煤矿区修复中外生菌根真菌对土壤碳库的作用机制

Ectomycorrhizal fungi (EMF) plays a significant role in plant stress resistance and soil carbon sequestration potential, however, it also degrades organic matter in barren soils. There have been a number of studies on the effect of EMF on plant physiological and biochemical characteristics in reclaimed mine, but the influences of EMF on soil carbon cycle still remain poorly understood. The simple reclaimed vegetation and poor carbon sequestration capacity are common in Shanxi mine areas. In this project, the effects of EMF on soil carbon pool will be studied in reclaimed coal mine through indoor and field experiments. There will be inoculated and un-inoculated EMF soil with different concentrations of fertilizers in culture pots, respectively. Soil physicochemical and microbial characteristics, EMF biomass, plant growth and resistance physiological indexes, and litter attenuation will be measured, and the feasible concentration of fertilizer to promote plant growth and soil carbon sequestration will be screened. Mycorrhizal and non-mycorrhizal seedlings will be planted in field treated with fertilizers, and the characteristics of soil, EMF, plants and litter will be detected. This project will aim to reveal the mechanisms of EMF on soil carbon sequestration and decomposition in barren mine soils. The results will provide scientific guidance for soil carbon sequestration technology, and make more local plants for ecological restoration in mine area, Shanxi Loess.

外生菌根真菌(Ectomycorrhizal Fungi, EMF)可提高植物抗逆性和土壤固碳潜力，但在贫瘠土壤中可降解有机质，目前矿区生态修复中EMF对植物影响研究甚多，而EMF对土壤碳库影响研究甚少。因此，本项目针对山西矿区植被复垦类型单一和固碳能力差的现状，拟通过室内和野外试验研究矿区使用EMF修复对土壤碳库的影响，在接种和未接种EMF培养钵中添加不同梯度的肥料，分析土壤理化和微生物特征、EMF生物量、植物生理生化指标和枯落物矿化动态，筛选促进植物生长和土壤固碳的施肥梯度，基于该梯度，野外施肥并栽培菌根化和非菌根化苗，检测土壤、EMF、植物和枯落物的上述指标；分析室内和野外数据，确定EMF在矿区贫瘠土壤中碳固定和降解角色的转换临界点。该项目的完成不仅可揭示EMF对土壤碳库的影响机制，而且可为提高山西工矿废弃地的固碳能力和拓宽修复物种的选择提供技术支撑。

外生菌根真菌(Ectomycorrhizal Fungi, EMF)可提高宿主植物的抗逆性及土壤的固碳潜力，但在贫瘠土壤中可降解有机质，目前关于矿区生态修复中EMF对宿主植物影响的研究甚多，而对EMF对土壤碳库影响的研究甚少。本项目以植被复垦类型单一且固碳能力差的山西矿区为研究目标，拟开展室内盆栽实验，在接种和未接种EMF培养钵中添加不同梯度的肥料，并分析土壤理化和微生物特征、EMF生物量、植物生理生化指标和枯落物矿化动态等指标，探究EMF修复对土壤碳库的影响；基于室内试验，野外施肥并栽培菌根化和非菌根化苗，检测土壤、EMF、植物和枯落物的上述指标，确定EMF在矿区贫瘠土壤中碳固定和降解角色的转换临界点。研究结果表明，（1）EMF可提高其宿主植物抗逆性，且EMF的接种量是影响外生菌根真菌侵染油松根系的关键因子，最适宜的接种量为3%；（2）土壤肥力条件可通过影响EMF的丰度、多样性和多酚氧化酶分泌能力间接影响其碳代谢功能。(3)土壤有机质为2.0-2.5%之间是EMF固定碳和降解碳的临界点，在有机质含量低于2.0%时，EMF促进了对土壤碳的降解，而在有机质浓度较高（3.5%）时，EMF更多是扮演固定土壤碳的角色。该项目不仅可揭示EMF对土壤碳库的影响机制，而且可提高山西工矿废弃地的固碳能力和拓宽修复物种的选择提供技术支撑。