贡嘎山东坡垂直带典型生态系统植物与土壤铅和镉的垂直分异
文献类型：学位论文
| 作者 | 唐荣贵
|
| 学位类别 | 硕士 |
| 答辩日期 | 2015 |
| 授予单位 | 中国科学院大学 |
| 授予地点 | 北京 |
| 导师 | 罗辑 |
| 关键词 | 含量 贮量 海拔梯度 HYSPLIT模型 潜在生态风险 |
| 其他题名 | The vertical differentiation of lead and cadmium in plants and soil of the typical ecosystems along the altitudinal belt in the eastern slope of the Gongga Mountain |
| 学位专业 | 环境工程 |
| 中文摘要 | 人类活动已经造成全球性的重金属污染。铅和镉作为“五毒元素”，在环境中积累会对人类健康和生态系统安全造成危害，被广泛关注。贡嘎山位于青藏高原的东部，我国一二级阶梯的交界，其东坡垂直带谱植被生态系统可以作为巨大的探针监测着区域乃至国家尺度环境的变化。本研究在贡嘎山东坡垂直带谱中选取四个典型生态系统作为研究对象，详细测定并分析了生态系统优势种植物与土壤各层次铅和镉的含量；利用野外调查的植物各组织和器官生物量、凋落物量、粗木质物残体(CWD)量、土壤重量，综合了前人植物生物量数据，计算出生态系统各层次铅和镉的贮量及其各层次的分配；分析了同一生态系统铅和镉含量和贮量的内部差异以及不同典型生态系统铅和镉含量和贮量的垂直分异规律；探讨了铅和镉在研究区的潜在生态危害评价及3000m附近生态系统铅和镉的地球化学特征；总结了铅和镉在该区域植物和土壤中可能的转移机制，为高山生态系统铅和镉的环境容量提供借鉴以及为铅和镉的生物地球化学行为提供参考。论文主要研究结果如下： (1) 植物生物量各层次的垂直分异 典型生态系统生物量随海拔升高表现出先增加后减少的趋势。乔木层、草本层生物量、地被层生物量、凋落物量以及CWD量均随海拔增加，先增加后减小。灌木层生物量随海拔增加，先增加再减小再增加。 (2) 生态系统植物部分铅和镉含量垂直分异 同一典型生态系统，植物凋落物与细根铅和镉含量显著高于其他组织和器官。干器官铅含量最小，枝中镉含量大于叶。植物根部铅和镉含量分别为：细根>中根>粗根。草本地下部分铅和镉含量显著高于草本地上部分。不同典型生态系统，草本层地上镉含量随海拔增加而增加。地被层铅和镉含量随海拔升高先增加后减小。凋落物铅含量随海拔增加而减小。 (3) 生态系统植物部分铅和镉贮量垂直分异 随海拔增加典型生态系统植物部分(包括凋落物与CWD)铅和镉的总贮量，呈抛物线变化，在2780m与3200m典型生态系统中间某处可能存在一个最大值。典型生态系统乔、灌层各组织和器官铅和镉贮量在中间海拔典型生态系统（2780m针阔混交林和3200m暗针叶林）中有最大值。草本层铅和镉贮量主要集中在草本层地下部分。随着海拔的增加，草本层、地被层、凋落物与CWD铅和镉的贮量先增加后减少。 (4)生态系统土壤部分铅和镉含量与贮量垂直分异 土壤O层与A层铅与镉含量显著高于其B、C层，并随着土壤剖面向下含量逐渐降低。典型生态系统土壤铅和镉贮量的垂直分异为：随海拔增加，先增加再减小。O层与A层土壤铅贮量随海拔增加先增加再减少。B层土壤铅贮量随海拔增加有较缓的增加。C层土壤铅贮量2200m与2780m典型生态系统大致相当。3200m与3800m典型生态系统大致相当，3200m典型生态系统铅贮量最大。 (5)生态系统铅和镉总贮量垂直分异 典型生态系统铅和镉的总贮量的垂直分异规律为：随海拔增加先增加后减小，海拔3200m暗针叶林生态系统达最大值。随海拔的增加，典型生态系统铅的总贮量从海拔2200m的常绿与落叶阔叶林的最小值不断增加到海拔3200m暗针叶林达最大值，随后小幅下降。典型生态系统镉的总贮量从海拔2200m常绿与落叶阔叶林的最小值缓慢上升到2780m，再迅速上升到3200m暗针叶林达最大值，而后又迅速下降。 (6) 生态系统铅和镉的地球化学特征及潜在生态危害评价 目前贡嘎山东坡典型生态系统的铅存在生态轻微危害，然而镉严重富集，应予以高度重视。潜在生态危害指数不仅考虑了土壤重金属的含量，而且将重金属的生态效应、环境效应等联系在一起。以贡嘎山3000m附近森林生态系统为例，初步计算出森林生态系统铅和镉年输入量、输出量以及年贮量。 |
| 英文摘要 | Human activities have caused global pollution of heavy metals. Lead and cadmium, "five toxic elements", whose accumulation of in the environment will do harm to human health and ecosystem security, has been widely concerned. The Gongga Mountain is located in the east of the Qinghai-Tibet Plateau, the border of our secondary ladder of China. The vegetation ecosystem of eastern slope of perpendicular band spectrum can be used as a huge probe to monitor regional and national scale changes of environment. In this study, four typical ecological systems in such perpendicular band spectrum are selected as research objects. Lead and cadmium concentrations among dominant plants and different layers' soil in different typical ecosystems were measured and analyzed using the field investigation of various plant tissue and organ biomass, litter production, coarse woody debris production and weight of soil, as well as combining the previous plant biomass data, lead and cadmium concentration and storage of each constituent from the ecological system was calculated ; Differences and distribution characteristic of Lead and cadmium concentrations and storages between internal ecosystem and different typical ecosystems are analyzed； The potential ecological risk assessment of lead and cadmium in the study area and the ecosystem geochemistry characteristics of lead and cadmium around 3000 m asl were explored; Possible transfer mechanism of Lead and cadmium between plants and soil are summarized in order to provide references in terms of environment bearing capacity of the mountain ecosystem of lead and cadmium and biogeochemical behavior of lead and cadmium; Main research results are as follows: (1) The vertical differentiation of each constituent of plant biomass Typical ecosystem biomass with increasing altitude shows the first increase after the decrease trend. Similarly，tree layer biomass，herb layer biomass, ground layer biomass，litterfall production as well as coarse woody debris production shows the first increase after the decrease trend. The shrub layer biomass increases with altitude, increased first and then decrease to increase again. (2) The vertical differentiation of Lead and cadmium content of ecological system In terms of the same typical ecosystem, litterfall and fine root of lead and cadmium concentrations is significantly higher than other tissues and organs. Xylem reach the bottom in terms of lead concentrations and twig is higher than leaves. Plant roots of lead and cadmium concentrations is in the order of: fine roots > mid roots> coarse roots. The aboveground herb is significantly higher than the underground part in terms of lead and cadmium concentrations. On the other hand, different typical ecosystem, aboveground part of herb layer cadmium content showed an increasing trend with the increase of altitude. Ground layer of lead and cadmium concentrations with increasing altitude showed the first increase after the decrease trend. Litterfall of lead concentrations also showed the first increase after the decrease trend. (3) The vertical differentiation of ecosystem plant constituents of lead and cadmium storage With the increase of altitude, typical ecosystem plant part (including litterfall and coarse woody debris) the total storage of lead and cadmium, showed a parabolic variation. There may be a maximum in the middle of the 2780masl and 3200masl typical ecosystem. Lead and cadmium storage of various tissues and organs in terms of tree and shrub layers reach the peak in the mid altitude (2780m and 3200masl). Herb layer of lead and cadmium storage are mainly concentrated in herb layer underground part. With the increase of altitude, herb layer, ground layer, litterfall and coarse woody debris of lead and cadmium storage showed the first increase after the decrease trend. (4) The vertical differentiation of ecosystem soil parts of lead and cadmium storage O and A layer soil of lead and cadmium concentrations is significantly higher than the B and C layers soil, the lead and cadmium concentrations gradually reduced from O layer to C layer soil. Typical ecosystem vertical differentiation of soil lead and cadmium storage are as follows: with the increase of altitude, the first increase then decrease. Lead storage of O and A layer of soil with increasing altitude increases first and then decreases. B layer soil lead storage showed a slow upward trend. There was a roughly similar value of lead storage in terms of 2200m and 2780m typical ecosystem and 3200m and 3800m. The 3200masl typical ecosystem of lead storage reach the peak. (5) The vertical differentiation of ecosystem total storage of lead and cadmium Typical ecosystem vertical differentiation regularity of the total storage of lead and cadmium is the first increase then decrease with the increase of altitude, and reaches the maximum at an altitude of 3200m. With the increase of altitude, the total storage of typical ecosystem of lead from 2200m of minimum value to 3200m maximum, then fell slightly. The total capacity of typical ecosystem cadmium from 2200m minimum slowly climb to 2780m, and then rapidly up to a maximum 3200m, then drops rapidly. (6) Potential ecological risk assessment of the ecosystem of lead and cadmium The evaluation results showed that the current typical ecosystem of eastern slope in the Gongga mountain. Lead showed an ecological slight damage, however, cadmium has heavily accumulated in the top-soil. Related institutions should pay attention to this phenomenon. Potential ecological harm index not only consider the concentrations of soil heavy metals, but take the ecological effect and environmental effect of heavy metal in to account. Taking around 3000m forest ecosystem for example, the forest ecosystem of lead and cadmium in term of input, output and reserves per year were roughly calculated. |
| 语种 | 中文 |
| 源URL | [http://ir.imde.ac.cn/handle/131551/14178]  |
| 专题 | 成都山地灾害与环境研究所_山地表生过程与生态调控重点实验室 |
| 作者单位 | 中国科学院成都山地灾害与环境研究所 |
| 推荐引用方式 GB/T 7714 | 唐荣贵. 贡嘎山东坡垂直带典型生态系统植物与土壤铅和镉的垂直分异[D]. 北京. 中国科学院大学. 2015. |
入库方式： OAI收割
来源：成都山地灾害与环境研究所
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