Effect Of Soil Microorganisms On Trunk Decay In Pinus Koraensis Standing Trees

The phenomenon of microorganisms causing the decay of living trees is prevalent in forest ecosystems.Although it is a common natural phenomenon,it poses a great threat to the health and value of forest ecosystems.In the investigation of the decay in living trees,it is found that there is a different in the probability of the occurrence of decay in the forest,which indicates that the ground conditions are closely related to the decay of the living trees.The Pinus koraiensis is mainly distributed in Changbai mountain to xiaoxing anling forest region,which is one of the dominant tree species in the northeast region,and also a precious protected species,with high ecological and economic value.In recent years,a lot of studies have found that many of the Pinus koraiensis in xiao xing’an mountains have been found to be seriously corrupt.Therefore,the paper taking the Pinus koraiensis in Liangshui nature reserve as the research object,preliminarily studied the relationship between the decay degree of Korean pine and the soil microbial characteristics,in order to provide theoretical basis and new ideas for prevention and treatment of Pinus koraiensis.The main research contents of this paper include:(1)Detection of decay degree of Korean pine.Using visual method and resistograph to find the corrupt Korean pine,and the wooden cores were drilled and back to the lab to measure weight loss ratios as the decay degree of Korean pine.(2)Effects of soil physical and chemical properties on soil microorganism.Soil physical and chemical properties and microbial characteristics(soil microbial quantity and species diversity)were measured,and the effects of soil physical and chemical properties on soil microbial characteristics were studied.(3)Study on the relationship between soil microbial characteristics and the decay degree of Korean pine trunks.According to the data measured before,combined with the influence of environmental factors and soil physical and chemical properties,the influence of soil microbial quantity and diversity on the decay degree of Korean pine trunks was discussed.The results showed that:(1)The weight loss rate of the wood core of was from 0-48.3%,indicating that the Korean pine in the Liang shui Nature reserve has different degrees od decay.(2)Soil microbial quantity and diversity were related to the soil physical and chemical properties.But the conclusions were different under different conditions.(3)In the 10 soil samples,we got 1496 fungal OTU and 1413 bacterial,and identified 203 known fungi species and 34 known bacteria species,fungi had more species than bacteria.Alfa diversity index(PD_whole_tree and Rank abundance)indicated that the diversity of fungi was higher than that of bacteria and the distribution of species was not uniform,the dominant species is relatively high.(4)Correlation analysis of Alfa diversity and decay degree of Korean pine showed that both fungal Alfa diversity and bacterial Alfa diversity had no significant coirelation with decay degree of Pinus koraiensis.One sample T-test showed that there was no significant difference in fungal alfa diversity between decay Pinus koraiensis and the healthy tree(Sig.(2-tailed)=0.062>0.05),and bacterial diversity(Sig.(2-tailed)=0.195>0.05)also had no significant difference between decay wood and the healthy one.