【作者】 袁小燕；

【导师】 阎建忠；

【作者基本信息】 西南大学 ， 土地资源管理， 2012， 硕士

【摘要】 农地利用变化的生态效应一直是土地利用／覆被变化研究的热点问题。已有的研究表明,不同的时空尺度下,农业劳动力非农转移引起的农地利用变化对生态环境的影响效果不同。因此,有必要继续从劳动力转移视角深入探索农地利用变化及其生态效应。农户作为山区最微观的经济活动主体,其生计活动对生态环境产生直接或间接干扰,从农户微观尺度分析生计活动对农地利用变化引起的生态效应,为研究农村经济与山区生态环境建设协调发展提供了很好的研究范例。目前生态压力的概念尚无明确定义,已有大量文献从不同的理论背景对生态压力进行描述解释,并且已经建立了广泛的评估方法,但是基于农户微观尺度关注生态压力的研究较少。特别是在人地关系复杂的山区,农户的生计策略与生态环境恢复与建设休戚相关。充分认识、理解农户生计活动对山区生态环境造成压力的来源及特征,寻求减缓压力、促进农户生计与生态环境同步改善的可持续途径,有必要开展农户尺度的生态压力定量评估。重庆市酉阳县是典型的“大山区、大农村”,也是统筹城乡改革发展的重点建设区域,随着统筹城乡改革步伐的发展,农户生计状况及山区生态环境正在发生深刻变化。选择该区域作为研究对象,为认识农户生计演化与生态环境变化的关系,寻求兼顾农村社会经济与生态环境可持续发展的途径,提供了典型的案例研究。本文以“农村劳动力转移”为切入点,基于“农户生计—土地利用—生态效应”的主要界面,认识理解山区不同生计类型农户的生计资产、生态压力的来源及表现特征,并在此基础上构建生态压力评估指标体系,采用因子分析法计算农户生态压力指数,即“农户生态压力指数=综合因子分值”,以定量评估农户尺度的生态压力。研究结果表明：(1)随着农户非农活动的增加,农户对自然资产的安排策略不同。①在土地初次分配的基础上,农户户均承包林地面积与承包耕地面积趋势一致：纯农型>一兼型>二兼型>非农型。②随着非农活动的增加,土地转出规模大小与农户非农活动强度成正比,即非农型>二兼型>一兼型>纯农型。③农户撂荒耕地的面积除了与农户本身拥有的耕地资源条件相关外,主要与农户家庭劳动能力相关,纯农型农户以老人为主,因此撂荒耕地面积最多。④随着自然资产的流动,一兼型农户逐渐成为山区农业生产的主力军,实际耕作面积呈如下趋势：一兼型>纯农型>二兼型>非农型。(2)随着农户非农收入的增加,农户对物质资产的拥有程度呈现明显差异。①一兼型农户中养殖大户最多,农户家庭拥有的牲畜资产规模最大。②在农药的使用上,二兼型农户施用农药的数量最多。③纯农型农户多致力于精耕细作,使用农膜数量最多。兼业型农户使用的除草剂剂量相对较大。④纯农型农户仍在使用自留种,使用种子的数量远远高于其他类型农户。⑤农户家庭化肥、农家肥的使用与其机械化程度密切相关,一兼型农户机械化程度高,运输农家肥数量多,使用化肥的数量最少；纯农型农户机械化程度最低,对化肥的依赖程度高,使用化肥替代农家肥。⑥对于能源的使用,纯农型农户使用的薪柴和煤炭数量最多,一兼型农户使用电能和沼气数量最多,仅部分兼业型农户家庭使用液化气和太阳能。(3)不同生计类型农户生计策略现状及未来调整的总体趋势大体一致。①农户生计资产组合呈现多样化趋势,非农活动多样化包括外出务工、经商、打零工、家庭经营副业等种类,农业活动多样化主要体现在种植策略及养殖策略多元化两个方面。②农户农业活动规模呈现缩小趋势,非农活动呈现扩大化趋势。③农户参与户籍改革的积极性普遍较低,山区农户彻底释放人口压力的潜力较低。(4)农户生态压力受影响因子的作用程度不同。农户生态压力的主要影响因子为土地投入因子和土地产出因子。土地投入压力大小为：非农型<一兼型<二兼型=纯农型；土地产出压力大小为：一兼型>纯农型=二兼型>非农型。(5)不同生计类型农户的生态压力大小不同。纯农型农户和一兼型农户主要处于一般压力状态,二兼型农户主要处于中等压力状态,非农型农户主要处于低等和一般压力状态。以农户生态压力均值判断不同类型农户总体压力大小,结果表明：二兼型(0.16)>一兼型(0.15)>纯农型(0.13)>非农型(0.11)。因此,为了降低山区农户生态压力,应以二兼型和一兼型农户作为主要的减缓对象；并选择减少化肥、农药、薄膜和除草剂的使用量,增加农家肥投入,巩固退耕还林成果等作为缓解压力的主要途径。更多还原

【Abstract】 The ecological effects of agricultural land use change have been the hot issues of land use/cover change research.A large number of studies have indicated that the effects of agricultural land use change on the ecological environment caused by the conversion of agriculture,which change with time-spatial variation.Therefore,it is necessary to make an in-depth study on agricultural land use change and ecological effects from the perspective of rural labor mobility.Households are the smallest economic activity subjects,whose livelihood activities can directly or indirectly affect the ecological environment. It is worthwhile to make an analysis of the ecological effects deriving from agricultural land use change caused by households’livelihood activities,which provide a good case for the study on coordinated development of rural economy and mountain ecological environment.Although there is no clear definition for ecological-pressure, a wide range of methods have been applied to assess the ecological pressure.The term appeared frequently in a large number of literatures of different theoretical background,but the ecological-pressure of peasant households is still lack of research. The households’ livelihood strategies are closely related to the eco-environment construction and restoration in mountain areas with complex relation of farmers and rural lands. In order to fully understand the sources and characteristics of eco-environmental pressure caused by households’livelihood activities, to seek ways to release pressure and promote the sustainable development of households" livelihoods and eco-environment, it is necessary to assess households’ecological-pressure.Youyang is a tipical county with mountainous region and big country coexisting in Chongqing,which is one of demonstration cities of balancing urban and rural development. In the process of urban and rural harmonious development, rural households’livelihoods and the ecological environment are taking place profound changes in mountainous areas.Taking Youyang county as a case study,it is benifical to understand the relationship between the evolution of households’ livelihoods and the eco-environment change,to seek ways to take into account the sustainable development of rural socio-economic and eco-environment. Based on the main interface households’livelihoods-land use-ecological effects, starting with Rural Labor Transfer, this paper not only studied livelihood assets of the different types of households and the sources and characteristics of their ecological-pressure, but also built an ecological-pressure evaluation system, using factor analysis to assess quantitatively households’ecological-pressure, households’ecological-pressure index =comprehensive factor scores namely. The results show that:(1)Households adjust their strategies of using natural assets with the increase of non-farm activities.①On the basis of the initial distribution of land, the per-household’area of contracted arable lands and contracted forest is consistent:pu re-agriculture households>agriculture-dependent households>non-farming-dependent households>non-agriculture households.②Households’land transfer area is propo-rtionate to non-farm activities time with the increase of non-farm activities, non-agriculture households>non-farming-dependent households>agriculture-dependent h-ouseholds>pure-agriculture households.③Households’abandoned arable land area is not only related to farmland conditions but also related to the family labor f-orce, and the aging pure agricultural households abandoned the most arable land area.④With the flow of natural assets, agriculture-dependent households gradually become the main force of the mountains agricultural production, the overall trend of actual farming area showed that agriculture-dependent households>pure-agricul-ture households>non-farming-dependent households>non-agriculture households.(2) There are obvious differences in physical assets distribution between households of different living styles.①Agriculture-dependent households have the most livestock assets.②Non-farming-dependent households use the most pesticide.③Most pure-agriculture households devote to intensive farming, so they need the largest amount of agricultural film. However, part-time peasant households tend to use more herbicide.④Pure-agriculture households prefer to reserve seeds, so they need the most grain seeds.⑤The amount of chemical fertilizers and farmyard manure is closely related to households’mechanization level. Agriculture-dependent households with high mechanization degree prefer farmyard manure to chemical fertilizers, but pure-agriculture households with low mechanization degree have to use chemical fertilizers instead of manure.⑥ifferent types of rural households are inclined to choose different types of household energy. Pure-agriculture households use most firewood and coal, and Agriculture-dependent households tend to use electrical energy and biogas; however, only part of part-time peasants households will choose liquefied gas and solar energy.(3)The overall trend of the status of households’livelihood strategies and the future adjustment willingness in study area keeps generally consistent.①The households’livelihood portfolio is demonstrating diversified trend. Non-farm diversification includes outside workers, business, doing odd jobs, household sideline, and so on. Agriculture diversification includes planting strategies diversification and breeding strategies diversification.②Farm agricultural activities show a narrowing trend, but non-farm activities show a expansion trend.③The fact that households are not interested in participating in the household registration reform reflects that the potential of releasing the population pressure is low.(4) The correlativity between influencing factors and ecological-pressure vari es with households. The main factors of households’ecological-pressure include the land input factors and land productivity factors. The land input factors reflect that non-agriculture households<agriculture-dependent households<non-agriculture households=pure-agriculture households. The land productivity factor reflects that agriculture-dependent households>pure-agriculture households=non-farming-depend-ent households>non-agriculture households.(5)Different households show different ecological-pressure. The study shows t hat pure-agriculture households and agriculture-dependent households have been i n general pressure state, that non-farming-dependent households in the state of th e medium pressure, that non-agriculture households in low and general pressure s tate.This paper determines the overall pressure according to the households’ecol-ogical-pressure mean value.The results shows that non-farming-dependent househo-lds(0.16)>agriculture-dependent households(0.15)>pure-agriculture households(0.13) >non-agriculture households(0.11).In order to reduce households’ecological-pressure, centering on part-time peasant households’livelihoods and achievements of conv-erting farmland into forest and grassland, it is quite advisable to reduce the am-ount of pesticides,chemical fertilizer,agricultural film and herbicides applied by p-easants with increasing farmyard manure.更多还原