矮林樟树氮素利用的根际生态学研究

Nitrogen is one of the important nutrients for plant growth. Microbial diversity and functional microbiology play a vital role in nitrogen transformation process. In addition to the ecological stability and environmental function, Cinnamomum camphora is raw materials for extract camphor oil. So there is short of raw materials in practice. Coppice cultural style is an important way to resolve this contradiction. This project was based on the previous survey results: 1) with the increases of the years of coppice culture, biomass showed a gradual decreasing trend; 2)nitrogen play an important role in the coppice biomass accumulation; 3) The total nitrogen content and the number of microorganisms in the soil are much lower than the high-forest under the same site conditions. It is unknown about the soil microbial community structure, nitrogen transformation microbial diversity and community structure and its impact on biomass content and nitrogen utilization under the way of coppice management. Compare to the high-forest under the same site conditions, this project will aim to analysis of Cinnamomum camphora roots ecology characteristics and its impact on the absorption of nitrogen from root biological characteristics, rhizosphere allelochemicals, soil microbial community structure, nitrogen transformation microbial diversity and community structure, cultivable nitrogen transformation microbial, and so on. The research results will provide a theory for sustainable development of coppice ecosystems.

氮素是植物生长的重要营养元素之一，土壤微生物多样性与功能群的组成对氮的转化过程及供应起着至关重要的作用。樟树除了其生态作用外，也是提取樟脑、樟油的原材料，然而在实际中存在着原材料短缺的突出问题。矮林经营方式是解决这一矛盾的重要途径。课题组前期研究发现随着矮林经营年限的增加，其生物量呈现降低的趋势，并且氮素是影响樟树矮林生物量积累的重要原因，矮林根际的总氮素含量及土壤中微生物的数量均大大低于相同立地条件下的樟树乔木林。对此原因还未见研究报道。本课题在前期的研究基础上，以相同立地条件下的乔木林为对照，探讨矮林作业方式下，樟树根际生态学特点及其对氮素吸收的影响，即从矮林樟树根系生物学特性、根际化感物质、土壤微生物群落结构特征、氮转化相关微生物群落结构及可培养氮素转化相关微生物等多个方面进行研究，结果将为樟树矮林生态系统的可持续发展提供理论依据。