根系--菌丝体--非共生微生物调控的竹林土壤碳过程及其对穿透雨减少和氮添加的响应

以菌根真菌作为碳交换媒介的菌丝网络将根际和非根际界面联系在一起，形成根系-菌丝体-非共生微生物系统。传统上对土壤呼吸组分的区分割裂了植物-微生物的联系，限制了人们对根系--菌丝体--非共生微生物交互效应调控土壤碳过程的认识。诸如干旱和氮沉降等环境变化引起土壤水分和养分的变化无疑将改变土壤微生物组成，并通过改变植物生理活动引起根际分泌物变化，进而在土壤层面重塑根际效应。然而，缺乏菌丝网络对环境变化响应的认识限制了对地下碳交换格局的理解，植物-微生物调控土壤碳循环的不确定性增加。亚热带地区是我国氮沉降的热点区域同时面临干旱影响，本研究拟依托在该区典型植被类型毛竹（丛枝菌根真菌植物）林开展的穿透雨减少和氮添加试验，结合微宇宙和稳定同位素示踪技术，辨析根系--菌丝体--非共生微生物系统在驱动土壤碳过程中的权衡效应，阐明其环境响应调控机理，揭示气候-植物-微生物互馈机制，为竹林可持续经营提供支撑。

As a medium of carbon exchange, mycorrhizal fungi are used to connect the rhizosphere and bulk interface to form a root mycelium symbiotic microbial system. The traditional distinction of soil respiration components cuts off the relationship between plants and microorganisms, and restricts the understanding of the interactive effect of the root system, symbiotic microorganisms and free living microbes on the soil carbon process. The changes of soil moisture and nutrients caused by environmental changes such as drought and nitrogen deposition will undoubtedly change the composition and activity of soil microorganisms, cause a variation in exudation by changing the physiological activities of plants, and thus remodel the rhizosphere effect in soils. However, the lack of understanding of the response of mycelium network to environmental changes limits the comprehension of the underlying carbon exchange pattern, and leads to the increase of uncertainty of plant-microbial feedbacks on soil carbon cycle. The subtropical region in China is suffering nitrogen deposition, and it is also facing the influence of drought. This study intends to analyze the trade-off effect of the root system, symbiotic microorganisms and free living microbes on driving the soil carbon process by using microcosmic technology and stable isotope tracing in throughfall reduction and nitrogen addition sites carried out in Moso bamboo (Phyllostachys edulis) forest, in order to clarify the mechanism of environmental response and reveal the interactive mechanism of climate-plant-microorganism, which provides support for the sustainable management of bamboo forests.