The Impact Of Natural Forest Succession And Planted Forest Growth On Soil Microorganism Diversity In Greater Xingan Mountains

Soil microorganisms are important components of the global ecosystems.So far,there have been a lot of studies on the effects of vegetation changes on soil physical and chemical properties,but there are very few studies on the effects of vegetation changes in soil microorganisms.Greater Xingan Mountain is one of the four major forest areas in China,and an important part of the global boreal forest.The effects of forest succession and plantated forest growth on soil microbial diversity after burning were helpful to understand the effects of artificial and natural disturbances on the biodiversity of the northern forest ecosystem.In this study,the spatial substitution for time method was used to select the typical sequences of natural forest succession after fire and the planted forest growth.The typical natural forest succession sequences include burnt site,brunch,birch forest,birch-larix mixed forest and the larix plantations include sites with ages of 29,39 and 50 years.The mineral soil(0-10 cm)samples were collected on each typical plot,and the composition of soil fungi,bacteria and archaea was determined by Illumina MiSeq high throughput sequencing technique.With natural forest succession,the Shannon indices of the bacteria was 5.70,5.69,5.90,5.75 and 5.90,showed a trend of increase firstly and decrease at last,then increased again.The Shannon index of the fungi diversity was 2.48,3.78,3.47,2.84 and 3.12,showed a trend of increase firstly and decreases at last,then increased again.The Shannon index of the the archaea diversity was 1.53,1.74,2.12,1.93 and 2.15,showed a trend of increase firstly and decrease at last,then increased again.The Simpson indices of the bacteria was 0.0090,0.0091,0.0128,0.0096 and 0.0091,showed a trend of increase firstly and decrease at last;The Shannon index of the fungi diversity was 0.2403,0.0557,0.0584.0.1758 and 0.0845,showed a trend of decrease firstly and increased at last,then decrease again.;The Shannon index of the the archaea diversity was 0.4537,0.2541,0.2229,0.2389 and 0.2460,showed a trend of decrease firstly and increase at last.In the natural forest succession,the main bacteria were Proteobacteiria,Acidobacteria,Actinobacteria and Planctomycetes,all of which showed the trend of increase firstly and decrease at last;the main fungi were Ascomycota,Basidiomycota and Zygomycota,in which Ascomycota showed a trend of decrease firstly and increase at last,the other two had an opposite trend;the main archaea were Crenarchaeota and Euryarchaeota,in which Crenarchaeota showed a trend of increase firstly and decrease at last and Euryarchaeota had an opposite trend.With plant forest growth,the Shannon index of the three soil samples was 5.92,5.66 and 5.89,showed a trend of decrease firstly and increases at last.The Shannon index of fungal diversity was 3.25,1.95 and 3.04,showed a trend of decrease firstly and increases at last.The Shannon index of the colony diversity was 1.82,2.05 and 1.45,showed a trend of increase firstly and decrease at last.The Simpson indices of the bacteria was 0.0077,0.0112 and 0.0080,showed a trend of increase firstly and decrease at last;The Shannon index of the fungi diversity was 0.1797,0.3108 and 0.1063,showed a trend of decrease firstly and increased at last,then decrease again.;The Shannon index of the the archaea diversity was 0.2847,0.2426 and 0.4637,showed a trend of decrease firstly and increase at last.In the planted forest growth,the main bacteria were Proteobacteria,Acidobacteria,Actinobacteria,Bacteroidetes,all of which showed the trend of decrease firstly and then increase at last;the main fungi were Basidiomycota,Ascomycota,Zygomycota,in which Basidiomycota showed increase firstly and then decrease at last,and the other two had an opposite trend;the main archaea were Crenarchaeota and Euwyarchaeota,in which Crenarchaeota showed a trend of decrease firstly and increase at last and Euryarchaeota had an opposite trend.For the two vegetation types,communities of bacteria,fungi and archaea were different from PCA analysis.From RDA analysis,the communities of soil bacterial,fungal and archae changes were affected by soil organic carbon,total nitrogen,total phosphorus and pH.This research could add new insights into the effects of natural forest conservation and artificial afforestation on boreal forest biodiversity.