昆嵛山林区赤松赤枯病病基指数模型

The Disease Based Index Model of Needle Blight Disease of Japanese Red Pine Kunyushan Mountains,China

【目的】构建赤松赤枯病病基指数(Disease based index,DBI)评价体系,定量评价与林分因子共同作用后,立地因子对赤松纯林中赤枯病发生程度的作用等级。【方法】在林龄相对一致(34±2)年的赤松纯林生态系统中设立临时样地,筛选影响赤松赤枯病发生的关键林分因子,建立关键林分因子与赤枯病病情指数的函数关系,选取最优模型作为主曲线;将主曲线等比值拉伸得赤枯病病基指数曲线群,其自下而上依次表示不同的病基指数,即立地对赤枯病发生程度的作用等级。【结果】1)基于森林病害发生的基本原理,提出病基指数的概念。2)确定赤松赤枯病病基指数的定量方法,它包含样地的设立、病情指数的调查、林分因子的调查、关键林分因子的筛选、基准点的确定、备选主曲线模型的建立、主曲线模型的确定和评价、主曲线的绘制及曲线群的建立共9个步骤。3)逐步回归分析表明,林分密度是影响赤松赤枯病发生的关键林分因子,依据所提定量方法建立主曲线方程:Q=65.61/(1+e-0.0015 x+2.32),决定系数R2=0.5198,说明拟合方程较可靠,用该模型预估赤松赤枯病的病情指数时,平均预估误差是5.35%。4)将赤枯病病基指数主曲线等比值拉伸得曲线群,即建立定量评价体系。体系中的5条曲线自下而上分别表示为:Ⅰ为极轻病害发生,Ⅱ为轻度病害发生,Ⅲ为中度病害发生,Ⅳ为重度病害发生,Ⅴ为特重度病害发生。【结论】赤松赤枯病病基指数主曲线模型和曲线群图可以定量评价赤松林的立地因子对赤枯病的潜在发生程度的作用等级,可为赤松纯林合理、有效的管理提供理论基础,将成为森林有害生物生态控制方法的重要组成部分。

【Objective】This paper aims to quantitatively evaluated the effects of site factors on the occurrence degree of Japanese red pine(JRP)needle blight disease in pure pine forests,by constructing the disease based index(DBI)evaluation system of the pine disease.【Method】Based on the main principles of forest disease occurrence,the result affecting the occurrence of JRP needle blight were attributed to the comprehensive effect of stand factors and site factors.Temporary sample plots were set up in the pure forest ecosystem of Japanese red pine with relatively consistent forest age(34±2 a)to screen the key stand factors affecting the occurrence of pine needle blight,establish the functional relationship between the key stand factors and the disease severity index of pine needle blight was established,and the optimal model was selected as the guide curve.The DBI curve group of pine needle blight was obtained by stretching the guide curve in an equal proportion,which in turn showed different disease based indexes from the bottom to the top,that is,the action level of the site on the occurrence degree of pine needle blight.【Result】1)Based on the mainprinciple of forest disease occurrence,the concept of disease based index(DBI)was proposed.2)The quantitative method of disease based index of JRP needle blight was determined,which contained contains 9 steps:set the plots,investigate the disease severity index of stands,investigate the stand factors,screen the key stand factors,determine the datum of stand factors,establish alternative guide curve model,determinate and evaluate guide curve model,draw the guide curve as well as establish the curve groups.3)Stepwise regression analysis showed that stand density was the key stand factor affecting the occurrence of JRP needle blight.The guide curve equation was established according to the proposed quantitative method:Q=65.61/(1+e-0.0015 x+2.32),and the determination coefficient R 2=0.5198,indicating that the fitting equation was reliable.When this model was used to estimate the disease severity index of JRP needle blight,the average estimation error is 5.35%.4)A quantitative evaluation system was established by stretching the main curves of the disease base index of red spot blight in equal proportions to form a curve group.The 5 curves of the system from bottom to top were:Ⅰ-light disease occurs,Ⅱ-mild disease occurs,Ⅲ-moderate disease occurs,Ⅳ-severe disease occurs,Ⅴ-especially severe disease occurs.【Conclusion】The guide curve model and curve group diagram of the disease based index of Japanese red pine needle blight can quantitatively evaluate the effect of site factors on the potential occurrence degree of pine needle blight,which can provide a theoretical basis for rational and effective management of pure Japanese red pine forest,and will become an important part of the ecological control method of forest pests.