Effects Of Different Planting Patterns On Understory Arthropod Communities Of Sophora Moorcroftiana

Sophora moorcroftiana is a small shrub of Sophora in Leguminosae.It is distributed in Xigaze,Lhasa,Linzhi and other places in the Brahmaputra River Basin of Tibet.S.moorcroftiana is an extremely valuable medicinal plant,an important forage plant in Tibet,and an important tree species for sand fixation in Tibet.However,it is easy to be eaten by pests.At present,There are few researches of the mechanism of pest disaster in S.moorcroftiana.Pesticide spraying is the main method for S.moorcroftiana pests control.However,Spraying with insecticides will bring serious"3R"problems and can damage the fragile ecological environment of Tibet.Therefore,it is urgent to find out the ecological control mechanism of the seed Pest of S.moorcroftiana.Some studies have shown that optimizing the community structure of crops can strengthen the natural control of pests.There are a large number of cases of planting single trees in forestry leading to pests outbreak.Inspired by the above,This paper studied the effect of different plant interplantingwith S.moorcroftiana(Purple-leafplumandS.moorcroftiana interplanting,Chinese pine and S.moorcroftiana interplanting,pure S.moorcroftiana Shrub)on arthropod diversity,arthropod community stability and the damaged rate of S.moorcroftiana seeds.And we can find an appropriate planting pattern in this way.This study mainly include the following aspects:1.Studied the arthropod community structure of different sample plot;2.Through the Principal Component Analysis of different groups in different sample plot,we can find the representative species of different groups in different sample plot;3.Studied the similarity analysis of different sample plots in the whole sampling period and in each month;4.Studied the time dynamics of different groups in different sample plot;5.Studied the time dynamics of the diversity comprehensive index and the stability index,and dealt with Principal Component Analysis and cluster analysis.6.Maked statistics for the damaged rate of S.moorcroftiana pods and seeds in different plots.The results of the research have shown that there were 2400arthropods were captured within four months in the whole sample plot.Among which,there were 848 arthropods were captured in the purple-leaf plum sample plot.There were 803 arthropods were captured in the control sample plot.There were 749 arthropods were captured in the Chinese pine sample plot.The order of the diversity index from large to small was the purple-leaf plum sample plot,the control sample plot,the Chinese pine sample plot;The order of the richness index from large to small was the purple-leaf plum sample plot,the control sample plot,the Chinese pine sample plot;For the evenness index,the purple-leaf plum sample plot was the same as the Chinese pine sample plot,and the control sample plot was the smallest;The order of the dominant concentration index from large to small was the control sample plot,the Chinese pine sample plot,the purple-leaf plum sample plot;The order of the score of Principal Component Analysis of the diversity comprehensive index from large to small was the purple-leaf plum sample plot,the control sample plot,the Chinese pine sample plot,were the same as diversity index and richness index.Intermsofstability analysis,it was found that the S_t/S_iratio of the Chinese pine sample plot was the lowest,the purple-leaf plum sample plot was the same as the control sample plot in this respect.The order of the S_n/S_pratio from large to small was the purple-leaf plum sample plot,the control sample plot,the Chinese pine sample plot.The order of the score of Principal Component Analysis of the stability comprehensive index from large to small wasthe purple-leaf plum sample plot,the control sample plot,the Chinese pine sample plot,were the same as stability index and the diversity index.The order of the damaged rate of pods and seeds of S.moorcroftiana from large to small wasthe purple-leaf plum sample plot,the control sample plot,the Chinese pine sample plot.The resultsof the research have shown thatsample plot with the higher diversity of the arthropod community,the higherstability of the arthropod community,the lowerdamaged rate of pods and seeds of S.moorcroftiana.Purple-leaf plum is the most suitable species to be planted with S.moorcroftiana in this study.Some studiesshowed When the Chinese pine were exposed to Gravitarmata Margarotana,its volatiles can repel this pests.The repellent effects made by Chinese pine bring about pests do harm to other plants.So the damaged rate of S.moorcroftiana were higher whitch planted with Chinese pine.The mechanism of the damaged rate of S.moorcroftiana whitch planted with the two plants,remain to be further researched.