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1.
Measures of the effects of agricultural practices on ecosystem services   总被引:3,自引:0,他引:3  
Agriculture produces more than just crops. Agricultural practices have environmental impacts that affect a wide range of ecosystem services, including water quality, pollination, nutrient cycling, soil retention, carbon sequestration, and biodiversity conservation. In turn, ecosystem services affect agricultural productivity. Understanding the contribution of various agricultural practices to the range of ecosystem services would help inform choices about the most beneficial agricultural practices. To accomplish this, however, we must overcome a big challenge in measuring the impact of alternative agricultural practices on ecosystem services and of ecosystem services on agricultural production. A framework is presented in which such indicators can be interpreted as well as the criteria for selection of indicators. The relationship between agricultural practices and land-use change and erosion impact on chemical use is also discussed. Together these ideas form the basis for identifying useful indicators for quantifying the costs and benefits of agricultural systems for the range of ecosystem services interrelated to agriculture.  相似文献   

2.
Valuation of ecosystem services has been sought as effective tools that enable the decision makers in designing the cost effective response policies for management of ecosystems towards alleviating the poverty especially in economically poor regions like South Asia. Various directions and linkages between poverty and degradation of ecosystem and reduced flow of ecosystem services can better be understood if the regulating services like hydrological flow and carbon sequestration by forest, and nutrient cycling and bioremediation: by wetlandv can be captured in monetary unit. South Asian Countries including India. Nepal, Pakistan and Bangladesh are the hotspots of poverty where poor depend upon various ecosystem services for their livelihoods and allocation of resource for conservation of ecosystems would have additional merit if regulating services are captured and internalized into the pubtic policy.The paperfirst raises problematic issues in valuation of regulatig ecosystem services, and attempts to link it withthe dependence of poor. Second, complexities of poverty-ecosystem dynamics are discussed. Thirdly, the possible in-tervention to achieve poverty alleviation goal is analyzed with the help of some examples from accounting and valua-tion of regulating services of lndian forest. Finally, the paper suggests that greater attention is needed to do credibleand better valuation of regulating Services so that insight from these ean be used in understanding the impact of degradation of ecosysterns On poor people.  相似文献   

3.
Climatic changes will affect the dynamics of a forest ecosystem. Consequently, carbon sequestration costs can only be estimated correctly if changes in climatic conditions are considered. This article determines the changes in mitigation costs of an optimal forest management regime in the presence of climatic changes and varying prices, and takes account of substitution processes between timber production and carbon sequestration at the stand level. The study demonstrates that in the presence of climate change the sequestration costs per ton of carbon increase with higher amounts of carbon sequestered per hectare. This finding can be used to identify a threshold for the amount of sequestered carbon per hectare below which the costs of carbon sequestration are hardly influenced by climate change.  相似文献   

4.
Land-use change has a significant impact on the world’s ecosystems. Changes in the extent and composition of forests, grasslands, wetlands and other ecosystems have large impacts on the provision of ecosystem services, biodiversity conservation and returns to landowners. While the change in private returns to landowners due to land-use change can often be measured, changes in the supply and value of ecosystem services and the provision of biodiversity conservation have been harder to quantify. In this paper we use a spatially explicit integrated modeling tool (InVEST) to quantify the changes in ecosystem services, habitat for biodiversity, and returns to landowners from land-use change in Minnesota from 1992 to 2001. We evaluate the impact of actual land-use change and a suite of alternative land-use change scenarios. We find a lack of concordance in the ranking of baseline and alternative land-use scenarios in terms of generation of private returns to landowners and net social benefits (private returns plus ecosystem service value). Returns to landowners are highest in a scenario with large-scale agricultural expansion. This scenario, however, generated the lowest net social benefits across all scenarios considered because of large losses in stored carbon and negative impacts on water quality. Further, this scenario resulted in the largest decline in habitat quality for general terrestrial biodiversity and forest songbirds. Our results illustrate the importance of taking ecosystem services into account in land-use and land-management decision-making and linking such decisions to incentives that accurately reflect social returns.  相似文献   

5.
Policymakers seeking to modify financial incentives to increase the flows of ecosystem services in and around tropical moist forests must consider where to focus their attention and what collection of incentives can effectively achieve policy objectives. In most cases, policymakers focus on extensively forested areas where the flows of ecosystem services between agriculture and the environment is generally characterized by massive flows of carbon and soil nutrients from forests to agriculture. In these forest margin areas the stock of primary forest is eventually exhausted and the cheap ingredients provided by nature to agriculture become increasingly scarce. At this point, policy interest generally wanes, and agriculture and the environment begin slow declines in ecosystem service exchange, often with negative consequences for rural poverty. How does one promote increased flows of ecosystem services from agricultural lands without increasing poverty when forests and soils have been depleted? Can the standard instruments, e.g., payments for ecosystem services, be effective in such situations, and if so, do the costs to society of securing these services increase? Here we focus on the flows of ecosystem services at the end of the cycle of converting primary forest to agriculture. Primary data from the Bragantina area in the southeastern Brazilian Amazon, an area cleared of primary forest decades ago, are used to characterize smallholder production systems, to describe the flows of ecosystem services into and from these systems, and to develop a bioeconomic model of smallholder agriculture capable of predicting the effects of several types of policy action on ecosystem services provided by and to agriculture, and on-farm household incomes and food self-reliance. Of particular interest is the Proambiente Pilot Program in Brazil, which uses smallholder payment schemes to induce farmers to manage land and forest resources in ways that generate more ecosystem services. Baseline results suggest that smallholder agriculture leads to a gradual loss of ecosystem services (mainly above-ground and root carbon) provided by secondary forest fallows, and that reduction in fallow age leads to reductions in plant diversity. Intensifying agricultural activities accelerates this process, but considerably increases smallholder incomes. Paying farmers for ecosystem services linked to the retention of secondary forests and the Proambiente program both increase area in forest fallow, but the latter substantially reduces farm income because of input use restrictions. In general, programs aiming to promote the production of ecosystem services should not limit farmers' choices of ways to provide them. Employment and food self-reliance issues associated with policy options for increasing on-farm stocks of carbon and plant biodiversity are also explored.  相似文献   

6.
文章使用手工收集和整理的2001-2013年我国上市公司设置分支机构的数据,考察了地区劳动力市场比较优势与上市公司跨区域资本配置行为之间的关系,以及劳动保护在上述关系中的作用。研究结果表明:(1)获取劳动力市场比较优势是上市公司跨区域资本配置的重要驱动因素之一,表现为上市公司更可能到劳动力资源丰富和劳动成本低的地区设置分支机构;(2)与上市公司注册地相比,一个地区的劳动力市场比较优势越明显,上市公司到该地区设置分支机构的可能性越大;(3)加强劳动保护强化了上市公司的上述行为。进一步研究发现,在民营性质和劳动密集度较高的上市公司中,为了获取劳动力市场比较优势,企业跨区域配置资本的可能性较大,劳动保护对上述关系的强化作用也较明显。  相似文献   

7.
This article considers the importance of robust planning for green infrastructure in fast changing Southern African cities. A key theme is the extent to which ecosystem services are valued publicly, and the opportunity costs of not investing in the green infrastructure. We explore green infrastructure through pairing insights of social–ecological resilience with perspectives on urban infrastructure transitions. By converging these views, we show how green infrastructure can be viewed as an innovative response to challenged urban environments.Through a Johannesburg case study, a number of ecosystem services constitute sources of resilience for an otherwise constrained city. While this is positive and to be valorised, many South African cities are in the midst of service delivery protests, so that resilient ecosystems, and the citizen networks that sustain these, are largely overlooked in planning processes.This article offers three key conclusions. First, a proper understanding of green infrastructure requires blending insights from social–ecological system thinking and infrastructure transition scholarship. Second, there is a paucity of knowledge around ecosystem services in Johannesburg, and that the planning to facilitate ecosystem service valuation is largely inadequate. Third, addressing this requires ecosystem valuations relevant to the unique conditions in developing world cities such as Johannesburg.  相似文献   

8.
Agricultural landscapes hold tremendous potential for producing a diverse stream of ecosystem services. Yet, because the spatial configuration of particular ecosystems is critical to the supply of many services, realizing this potential requires that farms be managed in a coordinated way across landscapes rather than as independent units. Under existing incentive programs, this level of coordination is typically neither required nor encouraged.Here we explore how to achieve such coordination from an institutional perspective using voluntary incentives rather than regulation. We focus on three services operating at contrasting scales, from local to global: pollination, hydrologic services, and carbon sequestration. First, we briefly illustrate how agricultural practices can diminish or enhance their provision. Next, we show how all three services require coordinated, landscape-scale management because provision depends upon particular spatial configurations, of which we provide several stylized examples. Finally, based on these stylized configurations, we evaluate the relative merits of three incentive designs-the “cooperation bonus,” the “entrepreneur,” and the “ecosystem service district”-to promote cross-farm cooperation to enhance service provision.All three incentive systems rely on rational self-interest, have cooperative configurations to promote ecosystem services across different scales, use tiered reward systems, and have a major voluntary element. They are distinct in certain key features. The cooperation bonus system rewards conservation even without cooperation but adds a bonus for cooperation. In the entrepreneur incentive, all tiers of reward are contingent upon cooperation. The ecosystem service district scheme is only partially voluntary and forces cooperation of all landowners once the district is formed. Our analysis of these heuristic alternatives integrates biophysical, economic, and institutional factors with the aim of addressing the suite of institutional barriers for landscape-scale management.  相似文献   

9.
This paper examines self-enforcing contracts as a financial mechanism for reducing carbon emissions from deforestation and forest degradation when the opportunity cost of the land (i.e., landholder type) is private information and is imperfectly correlated over time (i.e., partially persistent types). Because self-enforcement limits the feasible incentives, the conservation levels are constrained by the surplus created. Regardless of the degree of persistence of such opportunity costs across contracting periods, a first-best self-enforcing contract can deliver “additional” carbon sequestration beyond the business as usual scenario only if the value of forest conservation is sufficiently high. Otherwise, self-enforcing contracts can induce some, suboptimal level of carbon sequestration. The degree of persistence of opportunity costs across periods does not affect the amount of total payments provided in the optimal menu of contracts, but greater persistence of opportunity cost types leads to contracts that feature more of the total payment as a bonus in contracts for landholders with a high opportunity cost for their land and more of the total payment as an upfront fixed payment for landholders with a low opportunity cost.  相似文献   

10.
Agricultural landscapes can provide many valuable ecosystem services, but many are externalities from the perspective of farmers and so tend to be under-produced. This paper examines an effort to make direct payments for ecosystem services (PES) in an agricultural landscape. The Regional Integrated Silvopastoral Ecosystem Management Project is piloting the use of PES to induce adoption of silvopastoral practices in the Matiguás-Río Blanco area in Nicaragua. Silvopastoral practices could substantially improve service provision while retaining agricultural production, but they have found only limited acceptance among farmers. The Silvopastoral Project seeks to increase their adoption by paying farmers for the expected increase in biodiversity conservation and carbon sequestration services that these practices would provide. The Project developed an ‘environmental services index’ (ESI) and pays participants for net increases in ESI points. Although the Silvopastoral Project is still underway, it already appears to have succeeded in inducing farmers to increase substantially the use of practices that generate higher levels of ecosystem services. In the project's first two years, over 24% of the total area experienced some form of land use change. The area of degraded pasture fell by two thirds, while pastures with high tree density increased substantially, as did fodder banks and live fences. On-going monitoring indicates that these land use changes are in fact generating the desired services. Questions remain about the long-term sustainability of the approach, however. To ensure sustainability, long-term payments are likely to be needed, raising the question of how they will be financed. Payments by water users and by carbon buyers provide a partial answer to this challenge, but still leave many gaps.  相似文献   

11.
Hydropower can provide inexpensive, flexible fill-in power to compensate for intermittent renewable generation. Policies for hydropower dams maintain multiple services beyond electric generation, including environmental protection, flood control and recreation. We model the decision of a hydroelectric generator to shift some of its power production capacity away from the day-ahead energy market into a “wind-following” service to smooth the intermittent production of wind turbines. Offering such a service imposes both private and social opportunity costs. Since fluctuations in wind energy output are not perfectly correlated with day-ahead energy prices, a wind-following service will necessarily affect generator revenues. Seasonal wind patterns produce conflicts with the goal of managing rivers for “ecosystem services”—the maintenance or enhancement of downstream ecosystems. We illustrate our decision model using the Kerr Dam in PJM’s territory in North Carolina. We simulate the operation of Kerr Dam over a three-year period that features hydrologic variability from normal water years to extreme drought conditions. We use an optimization framework to estimate reservation prices for Kerr Dam offering wind-following services in the PJM market. Wind-following may be profitable for Kerr Dam at low capacity levels during some time periods if ecosystems services are neglected and if side payments, or reserves-type payments, are provided. Wind-following with ecosystem services yields revenue losses that typically cannot be recovered with reserves market payments. Water release patterns are inconsistent with ecosystem-services goals when Kerr Dam dedicates significant capacity to wind-following, particularly in drought years.  相似文献   

12.
Payments for ecosystem services (PES) programs aim to improve environmental outcomes by providing direct incentives to land managers for the provision of ecosystem services. Participation in PES programs is voluntary, so effective program design requires careful consideration of farmers' preferences. This study quantifies such preferences using a choice experiment. The study site is the East Usambara Mountains, Tanzania, an internationally recognized ‘biodiversity hotspot.’ We assess preferences for four payment approaches: constant and variable annual cash payments to individual farmers, a constant annual cash payment to a village fund on behalf of farmers, and an upfront manure fertilizer payment. We find that the manure fertilizer payment was statistically significant in motivating farmer participation while the group payment was non-significant. In addition, the relationship between the likelihood of participation and the stringency of conditionality is surprisingly non-linear. In a test of external validity, average willingness to accept (WTA) values are found to be similar to the average opportunity cost of maintaining land uses consistent with conservation objectives.  相似文献   

13.
We explore the welfare implications of agricultural expansion in the Brazilian Amazon by comparing spatially explicit estimates of soybean rents and the value of ecosystem services. Although these estimates are generated from different datasets, models, and estimation techniques, the values are comparable, such that the value of ecosystem services is greater than soybean rents for about 61% of the total area and 24% of the area where soybean rents are positive if protected areas are well enforced. Based on the balance between the benefits and costs of conversion, failure to value ecosystem services reduces total social welfare by 7.13 billion dollars annually relative to an optimum. Policy instruments that internalize the value of ecosystem services via protected lands, land conversion taxes, conservation subsidies, or excise taxes can avoid much of this loss. Regardless of intervention regime, policy makers should be cognizant of the diminishing net benefits of converting natural ecosystems to agriculture. Realizing the final 3.8% requires the conversion of an additional 15% natural ecosystems to soybean production.  相似文献   

14.
A payments for ecosystem services (PES) system came about in South Africa with the establishment of the government-funded Working for Water (WfW) programme that clears mountain catchments and riparian zones of invasive alien plants to restore natural fire regimes, the productive potential of land, biodiversity, and hydrological functioning. The success of the programme is largely attributed to it being mainly funded as a poverty-relief initiative, although water users also contribute through their water fees. Nevertheless, as the hydrological benefits have become apparent, water utilities and municipalities have begun to contract WfW to restore catchments that affect their water supplies. This emerging PES system differs from others in that the service providers are previously unemployed individuals that tender for contracts to restore public or private lands, rather than the landowners themselves. The model has since expanded into other types of ecosystem restoration and these have the potential to merge into a general programme of ecosystem service provision within a broader public works programme. There is a strong case for concentrating on the most valuable services provided by ecosystems, such as water supply, carbon sequestration, and fire protection, and using these as ‘umbrella services’ to achieve a range of conservation goals. The future prospects for expansion of PES for hydrological services are further strengthened by the legal requirement that Catchment Management Agencies be established. These authorities will have an incentive to purchase hydrological services through organisations such as WfW so as to be able to supply more water to their users.  相似文献   

15.
National parks and reserves are globally popular approaches to protecting biodiversity and the supply of ecosystem services. Because these protected areas limit agricultural development and exploitation of natural resources, they are frequently opposed in developing nations where reducing poverty is an important social objective. Conservation advocates argue that protected areas can alleviate poverty by supplying ecosystem services, promoting tourism and improving infrastructure. Thus ‘win-win’ scenarios may be possible in which ecosystems and their services are protected and poverty is alleviated. Previous studies (Andam et al. in Proc Natl Acad Sci USA 105(42):16089–16094 2008; 2010) suggest that Costa Rica’s protected area system reduced deforestation and alleviated poverty. We demonstrate that these environmental and social impacts were spatially heterogeneous. Importantly, the characteristics associated with the most avoided deforestation are the characteristics associated with the least poverty alleviation. In other words, the same characteristics that limited the conservation effectiveness of protected areas may have improved the social welfare impacts of these areas. These results suggest that ‘win-win’ efforts to protect ecosystems and alleviate poverty may be possible when policymakers are satisfied with low levels of each outcome, but tradeoffs exist when more of either outcome is desired.  相似文献   

16.
This paper analyses the role of global land management alternatives in determining potential greenhouse gas mitigation by land-based activities in agriculture and forestry. Land-based activities are responsible for over a third of global greenhouse gas emissions, yet the economics of land-use decisions have not been explicitly modeled in global mitigation studies. In this paper, we develop a new, general equilibrium framework which effectively captures the opportunity costs of land-use decisions in agriculture and forestry, thereby allowing us to analyse competition for heterogeneous land types across and within sectors, as well as input substitution between land and other factors of production. When land-using sectors are confronted with a tax on greenhouse gas emissions, we find significant changes in the global pattern of comparative advantage across sectors, regions, and land types. Globally, we find that forest carbon sequestration is the dominant strategy for GHG emissions mitigation, while agricultural-related mitigation comes predominantly from reduced methane emissions in the ruminant livestock sector, followed by fertilizer and methane emissions from paddy rice. Regionally, agricultural mitigation is a larger share of total land-use emissions abatement in the USA and China, compared to the rest of the world, and, within agriculture, disproportionately from reductions in fertilizer-related emissions. The results also show how analyses that only consider regional mitigation, may bias mitigation potential by ignoring global market interactions. For example, USA-specific analyses likely over-estimate the potential for abatement in agriculture. Finally, we note that this general equilibrium framework provides the research community with a practical methodology for explicit modeling of global land competition and land-based mitigation in comprehensive assessments of greenhouse gas mitigation options.  相似文献   

17.
While technological progress has fostered the conception of an urban society that is increasingly decoupled from ecosystems, demands on natural capital and ecosystem services keep increasing steadily in our urbanized planet. Decoupling of cities from ecological systems can only occur locally and partially, thanks to the appropriation of vast areas of ecosystem services provision beyond the city boundaries. Conserving and restoring ecosystem services in urban areas can reduce the ecological footprints and the ecological debts of cities while enhancing resilience, health, and quality of life for their inhabitants. In this paper we synthesize knowledge and methods to classify and value ecosystem services for urban planning. First, we categorize important ecosystem services and disservices in urban areas. Second, we describe valuation languages (economic costs, socio‐cultural values, resilience) that capture distinct value dimensions of urban ecosystem services. Third, we identify analytical challenges for valuation to inform urban planning in the face of high heterogeneity and fragmentation characterizing urban ecosystems. The paper discusses various ways through which urban ecosystems services can enhance resilience and quality of life in cities and identifies a range of economic costs and socio‐cultural impacts that can derive from their loss. We conclude by identifying knowledge gaps and challenges for the research agenda on ecosystem services provided in urban areas.  相似文献   

18.
Biodiversity loss is a problem of global concern affecting ecosystem functioning and services provided to humans. The Millennium Ecosystem Assessment is built on a conceptual framework that links biodiversity with the services ecosystems provide to society and human welfare. Numerous empirical studies have measured ecosystem goods and services in terms of economic values; however, less evidence is available of the indirect effect of biodiversity on these values. Based on this, we first compile market and non-market forest valuation studies and, secondly, explore the potential of an econometric modelling exercise by conducting a worldwide meta-analysis. This exercise aims to highlight the role of biodiversity indicators on valuation. In this way, we can study the underlying transmission mechanisms that explain to what extent biodiversity is related to human welfare. Furthermore, we also propose to evaluate the magnitudes of the respective distributional impacts, including the different ecosystem goods and services under consideration. Our results show that biodiversity indicators may have an underlying effect on forest ecosystem values, which also depend on the type of ecosystem services. Lastly, the results are discussed and analysed with respect to their policy implications concerning biodiversity conservation.  相似文献   

19.
This paper presents a bottom-up methodological framework for estimating some of the key ecosystem services provided by forests biomes worldwide. We consider the provision of wood and non-wood forest products, recreation and passive use services, and carbon sequestration. The valuation framework derives per hectare estimates by applying meta-analysis, value-transfer and scaling-up procedures in order to control for the existing heterogeneities across world regions and forest biomes. The first part of the study estimates stock values per hectare for each forest ecosystem service in the baseline year 2000 and in the year 2050. Results differ per geographical region and biome. Carbon stocks represent, on average, the highest value per hectare, followed by provisioning services, passive use and recreational values respectively. The second part provides an estimation of the welfare loss (or gain) associated with policy inaction in the period 2000–2050 leading to a change in the forest area. Welfare results are mixed and require a careful interpretation, ranging from a worldwide annual benefit of + 0.03% of 2050 GDP to an annual loss of −0.13%. The highest damage is expected in Brazil due to the increasing deforestation taking place in tropical natural forests, which is causing a considerable loss of carbon stocks.  相似文献   

20.
园林树木的服务功能直接影响着城市绿地系统和城 市生态系统的健康与稳定。但是,多年以来,园林树种选择机 制和方法却缺少理论支撑,常常具有主观性和随意性。通过上 海50种园林树种“植物功能性状-生态系统服务”评价框架的 构建和17个性状变量因子分析发现,树种功能性状与生态系统 服务之间存在一定的关联性。在形态上,树高决定了树木形态 和树冠大小,对小气候调节、径流调蓄、空气净化和消声减噪 等调节服务具有不同程度的贡献。叶片性状影响固碳释氧,以 及养分供给等生态系统过程,并最终反馈在树种种间服务差异 上。树种的文化服务直接与人类偏好相关,具有复杂性和特殊 性,需要根据实际需求做出权衡与取舍。“植物功能性状-生 态系统服务”评价框架为园林树种的选择和树种规划提供了一 种客观理性的方法,便于针对不同的生态系统服务提供相应的 树种选择依据,以实现城市绿地综合效益的定量化与最优化  相似文献   

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