In Xiaolong Mountain National Nature Reserve Of The Introduction Of Alien Species Japanese Larch Microbial Characteristics Study

The exotic tree species have been used to restore forest coverage over China and the world.Most previous studies focused on the affects of the exotic species on plant and animal community structure and original biodiversity and the exotic herbal plants were further found to affect the subsoil microbial diversity and function.Howeverm,few was made on how the exotic tree species influenced the local soil bacterial biomass or community structure.This study reported the relationship between soil microbial diversity and microbes of three main soil microbes about the introduced exotic-fast-growth tree species Japan Larch(Larix Kaempferi),Main results are summarized as follwing:(1) The Features of Microbial community structure of Larix kaempferi PlantationBy investigation of the distribution status of soil Microbiota,we find the bacteria having higher hydrolytic ability takes up a large proportion and Separation 6 kinds.of which Staphylococcus,Azotobacter was the kind of ascendant bacteria,Flavobacterium is Rare species.The quantity and Micro-organisms of actinomyces have a large differences and Separation 1 kind.In the all of fungi, There are only two species in the whole,Streptomyces,of which the dominant are Penicillium and Aspergillum.,and Rhizopus is the second.Alternaria was respectively distributed in 7 samples and 8 samples.From bacteria, fungi and actinomycetes number of micro-organisms account for a proportion of total,The greatest quantity of bacteria,actinomycetes second,smaller number of fungi.The total quantity of soil microbe of surface layer(0～10cm) is 10149.42×106 ind./g·dry soil,which middle layer(10～20cm) is 5336.872×106 ind./g·dry soil and under layer(20～40cm) is1896.08×106 ind./g·dry soil.That's the surface layer is middle level 1.9 times and under level 5.35 times.Bacterium occupies the overwhelming superiority.Each kind of soil microbe in different sampling points varies greatly.(2) Main physiological group of Soil bacteriaThe main physiological groups of soil bacteria have monitoring results in different areas.The overall performance is:Ammonifying bacteria＞Organic phosphorus decomposing bacteria＞Nitrogen-fixing bacteria＞Solution of potassium silicate bacteria＞Nitrite bacteria＞Cellulose-decomposing bacteria＞Nitrobacteria＞Sulfide bacteria. (3) The study on the diversity of soil microbial community of Larix KaempferiMicrobial community in the soil were analyzed and compared by species richness index,diversity index and evenness index.The result showed that Species Composition,Quantity Variation and Bio-diversities of different invironment of soil microbial community differed.The diversity index of different area displayed that Sample.7＞Sample.4＞Sample.5＞3 Sample.＞Sample.1＞Sample.9＞Sample.2＞Sample.6＞Sample.10.(4) Relation between soil microbial diversity and environment factersCorrelation analysis indicates that there exists a significant or highly significant relationship between the soil microorganisms and soil PH,soil moisture content.The quantity of actinomyces has a significant relationship with soil PH;The quantity of fungi has a significant relationship with soil moisture content,and has a less relationship relationship with soil PH.Soil microorganisms In physiological groups,Nitrobacteria has a significant relationship with soil PH and less relationship with soil moisture;Sulfide bacteria has a less relationship with soil PH,others have't significant correlation.Age of tree has a significant relationship with quantity of the soil microorganisms and less relationship with Elevation.