森林群落的水分自营作用及其定量模式研究
文献类型：学位论文
| 作者 | 田雨 |
| 学位类别 | 博士 |
| 答辩日期 | 2012-05-24 |
| 授予单位 | 中国科学院研究生院 |
| 授予地点 | 北京 |
| 导师 | 程根伟 |
| 关键词 | 森林-径流关系 自营作用 P-M 方程改进 定量模拟 森林群落 |
| 其他题名 | Study on Water Self-supporting Effects of Forest Community and Their Quantitative Modes |
| 学位专业 | 自然地理学 |
| 中文摘要 | 森林与水的关系问题是生态学与水文学研究的中心议题之一。作为陆地生态系统的主体，森林生态系统涵养水源、防止水土流失和维持水质的功能为国内外学者所公认，但是对于森林分布是否增加或减少河川径流量至今仍然没有形成一个统一的结论和圆满的解释，给准确评价和预测森林砍伐、林地退化、自然恢复、防护林建设等大规模生态变化的水文效应带来了难题，影响了生态建设工程的效益评估和决策实施。 森林具有改造环境的功能，为了满足自身的水分需求，森林会通过各种途径调节水分环境，在调节过程中会引起径流的变化。这是森林植被的共性，也可能是植被引起不同水文效应的本质，从这个角度出发有可能统一地解释区域水文现象的差异。本文首先通过野外观测试验，从森林水分动态变化的规律及其对植被生存影响的角度出发，探讨了植被-水分之间相互作用关系。在此基础上，对多年来国内外学者的研究结果进行了归纳和总结，解析了林木冠层、枯落物层和根系对水分的调节作用，总结了森林调节水分的机制，从而丰富了森林水分自营作用假说。然后，本文用该假说诠释了长期以来不同地区大相径庭的森林水文现象。此外，本文提出了森林水分自营作用主要环节的定量化方法。最后，将森林水分自营作用主要环节定量化公式耦合到流域产流模型中对该模型进行了改进。 裸地(BL)、无凋落物覆盖林地(FB)和有凋落物覆盖的林地(FL)的水分动态变化及其对森林树木生长的影响的研究结果表明：1) FL样地的土壤含水量最高，其次是FB样地，而BL样地的土壤含水量最低；2) 地上径流展现了与土壤水分相反的趋势 (FL |
| 英文摘要 | Forest/water relationship has been a main theme in the field of ecology and hydrology. It is universally acknowledged that forest ecosystem, the main body of terrestrial ecosystem, plays an important role in water conservation, soil erosion prevention and water quality modification.However, whether forest increase or decrease the streamflow remains debatable and the exsiting theories can not exlpain these phenomena systematically and successfully, which brings difficulties in accurate evaluation and prediction of hydrological effects of large scale ecological activities, such as deforestation, forestland degradation, natural vegetation recovery and shelter-forest construction, and affects the profit evaluation, decision-making and implementation of ecological constrction project. Forests have a specific function in improving water conditions to meet their water requirements by various means, which results in the change of runoff. This is the general character of forest vegetation, and may be the essence that forest brings different hydrological effects and phenomena. In this paper, based on the field observation, the correlation between vegetation and water was discussed from an angle of impact of water dynamics of forestland on plant survival; and then, on the basis of the domestic and foreign research results, the adjustment of tree canopy, ground litters and roots to water and the mechanism of water self-supporting of forest was summarized, and then a new theory, which is called forest′s water self-supporting hypothesis, was embodied. The hypothesis can systematically explain the different forest hydrological phenomena. Moreover, the quantitative indexes and quantitative formula were proposed. Finally, the distributed rainfall-runoff model for small-watershed in hilly region (SRMSHR) was modified by coupling with the quantitative formula. In this paper, time series water dynamics (soil moisture, surface runoff, subsurface runoff and water yield) of forestland with bare surface (FB), forestland with ground litter (FL) and bare land (NF) in Yanting Agro-ecosystem Station, SW China were investigated, and the height, basal diameter, leaf area, specific leaf area (SLA), above- and under-ground biomass of plant in the FB and FL plot were compared. Results showed 1) soil water content (SWC) of FL was the highest, followed by FB and NF; 2) subsurface flow for the three treatments revealed the same trend as soil moisture, and surface runoff revealed a contrary trend, however, the total runoff between them didn′t suggest a invariable trend; and 3) at the beginning of the observation, the height, basal diameter, single leaf area, SLA, aboveground biomass and underground biomass for the FL plot trees were almost equal to the FB plot (p>0.05). However, at the end of the observation, the height, single leaf area, aboveground biomass and underground biomass between the two plots revealed significant difference (p<0.005), although basal diameter and SLA didn′t reveal significant difference (p>0.05). The morphological characters (height, basal diameter and leaf area) and biomass of plant in FL plot were higher than that in FB plot respectively, indicating better growth status of plant in FL. This showed forest improved the water conditions, and the condition in turn stimulated the plant growth and further improved the water condition, so that was a virtuous cycle. The interaction between forest vegetation and water environment in forest ecosystem might be a survival strategy of forest vegetation. Further analysis showed forest vegetation could independently regulate the forest water environment to increase useful water supply, decrease useless water expenses, and creates a desired water environment through adjusting water and energy from macrocosmic and microcosmic perspective. The regulation was a comprehensive result of canopy, trunks, ground litters and root system. We call the regulation “water self-supporting of forest”. The regulatory effect is a positive alternation result of forest to surroundings, and reflects the adaptability of forest ecosystem. The adjustment can affect water yield, on one hand, forest can lessen runoff through canopy interception, litter storage and soil storage, and on the other hand, forest can also increase runoff because the decreased potential evapotranspiration may lead to less water consumption. The runoff volume is comprehensively determined by the two opposite effects. Generally, the comprehensive effects differ in different areas, which results in the inconsistent regional hydrological responses. The water self-supporting effects of forest are shown in two aspects: one is the regulation effect of forest to water storage and the other is regulation effects of forest to water consumption. The formulae for quantifying the main links of the two aspects, such as canopy interception, ground litter storage, soil storage, reflectance and impedance of canopy were summarized. On this basis, two assessment indexes for water self-supporting effects of forest, ΔS and ΔD, were also used for describing the effect of forest vegetation on water supply and water demand. The ΔS and ΔD were defined asΔS= S1−S0 and ΔD= - (D1−D0) respectively, where S1 and D1 stand for water supply and water demand amount of forestland in a given t period (mm/d) respectively, and S0 and D0 stand for water supply and water amount of the corresponding non-forestland in a given t period (mm/d) respectively (mm/d). Furthermore, the SRMSHR model was modified. The modified model coupled with the quantitative formulae of forest′s water self-supporting effects, improved the computational method of canopy interception, modified P-M equation, and added a new module. The modified model exhibited better simulation effect and certain practical value. It could better simulate the rainfall-runoff process and qualify the water supporting effects of forest. The present work will contribute in discovering the essence of different hydrological phenomena, promoting the development of forest hydrological theory, and scientifically evaluating forest hydrological effects. |
| 语种 | 中文 |
| 公开日期 | 2013-01-14 |
| 源URL | [http://192.168.143.20:8080/handle/131551/4806]  |
| 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 |
| 推荐引用方式 GB/T 7714 | 田雨. 森林群落的水分自营作用及其定量模式研究[D]. 北京. 中国科学院研究生院. 2012. |
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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