基于自然保护区属性的管理成本分析

从自然保护区的管理成本构成入手,分析了自然保护区属性对不同尺度上管理成本的影响方式,在分类总结自然保护区管理成本的分析方法基础上,提出基于自然保护区属性的管理成本分析流程。该研究结果可为准确掌握自然保护区管理成本规模与构成、科学评估与预测资金投入后的使用效率与保护效果提供支持,并可为揭示自然保护区复合生态系统格局与过程提供新思路。     

Use of linkage mapping and centrality analysis across habitat gradients to conserve connectivity of gray wolf populations in western North America

Centrality metrics evaluate paths between all possible pairwise combinations of sites on a landscape to rank the contribution of each site to facilitating ecological flows across the network of sites. Computational advances now allow application of centrality metrics to landscapes represented as continuous gradients of habitat quality. This avoids the binary classification of landscapes into patch and matrix required by patch-based graph analyses of connectivity. It also avoids the focus on delineating paths between individual pairs of core areas characteristic of most corridor- or linkage-mapping methods of connectivity analysis. Conservation of regional habitat connectivity has the potential to facilitate recovery of the gray wolf (Canis lupus), a species currently recolonizing portions of its historic range in the western United States. We applied 3 contrasting linkage-mapping methods (shortest path, current flow, and minimum-cost-maximum-flow) to spatial data representing wolf habitat to analyze connectivity between wolf populations in central Idaho and Yellowstone National Park (Wyoming). We then applied 3 analogous betweenness centrality metrics to analyze connectivity of wolf habitat throughout the northwestern United States and southwestern Canada to determine where it might be possible to facilitate range expansion and interpopulation dispersal. We developed software to facilitate application of centrality metrics. Shortest-path betweenness centrality identified a minimal network of linkages analogous to those identified by least-cost-path corridor mapping. Current flow and minimum-cost-maximum-flow betweenness centrality identified diffuse networks that included alternative linkages, which will allow greater flexibility in planning. Minimum-cost-maximum-flow betweenness centrality, by integrating both land cost and habitat capacity, allows connectivity to be considered within planning processes that seek to maximize species protection at minimum cost. Centrality analysis is relevant to conservation and landscape genetics at a range of spatial extents, but it may be most broadly applicable within single- and multispecies planning efforts to conserve regional habitat connectivity.     

Difference in the net value of ecological services between natural and artificial forests in China

Land degradation is a global problem that seriously threatens human society. However, in China and elsewhere, ecological restoration still largely relies on a traditional approach that focuses only on ecological factors and ignores socioeconomic factors. To improve the effectiveness of ecological restoration and maximize its economic and ecological benefits, a more efficient approach is needed that provides support for policy development and land management and thereby promotes environmental conservation. We devised a framework for assessing the value of ecosystem services that remain after subtracting costs, such as the opportunity costs, costs of forest protection, and costs for the people who are affected by the program; that is, the net value of ecosystem services (NVES). To understand the difference between the value of a resource and the net value of the ecosystem service it provides, we used data on VES, timber sales, and afforestation costs from China's massive national afforestation programs to calculate the net value of forest ecosystem services in China. Accounting for the abovementioned costs revealed an NVES of ¥6.1 × 10¹² for forests in 2014, which was 35.9% less than the value calculated without accounting for costs. As a result, the NVES associated with afforestation was 55.9% less than the NVES of natural forests. In some regions, NVES was negative because of the huge costs of human-made plantations, high evapotranspiration rates (thus, high water opportunity costs), and low forest survival rates. To maximize the ecological benefits of conservation, it is necessary to account for as many costs as possible so that management decisions can be based on NVES, thereby helping managers choose projects that maximize both economic and ecological benefits.     

Cumulative carbon emissions and economic policy: In search of general principles

We exploit recent advances in climate science to develop a physically consistent, yet surprisingly simple, model of climate policy. It seems that key economic models have greatly overestimated the delay between carbon emissions and warming, and ignored the saturation of carbon sinks that takes place when the atmospheric concentration of carbon dioxide rises. This has important implications for climate policy. If carbon emissions are abated, damages are avoided almost immediately. Therefore it is optimal to reduce emissions significantly in the near term and bring about a slow transition to optimal peak warming, even if optimal steady-state/peak warming is high. The optimal carbon price should start relatively high and grow relatively fast.     

River water quality management model using genetic algorithm

Conventional mathematical programming methods, such as linear programming, non linear programming, dynamic programming and integer programming have been used to solve the cost optimization problem for regional wastewater treatment systems. In this study, a river water quality management model was developed through the integration of a genetic algorithm (GA). This model was applied to a river system contaminated by three determined discharge sources to achieve the water quality goals and wastewater treatment cost optimization in the river basin. The genetic algorithm solution, described the treatment plant efficiency, such that the cost of wastewater treatment for the entire river basin is minimized while the water quality constraints in each reach are satisfied. This study showed that genetic algorithm can be applied for river water quality modeling studies as an alternative to the present methods.     

Monitoring,imperfect detection,and risk optimization of a Tasmanian devil insurance population

Most species are imperfectly detected during biological surveys, which creates uncertainty around their abundance or presence at a given location. Decision makers managing threatened or pest species are regularly faced with this uncertainty. Wildlife diseases can drive species to extinction; thus, managing species with disease is an important part of conservation. Devil facial tumor disease (DFTD) is one such disease that led to the listing of the Tasmanian devil (Sarcophilus harrisii) as endangered. Managers aim to maintain devils in the wild by establishing disease‐free insurance populations at isolated sites. Often a resident DFTD‐affected population must first be removed. In a successful collaboration between decision scientists and wildlife managers, we used an accessible population model to inform monitoring decisions and facilitate the establishment of an insurance population of devils on Forestier Peninsula. We used a Bayesian catch‐effort model to estimate population size of a diseased population from removal and camera trap data. We also analyzed the costs and benefits of declaring the area disease‐free prior to reintroduction and establishment of a healthy insurance population. After the monitoring session in May–June 2015, the probability that all devils had been successfully removed was close to 1, even when we accounted for a possible introduction of a devil to the site. Given this high probability and the baseline cost of declaring population absence prematurely, we found it was not cost‐effective to carry out any additional monitoring before introducing the insurance population. Considering these results within the broader context of Tasmanian devil management, managers ultimately decided to implement an additional monitoring session before the introduction. This was a conservative decision that accounted for uncertainty in model estimates and for the broader nonmonetary costs of mistakenly declaring the area disease‐free.     

Environmental deterioration of farmlands caused by the irrational use of agricultural technologies

Without considering the ecosystem-dependence of agricultural production, irrational use of agricultural technologies could bring only short-term economic benefits but leave long-term environmental deterioration. If some agricultural lands have to be abandoned because of these technologies such as chemical films or groundwater depletion, it will aggravate the burden of remaining lands for maintaining or enhancing production. Thus, agricultural production should be a part of public services, requiring the consideration of interests of different stakeholders and sustainability.     

Pigou meets Mirrlees: On the irrelevance of tax distortions for the second-best Pigouvian tax

This paper extends the Mirrlees (1971) model of optimal income redistribution with optimal corrective taxes to internalize consumption externalities. Using general utility structures and exploring both linear and non-linear taxes, it is demonstrated that the optimal second-best tax on an externality-generating good should not be corrected for the marginal cost of public funds, since it equals one in the optimal tax system. In the optimum, distortions of income taxes are equal to marginal redistributional gains. If the government does not have access to a non-distortionary marginal source of finance, the marginal cost of public funds can be either larger or smaller than one depending on subjective preferences for income redistribution. The optimal second-best corrective tax is then either higher or lower than the Pigouvian level. The findings in this paper generalize and amend prior results based on representative-agent models, shedding new light on the weak double-dividend hypothesis, and on the welfare gains of recycling revenue from environmental taxes.     

干旱地区水污染控制系统初探

应用数学规划方法,科学地组织污染物的排放或科学地协调各个治理环节,以乌鲁木齐市水磨河流域水污染控制系统为例,对干旱地区水污染控制系统进行了初步探索,从而得出干旱地区污水处理费用的合理负担,并得出污染物排放的数量,质量受自然地理条件制约的结论。     

基于成本核算的废旧动力电池回收模式分析与趋势研究

概述了动力电池流向、回收管理体系和回收模式等管理现状,总结提出了以新能源汽车生产企业、动力电池生产企业、第三方综合利用企业和产业联盟为回收主体的四种动力电池回收模式;考虑建设成本、运行维护成本、收集成本、贮存成本、运输成本、人工成本、税收成本、管理成本等8个构成要素,构建了废旧动力电池回收成本模型;核算了四种回收模式的废旧动力电池回收成本和利润情况.核算数据显示,回收1万t/a的废旧动力电池项目,在年总收益均为8500万元的条件下,四种回收模式的利润区间为-461~401万元.结果与趋势分析表明,我国可优先推广新能源汽车生产企业为回收主体的回收模式,便于迅速布局;市场成熟后以动力电池生产企业和综合利用企业为回收主体的模式将进入市场,专业性和技术性将大幅提升;当市场更加成熟,以产业联盟为主体的回收模式将更具优势,回收成本降到最低.综上,建议从避免重复建设,缩短资金周转周期,探索创新模式,构建绿色供应链以及完善回收法律体系等方面入手,进一步完善我国废旧动力电池回收体系.