【作者】 王丽；

【导师】 雷少刚；

【作者基本信息】 中国矿业大学 ， 土地资源管理， 2021， 博士

【摘要】 植被恢复是矿区生态系统恢复的重要前提。植被是干旱、生态脆弱环境的重要组成部分,植被健康状况影响矿区整体生态质量,因此西部矿区生态恢复的核心内容是植被恢复。围绕植被恢复研究存在的主要问题有:植被损伤和土壤损伤的单一研究较多,矿区采煤植被影响系统层面研究不足,采煤扰动下植被-土壤耦合损伤过程与协同自修复特征不明,同时植物光合生理自修复机制不清等。研究以中国西部神东矿区为目标区域,基于文献分析对已有相关研究成果进行归纳、总结和概括,初步构建矿区植被生态系统恢复力理论研究框架,并在框架指导下开展实验区采煤植被影响研究。首先基于不同应力区监测实验,初步探索采煤塌陷机理及其对植被生境的扰动特征;其次,应用无人机和高光谱技术,基于不同尺度探索矿区植被-土壤耦合损伤空间差异性;第三,基于长时间序列数据分析实验区不同尺度上植被自修复动态特征,揭示植被-土壤协同自修复规律,探索区域植被典型物种自修复光合生理机制;再次,应用结构方程模型定量评价矿区植被生态系统恢复力;最后,结合矿区植被恢复力评价结果,选取恢复力提升关键时间阈值点和典型区域,应用低影响开发技术和生态雨洪管理模型,构建分区差异性植被恢复力建设方案。研究主要结论如下:(1)西部矿区采煤塌陷及其环境扰动具有空间差异性。薄基岩、厚煤层、浅埋深综放采煤条件下,地表移动具有明显的空间分区特征,采空区的最大下沉速度比煤柱区大,采空区上方地表间隔出现台阶状裂缝,工作面边界附近出现动态裂缝;塌陷不同应力区的土壤受到扰动应力类型与强度不同,土壤性状损伤程度也表现出差异性,其中土壤体含量、土壤速效氮、速效磷和速效钾含量受塌陷扰动变化差异显著,可以作为后期研究植物损伤的关键环境因子;(2)植被-土壤耦合损伤表现出空间异质性。采煤塌陷扰动对植被健康造成损伤,进一步的分析表明采煤塌陷扰动对乔木和灌木生长影响显著,对草本影响较小;塌陷不同应力区的的杨树、柠条和油蒿均受到不同程度的损伤,中性区和压缩区的杨树、柠条和油蒿受损严重,拉伸区杨树、柠条和油蒿受损相对较轻,糙隐子不同应力区受损差异不明显;相较于非采区,不同应力区各植物样本不同SPAD值对应波段反射率差值显著减小,同时研究初步识别出不同应力区,采煤扰动下各典型植物光谱指数的特征波段;植被-土壤耦合损伤评价表明,中性区群落-土壤耦合损伤和种群-土壤耦合损伤均表现出强脱钩型,即土壤损伤与植被损伤耦合性最差,同时柠条-土壤在不同塌陷应力区均表现为强脱钩型,即柠条-土壤耦合损伤受采煤扰动影响较大,可作为后期个体恢复力研究典型植物;(3)植被-土壤协同自修复呈现出阶段性变化规律。采煤塌陷干扰对植被群落的生态效应具有阶段性特征,即群落自修复过程初步化分为初级阶段(自修复2年、16年)、中级阶段(自修复1、3、4和12年)和高级阶段(自修复6、8、10年),随自修复阶段增高,群落物种种类和数量均有所增加,优势物种由一年生草本植物演变为多年生草本植物;土壤有机质含量和速效磷含量是制约群落抵抗性的主要因素;土壤水含量是影响群落自修复性和鲁棒性的主要限制因子;黑沙蒿、狗尾草、硬质早熟禾、雾冰藜等等耐胁迫物种,受沉陷影响小,适应性较好,耐贫瘠性强,自修复力强,矿区植被修复与重建时可作为备选物种;不同自修复年限的群落-土壤自修复耦合类型均属于拮抗耦合状态,CK、自修复2a、6a、10a区域群落-土壤自修复协调度类型属于良好协调状态,其余属于属于处于中度协调状态;种群-土壤自修复耦合类型均属于拮抗耦合状态,协调度类型均属于处于中度协调状态;杨树-土壤、柠条-土壤和糙隐子-土壤自修复耦合类型均属于拮抗耦合状态,自修复1a、2a区域杨树-土壤和柠条-土壤自修复协调度类型均属于处于中度协调状态,自修复2a区域糙隐子-土壤自修复协调度高于ck和自修复1a区域,表明糙隐子受到扰动后较快自修复;(4)环境对植被系统恢复力影响大于采煤扰动对恢复力影响,植被生态系统恢复力随自修复时间变化特征与植被自修复特征一致。系统层面,环境子系统对植被生态系统恢复力的影响大于采煤扰动对植被生态系统恢复力的影响;因子层面,采深对植被生态系统恢复力的影响大于采厚对植被生态系统恢复力的影响,生长环境系统指标因子对恢复力的影响从大到小依次为土壤水含量、土壤养分含量、土壤容重;研究区植被生态系统恢复力随自修复时间变化特征表现为:自修复2年植被生态系统恢复力最低,之后植被生态系统恢复力逐渐增大,自修复8年后植被生态系统恢复力接近对照区植被,之后又逐渐下降;研究区植被生态系统恢复力空间差异表现为:自修复第2年(恢复力最低的年限),各区域植被生态系统恢复力由大到小依次为CK、压缩区、拉伸区、中性区。(5)基于LID的恢复力建设方案可以有效提升矿区植被系统恢复力,方案可在未来矿区生态恢复实践中开展实验应用。1年一遇暴雨强度背景下,3套恢复力建设方案均可明显提升实验区域的恢复力,随着暴雨强度重现期时间的增加,3套方案提升实验区恢复力的效果逐渐降低且各方案提升效果差异也越来越大,具体表现为恢复力建设方案3>恢复力建设方案2>恢复力建设方案1。论文研究可为西部矿区植被损伤与恢复提供理论参考和方法借鉴,研究成果对缓解西部矿区水资源压力,促进矿区生态恢复,实现煤炭资源可持续开发利用具有重要现实意义。该论文有图77幅,表61个,参考文献246篇。更多还原

【Abstract】 Vegetation restoration is an important prerequisite for ecosystem restoration in coal mining area.Vegetation is an important part of arid and fragile ecological environment.Vegetation health affects the overall ecological quality of the coal mining area.Therefore,the core content of ecological restoration in western coal mining area is vegetation restoration.The main problems of vegetation restoration research are as follows: There are many single researches on vegetation damage and soil damage,but the research on the system level of vegetation impact in coal mining area is insufficient.The characteristics of vegetation-soil coupling damage under coal mining disturbance are not clear,the law of collaborative remediation is not distinct,and the mechanism of plant photosynthetic physiological restoration is not lucid too.On the basis of above considerations,Shendong coal mining area in Western China was taked as the target area.Based on literature analysis,the relevant research results were summarized,and the theoretical research framework of vegetation ecosystem resilience in coal mining area was initially constructed.Under the guidance of the framework,the impact of coal mining vegetation in the experimental area was studied.Firstly,based on the monitoring experiments in different stress areas,the mechanism of coal mining subsidence and its disturbance characteristics to vegetation habitat were preliminarily explored;secondly,the spatial differences of vegetation soil coupling damage in coal mining area were explored based on different scales by using unmanned aerial vehicle(UVA)and hyperspectral technology;finally,based on long time series,the dynamic characteristics of vegetation self-healing at different scales in the experimental area were analyzed to reveal the law of vegetation soil collaborative restoration and explore the Photosynthetic Physiological Mechanism of typical regional vegetation species.On the basis of the above research,structural equation model was used to quantitatively evaluate the resilience of vegetation ecosystem in coal mining area;Finally,combined with the evaluation results of vegetation resilience in coal mining area,the key time threshold points and typical areas of resilience enhancement were selected.Based on the low impact development technology and the ecological rain flood management model,the construction scheme of regional differential vegetation resilience was constructed.The main conclusions are as follows:(1)There are spatial differences in mining subsidence and environmental disturbance in western coal mining area.Under the condition of thin bedrock,thick coal seam and shallow deep fully mechanized caving,the surface movement has obvious spatial zoning characteristics,the maximum subsidence speed of goaf is larger than that of coal pillar area,step cracks appear at the surface interval above the goaf,and dynamic cracks appear near the boundary of working face;the soil in different stress areas is disturbed by the type and intensity of stress The degree of soil damage is different with different degrees,among which the soil water content,soil available nitrogen,available phosphorus and available potassium content are significantly different from those of collapse disturbance,which can be used as the key environmental factors for the later study of plant damage;(2)The coupling damage of vegetation and soil shows spatial heterogeneity.The disturbance of coal mining subsidence causes damage to vegetation health.The further analysis shows that the mining subsidence disturbance has a significant impact on the growth of trees and shrubs,but has little effect on herbs;The poplar,Caragana and Artemisia oil in different stress areas are damaged to different degrees.Caragana and Artemisia annua in neutral and compression areas are seriously damaged.The damage of poplar,Caragana and Artemisia oleifera in the extension area is relatively light,and the difference of stress areas of saphenocarpa is not obvious;Compared with the non coal mining area,the reflectance difference of different SPAD values of different plant samples in different stress areas is significantly reduced.At the same time,the characteristic bands of spectral index of typical plants in different stress areas under coal mining disturbance are preliminarily identified;The coupling damage evaluation of "vegetation soil" showed that both the community soil coupling damage and population soil coupling damage in the neutral area showed strong decoupling type,that is,the coupling between soil damage and vegetation damage was the worst.Meanwhile,Caragana korshinskii soil coupling damage showed strong decoupling type in different collapse stress areas,that is,Caragana korshinskii soil coupling damage was greatly affected by coal mining disturbance,which can be used as an individual recovery research in the later stage Study the typical plants;(3)The vegetation and soil collaborative restoration showed a periodic change rule.The ecological effect of mining subsidence disturbance on vegetation community is characterized by stages,that is,the process of community self restoration can be divided into primary stage(2 years,16 years),intermediate stage(1,3,4 and 12 years)and advanced stage(6,8,10 years).With the increase of restoration stage,the types and numbers of species have increased,and the dominant species changed from annual herb to perennial herb;the content of soil organic matter and available phosphorus was the main factor restricting the resistance of community;Soil water was the main limit of community restoration and robustness;Artemisia ordosica,Setaria setifolia,Kentucky bluegrass and Chenopodium glaucum are stress tolerant species,which are less affected by subsidence;They have good adaptability and strong resistance to barrenness;These species have strong self-healing ability and can be used as alternative species for vegetation restoration and reconstruction in coal mining area;The self-healing coupling types of community-soil in different restoration years belong to antagonistic coupling state,whitch of community-soil in CK,restoration 2a,6a and 10 a are in good coordination state,and the rest belong to moderate coordination state;The self-healing coupling types of population-soil belong to antagonistic coupling state,and the coordination degree type belongs to moderate coordination state;The self-healing coupling types of poplar-soil,Caragana-soil and Lespedeza-soil belong to antagonistic coupling state;The self-repair coordination type of poplar-soil and Caragana-soil in restoration 1a and 2a regions are in moderate coordination state;The self-repair coordination scheduling of Lespedeza-soil in recovery 2a region is higher than that in CK and recovery 1a area;It shows that the rough Cryptodon scabra recovers quickly after being disturbed;(4)The influence of environment on the resilience of vegetation system is greater than that of mining disturbance,The change characteristics of vegetation ecosystem resilience with restoration time were consistent with that of vegetation self restoration.At the system level,the impact of environmental subsystem on the resilience of vegetation ecosystem is greater than that of coal mining disturbance;on the factor level;The influence of mining depth on vegetation ecosystem resilience is greater than that of mining thickness,and the influence of growth environment system index factors on the resilience is in the order of soil water content,soil nutrient content and soil bulk density;The results showed that the vegetation ecosystem resilience was the lowest after 2 years of restoration,and then increased gradually.After 8 years of restoration,the vegetation ecosystem resilience was close to that of the control area,and then decreased gradually;The spatial differences of vegetation ecosystem resilience in the study area are as follows: in the second year of restoration(the lowest restoration period),the order of restoration capacity of vegetation ecosystem in each region is CK,compression area,stretching area and neutral area;(5)The construction scheme of Resilience Based on Low Impact Development(LID)can effectively enhance the resilience of vegetation system in coal mining area.The scheme can be applied in the practice of ecological restoration in the future.Under the background of one-year return period of rainfall intensity,the three sets of resilience construction schemes can significantly improve the resilience of the experimental area.With the increase of the rainfall intensity return period time,the effect of the three schemes to enhance the resilience of the experimental area gradually decreases,and the difference of the improvement effect of each scheme is larger and larger;The improvement effect of resilience of each scheme from large to small is resilience construction scheme 3,resilience construction scheme 2 and resilience construction scheme 1.This paper can provide theoretical reference and method reference for vegetation damage and restoration in western coal mining area.The research results have important practical significance to alleviate the pressure of water resources in western coal mining areas,promote ecological recovery of coal,and realize the sustainable development and utilization of coal resources.There are 77 pictures,61 tables and 246 references.更多还原