【作者】 方广玲；

【导师】 吴斌； 张宇清；

【作者基本信息】 北京林业大学 ， 复合农林学， 2010， 博士

【摘要】 沙区具有植被覆盖度低、生物多样性差、系统稳定性差、水资源匮乏等生态脆弱特征。与此同时,毁林开荒、垦殖草地、过度放牧、滥采滥挖等不合理的人类活动,在破坏沙区生态系统平衡过程中起到加速作用。因此,沙区长期处于经济发展缓慢与生态环境恶化的双重困境。如何协调沙区生态环境建设与社会经济发展的关系,促进二者良性发展,成为一个重要课题。沙区土地利用变化作为人地关系作用结果的平面投影,成为该区生态环境与社会经济协调发展研究的的切入点。在此基础上,探索合理的沙区土地利用模式,是指导如何正确处理“生态脆弱区”人地关系,实现沙区人口、资源、环境与经济协调发展的需要,也是“生态脆弱区”人居环境建设的重要途径。盐池北部风沙区生态环境脆弱,经济发展落后,土地利用粗放,农业结构不合理,在沙区中具有一定典型性。本文通过对研究区五个乡(镇)大面积的实地调查,初步掌握该区土地利用结构特点,以及90年代以来的土地利用和农村经济变化情况。进一步搜集相关资料,进行遥感影像解译、统计数据处理与分析,计算描述土地利用变化的各项指数,进行盐池北部风沙区土地利用时空变化分析。在此基础上,利用主成分分析、典型相关分析法,对土地利用变化的驱动机制、社会经济效应进行研究。利用土地利用类型格局指数与沙地景观格局指数,分析盐池北部风沙区土地利用格局变化下的沙地景观响应。在上述综合分析基础上,建立研究区土地利用系统指标体系,对土地生态子系统与土地社会经济子系统耦合关系进行分析。研究目的在于,提出有利于沙区生态环境与社会经济可持续发展的土地利用模式,对实现沙区人类与环境协调发展具有现实意义,同时也为沙区土地利用系统研究,以及政府决策土地利用结构优化方向提供科学依据。本文主要的研究结论如下：(1)盐池北部风沙区近19年来土地利用变化比较剧烈,耕地和沙地的减少是1989-2007年间研究区土地利用变化的核心问题。禁牧封育、退耕还林还草促进了耕地、沙地向草地转化,也推动了草地覆盖度增加,以及草地向林地的转化。研究区水资源缺乏、风沙活动强度大,容易导致林地退化为草地,是沙区林业生态工程建设亟待解决的问题。草地是较为稳定的土地利用类型,只要避免人为垦殖和过度放牧,草地沙化的可能性较小。应合理配置林地、草地、耕地比重,选择耐干旱、耐风蚀的灌木树种与优质牧草复合经营,是今后土地利用优化的方向。(2)自然因素和人为因素是盐池北部风沙区土地利用变化的驱动力,其中,人为因素对研究区土地利用变化的贡献率达到89.2%,自然因素的贡献率为10.8%。人为因素在驱动土地利用变化过程中居于主导地位,包括生态保护政策、农业科技进步、农牧业经济发展、人口增长。生态保护政策与农业科技进步,对研究区土地利用变化过程的影响最显著。退耕还林还草政策实施对耕地变化的解释力最强,封育措施对沙地、草地变化的解释力最强,灌溉面积增加对林地变化的解释力最强。耕地、沙地向林地、草地的转化,最主要是生态保护政策实施与农业灌溉能力增强,保障沙漠化治理长期而稳定进行的强大动力源于政策支持。(3)研究区近19年来的土地利用格局变化具有良好的生态、社会、经济效应,促进了区域生态与社会经济的协调发展。在土地利用变化过程中,集中连片的沙地景观基本消失,以草地和林地为主导的土地利用格局正在形成。这表明通过恢复林草植被,构造合理的土地利用格局,能够有效防治沙漠化。耕地、沙地向草地、林地的转化,对农村经济总量与结构、农民就业与收入具有积极影响。发展林草产业,是促进沙区农村社会经济发展的重要途径。(4)1989-2007年,研究区近50%的沙化面积来源于耕地、林地和草地,一方面是由于近年来的人类活动影响,另一方面原因是历史时期人类地理环境变化所引起的自然环境变化。林业生态建设在沙漠化防治中发挥了重要作用,草地初期固沙效果不及林地明显,但是林地容易退化为草地和沙地是不容忽视的问题。针对沙区,需要进行传统林业生态建设思想的转变与模式的改进。沙区不适宜发展种植业,在农村社会经济发展过程中,应建立“半自给型种植业,商品型牧业,保护型林业”的农业结构,加大外界环境的物质、资金、技术输入,最大限度地控制生产用地。更多还原

【Abstract】 The characteristics of sandy area are low vegetation cover, biodiversity poor, poor stability of the system, water scarcity and other ecologically fragile features. At the same time, unreasonable human activities such as deforestation, grassland reclamation, overgrazing, excessive digging play accelerating role in the process of ecosystem balance destruction. Therefore, the sandy areas are on the double dilemmas of slow economic development and environmental degradation in a long period. It has become an important subject how to coordinate the construction of ecological environment and the relationship between socio-economic development, and how to promote both benign development. Sandy area land use change as a result the role of man-land relationship planar projection is the entry point of coordinated development of ecological environment and socio-economic study in this area. On this basis, to explore and rational land use pattern of sand area, is guidance on how to correctly handle the relationship between people and land ecologically fragile areas, to achieve sand area of population, resources, environment and coordinated economic development needs, but also ecologically fragile construction of human settlements important way.Northern of Yanchi is a region with vulnerable ecological environment, the lagging economics situation, extensive land use and irrational structure of agriculture, which is a typical of the sand area. On the base of field survey and related data collection, combined with remote sensing image interpretation and data post-processing and analysis, with the calculation of the index of land use change, this paper analyzed the land use change of Northern of Yanchi. On that basis, this paper studied the driving mechanism of land use change and socio-economic effects, using principal component analysis, canonical correlation analysis. Using index of land use pattern and sand landscape pattern indices, this paper analyzed the Northern of Yanchi of land use pattern change on the landscape of the sand.Based on the analysis above, the index system of land using which could be used to analysize coupling relationship between land ecological subsystem to land socio-economic subsystem was established. Suggesting land use patterns which is favorable for the sandy ecological environment and socio-economic sustainable development has practical significance for the realization of sandy harmonious development of mankind and the environment.Also,it can provide scientific basis to the study on sandy land use system,and decision-making by government in land use.The results show as follow.(1) Nearly for 19 years the Sandy Area of North Yanchi, land use changed dramatically from 1989 to 2007, the core issues of land use change in study areas was reduction of arable land and sand. Enclosing sand with prohibition of grazing and reforestation promoted farmlands and sand converted to grassland and the increasing of the cover of grasslands and reforestation.the study areas lack of water resources with intense drift activity. This easily result in forest degradation to the grassland. And this is a serious problem of sand forest ecological projects.sand forest ecological projects.grassland is stabler type of land use.(2) Natural and human factors driving salt pond in the Northern Suburb of land use change, which overwhelmingly dominant cultural factors, including ecological protection policy, agricultural science and technology, agricultural economic development and population growth. Ecological protection policies and agricultural science and technology in study areas land use change process, the most significant impact. Grain for Green policy on the farmlands, the strongest explanation of the changes, change in irrigated area to increase the explanatory power of most forest land, grassland fencing area to increase the explanatory power of the strongest changes. Farmlands to woodland, grassland conversion, the most important is the implementation of environmental policy and agricultural irrigation, enhanced security and stability for long-term desertification powerful impetus from policy support.(3) The variation of land use pattern manifasted favorable ecological, social and effect in studied area during 19 years. During the variation process of land use, centralized sandy land landscape disappeared while the land use pattern dominanted by grassland and forest is forming. This show s that desertification canbe effectively controled by recovering forest-grass vegetation and constructing reasonable land use pattern. The transformation of landy land and cultivated land to grassland and forest have positive influence to structure and economic aggregate of countryside and employment and income of farmers. The development of forest-grass industry is a improtant way to promote the development of rural economy development.(4) 1989～2007, nearly 50% sandy land in study areas originated from farmland, woodland and grassland, on the one hand is due to natural changes caused by geographical change on human history, the other reason is effects of human activities in recent years Forestry ecological construction play an important role in desertification prevention. Early is no better than a woodland meadow fixing obvious, but the problem that desertification area in forest is greater than that in grassland can not be neglected.For sandy area, It is Necessary to change traditional forestry building idea and the mode.To develop planting in sandy area is not suitable, we should establish a "semi-subsistence farming, commercial type husbandry, protection forestry type" agricultural structure in the process of socio-economic development in rural areas,we also should increase the external environment of the material, financial, technical input inorder to control production land maximum.更多还原