四川盐边县块菌产区优势植物及生态环境对块菌的影响

摘要

Multivariate regression tree (MRT)methodology was used to systematically analyze the effect of dominant plant species and environmental factors on the occurrence of truffles in the Yanbian region of Sichuan Province.A total of 58 seed plant species belonging to 47 genera from 29 families,and four kinds of fern belonging to four genera from four families were identified.The dominant tree species were Pinus yunnanensis,Keteleeria evelyniana,Cyclobalanopsis glauca and Pistacia weinmannifolia,while Coriaria nepalensis,Rhododendron simsii and Rapanea neriifolia were the dominant shrub species. Ageratina adenophora,Eupatorium odoratum and Bidens pilosa were the dominant herbaceous species.The main truffle hosts in the region were P.yunnanensis,K.evelyniana,C.glauca and P.weinmannifolia.MRT revealed that Pteris cretica var.nervosa,A.adenophora,P.yunnanensis,B.pilosa,Juglans regia and P. weinmannifolia were the main plant species affecting the occurrence of tuffles,with P.cretica var. nervosa,A.adenophora and B.pilosa exercising a negative impact and P.yunnanensis,K.evelyniana and P.weinmannifolia a positive effect.Our data also indicated that canopy density,slope,elevation,average tree height and diameter,and average shrub height were the main factors impacting on truffle occurrence. Within our investigation range, truffle occurrence increased with increasing canopy density, elevation, average shrub height and average tree diameter,and decreased with decreasing slope and tree height.%抽样调查了四川省盐边县块菌产区的植物群落优势物种、块菌生态环境情况，用多元回归树方法系统分析了优势物种和生态环境因子对块菌发生的影响。结果表明，盐边县块菌产区的优势物种共有种子植物58种，隶属29科47属，蕨类植物4科4属，该区域植物群落结构不是十分复杂，但呈现出一定多样性，主要优势乔木为云南松(Pinus yunnanensis)、云南油杉(Keteleeria evelyniana)、青冈(Cyclobalanopsis glauca)、清香木(Pistacia weinmannifolia)等，主要优势灌木及草本为马桑(Coriaria nepalensis)、杜鹃(Rhododendron simsii)、密花树(Rapanea neriifolia)、紫茎泽兰(Ageratina adenophora)、飞机草(Eupatorium odoratum)、鬼针草(Bidens pilosa)等。该区域块菌的寄主主要为云南松、云南油杉、青冈及清香木。多元回归树分析结果表明，凤尾蕨(变种)(Pteris cretica var.nervosa)、紫茎泽兰、云南松、鬼针草、云南油杉及清香木是关键的物种影响因子，其中凤尾蕨(变种)、紫茎泽兰及鬼针草表现为负向影响，而云南松、云南油杉及清香木则表现出正向影响。在生态环境因子中，郁闭度、坡度、海拔、乔木平均高、灌木平均高及乔木平均胸径是影响块菌发生的关键因子。在一定范围内，块菌的发生表现出随郁闭度增加、坡度减缓、海拔升高、乔木平均高降低、灌木平均高及乔木平均胸径的增加而增加的趋势。