青海木里煤田矿区人工植被种群自我更新与调控对策研究

Vegetation restoration is the foundation for the restoration and reconstruction of slag mountain ecosystem, and soil improvement is the precondition of vegetation restoration. In Muli coal field of Qinghai province, the ecological system was destroyed due to the long-term exploitation of coal and the neglect of the treatment of slag mountain (Coal mining residuals). We also have a certain research foundation on the vegetation restoration of the slag mountain in Muli coal mine area of Qilian Mountains. This project designs the following experiments to discuss the artificial vegetation population regeneration and the regulation strategy in the alpine area. Firstly, we design a two-factor improvement experiment with adding organic fertilizer and ferrous sulfate to select a combination of soil organic matter and pH value which should be beneficial to the self-renewal of plant population on slag mountain soil. Secondly, we use high-throughput sequencing method and Biolog ECO-plate culture method to study the genetic diversity and functional diversity of soil microbes, and to find out the collaborative relationship between microbial community dynamic and soil nutrients of slag mountain top soil. Thirdly, we want to investigate the number of top soil biological crust (SBC) and the population characteristics of vascular plants species in the two-factor experiments blocks, then to determine the effect of SBC on population regeneration of artificial vegetation. Through these experiments, the relationship among physical and chemical properties of surface soil, SBC, soil microorganism, plant population self-renewal will be analyzed under the background of soil improvement, which will provide reference for the ecological restoration in alpine mining area in the future.

植被恢复是渣山生态系统的修复和重建的基础，而土壤改良又是植被恢复的前提。在青海省祁连山木里煤田，由于长期开采煤矿且疏于治理渣山，导致大量原生植被被渣土堆积，使生态系统遭到破坏。基于我们在木里煤田渣山植被恢复方面的研究基础，提出本项目的试验设计：1）设计添加有机肥和硫酸亚铁的双因素渣山土壤改良试验，筛选出利于植物种群自我更新的土壤有机肥与pH值的组合；2）应用高通量测序法和Biolog-ECO 板培养法研究土壤微生物的遗传多样性和功能多样性，找出渣山表层土壤微生物群落动态与土壤营养的协同关系；3）调查渣山土壤改良试验样方内的生物结皮数量与植物种群特征，确定渣山表层土壤生物结皮对人工植被种群更新的影响。基于土壤改良背景下，研究分析渣山表层土壤理化性质、土壤生物结皮、土壤微生物与植物种群自我更新四者之间的相互关系，揭示人工植被种群自我更新机理与调控对策，为今后高寒矿区生态恢复提供借鉴和参考。

针对高寒矿区渣山人工植被恢复表层土壤养分不足和人工植被种群自我更新与调控问题，采用不同施肥处理，有机肥（M）和硫酸亚铁（F）配施以及有机肥（M）与羊板粪（S）配施的双因素控制试验，旨在探明高寒矿区渣山表层土壤性质，实现人工植被的自我更新与可持续恢复。结果表明：（1）有机肥和硫酸亚铁的配施处理F1M3、F0M3对渣土全氮、碱解氮、全磷、速效磷影响较大。（2）有机肥处理显著提高细菌Chao1指数和Shannon指数。与自然山体相比，细菌Chao1指数和Shannon指数在不同处理下均得到较好恢复。（3）有机肥处理显著提高拟杆菌门、假节杆菌属、农杆菌属、子囊菌门及微囊菌属等微生物相对丰度；硫酸亚铁处理显著提高放线菌门、假节杆菌属、青霉属及附球霉属相对丰度；有机肥和硫酸亚铁交互处理显著提高拟杆菌门、农杆菌属及微囊菌属相对丰度。细菌Shannon指数与植被高度、盖度及地上生物量之间存在极显著正相关关系。（4）植被高度、盖度、地上生物量以及有机质的含量与拟杆菌门多度存在显著相关。（5）有机肥与羊板粪配施渣土平地样地区域M1S3处理效果最佳，在坡地样地区以M3S2处理效果最佳。羊板粪相比有机肥对矿区渣土改良效果更好。（6）渣山未恢复区域基质理化性质较差，优势属有芽孢单菌属、GP6属、赤霉菌属、未识别囊菌属。自然山体土壤养分因放牧有所损失，渣山周边沼泽湿地土壤生态系统稳定，优势属有GP6属与GP16属。渣山微生物OTU数量（样品的有效序列数）比周边沼泽湿地原始群落高9.8%，比自然山体较高21.8%，细菌多样性在沼泽湿地中较高，而真菌在沼泽湿地比渣山未种草区域低。（7）建植3年后出现苔藓，主要在阴坡、半荫半阳坡出现，建植4年的生殖枝数量显著低于2年的、发芽率显著低于2和3年的。建植后4年，建议进行补播、施肥等管理措施，促进植被自然演替。