Impact of canopy and seasonal dynamics on oak and pine soil microbial community composition and other biological indicators in Garhwal Himalayas

摘要

The oak and pine litter influenced top soil (0-10cm) microbial communities were investigated for soil dehydrogenase enzyme assay (DHA), microbial biomass carbon (MBC), organic carbon (OC) and phospholipid fatty acid (PLFA) analysis in summer as well as in winter. The canopy cover and season in Garhwal Himalayas significantly affect soil DHA, MBC and OC. The study also reveals the impact of quality of different litter (Oak and Pine) on specific groups in the microbial community with respect to different season. For oak and pine soils, in summer the relative abundance of PLFAs were significantly higher than winter. Ratio of Gram-positive to Gram-negative bacteria and the fungal PLFAs in oak soil is significantly higher as compared to the pine soil. Actinomycetes PLFA lOMe 16:0 fractions were affected by season for oak soils. Pine soils in winter shown higher values of bacterial stress condition (ratio of cyl9:0 to 18:lw7c) as compared to oak soils. The principal component analysis (PCA) of relative abundance of PLFAs for summer and winter season showed variation. Canonical correspondence analysis shows the relation of pH, moisture, temperature and organic carbon on individual PLFAs. Soil metabolic status by dehydrogenase enzyme assay, viable carbonstatus by microbial biomass carbon, soil easily available carbon by organic carbon and microbial community composition of oak and pine litter influenced soil were studied. The results indicates how the relative abundance of microbial groups change with respect to canopy and season, however other microclimatic factors which regulate microbial diversity need to be study extensively.