A Study Of The Main Bamboo Resources And Their Diseases And Insect Pests In Four Districts(Counties) Of Northeast Sichuan

Being the most potential plant resources in the 21 st century around the world,bamboo,plays a significant positive role in improving the ecological environment and promoting local economic development.While,management status of bamboo,mostly stays in the primitive stage,rarely about diseases and pests of control.The diseases and pests effect bamboo's growing,and constantly influence it's ornamental value and industry utilities.As one of the world's bamboo distribution center and a birthplace,Sichuan possessing abundant bamboo resources,has drawn the government's attention at all levels in landscape and industry of bamboo.There were some studies on bamboo pests and diseases in Sichuan,major in Chengdu and Leshan,but none in Northeast of Sichuan.In order to make full use of bamboo resources,with the support of the fund of the third national census of forestry pests,the main bamboo resources and their diseases and insect pests were studied in the four districts(counties)of Northeast Sichuan(that are Wusheng,Qianfeng,Xichong and Gaoping)from October 2015 to October 2016.The results and conclusions as follows:(1)Species and distributions of bamboo: The bamboo resources divided into two parts in four studied areas,non-commercial forest and commercial forest.Timber forest is for commodity use and soil and water conservation forest is for public use.Sinocalamus affinis is the dominate spices in the four areas,it has the most widely distribution range.In other species,Gaoping district main contains Phyllostachys heterocycla and Phyllostachys praecox,while Bambusa intermedia,Dendrocalamus latiflorus and Phyllostachys bissetii for the other three areas.(2)Pests and diseases of main bamboo species: Based on the investigation of species and distributions,13 main bamboo species' pests and diseases in four areas have been investigated.A total number of 1018 specimens of pests were collected,52 kinds of insect pests and 12 kinds of bamboo diseases.There are 32 species of pests and 6species of diseases in WuSheng,36 species of pests and 8 species of diseases in Qiangfeng district,with 18 and 10 species in Xichong and 21 and 7 species in Gaoping.The pests belong to 3 orders,35 families,they are Hemiptera,Lepisoprera andColeoptera.Diseases mostly mean sooty mould,leaf(stem)rust and Black scurf disease.There are 21 pests of species and 7 species of diseases threatening bamboo's healthy growing,like Takecallis taiwanus,Melanaphis bambusae,Notobitus meleagris,Algedonia coclesalis,Cyrtotrachelus buqueti,Black scurf disease,bamboo leaf(stem)rust and sooty mould.(3)Pests diversity in the four areas: The species(S)from high to low is: Qiangfeng district,Wusheng,Gaoping district and Xichong.In terms of Dominance index(D),Xichong district is significantly higher than other areas,and Qianfeng is the lowest district.The Shannon-Wiener index(H?)is consistent with the trend of the number of species.But there is the highest Pielou' evenness index(J)in Gaoping district,and the lowest is Wusheng district.(4)Pests and diseases similarities in the four areas:(1)Pests: Nanchong and Guan'an city have lower similarity degree,while Xichong and Gaoping in Nanchong city and Wusheng and Qiangfeng in Guan'an city have high similarity degree respectively.(2)Diseases: Nanchong and Guan'an city have lower similarity degree,too.The result of the 4 areas is: Wusheng and Qiangfeng > Xichong and Gaoping >Wusheng and Gaoping > Qiangfeng and Xichong = Qiangfeng and Gaoping >Xichong and Wusheng.(5)Pests similarity clustering analysis in the 4 areas: Gaoping and Xichong in Nanchong city come into a class,Qiangfeng and Wusheng in Guan'an city come into another class,while the two classes finally get together for a broad category.It gives a conclusion that districts form the same city has higher similarity than districts that from different cities.(6)Pests and diseases varieties of different hosts: Bamboo's pests and diseases has significant relationship with it's species and it's distribution area.Different bamboo species have different levels of sensibility to different pests and diseases.In this study,Sinocalamus affinis is the most susceptible species to pests and diseases,it is a widely host and widely infected,too.Phyllostachys bissetii is the next and the next are Phyllostachys bambusoides,Dendrocalamus latiflorus,Phyllostachys heterocycla and Phyllostachys heteroclada.(7)Elevation's effects: Elevation of the studied areas ranges from about 200-1100 m,while the pests and diseases mainly concentrate in the 200-400 m,notably in250-350 m.In this altitude range,pest and diseases is the most widely happened and form the most serious injuries.Lower or higher altitude areas seem to have less happening of pests and diseases.(8)Stand composition's effects: Compared bamboo-only forest with mixture forest,the bamboo-only forest have more pest and disease than mixture forest,that the Gaoping district have the most strongest proofs.Then we did a analysis about Sinocalamus affinis,finding that the stand structure with “ bamboo 60% or bamboo70% ” that have the least pests and diseases.(9)Based on the analysis of the conditions of the forest site(altitude,soil,stand composition),the distribution of bamboo resources and the situation of bamboo diseases and insect pests in the 4 areas:(1)Though the 4 areas have mild climatic conditions,there exist serious soil erosion problems.It is suggested that the 4 areas should increase the use of bamboo in solving the problem of soil and water conservation.(2)Based on the bamboo resources and it's pest and disease status,reconstructions and strengthening resistance of bamboo is needed first,then the further use of it's value,like: edible value and tourism value,etc.(3)According to the altitude and soil's effect,in the early establishment of bamboo forest should take full account of the impact of soil on bamboo plants,and to avoid the altitude of 250-300 m to set up bamboo area,and to avoid using pure bamboo.Detection of soil nutrient content,clearing the branch of insect pest,improving environmental conditions,to ensure the healthy growth of the bamboo forest which has low outputs and efficiency.(4)The prevention and control suggestions of bamboo diseases and pests in the 4 area: Among solutions,take monitoring and prevention actions for priority.Improve site conditions and management methods,and enhance the bamboo area of resistance.All in all,take biological control for the first,and reduce the use of chemical pesticides.