Research Advancement in Responses of Soil Microbial Residues of Tropical Forest to Increased Nitrogen Deposition
Soil carbon dynamics is closely related to soil microbial process. Nitrogen deposition produces direct or indirect effect on soil microorganisms and consequently affects Soil C transformation and cycling. Microbial residues are important source to soil C pool and play essential role of soil C accumulation in long terms. Amino sugar is a biomarker of microbial residues and its accumulation and transformation is an indicator of soil organic C transformation process by microorganism. Till now, the research on the effect of N deposition on soil C dynamics has been focused on temperate forest of North sphere where N supply is limited. Little attention was paied to tropical forest where N is saturated.
Prof ZHANG Xudong and Prof HE Hongbo in the Research Group of Matter Cycle with their coworkers investigated the effect of N addition on soil microbial residues in a tropical research station-Dinghushan station using amino sugar as biomarker. It was found that N addition did not affect soil fungal and bacterial residues, but high rate (150 kg N ha-1yr-1) significantly reduced the contribution of microbial residue to the soil organic C. The results illustrated the changes in the contribution of microbial residues to soil organic C pool have important indication role in the prediction of the effect of global changes to soil carbon pool.
The results were published in Soil Biology & Biochemistry entitled as High Nitrogen Deposition Decreases the Contribution of Fungal Residues to Soil carbon Pools in a Tropical Forest Ecosystem. The work was supported by a 973 project (No. 2014CB954400), NNSFC (（No. 41571238, 41571237） and Special Biology Project (No. XDB15010303).