【作者】 金家琪；

【导师】 何丙辉；

【作者基本信息】 西南农业大学 ， 水土保持与荒漠化防治， 2005， 硕士

【摘要】 生态修复是为了加速已被破坏生态系统的恢复,包括生态自然修复和人工修复两个部分。它主要研究生态系统退化的原因、退化生态系统的修复方法、生态学过程与机理的科学,研究对象是退化的生态系统。生态修复模式的研究是充分利用生态修复理论,寻找人与自然和谐相处的最佳途径,使人类能够充分发挥人的主观能动性,合理利用自然为人类服务。贵州省赤水市是水利部和长江水利委员会水土保持局选定的“水土保持生态修复试点工程”试点县,也是长江流域水土流失治理重点县。赤水河是长江的一级支流。本论文依托于赤水市生态修复项目,从水土保持生态修复的概念出发,论述生态修复的理论基础,分析赤水市生态退化的机理,根据赤水市生态修复区的生态环境现状和生态修复试点县的经验,提出赤水市水土保持生态修复措施和修复模式。研究的结果主要包括: (1)生态修复区生态环境问题主要表现在森林破坏、水土流失、土地退化、作物产量低等方面,生态退化的原因除了水、土、坡等自然因素外,人类对资源的不合理开发利用和传统经济行为模式是生态退化的主要驱动力,主要体现在人口快速增长、毁林(草)开荒、陡坡垦殖、超载过牧、乱砍滥伐、树种单一、不合理土地利用结构、低层次产业结构等方面。 (2)对生态修复区生态环境进行评价的结果表明;修复区的植被覆盖度较好,生物多样性较好,适合人类生存,但人类对自然的影响超出了生态承载能力的范围,即生态修复区的发展处于一种不可持续的状态,生态有退化趋势。从各种评价因子可以看出,①修复区的生态环境质量指数(EQI)为60.71,评价级别为:良。生物丰富度指数为36.18,植被覆盖度指数为39.06,水网密度指数为71.46,土地退化指数为5.12,污染负荷指数为0.58,在这些因素中影响生态退化的主要因子是生物植被。②生态修复区的人均生态足迹为1.546 hm~2,人均生态承载力仅为1.094 hm~2,赤字0.452 hm~2。存在生态足迹赤字的原因是过去对自然资源的过度利用造成的。③年均侵蚀模数为1214 T/km~2.a,水土流失大于水土流失允许量,生态有退化趋势。 (3)提出生态修复措施为:退耕还林、封禁治理、荒山荒坡造林、农田工程、草地改良、农村能源工程、生态移民工程。 (4)对坡耕地、梯田、荒地、经果林、水保林、封禁治理6种不同生态系统类型作土壤理化性质分析,结果表明:在经过人工诱导修复的不同生态系统类型中,土壤理化性能指标均反映出了不同程度的改良效果。①在物理性质方面,其垂直剖面上的平均土壤容重,荒地比更多还原

【Abstract】 Ecological rehabilitation research the cause of ecosystem degradation, rehabilitating method of degraded ecosystem, and ecological process and mechanism on degraded ecosystem. It includes natural and artificial rehabilitation ,which speed up the restoration of destroyed ecosystem.. Chishui Municipality of Guizhou Province is experimental unit of Ecological Rehabilitation of Soil and Water Conservation Experimental Project which is chosen by Ministry of Water Conservancy and Water and Soil Conservationation Bureau of Changjiang Water Conservancy Commission . ChiShui river is a first class branch of ChangJiang river. In this paper, the theoretical and mechanism of ecological restoration is discussed and eco-rehabilitation measures and modes of soil and water conservationation in Chishui Municipality is pointed out, which based on the eco-environmental situation of eco-rehabilitation region and experience of eco-rehabilitation of experimental county in Chishui Municipality. The results are as follows.(]). Environmental problem of ecological rehabilitation area primary includs forest devastation, soil and water loss , land degradation, crop poor yield and so on.Tthe main causes of ecological degradation include irrational utilization and traditional economic modes which embodied population rapid growth, destroying forest and opening up wasteland, tillage in steep slope, excess graze, mangling trees, single tree variety, irrational utilizing land and low level industrial structure except for natural reasons such as water, soil and slope.(2). The evaluation of ecological environment in eco-rehabilitation region indicate that vegetation coverage and biodiversity are preferable in ecological rehabilitation region, but the man’s influence on nature overstep ecological capacity. That is to say, the development of eco-rehabilitation region is unsustainable and there might be degradation tendency. All evaluation factors show: (1) the Environmental Quality Index (EQI) of ecological rehabilitation area is 60.71 and grade of evaluation is good. Biology Abundance Index is 36.18, Plant Cover Index is 39.06, Hydrographic Net Density Index was 71.46, Land Retirement Index is 5.12, and Pollution Load Index is 0.58. In theseindexes the vegetation is the main factor influenced ecological degradation, (2)the ecological footprint is 1.546 hm2 per capita, the ecological capacity is only 1.094 hm2 per capita, and deficit is 0.452 hm2 per capita in ecological rehabilitation area. The cause lied in the fact that we excessively exploited resources in the past. (3) the average erosion modulus is 1214 t/km2.a, the amount of soil and water lose is more than the allowed amount, and the environment tends to degeneration. (3). Some effective measures were brought forward to restore ecosystem, including cropland to forest and grassland, closing hillsides to administrate, planting trees on waste hill and slope, fanning engineer, improving grassland, rural energy engineering and ecological emigration engineering.(4). Soil physical and chemical characters of six ecosystem types -farmland on slope, terrace,wasteland, economic and fruit forest, forest for preserving water and soil and closing hillsides to administrate ia analyzed, the result of study shows that in different ecosystem types which received manual inducing restoration, soil physical and chemical indexes reflect improving effects of different degrees. Firstly at the aspect of physical character, the average bulk density of soil of wasteland is more than that of economic forest, fruit forest and soil and water conservation forest, farmland slope is more than terrace in their vertical section. The average bulk density of soil became larger with layer of soil depth increasing, and the changing rule of soil porosity is quite the reverse with the average bulk density of soil among the different layers of soil. Second at the aspect of chemical character, the organic contents of forest for preserving water and soil, economic forest ,fruit forest and closing hillsides to administrate are more than that of wasteland as control. The average of organic, total N and total P contents of the terrace are all more than those of the hillsides cultivated in the different layers of soil. The total N and P contents of forest for preserving water and soil, economic and fruit forest and closing hillsides to administrate were more than those of wasteland.(5). Soil fertility of bare soil , grassplot, shrub-tree land, pure conifer forest land, pinus armandii mixed forest land and deciduous broad-leaved forest land is comparatively analyzed, findings shows that the difference of Soil Fertility Index (SFI) of six communities is significant. The Deciduous broad is maximum, and the bare soil is minimum. In the light of SFI, the turn from high to low is Deciduous broad-leaved forest, Pinus armandii mixed forest, Shrub-tree, Herbacous, Pure conifer forest and bare soil.(6). Accordding to the analysis of species diversity and biomass in each restoration phases after cropland to forest, the results suggest that after cropland to forest 5 years, vegetation coverage degree increasing quickly. It rises from 92% to 96% in stable state, and Shannon-wiener Index rises from 1.63 to 2.3, then descends gradually to 1.41 in stable state. Biomass of community increasing gradually, it rises form 2.35 kg/m2 to 7.16 kg/m2, every meter square increase 4.8 kg averagely.更多还原