黄土高原矿区退化生境土壤-植被协同恢复模式及生态效应研究

This reseach project will take soil-vegetation system as an integrated research object, from the angle of "vegetation-soil-microbial synergistic restoration", and focus on the "Development of synergistic restoration models of soil-vegetation systems and evaluation of their ecological effects on degraded mining areas of the Loess Plateau" by using state-of-the-art techniques, such as remote sensing and GIS, multifactor comprehensive diagnosis, quantitative classification and ordination, PCR-DGGE, etc. By focused investigation and diagnosis the degraded habitats in the mining areas of the Loess Plateau, and evaluation of the capacity of their soils to support vegetation, we will develop synergistic restoration models of habitat-specific soil-vegetation systems. By selecting field plots that are similar to our developed synergistic restoration models at the three typical mining areas (Yangquan, Luan and Pinsuo) on the Loess Plateau, we will conduct in-stiu validation tests and monitoring of the synergistic restoration models, and explore their succession dynamics of the models. After in-stiu monitoring of the synergistic restoration models of the soil-vegetation systems, we will screen dominant soil microorganism populations and identify the coupling mechanisms between vegetation restoration and soil quality under different recovery periods and different synergistic restoration models. By evaluating the ecological effects of soil and vegetation improvements of different synergistic restoration models, we will create a database of monitoring ecological effects, optimize and present the best synergistic restoration models with the dynamic control strategy, focusing on resolving the key issue of quickly establishing self-sustaining soil-vegetaion systems for mining areas on the Loess Plateau. This will achieve the overall goals of advancing synergistic restoration of degraded soil-vegetation systems and improving ecological restoration efficiency, enviromental quality and sustainable development of degraded mining areas on the Loess Plateau, while also providing a scientific basis and technical support for transfer of this technology to similar mining areas elsewhere in China.

本项目拟以土壤-植被系统为研究对象，从"土壤-植被-微生物"协同恢复视角，整合遥感与GIS、多因子综合诊断、数量分类与排序、PCR-DGGE等技术，综合开展黄土高原矿区退化生境土壤-植被协同恢复模式及生态效应研究。通过黄土高原矿区退化生境诊断和土壤植被承载力评价，构建土壤-植被协同恢复模式；分别在阳泉、潞安和平朔3个典型矿区选择与所构模式类似的样地，通过模拟试验与定位监测研究，探讨土壤-植被协同恢复模式的演替动态，筛选土壤微生物优势类群，揭示不同恢复模式和不同恢复时段下植被恢复与土壤质量的耦合机制；通过不同恢复模式的生态效应评价，进一步优化完善恢复模式，构建其生态效应监测数据库，提出不同恢复模式的动态调控方案，重点解决在黄土高原矿区退化生境快速建立自我维持的土壤-植被生态系统这一关键问题，提高矿区生态恢复效率、促进其环境质量改善和持续发展，并为全国类似矿区的生态恢复提供科学依据和技术支撑。

黄土高原是我国重要的能源基地和全国典型的生态脆弱区，开展其矿区退化生境生态恢复研究具有显著的全国示范效应。本项目以土壤-植被系统为研究对象，从“土壤-植被-微生物”协同恢复视角，整合遥感与GIS、多因子综合诊断、数量分类与排序、高通量测序等技术，综合开展了黄土高原矿区退化生境土壤-植被协同恢复模式及生态效应研究。主要研究内容和重要结果为：.(1) 通过实地调查采样和遥感影像信息提取，对山西阳泉、平朔等典型矿区生境退化现状与态势的多因子综合诊断研究表明，土壤水分、速效养分、有机质等是影响矿区生态恢复的关键限制因子。.(2) 通过不同类型退化生境的土壤植被承载力及其生态恢复潜力评价，构建了基于土壤水分植被承载力的黄土高原矿区退化生境土壤-植被协同恢复模式，包括旱榆+刺槐、油松+刺槐、紫穗槐-高羊茅、沙棘-紫花苜蓿、紫花苜蓿等模式。.(3) 通过100m×100m、50m×50m和10m×10m典型人工林、灌、草固定样地定位监测研究表明，不同植被恢复模式下土壤水分季节变化和垂直分布差异显著。人工植被恢复明显改善土壤肥力，植物根际与非根际土壤养分差异显著。根际土壤速效养分、有机质等均显著高于非根际。高通量测序表明，根际土壤的细菌多样性指数一般高于非根际，优势类群以变形菌门(Proteobacteria)、酸杆菌门(Acidobacteria)、子囊菌门真菌等为主。.(4) 采用空间代替时间方法，通过数量生态分析和温室控水实验，揭示了人工植物群落和自然定居植物群落演替动态及土壤-植被耦合机制。.(5) 采用主成分分析方法，对不同土壤-植被协同恢复模式的生态效应评价表明，不同恢复模式的生态效应差异显著，验证了所构建刺槐+油松林等模式的恢复效果，并构建了其生态效应监测数据库。.因此，在黄土高原矿区生态恢复初期阶段应以人工恢复为主，中后期阶段以自然恢复为主、人工恢复为辅，整个恢复阶段应加强科学管护和动态调控。耕地、林地、人工牧草地恢复宜分别采用紫花苜蓿培肥模式，乔灌草、灌草复合配置模式和“豆科+禾本科牧草”复合配置模式。