丛枝菌根真菌在内蒙古草原煤矸石山生态重建中的作用机理及应用研究

In recent years, the problems of ecological destruction and environmental pollution, which were induced by coal mine spoil banks produced in coal mining and mineral processing, have seriously threaten the development of the society and economy of Inner Mongolia. How to resolve these problems have became the most concentrated and emergent work on nowadays. Ecological reconstruction is the best way for comprehensive control of coal mine spoil banks at home and abroad. However, the natural restoration process of vegetation is extremely slow because of extreme site environment. Arbuscular mycorrhizal fungi (AMF) as symbiotic microbes directly link soil and plant root system plays an important role in improving soil environment, increasing nutrition uptake, plant stress physiology and maintaining the stability of plant community. However, there is few studies focus on the application and mechanisms of arbuscular mycorrhizal fungi on ecological reconstruction of coal mine spoil banks in the Inner Mongolia grassland ecosystem.Many new theories and techniques are urgent to be solved. The research is conducted to investigate indigenous AMF sources of coal mine spoil banks in Shiguai distirct of Baotou, Inner Mongolia. The experiments are designed to research mechanisms and effects of indigenous and exogenous AMF on improving plant individuals and groups to adapt to special habitats of coal mine spoil banks in the Inner Mongolia grassland ecosystem. Further, the research is conducted to investigate the real effect of mycorrhizal technique and amelioration measures of soil on ecological reconstruction of coal mine spoil banks in the Inner Mongolia grassland ecosystem through field plot experiment. The research will provide economic and viable technique for comprehensive control of coal mine spoil banks in the Inner Mongolia grassland ecosystem.

近年来，内蒙古地区的煤炭开采导致了煤矸石的大量堆存，给草原生态系统造成了严重的生态破坏与环境污染，制约了社会、经济持续健康发展，成为急待解决的问题。生态重建是国内外煤矸石山综合治理的最佳途径，但由于其立地环境极端恶劣，植被自然恢复过程极其缓慢。作为直接联系土壤与植物根系的共生微生物，菌根真菌对于改良土壤环境、促进养分吸收及在植物逆境生理和维持群落稳定性中均发挥着重要的作用。然而，具体到丛枝菌根真菌在草原生态系统煤矸石山生态重建中的作用机理及应用研究尚属空白，许多理论和技术问题亟待解决。本研究拟选择包头石拐区煤矸石山为研究对象，通过生物学盆栽试验从四个方面研究接种土著和外源丛枝菌根真菌增强植物个体及群体适应草原生态系统煤矸石山特殊生境的作用及主导机制；同时结合基质改良措施进行野外实地小区试验，探讨丛枝菌根真菌在草原煤矸石山生态重建中的实际应用效果，为煤矸石山综合治理提供经济、可行的技术选择。

近年来，内蒙古地区的煤炭开采导致了煤矸石的大量堆存，给草原生态系统造成了严重的生态破坏与环境污染，制约了社会、经济持续健康发展，成为亟待解决的问题。生态重建是国内外煤矸石山综合治理的最佳途径，但由于其立地环境条件极端恶劣，植被的自然恢复过程极其缓慢。作为直接联系土壤与植物根系的共生微生物，丛枝菌根（AM）真菌对于改良土壤环境、促进养分吸收及在植物逆境生理和维持群落稳定性中发挥着重要的作用。本项目通过接种AM真菌主要研究其在增强植物适应草原生态系统煤矸石山特殊生境中的作用及机制，探讨AM真菌在草原煤矸石山生态重建中的实际应用效果。研究结果表明，对于三种类型的煤矸石基质来说，接种AM真菌均可以不同程度的促进植物对矿质营养元素N、P和K的吸收，降低菌根植物C:N:P比和植株体内的重金属浓度，显著促进了植物在煤矸石基质上的定植和生长；接种F. mosseae、R. intraradices和C. etunicatum分别对新排、风化和自燃煤矸石中植物抗基质复合逆境的促进作用最为明显。接种AM真菌可以显著增加水分胁迫条件下自燃和风化煤矸石基质中植物对多种矿质营养元素的吸收，调节植株C:N:P比，增加叶片鲜重含水量及水分利用效率，加快复水速率，有效地改善植物水分状况，提高植物的抗旱能力。在煤矸石表层覆土和接种AM真菌条件下，小于2%的牛粪添加量显著促进了植物对矿质营养元素的吸收，降低了植株C:N:P比，促进了植物的生长，牛粪添加强化了3种类型煤矸石山上AM真菌对植物的菌根效应；而大于4%的牛粪添加量显著抑制了植物的生长，削弱了AM真菌对植物的菌根效应。综合分析表明，AM真菌对煤矸石山上植物抗逆性的影响，是由煤矸石基质的性质、菌种类型、牛粪添加量和植物品种等多种因素综合决定的。研究结果证明，AM真菌对于增强植物适应不同类型煤矸石山的复合逆境以及在草原生态系统不同类型煤矸石废弃地上重建植被均具有一定的潜在作用，研究结果将为草原煤矸石山综合治理提供经济、可行的技术选择。