【作者】 张莉；

【导师】 何丙辉； 张小林；

【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】 长江是我国的黄金水道,其流域面积为180万km~2,约占我国国土总面积的1/5;人口约4亿,占我国总人口的1/3;国内生产总值约占1/3,包括了9个省、市和自治区,在国内具有举足轻重的地位。而且包括了东部经济发达区和中西部贫因地区,其生态环境资源构造和经济发展均具有典型性和代表性。但是由于人类对资源的不合理利用,使得长江流域生态环境受到了严重破坏。其中水土流失是主要存在的问题,它影响到人与自然的和谐发展。长江流域水土流失分布最为集中的地区为长江上中游地区。据调查,坡耕地、荒山荒坡、疏幼林地是长江上中游地区土壤侵蚀的主要地类。这些地类均可通过采取一定的措施,发挥生态自我恢复能力,达到恢复植被、保持水土、建立良性生态系统的目的。这是因为长江流域大部分地区位于东亚副热带季风区,自然条件优越.年均降雨量约1100 mm,雨量充沛,气候温和,植物种类繁多,大部分地区植物可全年生长,十分有利于植物的繁衍和生态的恢复。本文选取了长江上中游的十个点,分别是重庆璧山、巫溪、陕西太白、甘肃两当、贵州赤水、云南姚安、湖南隆回县、江西安义县、四川平昌县、湖北夷陵等长江流域“水土保持生态恢复工程”试点县,跨越地域边界,通过对每个项目区植被、土壤、气候等自然资源和人口、经济等社会资料进行调查后,其从气候区、植被带、地貌单元、土壤地质和人类影响五个方面,将十个点聚类为四种不同的类型区,然后从四个不同类型区中选择四个代表县小流域进行研究,首先研究土壤肥力在生态恢复前和生态恢复后的变化;然后研究生态恢复前后植被的变化,以及植被变化的影响因素,在这个研究中将四个代表区采用不同的布设方法,生态恢复植被监测的研究也采用不同的方法,分别对各个代表区进行分析,然后进行纵横向比较水土保持生态恢复的主要过程及影响因子;其次进行综合效益分析,研究水土保持生态恢复对流域生态环境改善和社会经济发展的作用。其研究结果如下: (1) 十个试点县分区结果为:云南姚安属于滇中高原盆地北亚热带常绿阔叶林带;贵州赤水、重庆璧山、四川平昌属于四川盆地中亚热带常绿阔叶林带;江西安义、湖南隆回属于湘赣丘陵中亚热带常绿阔叶林带;重庆巫溪、湖北夷陵、陕西太白、甘肃两当地处秦岭大巴山一带,气候类型为北亚热带,植被为常绿阔叶树的针阔混交林带,综合气候、地貌和植被特点将这几个地区分为一类,即秦巴山地北亚热带常绿阔叶树的针阔混交林带。 (2) 在四个典型区中分别选取其中一个作为代表性样方进行研究,其土壤理化性质变化结果如下:四个代表地区土壤pH值均偏酸性,并且四个调查地pH值都比恢复前酸性增强,这是因为在自然植被的覆盖下,有机质的积累和分解对土壤盐基组成有一定影响,进而影响土壤的酸碱性。由于植被覆盖度提高,枯枝落叶会产生有机酸,因此这也是恢复后pH值降低的原因之一。有机质是土壤的重要组成部分,它在土壤物理性质上对土壤水、热、气等各种肥力因素起着重要的调节作用.对土壤结构、耕性也有重要的影响,生态恢复后土壤有机质含量都有提高;增长幅度分别为云南姚安县洋派河小流域127.2%,江西安义龙津镇小流域更多还原

【Abstract】 Yangtze river is the golden channel in our country, with the watershed area about 1800 000 km2, and occupy about 1/5 area of the whole country; with the population about 0.4 billion, which occupy 1/3 of the general population; its GDP is about 1/3 of that in the whole country, including 9 provinces, cities and municipality, so the Yangtze river watershed is holding the balance in he whole country. Especially the watershed includes the economy developed east area and poor region in middle-west, and with the typical and representative entironment structure and economy development. However, because of the absurd utilization overindulge management, the entironment of the Yangtze River watershed is in havoc. The soil and water loss is the main problem, which influence the harmonious development of nature and the human beings. The most concentrated area of the soil and water loss in this area is the middle and upper reaches. According to investigation, the sloping plow land, barren hills and slopes, sparse young woodland are the main erosion land use type in the middle and upper reaches of the Yangtze River. Under taking some measure, these kinds of lands can play self-restoration ability to achieve renewing plants, soil and water conservation, constructing good ecosystem. It’s because that most of the Yangtze River watershed area locates in the east-Asia tropic monsoon region, with superior nature condition, and annual rainfall about 1100mm, flush precipitation, moderate climate, and various kinds of plants, the plants in most of this area grow nearly during the whole year, so it’s in favor of multiply and restoration. Lately, the development of the restoration ecology stress no matter in the terrain or in the theory, it should span the border, effective restoration ask for more cooperation in more regions even nations, in year 2004, the theme of the 15th international ecology restoration is restoration landscape and design. Guiding by the trend of lately ecological restoration, this paper selects 10 spots in the middle and upper reaches of the Yangtze River, e.g. bishan in Chongqing, wuxi, taibai in Shanxi, liangdang in Gansu, chishui in Guizhou, yaoan in Yunnan,huilong country in Jiangxi, anyi country inJiangxi, pingchang country in Sichuan and yilin in Hubei, which are in the Yangtze River "Soil and Water conservation ecological restoration Project" experimental unit, span the terrain boundary, by the investigation of the plants, soil, climate etc natural information and population, economy etc social information of the project spots, base on the climate region, plant trip, physiognomy unit, soil geology and human influence, cluster these 10 spots into 4 different typical area, then choose 4 representative areas form the 10 spots to studying. Firstly, research on the change of the soil fertility between before restoration and after restoration; secondly, the plant change between before restoration and after restoration, and the factors influence the plant change. Therefore take different measures in these 4 representative areas, and so did the restoration plant inspect, analyze separately every representativearea, and then compare the main process and influence factors during the restoration of soil and water conservation vertically and horizontally; carry on comprehensive benefit analyses and study restoration of water and soil conservation to the improvement of ecological environmental and development of society and economy. The study results are:(1) Yunan, yaoan belongs to plateau-basin north subtropical zone evergreen broad leaf forest belt in the mid-yunnan; Guizhou, chishui,Chongqing, bishan,Sichuan, pingchang belong to Sichuan basin evergreen broad leaf forest belt of middle subtropical zone; the climate belt of Jiangxi, anyi,Hunan, longhui belong to xiang-gan hills middle subtropical zone evergreen broad leaf forest belt; Chongqing Wuxi, Hubei yiling, Shanxi taibai, Gansu liangdang locate in Qinling Mountains and Daba mountain area, type of climate is north subtropical zone, vegetation in this area is mix and evergreen broadleaf forest of the needle-broadleaf tree belt, comprehensive climate, physiognomy and vegetation characteristic, divide these areas into one kind, belong to north subtropical zone, Qinling-bashan mountain region of mix and evergreen broadleaf forest of the needle-broadleaf tree belt.(2) Choose one of the four typical districts as representative spot to go on research the soil fertelizer,the pH value of the soil is acid and after repairing, the acid in the four investigation is to strengthen, this is because under the cover of the natural vegetation, the accumulation and resolving of the organic matter influence the saline constitution of the soil, thus influence the acid and alkalescence of soil. Because fallen leaf can produce organic sour, this is one of the influence factors among them that pH increases after repairing too. Organic matter is one of the most important component of soil, , it influence soil water, hot, air etc various kinds of fertility factors in soil physical property and have an important influence on the soil structure, ploughing too, the organic content of soil has been improved after the restoration; respectively: yangpai small watershed in yaoan country, yunan 127.2%, longjin town small watershed in anyi, jianxi 20.57%jianshan No.1 small watershed in pingchang, sichuan 12.2%, hongchiba small watershedin wuxi ,chongqing 40.6%. Among them the organic content increased most is Yaoan of Yunnan, the main reason is the introduction of the Australian Acacia with better nitrogen fixation, and improves the soil fertility at the initial stages of ecological restoration.(3) Though the ways to investigate the vegetation in four trial zone are different, according to the result of the analysis, the covering degree of vegetation has been improved after restoration; the improvement of vegetation cover degree is useful to water and soil conservation and stability of forestry ecosystem. The vegetation cover relates with the location of the ecological restoration area, take pingchang, Sichuan as an example, one region with different flow area, its effect of ecological restoration is different, the main constructive plant type is not the same , the bear effect degree is更多还原