Analysis On The Present Situation Of Forest Diseases And Pests And Prediction Of The Spatial Distribution Of Major Diseases And Pests In Shishi

Forest protection is the key to national reserve wood security and ecological security.Forest pests and diseases not only affect the structure of the existing forest ecosystem but also bring huge economic losses.This research takes Shishi city as the research area,and through field surveys,we grasp the types,occurrence,and distribution of forest diseases and insect pests in Shishi city.And we use the Max Ent model to predict the potential distribution of the main diseases and insect pests affecting the forest of Shishi,including Poliotelium hyalospora(Saw.)Mains,Poophilus costalis Walker,Clania minuscula Butler and Odontotermes formosanus Shiraki.And we try to explore the influencing factors of its occurrence,and finally put forward comprehensive control strategies for diseases and insect pests,with a view to providing a reference for regional forest pest and disease protection.The main findings are as follows:(1)There were 87 species of pests and diseases in Shishi city,of which 31 species of forest diseases were mainly fungal diseases,accounting for 87.08%;56 types of forest pests were dominated by hemiptera and lepidopteran insects,accounting for the proportions were 44.62% and 35.72%.(2)The most severely affected species in Shishi city were Casuarina equisetifolia Forst.,Cinnamomum camphora(Linn.)Presl.,Pinus massoniana Lamb.,and Podocarpus macrophyllus(Thunb.)D.Don,Ficus altissima,Acacia confusa Merr.,Cycas revoluta Thunb.,Dimocarpus longan Lour.,Kandelia candel(Linn.)Druce etc.Among them,Dimocarpus longan Lour.and Pinus massoniana Lamb.were the most common types of pests and diseases,with 12 and 10 types of pests and diseases respectively.Summer was a period of high incidence of pests and diseases,with the most types of pests and diseases occurring,21 species,and the lowest in winter,only 5 species.Among the townships,Lingxiu had the most types of pests and diseases,with a total of 52 species.(3)Based on 17 environmental factors such as climate,temperature and altitude,the Max Ent model was used to predict the spatial distribution of diseases and insect pests of Poliotelium hyalospora(Saw.)Mains,Poophilus costalis Walker,Clania minuscula Butler and Odontotermes formosanus Shiraki in Shishi City,which have highly frequency in the field survey.The results showed that Hanjiang Town,Xiangzhi Town,Hongshan Town and Yongning Town have high-adapted forecast distribution;and the of Clania minuscula Butler has wider high-adapted area in Shishi,followed by Poliotelium hyalospora(Saw.)Mains.(4)Elevation has the greatest impact on Poliotelium hyalospora(Saw.)Mains.Temperature and precipitation in summer are important environmental impact factors for the potentially suitable distribution areas of Poophilus costalis Walker,Clania minuscula Butler and Odontotermes formosanus Shiraki.We recommended to take corresponding early warning and prevention measures against those diseases and insect pests in spring and summer.