| Ziwuling National Nature Reserve in Shaanxi Province is located in Fuxian County,Shaanxi Province.It is one of the areas where the Ziwuling Mountains have relatively concentrated vegetation resources and animal and plant resources.It plays an important role in maintaining ecological balance,regulating regional climate and conserving biodiversity in Shaanxi,Gansu and other areas.In order to investigate the diversity and community characteristics of ground-dwelling beetles in the protected area,in this experiment,from May to September 2017,the species composition and quantitative distribution of ground-dwelling beetles in the five forest types of the protected area were investigated using the pasteurization method and the net trapping method.At the same time,the edge effect of 3 kinds of edge types in this area was analyzed,the main results were as follows:1.A total of 7260 ground-dwelling beetle specimens were collected from five forest types in the Ziwuling National Nature Reserve in Shaanxi Province,belonging to 25 families,90 genera and 110 species.At the level of the family,Carabidae,Chrysomelidae and Coccinellidae are the dominant groups in the area's ground-dwelling beetles,which accounted for 68.98%of the total number of individuals;followed by Tenebrionidae,Scarabaeidae,Melolonthidae,Cerambycidae,Meloidae,Rutelidae and Curculionidae.At the species level,the percentage of Calathus halensis,Amara plebeja and Chrysomela populi in the total number of individuals were greater than 10%,which were the dominant species of the ground-dwelling beetles in the protected area.2.The community diversity and quantitative distribution of the ground-dwelling beetles were different in different forest types.The individuals number and number of species of ground-dwelling beetles in five types of forest were reduced in order of coniferous broad-leaved mixed forest,deciduous broad-leaved mixed forest,Quercus liaotungensis forest,Pinus tabulaeformis forest,deciduous broad-leaved shrub.The ranking order of richness index and diversity index were:coniferous broad-leaved mixed forest>deciduous broad-leaved mixed forest>Quercus liaotungensis forest>Pinus tabulaeformis forest>deciduous broad-leaved shrub;The variation trend of the evenness index was:coniferous broad-leaved mixed forest>deciduous broad-leaved mixed forest>deciduous broad-leaved shrub>Quercus liaotungensis forest>Pinus tabulaeformis forest.The trend of the dominance index was:deciduous broad-leaved mixed forest>Pinus tabulaeformis forest>Quercus liaotungensis forest>deciduous broad-leaved mixed forest>coniferous broad-leaved mixed forest,this difference was related to the complex environmental features of each territory,and it was also influenced by human management activities.3.According to the temporal dynamics of the ground-dwelling beetles collected from different forest types showed that May and August were the peaks of the occurrence and activity of ground-dwelling beetles.The richness and diversity indices of the ground-dwelling beetles each month were basically the same,with the May and August being the highest,the June lower,the July starting to rise,the September lowest,and the species diversity index as a whole at a higher level.The evenness index showed little difference between different months,and it was highest in August,showing that the species of the ground-dwelling beetle were diverse and distributed relatively evenly,and the community structure was relatively stable.The peak period of Carabidae in the three kinds of dominant families was in May and August,the number of individuals in the Chrysomelidae in July and August was relatively high,the species of Coccinellidae was the most abundant in May.4.The similarity analysis of the species of ground-dwelling beetles in different months and different forest types showed that the community composition of the ground-dwelling beetles was the highest in May and August,which was 0.805.The species similarity coefficient of ground-dwelling beetles was the lowest in May and September,with a value of 0.493,and the other months were moderately similar.There were 84 species of common ground-dwelling beetles in coniferous broad-leaved mixed forest and deciduous broad-leaved mixed forest,with the highest community similarity of 0.824.However,the similarity coefficient values between deciduous broad-leaved shrub and broad-leaved mixed forest and Quercus liaotungensis forest were relatively low,which were 0.562 and 0.536 respectively.The similarity coefficient values among the other forest types ranged from 0.6 to 0.8,which showed a higher similarity of the community composition of the ground-dwelling beetles.5.The edge effect analysis of the three edge types revealed that the EH'value of broad-leaved-coniferous forest edge and the farmland-grass edge were greater than 1,EC value less than 1,indicating a positive edge effect.It shows that the species and diversity of the ground-dwelling beetles at the edges were higher than those in the adjacent habitats.But the EH'value of farmland-grass edge slightly greater than 1,while the EC value was very close to 1,showing that the positive effect of the edge was weaker.However,the EH'value of the coniferous broad-leaved mixed forest-shrub edge was less than 1 and the EC value is greater than 1,showing a negative edge effect. |
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