基于复杂网络的露天煤矿复垦土壤有机碳累积的影响因素研究

发布时间：2018-01-18 08:14

本文关键词：基于复杂网络的露天煤矿复垦土壤有机碳累积的影响因素研究　出处：《中国地质大学(北京)》2017年硕士论文　论文类型：学位论文

【摘要】：影响土壤有机碳累积的因素众多,过程也极为复杂,而科学合理确定影响土壤有机碳累积的因素不仅可以改善土壤理化性质,也可以更好的恢复矿区生态环境。本研究通过对安太堡露天煤矿南排土场、内排土场、西排土场50个复垦样点的土壤、地形、植被参数进行采集和测定。应用SPSS进行相关性分析,并基于Gephi软件进行复杂网络指标计算,通过度值、紧密中心度、稳健性等指标分析影响土壤有机碳累积的主要因素及影响路径,探讨土壤、地形和植被因子对土壤有机碳累积的影响机理。通过研究得出以下结论:(1)全氮和砂粒含量是影响土壤有机碳的最主要土壤因素,郁闭度和植被盖度是最主要的植被因素,而地形因素的变化对土壤有机碳的影响并不显著。(2)度值、紧密中心度、介数中心度、平均路径长度以及平均聚类系数从不同方面反映各因素在影响土壤有机碳累积的过程中的作用。对网络指标进行描述性统计分析,平均路径长度为1.824、平均聚类系数为0.588,此网络具有随机网络特征和局部小世界特性,社团化结构特别明显,即土壤物理性质之间的关系紧密,土壤化学性质和植被指标之间关系紧密。全氮、黏粒、粉粒、砂粒、蓄积量、郁闭度的度值较高,影响土壤有机碳累积的作用较大。(3)全氮的介数中心度最高,在网络的相互作用过程中起主要的连接作用,影响其他因素和土壤有机碳的相互影响;砂粒和粉粒的介数中心度也比较高,且二者连接土壤理化性质和地形指标,地形对土壤有机碳的影响主要是通过黏粒和粉粒来实现的。(4)平均路径长度较小,聚类系数较高说明网络结构紧凑,改变部分因素对土壤有机碳累积的影响较小。全氮、蓄积量和砾石含量的变化对整个网络的稳定以及土壤有机碳累积的影响最大,增加全氮含量和改善土壤物理性质是影响土壤有机碳累积的最有效措施。蓄积量和郁闭度可以显著影响土壤有机碳的积累,因此应当选择阔叶类树种进行植被重建;增加植被盖度可以增加土壤有机碳的积累,应选择乔-灌-草的复垦模式。
[Abstract]:There are many factors affecting the accumulation of soil organic carbon, and the process is very complex, and scientific and reasonable determination of factors affecting the accumulation of soil organic carbon can not only improve the physical and chemical properties of soil. Also can better restore the ecological environment of mining areas. This study through the Antaibao opencast coal mine south dump, inner dump, West dump 50 reclamation sites of the soil, topography. The vegetation parameters were collected and measured. The correlation analysis was carried out by using SPSS, and the complex network index was calculated based on Gephi software. The main factors affecting the accumulation of soil organic carbon and the influence path were analyzed, and the soil was discussed. The effects of topography and vegetation factors on soil organic carbon accumulation. The following conclusions are drawn: total nitrogen and sand content are the most important factors affecting soil organic carbon. Canopy closure and vegetation coverage were the most important vegetation factors, but the change of topographic factors had no significant effect on soil organic carbon. The average path length and the average clustering coefficient reflect the effect of various factors on the process of soil organic carbon accumulation from different aspects. The descriptive statistical analysis of network indicators showed that the average path length was 1.824. The average clustering coefficient is 0.588.This network has the characteristics of random network and local small world, and the association structure is especially obvious, that is, the relationship between soil physical properties is close. Total nitrogen, clay, silt, sand, accumulative capacity and canopy density were higher. The effect of soil organic carbon accumulation on soil organic carbon accumulation was greater. (3) Total nitrogen had the highest center, which played a major role in the interaction between the network and other factors and the interaction of soil organic carbon. Sand and silt also have high center of intermediation, and they are connected with physical and chemical properties of soil and topographic index. The influence of topography on soil organic carbon was mainly achieved by clay and silt. The average path length of soil organic carbon was smaller, and the higher clustering coefficient showed that the network structure was compact. The change of some factors had little effect on the accumulation of soil organic carbon. The change of total nitrogen, accumulation and gravel content had the greatest influence on the stability of the whole network and the accumulation of soil organic carbon. Increasing total nitrogen content and improving soil physical properties are the most effective measures to affect the accumulation of soil organic carbon, and the accumulation and canopy can significantly affect the accumulation of soil organic carbon. So we should choose broad-leaved tree species for vegetation reconstruction. The accumulation of soil organic carbon can be increased by increasing vegetation coverage, and the reclaimed model of Arbor, shrub and grass should be chosen.
【学位授予单位】：中国地质大学(北京)
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：S153.6;TD88

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