生态系统服务价值对土地利用变化的响应——以四川省内江市为例

本研究的目的为利用生态系统服务价值指标量化土地利用结构变化的生态效益,以此判断研究区当前的土地利用模式是否可持续。研究方法为生态系统服务功能的经济价值评估、环境经济学方法、灰色预测模型。研究结果显示,1996～2004年间,由于土地利用结构的变化,内江市的生态系统服务价值共损失4335.26万元;同时,在假设内江市保持现状土地利用方式、资源消耗和污染排放水平不变的情况下,预计到2010年,内江市的生态系统服务价值将比2004年再减少96829.18万元。研究结论：内江市生态系统服务价值的衰减主要由人工生态系统的扩张引起,因此编订科学的土地利用规划、优化土地利用结构已是当务之急。     

生物多样性对城市生态系统服务功能的影响

生物多样性是生物及其与环境形成的生态复合体,以及与此相关的各种生态过程的总和,具有十分重要的价值,是人类生存的物质基础。本文在分析我国城市生物多样性的现状和特征的基础上,论述了生物多样性在支撑城市自然生态亚系统、提高城市空气质量、修复污染土壤、降低噪声、改善土壤状况增加空气湿度、降低城市热岛效应、提供居民食品与医药及工厂原料、影响城市生态安全方面的作用;提出完善政策与法规,开展入文教育,拓展国际合作,确定保护优先序列和分层次保护机制,建设生态园林,防止生态入侵是避免城市生物多样性衰减的有效对策。     

Valuing Provisioning Ecosystem Services in Agriculture: The Impact of Climate Change on Food Production in the United Kingdom

This paper provides an estimate of the contribution of the ecosystem to the provisioning services generated by agriculture. This is achieved by valuing the changes in productivity generated by a marginal alteration in ecosystem inputs. As an example, we consider the variation in rainfall and temperature projected by the recent UK Climate Impacts Programme. The analysis implements a spatially explicit, econometric model of agricultural land use based on the methodology recently developed by Fezzi and Bateman (Am J Agric Econ 93:1168–1188, 2011). Land use area and livestock stocking rates are then employed to calculate farm gross margin estimates of the value of changes in provisioning ecosystem services. Findings suggest that the variation in ecosystem inputs induced by climate change will have substantial influence on agricultural productivity. Interestingly, within the UK context climate change generates mainly positive effects, although losses are forecasted for those southern areas most vulnerable to heat-stress and drought.     

Telecommunications Regulation and New Services: A Case Study at the State Level

This study introduces methodology to quantify the effects that regulation has on the innovation and the introduction of new products, and compares state-regulated services in Indiana under rate of return regulation (RoRR) and under alternative regulation. The econometric model comprises a count process (for innovation) followed by a duration process with selection (for regulatory delay). When the firm is released from RoRR, the rate of service creation triples and expected approval delays nearly disappear. The firm may have introduced up to 12 times as many services to consumers if the alternative regulation had been in place the entire time.     

基于土地利用变化的生态系统服务功能价值流向及损益评估

土地利用与土地覆被变化对生态系统服务功能价值具有重要的影响.文章以锡林郭勒草原国家级自然保护区为例,利用1987年、2000年和2005年的遥感影像数据,通过建立土地利用转移矩阵,计算了研究区1987～2005年的生态系统服务功能价值流向及损益情况.结果表明:(1)1987～2005年之间,研究区服务价值的损失量较大,其中草地的服务价值损失了近3亿元.(2)草地覆盖度的变化、草地沙化以及开垦是草地服务价值下降的主要原因.(3)湖泊和沼泽面积的减少,也是这一时期的一个显著特征,是研究区生态系统服务功能价值下降的重要原因之一.(4)研究区生态系统服务功能价值与土地利用变化有很大的相关性.     

滨海湿地生态系统服务及其价值评估——以胶州湾为例

选择胶州湾湿地作为研究区域,研究了其生态系统服务的类型并评估了各类生态系统服务价值。结果表明:2009年胶州湾湿地生态系统服务总价值为152.71×107元。其中,食品生产占56.57%,这表明胶州湾湿地物质产品供给占重要地位。其次调节功能占36.12%,在胶州湾湿地生态系统中也发挥重要作用。研究只对胶州湾湿地主要生态系统服务开展了评估,因此仅为一个保守估计。     

湿地生态系统健康评价研究——以黑龙江省七星河国家级自然保护区为例

文章以压力-状态-响应模型作为框架建立了一套湿地生态系统健康评价指标体系,运用层次分析法确定指标权重,并运用模糊综合评价法计算黑龙江省七星河国家级湿地自然保护区的健康度,根据压力、状态和响应分析的结果,提出湿地管理的建议.     

土地利用总体规划的县域生态系统服务价值变化预测研究——以河北省昌黎县为例

以河北省昌黎县为例,将生态系统服务价值评估引入到土地利用总体规划及评价中。对研究区的土地利用总体规划进行分析,在地类归并、转换的基础上,对应中国陆地生态系统单位面积生态系统服务价值,计算昌黎县在规划基期和末期两个时点的生态系统服务价值总量。由计算结果可知,昌黎县生态系统服务价值在规划期内呈上升趋势,共增加7174.64万元,即若严格落实规划,该县生态环境到规划期末将显著改善。分析其原因,主要是规划期内耕地、水体、自然保留地的减少和林地、园地的增加。     

Two Tales on the Returns to Education: The Impact of Trade on Wages

This paper uses micro data from the Current Population Survey combined with data from the US International Trade Commission and Bureau of Economic Analysis to evaluate the impacts of international trade (import penetration and export intensiveness) on wages with a special focus on the returns to education. Consistent with the literature, our empirical analysis provides evidence that the wage rates of similarly skilled workers differ across net‐exporting, net‐importing, and nontradable industries. Our results add to the literature by showing that the wage gap usually found across importing and exporting industries vanishes for highly skilled workers (workers with college degree and beyond) when we control for the cross‐effect between international trade and education, but the wage gap due to international trade still persists for low‐skilled workers. This finding supports the view that education serves as an equalizer and counterbalances the adverse impact from import penetration on wages of highly skilled workers.     

人工湿地生态系统服务分类及其价值评估——以临沂市武河湿地为例

湿地生态系统为人类的存在和发展提供了大量的必需品和服务。很多国家把发展人工湿地作为净化城市污水的一种途径。文章以临沂市武河湿地为例,根据国内人工湿地的建设目标和湿地生态系统的特点,重新划分人工湿地生态系统服务,建立了评价各个生态系统服务价值的评价方法。评价结果发现,武河湿地不仅实现了净化城市污水、改善当地居民健康、发展湿地旅游等设计目标,还带来了生物多样性增加等生态和社会经济效益。     

Exports, Returns to Scale, and Total Factor Productivity: The Case of Taiwanese Manufacturing Industries

The paper examines the relevance of international scale economies and international market efficiency of trade based on the firm-level data of Taiwanese manufacturing industries. The author first constructs a simple analytical framework to measure the extent of scale economies and total factor productivity for each firm. The measurements of scale economies and total factor productivity are then used to investigate the relationships among exports, scale economies, and productivity. Significant external scale economies associated with exports and a strong positive relationship between the individual firm's productivity and its own export intensity are observed.     

The Impact of Liberalizing Barriers to Foreign Direct Investment in Services: The Case of Russian Accession to the World Trade Organization

In this paper a computable general equilibrium model of the Russian economy is used to assess the impact of accession to the World Trade Organization (WTO), which encompasses improved market access, Russian tariff reduction, and reduction of barriers against multinational service providers. It is assumed that foreign direct investment in business services is necessary for multinationals to compete well with Russian business services providers, but cross‐border service provision is also present. The model incorporates productivity effects in both goods and services markets endogenously, through a Dixit–Stiglitz framework. It is estimated that Russia will gain about 7.2% of the value of Russian consumption in the medium term from WTO accession and up to 24% in the long run. It is also estimated that the largest gains to Russia will derive from liberalization of barriers against multinational service providers. Piecemeal and systematic sensitivity analysis shows that the results are robust.     

崇左市土地利用变化对生态系统服务价值的影响

研究土地利用变化对区域生态系统服务价值的影响具有重要意义.本文基于生态系统服务功能价值理论,根据崇左市土地利用变化的情况,定量估算了其土地生态系统为人类提供服务的经济价值.结果表明,1996～2000年崇左市土地生态服务价值总体表现为先降后升态势,区域各县(市)土地利用的生态价值变化表现出较大的空间差异.生态系统价值变动的根本驱动因素是农业用地内部各种用地类型之间的竞争.单位GDP对应的生态系统的服务价值在持续下降,当前土地利用结构调整中重视经济发展,而对生态环境重视不够,经济发展的同时牺牲了生态环境的生态服务功能和价值.