From the Holocene to the Anthropocene: A historical framework for land cover change in southwestern South America in the past 15,000 years

The main forest transitions that took place in south-central Chile from the end of the last glaciation to the present are reviewed here with the aim of identifying the main climatic and socio-economic drivers of land cover change. The first great transition, driven primarily by global warming, is the postglacial expansion of forests, with human populations from about 15,000 cal. yr. BP, restricted to coastlines and river basins and localized impact of forest fire. Charcoal evidence of fire increased in south-central Chile and in global records from about 12,000 to 6000 cal. yr. BP, which could be attributed at least partly to people. The subsequent expansion of agriculture led to much clearing of forests and the spread of weeds and other indicators of open habitats. The Spanish colonial period in America may have been followed by a transient expansion of forest cover into abandoned land, as indigenous population declined rapidly due to disease and slaughter. The 18th and 19th centuries brought about extensive loss of forests due to the massive impact of lumber extraction for mining operations both in central Chile and in western North America. Two centuries of intensive deforestation, coupled to grazing by cattle and extremely variable rainfall had long-lasting effects on forest cover in south-central Chile, which persist until today. The transition from a preindustrial to an industrial society brought about the “golden age” of timber harvest, assisted by mobile sawmills and railway transportation since the late 1800s. These advances led to the exhaustion of native commercial timber by the late 20th century in south-central Chile. In North America, harvestable stands were exhausted in New England and the Midwest around 1920. Settlement of the independent territories in the late 1800s and early 1900s implied vast burning and clearing of land and mounting soil erosion. Industrial forestry, based on government-subsidized massive plantations of short-rotation exotic trees, developed in the late 20th century, in connection with postindustrial displacement of exploitative activities from developed to third-world nations. In the last two decades, economic globalization and free trade promoted the expansion of new crops and further decline of woodlands, despite modest increases in forest cover. These patterns are repeated in many Latin American countries. To prevent further depletion of native forest resources and to provide an insurance against climate change, in the 21st century developing nations should aim at: (1) relocating subsidies from fiber farms to restoring diverse forest cover, (2) promoting ecosystem management of diverse forest and crops within landscapes, and (3) fostering diverse cultural relationships between people and their land.     

福建省国有林场营林投资经济效益评价研究

运用净现值法和内部收益率法,用福建省国有林场杉木生产过程中发生所有费用和木材生产过程中发生费用的资料,研究福建省国有林场营林投资经济效益。结果表明:国有林场林业投资有一定的经济效益,但经济效益还是比较低;以6%的资本利率,杉木投资的净现值为178.53元/hm2。林业税费政策调整以后,林业投资收益主要取决于造林抚育的支出水平。     

中国式“荷兰病”与中国城乡就业研究

文章从来源于入世后外向型劳动力密集型产业繁荣的中国式"荷兰病"理论出发,对中国式"荷兰病"通过"支出效应"、"资源转移效应"和"人民币汇率效应"等渠道影响中国城乡就业的情况进行了实证研究。在"中国式荷兰病"的影响下,我国就业城镇化趋势明显,传统就业主渠道丧失,特别是就业增长越来越严重地依赖于外向型劳动力密集型产业的持续繁荣以及大规模从事加工贸易的东部沿海地区。文章建议规范和鼓励城镇服务业发展、支持企业产品与产业结构调整、扩大人民币汇率浮动区间以及加大中央政府财政反哺农业和中西部地区等措施来确保中国经济与城乡就业的可持续发展。     

Economic and environmental impact of the CAP mid-term review on arable crop farming in South-western France

The issue addressed in this paper is whether implementation of the CAP MTR, (involving decoupled payments reduced by “modulations” and subject to cross-compliance measures) can be effective in improving the environmental impact of arable farming. The focus is on two French cross-compliance measures (compulsory buffer strips along rivers and crop diversity). A farm-level bio-economic model incorporating yield uncertainty is built and adjusted to represent two typical arable farms in the Southwest of France. The model also combines agro-environmental indicators. The results indicate that a simple decoupling of direct payments, without cross-compliance measures, has no impact on allocations between different crops. If cross-compliance measures are imposed, a small reduction in the cultivated area of irrigated crops is observed. The penalty levied (1% of the total subsidy paid) when farmers do not comply with the “buffer strips” requirement is sufficient for both farm-types. Decoupling and modulation result in a fall in the total gross margin of around 3%, principally because of the 5% modulation rate, while the “buffer strips” requirement leads to a further decrease of around 1%. Moreover, this requirement improves the environmental indicators at the farm level.     

黑龙江省宝泉岭垦区耕地动态变化及集约利用评价

以宝泉岭垦区为研究单元,采用土地利用变化速率、土地利用程度综合指数等概念就数量和程度上分析1994-2008年耕地利用的动态变化过程,在此基础上,从投入强度、利用程度、产出效益、持续状况四个方面选取16个指标构建耕地集约利用评价体系,对研究区耕地集约利用程度进行定量分析及评价.研究结果表明:1.研究期内宝泉岭分局及各农...     

重庆市耕地资源非市场价值估算

研究目的：探讨耕地资源非市场价值内涵,估算重庆市耕地资源非市场价值。研究方法：运用生产成本法、影子价格法等估算方法,估算重庆市1997-2011年的耕地资源生态服务和社会服务非市场价值。研究结果：（1）重庆市单位面积内耕地资源生态服务价值和社会价值总体上呈波动上升趋势;（2）重庆市耕地资源生态服务价值中,营养循环功能价值、净化环境功能价值和大气调节功能价值上升幅度较大且所占比重较高;（3）重庆市耕地资源社会服务价值从高到低：基本生活保障价值（44.49%）＞粮食安全功能价值（36.87%）＞失业保障价值（18.63%）,且基本生活保障价值呈下降趋势,粮食安全功能价值提升幅度较快;（4）农民作为耕地资源非市场价值体系的最基础价值主体,其价值需求尤其值得关注。研究结论：科学认识耕地生态和社会两大非市场价值,有利于耕地资源可持续利用。     

天津市二次调查中边缘化耕地分析及探讨

本文以天津市二次调查中耕地认定过程存在模糊的土地作为研究对象,将不稳定和可调整的耕地列入边缘化耕地范畴。通过对全市边缘化耕地的类别、数量和分布情况等进行分析和研究,首次摸清全市边缘化耕地家底,为天津市耕地保护、耕地占补平衡、耕地后备资源补充等土地资源管理和土地参与宏观调控提供决策依据。     

双边佣金约束的荷式拍卖问题研究

对于各种交易方式来说,荷式拍卖在农副产品交易中占有重要地位,具有广泛的发现产品市场需求和形成合适市场价格的作用。中国的农产品流通模式呈现“小生产,大流通”的特点,在这种流通模式下,拍卖行的存在,对农产品交易起着举足轻重的作用。拍卖行为买卖双方提供交易服务,并收取一定佣金。在标准拍卖模型中引入佣金变量,分析买卖双方同时支付佣金时的均衡策略,可得出竞买人数作为内生变量时,佣金结构变化所带来的影响。     

荷兰地下水税的终结及借鉴

通过系统研究荷兰地下水税从诞生到终结的全过程,从制度设计、环境影响、经济作用、纳税人影响以及对地下水管理作用5个维度对其失败原因进行剖析,借鉴其经验教训,提出我国水资源税改革在政策制定和实践探索中应注意的问题及相应的对策建议,为我国水资源税费改革提供参考。     

坚守“18亿亩耕地红线”中的政府角色思考

耕地保护关系着国家的粮食安全问题.随着经济的发展,人们对改善生活条件的要求更加迫切,耕地保护工作愈发显得重要.从中央到地方各级政府是耕地保护的主体,负有建设管理和保护耕地的责任,但由于地方政府的角色失位,对相关法律法规漠视,执法不严,违法用地现象普遍.今后应进一步落实地方政府责任,提高地方政府的耕地保护伦理意识,为耕地保护创造良好的工作机制.