Soil Microbial Community Structure And Its Influencing Factors Under Different Land Uses

The soil microbes play an important role in terrestrial ecosystem,and regulate the biogeochemical cycle process.Meanwhile,the soil microbes is sensitive to land use change and have different responses for these changes in soil system.We selected the two point of view that the conversion from natural secondary forest(SF)to larch plantation(LP),farmLand(FL),bareland(BL)and afforested the four tree species(korean pine plantation,poplar plantation,larch plantation,mongolian pine plantation)from abandoned land on coal-mining depression land,to determine the several soil physicochemical property such as soil organic carbon,total nitrogen,pH,soil moisture,bulk density and phenols(total phenol,complex phenol,water-souble phenol),phenolic acids(ferulic acid,2,4-dihydroxybenzoic acid,7-hydroxycoumarin,Abietic acid and other 11 phenolic acids),and soil microbial communities(PLFA method)to discuss the response on microbial communities under the land use change,and analyse the influencing factor of microorganisms.The results are as follows:(1)The soil nutrient content was highest in SF,and decreased with the increase of depth.The total phenol and water-souble phenol content was highest in LP,and higher than others land use significantly,however there was no difference between different depths.The phloroglucinol,Shikimic acid,Cinnamic acid and ?-sitosterol content were higher than others phenolic acids in four land uses.The ferulic acid,2,4-dihydroxybenzoic acid,?-sitosterol,linoleic acid and phloroglucinol content were highest in SF than oher three land uses.The ferulic acid,2,4-dihydroxybenzoic acid,7-hydroxycoumarin,?-sitosterol and linoleic acid content decreased with the increase of depth.The total PLFA and bcateria were higher LP than others land uses in 0-5 cm,but the SF was better than others in 5-20 cm.the microbial PLFAs were higher than FL and BL in the whole.(2)The change of soil nutrient content was biggest in poplar plantation and performance best among four species,however were worst in mongolian pine plantation.Similar to Fendou forest farm,the total and complex phenol were highest and there had a contrast trend between complex and water-souble phenol,that further demonstated the complex and water-souble had sustained a dynamic balance.(3)In soil physicochemical property aspects,whether in Fendou forest farm or on coal-mining depression land,the soil organic carbon and total nitrogen had a positive relation with fungi and fungi:bacteria(F:B)significantly(0-10 cm in Fendou forest farm,0-20 cm in on coal-mining depression land).And the total nitrogen and phosphorus had a positive relation with fungi communities significantly in 10-20 cm in Fendou forest farm,particularly total phosphorus had a strong effect with microbes.In soil phenols and phenolic acids aspects,the results demonstated that the total phenol showed to a positive relation in 0-5 cm and had a negative relation in 5-10 cm with soil microorganisms respectively.The phenol had a stronger effect than soil physicochemical factors with microbial communities by redundancy analysis.However,the three pheonls had no obvious relation with microorganisms in on coal-mining depression land,may be the afforestation time was too short.(4)Comprehensive the result of cluster analyse about 11 kinds of phenolic acids and soil microbial communities in Fendou forest farm and coal-mining depression land,the ferulic acid and?-sitosterol had promoted the soil microbes,particularly fungi and F:B.The phloroglucinol and linoleic acid had no or a weakness effect on microorganisms and the cinnamic acid had an inhibiting effect.Our study discussed and analysed soil nutrient,phenolic acids and soil microbes and the influence factor of microorganisms,thought soil carbon had a strong effect on fungi,and we found phenols,ferulic acid and ?-sitosterol had an important effect on microbial communities and composition after comparsion and analyse in soil phenols and phenolic acids aspects.This had important meanings for scientific and sustainable forest management in this region in future.