Assessing the shelf life of cost‐efficient conservation plans for species at risk across gradients of agricultural land use

High costs of land in agricultural regions warrant spatial prioritization approaches to conservation that explicitly consider land prices to produce protected‐area networks that accomplish targets efficiently. However, land‐use changes in such regions and delays between plan design and implementation may render optimized plans obsolete before implementation occurs. To measure the shelf life of cost‐efficient conservation plans, we simulated a land‐acquisition and restoration initiative aimed at conserving species at risk in Canada's farmlands. We accounted for observed changes in land‐acquisition costs and in agricultural intensity based on censuses of agriculture taken from 1986 to 2011. For each year of data, we mapped costs and areas of conservation priority designated using Marxan. We compared plans to test for changes through time in the arrangement of high‐priority sites and in the total cost of each plan. For acquisition costs, we measured the savings from accounting for prices during site selection. Land‐acquisition costs and land‐use intensity generally rose over time independent of inflation (24–78%), although rates of change were heterogeneous through space and decreased in some areas. Accounting for spatial variation in land price lowered the cost of conservation plans by 1.73–13.9%, decreased the range of costs by 19–82%, and created unique solutions from which to choose. Despite the rise in plan costs over time, the high conservation priority of particular areas remained consistent. Delaying conservation in these critical areas may compromise what optimized conservation plans can achieve. In the case of Canadian farmland, rapid conservation action is cost‐effective, even with moderate levels of uncertainty in how to implement restoration goals.     

Food production in the city: (re)negotiating land,food and property

This paper addresses issues of access to land for food production in Toronto by offering fresh perspectives on urban agriculture in the neo-liberal city of the global north. It examines attempts to scale up urban agriculture that emphasise changing the relationships between land access, property and new collaborative relationships among different stakeholders. These initiatives involve renegotiating access to land for growing food between private property owners and landless growers, concomitant shifts in control over valued resources and commercialisation. These shifts are often based on relations of trust within a sharing economy rather than public battles over political decisions to develop urban agriculture lands. Growing food on private lands in the city is political in challenging taken-for-granted ideas and practices of property and urban agriculture. New approaches offer options for training and income, as well as expanding the land base for urban agriculture. Small-scale farming projects are affirmative political manoeuvres. They challenge urban residents to consider land for food production across the categories of public and private property. We document three approaches that challenge current property relations: temporary use of a development site through “soft” squatting; redesignating suburban backyards for farmer training and community-based and private food production; and garden sharing of private home backyards for urban food production and commercial growing. Such initiatives articulate alternative visions of sustainability and food security that rely on principles of collaboration and a sharing economy that challenge prevailing notions of property ownership and food security.     

我国绿色产业投资机制建立与启动

本文针对当前我国绿色产业投资机制存在的诸多问题，从产权、市场、制度等方面剖析了绿色产业投资机制扭曲的内因，并在此基础提出了完善绿色产业投资机制的思路与对策     

治污投资方向选择的灰靶决策法

依据灰色决策的基本原理，结合治污投资方向选择的决策实际，采用灰靶决策法对治污投资方向进行优化决策，结果表明，灰靶决策法原理直观、计算简便、精确度高，是治污投资方向选择优化决策的一种有效方法。     

Strategies to overcome barriers to the development of sustainable agriculture in Canada: The role of agribusiness

Strategies to involve agribusiness in the development of sustainable agricultural systems have been limited by the lack of a comprehensive conceptual framework for identifying the most critical supportive policies, programs and regulations. In this paper, we propose an efficiency/substitution/redesign framework to categorize strategies for modifying agribusiness practices. This framework is then used to identify a diverse range of short, medium, and long-term strategies to be pursued by governments, community groups, academics and agribusiness to support the transition. Strategies discussed include corporate greening, ethical investment, changing the legal status of the corporaton, new business forms and the development of ecological economics.     

THEORY AND REALITY IN ALLOCATING FEDERAL RESOURCES TO WATER RESOURCES DEVELOPMENT1

ABSTRACT: Federal spending on water resource development projects exceeds $10 billion annually. This paper examines the economic theory and practice on which the Federal water resource development plans are based. Existing theoretical and applied problems result in overinvestment. These include 1) no standard of value for the tradeoff of environmental objectives with economic objectives; 2) benefits based on “willingness to pay,” but beneficiaries pay only a fraction of a project's costs; 3) beneficiaries “shop around” among program purposes in order to reduce their commitments; and 4) benefit/cost (B/C) analyses are based on a discount rate, which is consistently below the Federal borrowing rate. Furthermore, the Government Accounting Office (GAO) frequently finds that the agency regulations are inadequate and result in inconsistent and questionable benefit computations. The President has proposed a series of water policy reforms, to reduce some of the apparent overinvestment in water resource development, but fundmental corrective action rests with the members of Congress.     

AN APPLICATION OF OPERATIONS RESEARCH METHODS TO BEACH RENOURISHMENT PROJECTS1

ABSTRACT: Mathematical models have been widely used in business to minimize cost and maximize profit. In this paper such models are used to help determine the optimum strategy for a beach renourishment project including the initial and subsequent fill quantities and the length of a complete renourishment cycle. The importance of considering economic factors is emphasized, and the sensitivity of the optimal values to changes in the basic parameters of the models are discussed. The possible extensions and limitations of the models are considered.     

WATER-BASED ACTIVITY INVOLVEMENT FOR RECREATION CONSUMERS AT STATE,FEDERAL, LOCAL,OR PRIVATE FACILITIES1

ABSTRACT: The water-based activity involvement of participants at state and federal and local and private facilities identified by using participation rate groups is examined. No differences between participant groups within activities based on socio-economic characteristics were found. However, groups of highly active individuals were identified at both types of properties. It is suggested that social action system variables be added to traditional social aggregate variables to assist the understanding of leisure involvement.     

Levels and Influencing Factors of Noise Pollution from Small-Scale Industries (SSIs) in a Developing Country

A study was carried out to determine levels and factors that influence noise pollution from small-scale industries (SSIs) in Dar es Salaam City Tanzania. Two sites for wood- and metalworks industries were investigated. Both sites exhibited equivalent noise levels higher than 90.0 dBA, the permissible exposure level limit for occupational noise. At a woodworks SSI, noise levels were found to correlate well with machine-use age, wood-feed speed, and wood-cut depth. Additionally, noise emanating from both types of SSIs was found to influence the level of environmental noise in the neighborhood of the SSIs. One woodworks SSI was found to have a circle of influence of about 140 m. The study concluded that SSIs present a serious source of environmental noise pollution in their neighborhoods. Noise pollution from SSIs is greatly influenced by the type of SSIs and the activities they carry out, the type and age of machines they use, their location relative to residential areas in their vicinity, and in-house noise control measures.