Changes Of Leaf Litter Carbon Compounds And Their Relationship With Phyllosphere Microbial Community During Decomposition

After vegetation restoration on the Loess Plateau,there is an increasing need for improving the ecological service function of forest ecosystem.One of the essential target is to deepen the understanding of C turn over from leaf litter into soils,which contribute to important C cycle in forest.In order to develop the carbon sequestration capacity,the act of microorganisms in the forest leaf litter during decomposition process is urgently required.Phyllosphere microbial community of leaf litter decomposition plays a significant role in organic matter decomposition and nutrient cycling in forest ecosystem.From micro-ecology pint of view,leaf litter decomposition is the core and basis for the ecological restoration in the area of the Loess Plateau.In order to go through all the above mentioned points we designed a proper research plan and have been doing the investigation.The investigation mainly focus on: i)The change of typical forest communities in leaves during the decomposition of nutrients stoichiometric ratio and structural carbohydrates;and ii)The relationship between phyllosphere microbial community structure and leaf litter nutrients during decomposition.The experiment was carried in Ziwuling forest,Loess Plateau,China.Three broad leave tree: CL(Cihuai litter or Locust litter),LL(Liaodong Oak)and SL(Shaoyang litter or Aspen leaf litter)were selected as targeting leaf litter.The decomposing litter bag method was implemented and leaf litters were analyzed for the nutrients(C,N,P)changes,(C:N:P)ratio and carbohydrate compounds dynamics.In addition,high throughput sequencing based Illumina platform was used for microbial community analysis.The overall results of the study are summaries below:1)Substantial leaf litter C losing was detected at the first 6 months and then it decline constituently and nitrogen fluctuated throughout the decomposition process.However,phosphorus had high losing rate at the end of decomposition.And the nutrients ratios declined with decomposition.2)Decomposing time was more influential factors for both primary nutrients and structural carbohydrate than tree species and it shows a significant difference over the decomposition periods.3)In terms of microbial community diversity and richness,locust and oak leaf litter at the10 and 12 months decomposing were outnumbered comprising with the rest samples.Proteobacteria and Actinobacteria are the most dominant bacterial phyla.Fungal communitydiversity indices illustrate that samples decomposed around one year(10 to 12 months)had very high trends in both;richness and diversity.Moreover,Ascomycota and Basidiomycota were the largest dominator phyla among fungal communities.4)There are a significant positive correlation between microbial communities and leaf litter's nutrients(primary nutrients and structural carbohydrates).5)Carbohydrate and amino acid metabolism were the highly stimulating functions during8-10 months leaf litter decomposition,followed by up by the xenobiotics biodegradation and metabolism,lipid metabolism and energy metabolism.For further study in this area,it is suggested in order to deeply understand and find out more reasonable results for scientific evidences,the likewise analysis should be done in soil from the same plats.It will provide more accurate and comparative data.