高寒草地土壤有机质化学对土壤N转化功能分子生态网络的影响

Soil microbes are the engines that control soil nitrogen (N) transformation, in the natural environment, the soil N transformation microbial groups form a complex interactive network through the mutually beneficial symbiosis, competition, predation and other interactive relationships. Soil organic matter is the source of nutrients and energy for soil microbes. Whether soil organic matter could affect the biogeochemical processes of N transformation by affecting soil microbes and their complex interaction network? This study tries to focus on this issue by studying the typical alpine grassland ecosystem in the northern Tibet of China and the Rocky Mountains of US. In the present study, the chemical composition and constituent of soil organic matter would be determined by using Pyrolysis GC/MS in alpine grasslands, and the fingerprints of soil organic matter would be constructed. Furthermore, the N transformation functional genes of soil microbes would be identified based on the GeoChip 5.0 high throughput microarray technique, and function molecular ecological networks for soil N transformation would be constructed. The aim of this study is to reveal the influence extent and pattern of soil organic matter chemistry on the molecular ecological networks of soil N transformation. And further to reveal the key factor and its mechanism of affecting the alpine grassland soil N transformation microbial function from soil organic matter chemistry perspective.

土壤微生物是土壤N素转化的引擎，在自然环境中，土壤N转化微生物类群通过互利共生、竞争、捕食等交互关系形成一个复杂的交互网络，土壤有机质是土壤微生物生命活动所需养分和能量的来源，那么土壤有机质是否会通过影响土壤微生物及其形成的复杂交互网络，从而影响N转化的生物地球化学过程呢？本研究就针对这一科学问题，以中国藏北高原和美国落基山脉的典型高寒草地生态系统为研究对象，通过热裂解气质联用技术（Py-GC/MS）技术测定高寒草地土壤有机质的化学成分和化学组成，构建土壤有机质的“指纹图谱”，通过GeoChip 5.0高通量基因芯片技术筛选土壤微生物的核心N转化功能基因，构建土壤N转化功能分子生态网络，探讨高寒草地生态系统土壤有机质化学成分和化学组成对土壤N转化功能分子生态网络影响的程度和方式，尝试从土壤有机质化学和微生物分子生态网络角度揭示影响高寒草地土壤N转化的关键因子及其微生物机理。

土壤有机质作为土壤微生物生命活动所需的能量和养分来源，是否会通过影响作为C、N转化的引擎的微生物从而间接影响生物地球化学过程。本研究选取青藏高原广泛分布的高寒草地为研究区域，通过热裂解气质联用技术（Py-GC/MS）技术测定高寒草地土壤有机质的化学成分和化学组成，构建土壤有机质的“指纹图谱”，通过16SrRNA与宏基因组测序相结合的手段探究土壤微生物组成、结构和功能，探讨高寒草地生态系统土壤有机质化学成分和化学组成与涉及C、N、P转化的酶活性以及环境因子之间的关系。比较高寒草地土壤微生物的组成及优势微生物，建立高寒草地土壤微生物与环境的相关网络，探索土壤微生物群落在高寒草地物质循环中独特的生态学功能。尝试从土壤有机质化学成分和化学组成角度揭示影响高寒草地C、N转化微生物的关键因子及其作用机理，并为揭示高寒特殊环境中土壤C、N转化机理提供进一步分子水平的视角。