No‐take marine reserves and illegal fishing under imperfect enforcement

No‐take marine reserves have been increasingly advocated as an effective means of supporting marine ecosystems and conserving fisheries resources. A major problem that can hinder the effectiveness of no‐take reserves is the incidence of illegal fishing, which has created significant ecological and economic losses in global fisheries. We construct a bioeconomic model to explore the connection between the effects of no‐take reserves and illegal fishing activities in relation to the level of regulatory control of illegal activities in the reserve and fished areas. Our parameterised model shows that the effects of no‐take reserves on both the extent of illegal fishing and the fish biomass critically depend on illegal fishing regulations and the scale and patterns of fish dispersal. In a fishery where illegal fishing can only be partially controlled, increasing the size of the no‐take reserve may result in a lose‐lose situation in which the level of illegal fishing effort increases and the total biomass decreases. Our results further show that when the pattern of fish dispersal is density dependent, imposing a stricter control on illegal fishing in either reserves or fished areas increases the aggregate level of illegal fishing.     

Asset Pricing in Created Markets

We investigate the applicability of the present-value asset pricing model to fishing quota markets by applying instrumental variable panel data estimation techniques to 15 years of market transactions from New Zealand's individual transferable quota (ITQ) market. In addition to the influence of current fishing rents, we explore the effect of market interest rates, risk, and expected changes in future rents on quota asset prices. The results indicate that quota asset prices are positively related to declines in interest rates, lower levels of risk, expected increases in future fish prices, and expected cost reductions from rationalization under the quota system.     

Evaluating the benefits from transport infrastructure in agriculture: a hedonic analysis of farmland prices

Access to transport infrastructure generates a range of benefits to the agriculture sector; many of which are difficult to measure directly. In this study, we use hedonic regression analysis of farm‐level data to examine the contribution of transport infrastructure to the value of farmland traded between 2009 and 2011 through its impact on farm productivity. We show that a one per cent reduction in the cost of transportation between farms and ports leads to a 0.33 per cent increase in land prices, and there is no significant difference between rail and road transportation at the aggregate level. Moreover, the benefits generated by particular types of infrastructure services vary between industries and with farm size, suggesting there are multiple channels through which public infrastructure influences agricultural production. Our findings help to inform future investment decisions in Australia and in other countries by providing new evidence regarding the benefits of existing transport infrastructure.     

Valuing recreational fishing in Tasmania and assessment of response bias in contingent valuation*

We report results from contingent valuation studies in each of two Tasmanian fisheries that estimate the value of a day’s recreational fishing. Published studies estimating the economic value of recreational fishing in Australia and New Zealand are limited, although the economic and social benefits associated with this activity are sizable and the importance of understanding the behaviour of recreational fishers for the sustainable management of aquatic resources is well recognised. In our contingent valuation surveys, we use a double‐bounded version of the dichotomous choice question, which improves the statistical efficiency of the estimates relative to those based on a single dichotomous choice question. We test and control for response bias, in the form of anchoring and a shift effect, that may occur in data collected using a double‐bounded dichotomous choice (DBDC) elicitation format. We highlight the importance of identifying and correcting for response bias in DBDC models on a case‐by‐case basis. Our estimation results show that there is no significant difference in the willingness to pay for a day of recreational fishing across individuals who caught different number of fish in either fishery. This suggests that high and low catch fishers placed the same value on a day’s fishing.     

Economic valuation of recreational fishing in Western Australia: statewide random utility modelling of fishing site choice behaviour

Allocation of fish resources is a controversial subject. This is partly because of our limited understanding of the values of fishing opportunities. This study investigates fishing site choices in Western Australia using national survey data covering eight major fishing regions and forty‐eight fishing sites. We estimate a random utility model (RUM) of site choice with a supporting negative binomial model of angler‐specific expected catch rates. Value estimates for fish types, fishing site attribute changes and access values are presented and discussed.     

海洋生物资源可持续利用的复杂性与管理议题

海洋生物资源管理是一项相当复杂的任务,其复杂性不仅源于资源和环境本身的不确定性和复杂性,鱼类种群内部、种群之间以及种群与环境之间复杂的相互依赖和相互作用等;也源于人类心理与行为的复杂性,人类知识以及以此为基础所建构的制度的局限性。因此,要确保海洋渔业可持续发展,就不仅需要自然科学的支撑,更需要社会科学的支撑。     

湛江海洋捕捞业的发展及面临的挑战

湛江地处祖国大陆最南端的雷州半岛,三面环海,海岸线占全国的8%以上,海洋渔业资源极其丰富,为湛江发展海洋捕捞业提供了良好的条件。论文从捕捞产量、渔船结构、劳动力结构、技术进步以及资金投入等方面介绍了湛江海洋捕捞业的发展现状,定量分析了捕捞量以及捕捞效率两个方面的影响因素。随着2004年中越北部湾渔业协定的生效,湛江海洋捕捞传统作业区域大大减少,捕捞能力过剩问题更加突出。同时,湛江海洋捕捞业还面临诸如捕捞基础设施不足、科技含量偏低、转产转业难度大等诸多问题,亟待在今后的发展过程中逐步完善。     

Farm-scale ecological and economic impacts of agricultural change in the uplands

Recent decades have witnessed substantial losses of biodiversity in Europe, partly driven by the ecological changes associated with intensification of agricultural production. These changes have particularly affected avian (bird) diversity in marginal areas such as the uplands of the UK. Future trends for upland birds will likely be impacted by changes in agricultural support regimes, such as those currently envisaged in on-going reforms of the Common Agricultural Policy. We developed integrated ecological-economic models, using seven different indicators of biodiversity based on avian species richness and individual bird densities. The models represent six different types of farms which are typical for the UK uplands, and were used to assess the outcomes of different agricultural futures. Our results show that the impacts of these future agricultural scenarios on farm incomes, land use and biodiversity are very diverse across policy scenarios and farm types. Moreover, each policy scenario produces un-equal distributions of farm income changes and gains and losses in alternative biodiversity indicators. This shows that generalisations of the effects of policy and pricing changes on farm incomes, land uses and biodiversity can be misleading. Our results also suggest that a focus on umbrella species or biodiversity indicators (such as total species richness) can miss important compositional effects.     

Dynamic land use and land cover changes and their effect on forest resources in a coastal village of Matemwe,Zanzibar, Tanzania

Recent land cover change estimates show overall decline of tropical forests at the regional and global scales caused by multiple social, cultural and economic factors. There is an overall concern on the prevailing land use practices, such as shifting cultivation and extraction of forest materials as agents of forests losses, but also new, emerging land uses are threatening tropical forests. Understanding of the long-term development and driving forces of forest changes are needed, especially at local levels where many decisions on forest policies and land uses are made. This paper addresses the importance of such information for improved estimates of forest dynamics by studying local level land cover and land use changes during the last 50–70 years in the Eastern African tropical island of Zanzibar, Tanzania. The paper discusses the role of traditional and new land uses mainly subsistence farming, tourism and government interference through tree planting, in the long-term development of the forests at the village level. The material for the study is gathered from the interpretation of archival maps and aerial photographs combined with contemporary digital aerial photographs. The analyses are based on the mapping, spatial sampling and spatio-temporal change trajectory analysis (LCTA) of forest land cover, forest land uses and settlement patterns with GIS and statistics. Six distinct forest land cover change trajectories were identified and these illustrate dynamic and heterogeneous nature of the forests. Closed forest cover has dominated throughout due to cyclical land use patterns, but over 70% of the land area has been continuously transforming between closed, semi-open and open land cover conditions. Land use turnover rates indicate that hardly any forest areas are left untouched from the forces, which remove and re-establish forest vegetation in the long run. Land cover and land use change trajectories are spatially fragmented in the studied landscape. Majority of forest loss-gain dynamics is caused by shifting cultivation, while forest losses are most dramatic along the coast, where traditional and new land uses meet and land uses pressures are highest. The study suggests that landscape change trajectory analyses, where contemporary and historical information on land uses and land cover changes are spatially linked, can provide valuable aspects into local level forest land use planning and management strategies. For the case study, the findings suggest the following key forest management strategies for consideration: (1) establishment of a protected forest/scrubland in participation with the local stakeholders, especially the farmers, (2) promotion of areas for permanent agricultural practices, while simultaneously introducing management controls in the traditional slash-and-burn farming areas, and (3) promoting new livelihood opportunities for the farmers, who have traditionally been dependent on forest resources, meanwhile introducing alternatives for fuel wood for cooking.     

The adaptive efficiency of land use planning measured by the control of urban sprawl. The cases of the Netherlands,Belgium and Poland

The paper aims to position the concept of adaptive efficiency in planning theory, by providing insights on the conditions that explain why land use planning in some institutional contexts is able to adapt and improve more efficiently than in others. This is done by focusing on a specific planning goal: the control of residential sprawl. The paper presents a theoretical framework based on two models, one on the coordinating mechanisms regarding the use of land and one to explain institutional changes. This framework is exploited with empirical case studies where we compare the control of sprawl in the Netherlands, Belgium and Poland. The analysis diagnoses a duality of planning practices. Even though planning failures occur in the Netherlands as well, we provide evidence that Dutch land use planning has been able to efficiently adapt regulatory instruments and collaborative practices to societal changes. By contrast, Belgian and Polish planners face huge difficulties to incorporate new initiatives to control urban sprawl or, in more general terms, to reinforce their influence on land uses.     

A modified production possibility frontier for efficient forestry management under the New Zealand Emissions Trading Scheme

Carbon sequestered through increased forest biomass provides a low cost means to curb emissions and has become a major focus of New Zealand's Emissions Trading Scheme. We present a forest planning optimisation model where land use is governed by forest owners maximising the returns to both timber harvest and carbon sequestration. By varying carbon prices, we model efficient trade‐offs between the two forest activities along a modified production possibility frontier for four distinct wood supply regions in New Zealand. Results show that while more productive regions such as the Central North Island (CNI) and Northland have a greater capacity as a carbon sink, it is the less productive regions that have a comparative advantage in carbon sequestration in terms of a lower cost of wood production revenue foregone. However, moderate increases in carbon uptake can be achieved in the CNI at low opportunity cost by subtle changes in forestry management. The implication for policy‐makers is that initial increases in carbon sequestration will be achieved at the lowest cost to society by favouring high volume timber production in some productive woodland areas and/or by more carbon farming in less productive areas.     

The dynamics of land-cover change in western Honduras: exploring spatial and temporal complexity

This paper presents an econometric analysis of land‐cover change in western Honduras. Ground‐truthed satellite image analysis indicates that between 1987 and 1996, net forest regrowth occurred in the 1015 km² study region. While some forest regrowth can be attributed to a 1987 ban on logging, the area of forest regrowth greatly exceeds that of previously clear‐cut areas. Further, new area was also deforested between 1987 and 1996. Thus, the observed land‐cover changes most likely represent a complex mosaic of changing land‐use patterns across time and space. Using satellite imagery from 1987, 1991 and 1996, we estimate a series of models, including binary probit models for each date, and a random‐effects probit model using panel techniques. We also experiment with spatial sampling schemes designed to reduce residual spatial autocorrelation, and qualitatively compare the impact of spatial sampling on model accuracy. Lastly, we find that changes in relative prices, infrastructure improvement, and topography are all significantly related to changing land‐cover patterns.     

The impact of sustainable energy production on land use in Britain through to 2050

Historically, land use in Britain has been shaped by the environment's capacity to provide energy as well as food, water and shelter. Over the next decades, energy will again become a major driver in land cover change as we seek to capture the necessary energy to replace fossil fuels, reduce environmental damage and substitute for insecure supplies. Britain was one of the first places to exploit fossil fuels extensively, initially coal, and it has the potential to generate considerable amounts of renewable energy from tides, waves, the wind, biomass and sunlight. The UK Government's policy is to develop a suite of technologies that will provide a resilient supply without compromising its economy or its international commitments to environmental protection.This paper examines the three major terrestrial options for renewable energy and assesses each by successively filtering them for feasibility, achievability and practicality incorporating existing developments, designation and public opinion. Technology and opinion are dynamic, so the outputs need to be viewed as indicative of alternative scenarios rather than as fixed forecasts. Implications for changes in the energy supply infrastructure needed to match the new supply chains are highlighted.The demand for energy depends on the demographic profile (population size, age distribution, lifestyle and expectations) and on economic activity. Here total demand is predicted using the UK Energy Research Centre's Energy 2050 model, which uses linear programming to balance economics and environmental capacity by major demand sectors in five-year time steps. The core model often generates challenging results.     

Risk management in public land development projects: Comparative case study in Finland,and the Netherlands

Public land development is an approach where the public authority acquires land for development, services the land with public infrastructure, and transfers the serviced building plots to private building developers or self-developing end-users. Motivations to use public land development can be divided to planning goal related motivations and financial motivations. In this paper, we study management of public risks related to the use of public land development by analysing case studies located in Finland and the Netherlands, countries known to have strong tradition in public land development. Our findings indicate that, whereas public land development has efficiencies in managing the risks related to the achievement of public planning goals, the management of the financial risks related to the public land development approach can be remarkably difficult even in countries with wide experience in public land development.     

Management flexibility,price uncertainty and the adoption of carbon forestry

A price on carbon has the potential to drive significant land use change through reforestation. Understanding the likely locations and extent of these changes is therefore a key focus for researchers and policy makers. Models of reforestation based on net present values (NPV) typically compare the economic returns of carbon forestry to alternative land uses. However, these models often neglect the impact of uncertainty. Two sources of uncertainty highly relevant to carbon forestry are the opportunity cost of the land on which the trees are established (i.e. future returns from alternative land uses) and carbon prices. In addition to foregoing the current land use, a landowner making a permanent land use change such as carbon forestry is also giving up the opportunity to change management in the future, for example by changing crop mix in response to commodity price changes. We develop a Monte Carlo model to demonstrate the value of management flexibility, based on a case study property in Australia. While in the absence of management flexibility carbon forestry is more profitable than the current land use, under uncertain future commodity prices it is less attractive to a landowner. We go on to show that, even if the returns from carbon exceed those from more flexible agricultural land use, uncertainty over future carbon prices is likely to delay the adoption of carbon forestry. Overall the models presented in this paper demonstrate that the adoption of carbon forestry is likely to be substantially lower, and slower, than models based on static values would suggest.     

基于城镇地籍调查的镇驻地土地利用特征分析——以山东省胶州市胶北镇为例

基于城镇地籍数据,分析镇驻地土地利用特征,提出加强和改进镇驻地土地利用和管理的政策建议,对促进镇驻地土地集约利用有重要意义.以山东省胶州市胶北镇驻地为研究对象,采用文献分析、实地调查和统计分析相结合,分析了土地利用现状和结构、土地利用强度、建设用地、宅基地等土地利用特征.结果表明,研究区人均建设用地、工业用地、道路用地指标值偏大,住宅用地、绿化用地、基础设施用地等指标值偏低,宅基地利用粗放、一户多宅问题突出,土地利用强度有待提高.针对镇驻地土地利用存在的问题,提出了优化土地利用结构、改善生态环境、提高土地利用效率、完善土地管理制度等土地利用和管理建议.     

Trends in the economic capacity of the Danish fishing fleet, 1996-2002

The Danish fishing industry has gone through a turbulent period of declining catches and modest economic performance. In order to address these concerns, capacity reduction initiatives, mainly through vessel decommissioning, have sought to relieve pressure on fish stocks and improve the profitability of fishing vessels that remain in the fishery. It is the main purpose of this paper to analyse the capacity utilization trends of the four main commercial fleet segments of trawlers, netters, Danish seiners and industrial (fish for reduction) vessels. Annual cost and earnings data (1996-2002) for fishing vessels of the various fleets are applied to three data envelopment analysis models, which evaluate capacity utilization in terms of catch volume, catch revenue and short-run profit. Results suggest that considerable cutbacks in fleet capacity are required, in the range of 30-50%, if full capacity utilization is to be achieved. A preliminary discussion with respect to the impact of fleet capacity reduction initiatives on fleet performance concludes the paper.     

城镇住宅用地集约利用评价研究——以郑州市为例

采用对比分析、归纳分析和实证分析等方法,以郑州市为例,研究了住宅用地的特点、集约利用的内涵和评价指标体系。研究结果表明:(1)城镇住宅用地具有用地多、类型多、投资多、分布广的特点;(2)住宅用地属于生活性用地,集约利用的内涵不但要体现合理的城市规划与布局,更应体现居住的舒适程度;(3)住宅用地集约利用评价指标包括土地投入水平、土地利用程度、土地利用效率3个因素,宗地基础设施投入程度、建筑密度、容积率、绿化率和基准地价实现程度5个因子;(4)郑州市住宅用地普遍存在过度集约的现象,住宅环境质量不尽人意。研究所建立的住宅用地集约利用评价指标体系是科学可行的,分用途的土地集约利用评价结果对制定土地利用政策具有较高的针对性和实用性。     

我国鱼粉市场需求的影响因素及对策分析

文章以鱼粉、工业饲料以及养殖业等统计数据为依据,分析了我国鱼粉消费量居高不下的原因和消费特征,发现下游无论是饲料生产企业还是终端养殖(户)企业都存在严重的鱼粉低效率使用问题,同时我们发现鱼粉消费特征与我国养殖业特征存在一致性。当前,面对如何解决我国鱼粉市场需求增长过快造成的供不应求问题,宏观层面,政府部门需加强对渔业捕捞和海洋环境保护的规范管理,同时制定正确引导养殖业发展的政策,以及尽早建立鱼粉配方衡量指标的标准化体系;微观层面,处于鱼粉行业产业链中从生产到最终消费每一环节的参与者都需要更加理性地对待采购和使用。     

公路基础设施建设对耕地利用转型的影响及门槛效应研究

研究目的:探究公路基础设施建设对耕地利用转型的影响和门槛效应。研究方法:投影寻踪模型,动态空间Durbin模型和面板门槛回归模型。研究结果:(1)公路基础设施建设对耕地利用转型的空间溢出效应比直接效应更为显著,空间溢出效应表现为周边省份公路密度的提高会促进本省份耕地利用转型;(2)公路基础设施建设对耕地利用转型具有促进作用,主要是通过推动耕地功能形态转型实现;(3)公路基础设施建设对耕地利用转型影响存在单一门槛效应,表现为公路基础设施建设对耕地利用转型的正向影响呈先升后降的变化特征,并且当前公路基础设施对西部地区耕地利用转型的促进作用大于东、中部地区。研究结论:应结合公路基础设施建设现状,优化公路基础设施布局,提高公路基础设施建设促进耕地利用转型和农业发展的区域协同作用。