,49 genera and 73 species. Tenebrionidae was the absolute dominant group, accounting for 77.15% of the total individuals.Followed by Melolonthidae, accounting for 13.10% of the total individuals. Species richness index was in turn, Leymus seculinus community habitat> Atemisia ordosica-Stipa capillata community habitat> Caragana korshinskii-Atemisia ordosica community habitat. The indicator value method analysis results showed that Elateridae can be used as characteristics indicator species of Leymus seculinus community habitat. Blaps femoralis, Microdera kraatzi, Corsyra fusula, Diphycerus davidis and Agrypnus musculus were the characteristics indicator species of this habitat. Anutolica nureti and Mantichorula semenowi had special preference of Atemisia ordosica-Stipa capillata community habitat. Anutolica amoenula and Pseudotaphoxenus brevipennis etc. can be used as characteristics indicator species of Caragana korshinskii-Atemisia ordosica community habitat.