Influence Of Change Carbon Input On Soil Microbial Quantity And Enzyme Activity In Cinnamomum Camphora Plantation

Soil microorganism are main parts of the forestry ecosystem, and play vital roles in energy conversion, material cycling, development and maturation of soil. Soil enzyme plays an important role in the ecosystem, soil enzyme activity performance is a direct reflection of the strength and direction of soil biochemical processes. The number of microorganisms, organic matter content are closely related to the size of soil enzyme activity. Cinnamomum Camphor is a representative of subtropical evergreen broadleaf forest species. In this study, we treated with five treatments and control (CK), extra litter addition with root (LAR), litter removal with root (LRR), extra litter addition without root (LANR), litter removal without root (LRNR), control without root (CNR). We use traditional isolation methods to investigate soil properties, soil microorganism quantity, soil enzymes activity, and analysis the relation was conducted between the number of microorganism quantity and soil enzyme activity of the forest ecosystem,(1)CK:Total C (15.28mg-g-1), Total N (1.49mg-g-1), C/N (10.20), water content (22.46%). Total C:LAR reaches maximum value (23.94mg-g-1), CNR reaches minimum value(13.85mg-g-1). Soil total C content increased under add litter, soil total C content decrease without of roots. LRNR reaches maximum value (2.10mg·g-1), Soil total N content increase under litter removal without root. Soil C/N increase under add litter, LAR reaches maximum value (12.69). Soil C/N decreased under removal of roots, CNR reaches minimum value (8.64). Soil water content increase under add litter. LANR reaches maximum value (23.16%)(2) Microorganism quantities under CK, LRR showed that bacteria> actinomycetes>fungi; Microorganism quantities under LAR, LANR, LRNR, LRR show that bacteria>fungi>actinomycetes. Number of bacteria and fungi increased under add litter (LAR>LRR, LANR>LRNR); Number of bacteria and actinomycetes decreased under removal root (LAR>LANR, LRR> LRNR, CK>CNR). Number of bacteria under removal root decreased in April, July and October (CK>CNR); root has negative effect on number of fungi after removal litter in April, July, October (LRNR>LRR). Number of actinomycetes decreased under add litter (CK>LAR) The root and litter simultaneously effect on the number of microorganisms had obvious positive efficiency.(3) Protease, dehydrogenase, acidic phosphatase and urease activity improve under add litter (LAR>LRR, LANR>LRNR);protease, dehydrogenase, acidic phosphatease and urease activity declined under removal litter (CK>CNR). Root effect on Catalase activity had obvious negative efficiency under removal litter or add litter.(4) Correlation analysis of soil properties and microbial quantity showed that LAR, LRR:Actinomyces had significant negative correlation with total C, total N and C/N. CK, CNR:Fungi had significant positive correlation with total C and C/N. LANR, LAR, LRNR, LRR:Actinomyces had significant negative correlation with total N. Actinomyces, fungi and soil total microorganisms had positive correlation with soil water content under five treatments and CK. Therefore, actinomyces is suggested as the biological indicators of soil organic matter.(5) Correlation analysis of soil properties and enzyme activity showed that LAR, LRR:Acidic phosphatase has significant negative correlation with total C, total N and C/N. CK, CNR:Proteinase, Acidic phosphatase, dehydrogenase had significant positive correlation with C/N. LANR, LAR, LRNR, LRR:catalase had significant positive correlation with total C, C/N. Proteinase had positive correlation with soil water content under five treatments and CK. Therefore, catalase and Acidic phosphatase are suggested as the biological indicators of soil organic matter.(6) Correlation analysis of enzyme activity and microbial quantity showed that soil microbial quantity had correlation with four soil enzymes (Proteinase, dehydrogenase, urease, Acidic phosphatase), without catalase. LAR, LRR:soil microbial quantity had significant negative correlation with four soil enzyme. CK, CNR:Proteinase had significant correlation with actinomyces, fungi. Dehydrogenase, urease, Acidic phosphatase had significant correlation with actinomyces, fungi and total microbial quantity. LANR, LAR, LRNR, LRR:Bacteria, total microbial quantity had significant positive correlation with four soil enzymes. Therefore, soil enzyme activity is suggested as the biological indicators of microbial quantity.