Species Diversity And Spatial Distribution Pattern Of Coleoptera Beetles In Helan Mountain

Helan Mountain is the core area of the Alashan-Ordos Center,which is an important biodiversity center in the north of China.It is important to study the biological diversity and spatial distribution pattern of Coleoptera in this area.In this dissertation,based on a large amount of Coleoptera specimens including beetles habitat distribution information from Ningxia Universty and field investigations in Helan Mountain,species diversity and spatial distribution pattern of Coleoptera beetles were investigated.The beetles richness were collected by equal-area grid method based on G1S technoiosy.Based on GIS model of species range maps the distribution patterns of Coleoptera species are studied.By the beetle habitat analysis,some equal-area quadrangle srids are used as seographic units to collect distributional data of the species supported by Maplnfo Professional Version.All the arids with the distributional data of binary attribute are divided into groups by hierarchical cluster analysis according to Jaccord distance.The influence factors and the spatial distribution of the beetles diversity and fauna differentiation using PCA and multiple regression were analyzed,in order to explain the spatial distribution pattern and fomiation mechanism of Coleoptera insects in Helan Mountain.The main results of this dissertation as follows:(1)Coleoptera insects in Helan Mountain are rich in diversity and obvious dominant croups.In this study,there are 469 species of 252 eenera in 31 families of Coleoptera in Helan Mountain.Amons them.there are 2 families,34 senera and 101 species belonging to the subspecies of meat,and 12 subfamilies belonging to 12 falilies.29 falilies and 218 genera.368 species.Six falilies,including Carabidae,Pseudomonas.Ceratosaurus,Cerambycidae,Elephantidae and Coccinellidae,are dominant families,including lore genus and species.102 new beetles were added to the Helan Mountain area,and 22 new Ningxia records were added.Vertical distribution in vegetation,the mountain sparse forest belt and the mountain shrub belt have higher species richness and larger G-F index.(2)Palaearctic orisin.Totally 381 species belonging to Palaearctic,were the dominant fauna component in the area.The element of Mongolia-Xin play an important roles in the cerainbycid fauna and had closely related to Northeastern and North of China.The proportion of Palaeonortherian species gradually increased with the increase of altitude.(3)The species diversity and fauna differentiation intensity of Coleoptera in Helan Mountain showed obvious characteristics in horizontal and vertical distribution.In the horizontal direction,different categories and fauna differentiation of Coleoptera are the larsest in the middle of Helan Mountain.the southern part is higher than the northern part,and the west part is higher than the eastern part.The increase in the fauna differentiation intensity is conducive to the increase of species richness.Based on the binary similarity clustering,Coleoptera beetles of geographical grid are distributed into three geographic units,the first is desert xerophilic landscape beetles geographical group in the northern section,the semi-hygric landscape beetles geographical group in the middle and western part,and the semi-xerophilicg eographical beetles geographical group in the middle-east and south.The diversity of family,genus and species showed an asymmetric single-peak pattern,and the fauna differentiation intensity of the genus showed an upward trend,and the fauna differentiation intensity of family showed a single-peak curve along elevation gradient.The consequences to test Rapoport,s rule by Stevens'method,Pagel's method and cross-species method conformed the Rapoport's rule.However,the results by mid-point method rejected the Rapoport's rule and suggested a unimodal model because of mid-domain effect.(4)The hydrothermal factors caused by altitude affect the distribution pattern of the coleopteran insects and the differentiation intensity of the fauna.Temperature and precipitation are common factors affecting species diversity and fauna differentiation intensity of families and genus.The species diversity of Coleoptera beetles,the fauna differentiation of the family and genus were significantly negatively correlated with the annual average temperature,and were positively correlated with annual rainfall,and positively correlated with vegetation coverage.Increased terrain complexity promotes species diversity and fauna differentiation intensity of families and genus.