Strategic targeting of agricultural conservation easements as a growth management tool

Public and private programs have preserved an estimated 730,000 ha of agricultural land in the United States by acquiring agricultural conservation easements (ACEs) that retire a property's development rights. ACEs could be a potent tool for smart growth if strategically targeted. This paper attempts to quantify measures of strategic targeting of ACEs as guidance for planners. Evaluating the placement of 157 ACEs in the San Francisco Bay Area of California produced mixed results. Preservation and development of agricultural land were both consistent with general plans. In contrast, we found little evidence of ACEs being used on a regional scale either to reinforce urban growth boundaries or to coalesce with other open space to form large contiguous blocks of protected areas. We used the TOPSIS method (Technique for Order Preference by Similarity to Ideal Solution) to identify the most strategic agricultural lands, which are quite different from where easements have been established through 2002. We encourage planners to consider strategic targeting of ACEs as a politically acceptable mechanism to complement traditional planning tools to minimize low density sprawl.     

海洋功能区划制度对我国海域资源配置的指导价值分析

海域资源配置问题日益受到国家海洋管理部门的重视,国家开展海域资源配置工作,需要从我国海洋功能区划法律制度中寻找基本依据。论文分析了海洋功能区划制度的基本内涵、发展历程和基本特征,探讨了海洋功能区划制度与海域资源配置的内在联系,研究了海洋功能区划制度对海域资源配置的指导价值。     

辽东湾顶部区海洋资源的开发利用与保护机理研究

辽东湾顶部区海洋资源丰富，海洋产业已初具规模，但在开发利用过程中也存在诸多问题和矛盾，如不妥善解决，就会影响到该区海洋经济的健康发展，因此必须采取有效的措施加以协调解决；分析了该区资源开发利用中存在的问题和矛盾；提出了解决矛盾和问题的一些措施，以期对该区在未来资源开发利用与环境保护中有所帮助。     

Soil conservation and technical efficiency among hillside farmers in Central America: a switching regression model*

The main objective of this paper is to evaluate and analyse technical efficiency (TE) levels for hillside farmers under different levels of adoption of soil conservation in El Salvador and Honduras. A switching regression model is implemented to examine potential selectivity bias for high and low level adopters, and separate stochastic production frontiers, corrected for selectivity bias, are estimated for each group. The main results indicate that households with above-average adoption show statistically higher average TE than those with lower adoption. Households with higher adoption have smaller farms and display the highest partial output elasticity for land. Constraints in the land and credit markets are likely explanations for these differences. In addition, all estimated models show that TE has a positive and significant association with education and extension.     

向海自然保护区芦苇湿地资源开发与丹顶鹤栖息地保护

向海自然保护区芦苇资源丰富,芦苇湿地又是丹顶鹤的重要繁殖栖息地,芦苇资源开发与丹顶鹤栖息地保护之间存在一定矛盾。2002年春季,向海湿地芦苇面积21 663hm2,芦苇总产量为13 700t,随着干旱的加剧,芦苇产量逐年降低;调查了丹顶鹤的迁徙动态及繁殖情况,探讨了芦苇资源的刈割方式对丹顶鹤的影响,不同的刈割方式对丹顶鹤繁殖的影响较大;提出了芦苇资源合理开发与丹顶鹤栖息地保护有机结合的对策。     

渔业财产权与海洋渔业资源养护制度的构建

我国海洋渔业资源面临衰竭的威胁,以政府主导型管理为手段的传统模式虽然在一定时期内起到了遏制“非法捕捞”的作用,但是在我国个人财产权法律制度不断健全的当今时代,确有必要倡导构建以私权利为核心的民间秩序,维护我国海洋渔业资源的养护制度,消除“公地悲剧”现象。创设渔业财产权概念是防止公地悲剧的最有效的措施。我国应当大胆借鉴英美法上的财产权概念,确立入渔机会的财产权属性。为此,我国《渔业法》再次修订时应当适度平衡渔业资源的财产权与执法成本之间的微妙关系。     

我国海洋生态系的恢复重建与渔业资源可持续利用

认真分析我国海洋生态系退化原因，根据生态系统恢复重建的理论，参照内陆水域生态恢复重建的理论与实践，并按照可持续渔业的原则，提出海洋生态系恢复重建的基本原理在于要以生物多样性为基础．以营养链为网络，在适当海域恢复不同层次的生态链，恢复重建海洋生态系的完整性；并据此提出以实施海洋生态系恢复重建来实现渔业资源可持续利用的战略构想：海洋生物多样性与生态系营养链的恢复重建、海洋渔业捕捞强度、养殖密度控制和加强海洋环境保护等。     

The impact of agricultural conservation easement on nearby house prices: Incorporating spatial autocorrelation and spatial heterogeneity

The impact of farmland under agricultural conservation easement (ACE) contract on the values of nearby residential properties is investigated using housing sales data in two Pennsylvania counties. ACE-protected farmland had a positive impact on nearby property values in one study county but a negative impact in the other. The paper also looks at the impact of forest land use, and discovers that preserved forest land had a positive impact on the nearby property values in both counties. House prices showed strong spatial correlation in both counties, and a spatial error components (SEC) model fit the data better than the OLS model, a spatial-lag model (SLM), or a spatial autoregressive error model (SEM). Geographically weighted regression (GWR) showed that the impact of ACE-protected farmland on nearby property values varied within one of the two study counties, with positive impacts in some parts of the county and negative impacts in other parts. The impact of forest cover on property values also varied, with positive impacts within both counties. A new hybrid GWR-SEC model is introduced that incorporates both spatial correlation in prices and spatial heterogeneity in the model parameters. Statistical goodness of fit measures showed that the GWR-SEC model fit better than the GWR model or a hybrid GWR-SEM model.     

Decision-making in soil conservation: application of a behavioral model to potato farmers in Sri Lanka

Soil erosion is one of the most devastating problems in the upper watershed areas in Sri Lanka. Erosion-prone cultivation of vegetables (especially potatoes) on steep slopes, without soil conservation measures, has become a major problem in the recent past. Soil erosion has significant impacts on on-farm as well as off-farm activities. Although various institutions have launched programs to introduce soil conservation techniques, these have not yielded expected results mainly due to a lack of understanding of the potato farmers’ behavior on investment decisions on soil conservation. Hence the conceptual model on investment decisions on soil conservation was tested in this paper. The analytical results of the generalized least square model indicated the importance of personal and economic, as well as institutional, factors in decision-making in soil conservation. Therefore, obtaining farmer adoption of erosion-control practices will require the use of various implementation tools such as education, subsidies, and technical assistance. Low willingness to invest in soil conservation indicated the necessity for public installation of conservation structures if they are to be widely used in potato farmlands in the upper watersheds in Sri Lanka.     

Protected areas in fisheries: a two‐patch,two‐species model*

The use of marine protected areas as a fishery management tool has been suggested as a hedge against management failures and variation in harvests. A stochastic bioeconomic model of a hypothetical predator–prey fishery is used to test the performance of protected areas in a fishery with heterogenous environments. Protected areas are analysed under density‐dependent and sink‐source dispersal relationships between the subpopulations that occur within the fishery. Differing management structures governing resource extraction are analysed. The focus of the study is placed on the biological and management characteristics that yield benefits to both fishers and society. It is shown that the establishment of a protected area improves fishery rent and lowers harvest variation. This result is sensitive to both current management controls and the correlation between species and patches.     

The tragedy of the commons: property rights and markets as solutions to resource and environmental problems

In one way or another, all environmental and natural resource problems associated with overexploitation or under provision of public goods, arise from incompletely defined and enforced property rights. As a result private decision makers do not consider or internalize social benefits and costs in their production or investment actions. The gap between private and social net returns results in externalities – harmful effects on third parties: overfishing, excessive air pollution, unwarranted extraction or diversion of ground or surface water, extreme depletion of oil and gas reservoirs. These situations are all examples of the 'The Tragedy of the Commons'. In this paper, I consider options for mitigating the losses of open access: common or group property regimes, government tax and regulation policy, more formal private property rights. I briefly summarize the problems and advantages of each option and describe why there has been move toward rights-based instruments in recent years: ITQ (individual transferable quotas), tradable emission permits, and private water rights. Introductions to the papers in the special issue follow.     

Water rights: a comparison of the impacts of urban and irrigation reforms in Australia

Although there has been a policy thrust towards making all Australians more cognisant of the relative scarcity of water resources, the approach adopted for urban dwellers differs markedly from that applied to irrigators. These differences are examined from a property-rights perspective focussing primarily on the institutional hierarchies in the Victorian water sector. The analysis reveals significant attenuation of urban dwellers' rights, presumably on the basis of the information deficiencies that circumscribe urban water use. Alternative policy options are then proposed, which might alleviate some of these information deficiencies and simultaneously address the efficiency losses that attend the present arrangements.     

Sharing property value losses: The spatial concentration of development rights as a way to limit urban sprawl

The examination of the literature on land value capturing and compensation shows that strategies based on the sharing of value losses deserve increased attention. This topic is relevant also with regards to the Swiss context of the study: following the entry into force of more stringent antisprawl provisions at the federal level, numerous peripheral municipalities must reduce the size of the designated building zones and withdraw development rights from landowners. Two municipal cases are presented: the first illustrates the difficulties currently faced by Swiss municipal authorities; the second shows a possible way of dealing with these difficulties. In this second case, a specific instrument that allows for the sharing of property value losses was implemented in the past. This instrument, which we will call the spatial concentration of development rights, is analyzed along with the conditions that made possible its successful implementation. The political and technical transferability of this instrument outside its original context is also addressed. The results show that the sharing of property value losses helps to deal with equity issues while being less demanding in terms of institutional change compared to the creation of a TDR system in Switzerland. Thus, the sharing of property value losses deserves being discussed as a suitable approach while implementing antisprawl policies in peripheral areas.     

Contract theory and agricultural policy analysis: a discussion and survey of recent developments*

This paper surveys some recent developments in contract theory and illustrates how this theory might be useful for conceptualising policy issues related to vertical coordination and contracting in the agro‐food industry. The article begins by surveying contract theory to identify key economic distortions that can potentially justify government involvement. Next, the general ingredients of agricultural contracts that are most likely to create inefficiencies are discussed. Finally, controversial aspects of real‐world agricultural contracts are highlighted and lessons from the theory are used to determine whether government intervention is justified. Actual legislation that has been proposed in the USA is analysed where appropriate and topics that await further research are also discussed.     

Ecological response to urban development in a changing socio-economic and climate context: Policy implications for balancing regional development and habitat conservation

Rapid land use/cover changes (LUCC) have triggered severe habitat degradation over recent decades. Existing studies mainly focus on how LUCC per se affects habitat quality, while less attention is paid to the integration of LUCC, socio-economic development and climate change as a land use system, and to investigate their synergistic impacts on habitat quality. This study addresses this issue by incorporating a top-down system dynamic model, a bottom-up cellular automata and a habitat quality assessment model. The potential impacts of urban growth, socio-economic development and climate change on habitat quality of Hubei Province, China, were predicted under the four IPCC RCP scenarios. Overall, construction land was predicted to expand fast whereas forested land and cultivated land to shrink significantly from 2015 to 2030, but RCP 2.6 and 4.5 scenarios may maintain higher habitat quality compared with RCP 6.0 and 8.5 scenarios. Severe habitat degradation is likely to occur in the megacity’s surrounding ecosystems under RCP 2.6 and 8.5 scenarios, while the degradation is more likely to occur in middle-sized and small cities under RCP 4.5 and 6.0 scenarios. Further, our findings suggest that fixed asset investments and technology innovation play important roles in mitigating the negative impacts of urban and socio-economic development on habitat quality. This study should provide a useful approach for decision makers to design alternative development scenarios and to strike a balance between regional development and habitat conservation.     

Contribution of associated trees to long-term species conservation,carbon storage and sustainability: a functional analysis of tree communities in cacao plantations of Central Cameroon

In Central Africa, most cacao is still cultivated in low-input agroforests where cacao associated trees are traditionally valued by farmers. These systems are sustainable on the long run, support biodiversity conservation and carbon storage. Yet, little knowledge exists on the contribution of tree community management to explain such results. In Central Cameroon, we investigated cacao agroforest associated tree community contributions to the long-term (i) maintenance of tree species encountering a conservation issue and (ii) carbon storage. We further simulated the simplification of these systems by checking for the effect of tree density decrease on community functional groups or traits. Finally, we linked farmers’ use of associated trees to their functional features and conservation status. Cacao agroforestry systems were able to combine high levels of species richness with long-term conservation abilities and carbon storage. Simplification emphasized consistent shifts of functional traits/groups that will change the way they function and alter the existing balances between different associated tree uses. Since traditional agroforests are now foreseen as providers of timber/non-timber forest products, our study argues that this paradigm change in such low-input systems - if carried improperly - is likely to impair the provision of the services they currently provide as well as their sustainability.     

Internalising the costs of fragmentation and nutrient deposition in spatial planning: Extending a decision support tool for the Netherlands

The Land Use Scanner (LUS) is a decision support system for land use planning that is widely used in the Netherlands. The model yields solutions that have a high resolution (500×500 m) and reflect economic equilibrium in the land market, in which eighteen types of land use and nine aggregated habitat types competitively bid for locations. Here, an extension to the LUS is presented that enables the internalisation of environmental externalities. The focus in this study is on two important externalities, namely ammonia emissions from agriculture and habitat fragmentation. We simulate four IPCC-based land use scenarios and assess the level of fragmentation of the nine habitat types. We also perform sensitivity analyses in the most market-oriented scenario on the effectiveness of market-based instruments in promoting more efficient land allocation. The simulation results suggest that particularly the habitat type ‘rain-fed mires and bogs’ is susceptible to fragmentation. The sensitivity analyses show that internalising the damage costs of fragmentation resulted in smaller changes in land allocation than internalising those of nitrogen deposition. For both instruments, the policy effort was large in relation to the efficiency gains in land allocation.     

Improving rural livelihoods through the conservation and use of underutilized species: evidence from a community research project in Yemen

The aim of this paper is to analyse the impact of a set of interventions related to conservation and use of neglected and underutilized species (NUS) on people's livelihoods. Specifically, a simultaneous three-equation model of households' participation on underutilized crops conservation and income generation activities is applied to evaluate the outcome of a pilot research project implemented by Bioversity International in Yemen between 2002 and 2005. Results generated show a relation between project participation and the perceived yield increase demonstrating the importance for farmers to actively participate in the project's activities and subsequently apply agronomic practices learnt to improve their livelihood. The generated benefits incentivized farmers to continue to apply the interventions beyond the lifetime of the project ensuring thus a sustainable process in which exogenous interventions, once adopted by farmers become integrant part of farmer's agronomic practices.     

Do stronger intellectual property rights induce more agricultural trade?: a dynamic panel data model applied to seed trade

Do stronger intellectual property rights (IPRs) induce more agricultural trade? Based on panel data for 60 countries during 1990–2000 and using a dynamic panel data model, this article assesses whether and how national differences in IPRs affect the trade flow of planting seeds imports from the United States. The empirical results show that whether or not a country adheres to IPRs agreements has no discernible impact on planting seeds that are imported from the United States, implying that the strengthening of IPRs seems not to induce more agricultural trade. This result sheds some light on the debate in the theoretical literature on the importance of IPRs and trade.     

海洋文化产业集群内在规律及发展思路探讨——以浙江舟山为例

海洋文化产业是文化产业中特殊的组成部分,是当代文化产业的一个前沿研究领域。本文运用理论研究和实地调查相结合的方法,列举舟山群岛鲁家峙、岱山东沙镇、普陀山、朱家尖、沈家门、长峙岛、蚂蚁岛、太阳谷、朱家尖白山、桃花岛等实际案例,从文化产业集群三大核心定律出发,即产业链组合与延伸的规律、区位优势与选择的规律、产业集聚与联动的规律,充分揭示了舟山群岛海洋文化产业集群的内在规律及发展思路,提出舟山应结合各个岛屿的资源禀赋特征,因岛制宜构建不同种类的海洋文化产业集聚区的建议,对于舟山群岛海洋文化产业集群发展具有一定的指导意义。