Relationship Between Ecological Stoichiometric Characteristics And Fungal Diversity Of Fallen Logs And Soil

Fallen logs,as an important component of forest ecosystem,not only can provide habitat for forest biodiversity,but also can be an important nutrient reservoir.And forest soil provides a natural habitat for the survival and reproduction of animals,plants and microorganisms.Based on the theory of ecological stoichiometry and forest ecology,the ecological stoichiometric characteristics of evergreen broad-leaved forest,coniferous broadleaved mixed forest and mountain coppice,were studied quantitatively in this paper.High-throughput sequencing and direct gradient analysis were used to analyze the fungal species composition and fungal diversity of fallen logs and surface soil during the decomposition of fallen logs in different forest types.The relationship between C:N:P and fungal diversity in fallen logs and surface soil was further explored.The results are as follows:(1)In terms of abundance and important value of fallen logs,the dominant tree species of the whole community were Cyclobalanopsis glauca,Prunus hystrix and Castanopsis eyrie.Castanopsis hystrix is a common dominant tree speices of falle logs in both evergreen broadleaved forest and coniferous broadleaved mixed forest,and the dominant tree species in mountain coppice are Cyclobalanopsis glauca and Ligustrum lucidumum.(2)There was a significant difference in the ecological stoichiometric characteristics of forest soil in different forest communities.The differences of the organic carbon content,the total P content,N/P and C/P between different forest communities were extremely significant(P < 0.001).The total N content and C/N were significantly different among different forest communities(P < 0.05).Except organic carbon content,the total P content,N/P,C/N and C/P,there was a extremely significant difference between different forest communities(P < 0.001),and the total N content was significantly different(P < 0.05).(3)The sequencing of Illumina platform revealed that there were 80491 OTUs of fungi in fallen logs in three forest communities,which belonged to 10 phylums,32 classes,126 orders,319 families and 990 genera.There were 46936 OTUs of soil fungi,belonging to 11 phylums,38 classes,134 orders and 134 families.In terms of fungal endemic genera and diversity in fallen logs,the evergreen broad-leaved forest was the most.The endemic genus and diversity of soil fungi in coniferous and broad-leaved mixed forest were the most.The endemic genera and diversity of fungi in mountain coppice were the least,whether in fallen logs or in soil.(4)The analysis of canonical correspondence(CCA)revealed that altitude,P content of soil and pH of fallen logs were the main factors affecting the wood fungi diversity and distribution.There was a significant correlation between the diversity of fallen logs and the diversity of soil fungi.Take Ligustrum lucidum as an example,the species and the number of dominant genera of fungi were changing with the decomposition of fallen logs.There was a significantly negative correlation of chao1 index between fallen logs and soil fungi(P < 0.05).There was a significantly positively correlation between chao1 index of fallen logs and simpson index of soil(P < 0.05).There were nine common families and four common genera in the fallen logs and soil fungi.In general,there were differences in C:N:P and fungal diversity among different forest community types.The correlation between the physical properties and C:N:P differed among different forest community types,and the correlation between C:N:P in fallen logs and C:N:P in forest soil was significant.Altitude,P content of soil and pH of fallen logs were the main factors affecting the wood fungi distribution.and diversity.There was a certain correlation between fungal diversity in fallen logs and soil fungal diversity.