Analysis And Forecast Of Typical Forestry Diseases

Spruce(Picea)and pine(Pinus tabulaeformis,Pinus armandii)are the dominant tree species in Wenzhou county and Maoxian county of Aba Prefecture.The needle-cast disease of spruce and the blight disease of pine are their main diseases,and the occurrence of these diseases is serious in the local,which has a great negative impact on the ecological construction and sustainable development of forestry in Wenzhou county and Maoxian county.In view of this situation,this paper mainly made the following aspects of the study.(1)In order to predict the diseases of spruce and pine in Wenzhou county and Maoxian County timely and accurately,this paper used Arc GIS and other tools to deal with the year of 2015's remote sensing monitoring results of spruce and pine diseases in Wenzhou county and Maoxian County intersecting with geographic conditions census data,and combined with historical data provided by the local forestry department and meteorological department to analyze the main factors affecting the occurrence of spruce and pine diseases such as topography,stand structure,soil type and human activities.(2)In order to master the law of spruce and pine diseases in the study area,this paper made reasonable prediction of the occurrence trend of spruce and pine diseases in the next few years.In this paper,I used the mathematical statistics methods such as Markov chain combined with the historical data of spruce and pine diseases in Wenzhou County from 2003 to 2014,to predict and verify the incidence of the disease in 2015.(3)The needle-cast disease of spruce and the blight disease of pine are all caused by fungus,which is deeply influenced by the meteorological factors.This paper used the principal component regression method and stepwise regression method to deal with meteorological data,such as temperature,precipitation and other meteorological factors to predict the happening of the disease area,created the corresponding prediction models,and selected the appropriate disease prediction model through the forecast precision.The results show that the spruce and pine diseases in Wenzhou county and Maoxian counties of Aba Prefecture are mainly affected by the temperature and rainfall in the local plantation from May to July.At the same time,the topography factors such as elevation,slope and slope direction,Age group,canopy density and other factors,as well as roads and water systems,soil types and other environmental factors also have an important impact on the spruce and pine diseases.Finally,based on the correlation analysis with regression analysis,the prediction models of spruce and pine diseases in Wenzhou County was established,which predicted the value of occurrence of spruce and pine diseases in 2014 and 2015,and the prediction accuracy is more than 80%.The main contents of this paper are as follows:(1)From the standpoint of forest stand,topography and geographical conditions' point of view,this paper explores the effects of these factors on the diseases of spruce and pine,and analyzes the characteristics of spruce and pine diseases in the study area in 2015,and explains the necessary conditions for diseases' occurrence;(2)According to the data of the area of disease occurrence and the meteorological data collected over the years,the Markov chain method was used to predict the occurrence degree of spruce and pine diseases in Wenzhou county.(3)Two regression analysis methods including component regression method and stepwise regression method were used to analyze the occurrence area of spruce and pine diseases.And The results of the prediction will provide the theoretical basis for the prevention and control of pests and diseases in the study area.