可培养土壤微生物数量与红松活立木干基腐朽程度的关系  

Relationship Between Cultural Soil Microbial Quantity and Butt Decay Degree of Pinus koraiensis Standing Trees

作　　者：徐华东[1] 狄亚楠 曹延珺 王立海[1] 王海滨[1] Xu Huadong;Di Yanan;Cao Yanjun;Wang Lihai;Wang Haibin(Northeast Forestry University,Harbin 150040,P.R.China)

机构地区：[1]东北林业大学,哈尔滨150040

出　　处：《东北林业大学学报》2019年第1期52-55,共4页Journal of Northeast Forestry University

基　　金：国家自然科学基金项目(31570547;31870537);黑龙江省自然科学基金项目(E2016002);中央高校基本科研业务费专项基金项目(2572016CB14);哈尔滨市应用技术研究与开发项目(2017RAOXJ078)

摘　　要：在五营国家森林公园建立的样地内,利用无损检测技术选取存在腐朽的典型红松活立木作为样木。在样木根部四周0～20 cm深度处采集土样,采用传统培养法对土壤微生物进行分离培养并计数。同时,使用树木生长锥取样木的健康和腐朽试样木芯,通过测定木芯质量损失率,量化表征红松活立木干基腐朽程度。采用逐步回归分析和通径分析方法,量化研究不同种类微生物数量和红松活立木干基腐朽程度之间的关系。结果表明:腐朽红松根部土壤细菌数量最多,占绝对优势,放线菌次之,真菌数量最少;土壤真菌数量和放线菌数量与红松活立木干基腐朽程度存在正相关关系(R^2=0.504,p=0),真菌的直接正效应贡献(直接通径系数P_(2y)=0.413)大于放线菌(P_(3y)=0.407);土壤细菌数量对红松活立木干基腐朽的直接贡献不显著(P_(1y)=-0.312,p=0.106>0.05),但是细菌数量通过影响真菌的数量,对红松活立木干基腐朽具有间接负效应贡献(间接通径系数P_(x1-x2)=-0.225)。For internal reason of butt decay of Pinus koraiensis standing trees,the relationship between soil microorganisms quantity and butt decay degree of standing trees was discussed.A non-destructive test method was employed to evaluate internal decay condition of P.koraensis standing trees and select tree specimens at sample plots in Wuying National Forest Park.Soil samples that collected at root of each tree were used to isolate soil microbes.The number of soil microbes was counted by a traditional culture method.At the same time,three increment cores(one is intact,and the other are decay)from each tree specimen were obtained and used to measure weight loss,and then determine butt decay degree.Finally,the relationship between butt decay degree and soil microbial quantity was analyzed by stepwise regression analysis and path analysis method.There were large differences in quantity of bacteria,actinomycetes and fungi at root soil under trees specimens.The quantity of bacteria in soil was much more than actinomycetes and fungi.Fungi and actinomycetes were positively correlated with butt decay degree(R^2=0.504,p=0).As known from path analysis,the direct effect of fungi(direct path coefficient P2y=0.413)was greater than actinomycetes(P3y=0.407).The direct effect of bacteria on butt decay degree was not significant(P1y=-0.312,p=0.106 >0.05),but it had a negative effect on butt decay degree by affecting fungi number(indirect path coefficient Px1-x2=-0.225).

关 键 词：红松 活立木 干基腐朽程度 土壤微生物 

分 类 号：S718.521.3[农业科学—林学]