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1.
Does status matter in community-based forest management? If so, are the high-status households more benefited than the low-status households? What drives status differences, if any, in the appropriation of forest resources? To address these questions, we draw on a theory of status and resource use that defines one’s status as one’s relative position in a group on the basis of power, prestige, honor and deference. Following this perspective, we surveyed the heads of 341 forest-based rural households in India from 2009 to 2010. We find that collective actions themselves are status-driven and the high-status households are more interested and involved in status-maintaining collective actions such as decision-making and implementation, while the low-status households perform general tasks like forest patrol. Moreover, the high-status households derive benefits from local forest significantly more than the low-status households. Further, decomposition analysis shows that a household’s prestige and honor measured by its access to social resources, problem faced and useful contacts explain about 56 % of the status gap in forest benefits, while socioeconomic characteristics explain only 16 % of the gap. Thus, due emphasis on household status from a broader socioeconomic perspective is required to reduce inequality in participation and the distribution of forest benefits in co-management.  相似文献   

2.
Past increase of atmospheric CO2 involves significant contributions from both fossil and biospheric sources. The latter are controversial, partly because these CO2 releases may be balanced by accelerated regrowth following clearing of some forests, while others were being converted to agricultural or other nonforest land. A simulation model was used to reconstruct changes since 1860 and project four hypothetical future scenarios of CO2 injection to 2460. Nineteen compartments and their exchanges of carbon were considered. Areal extents of tropical forests, other wooded ecosystems, and nonforests were incorporated into the model. Rapidly and slowly exchanging pools of carbon per unit area were projected by integrating income-loss differential equations numerically. Estimated cumulative releases of CO2 from fossil fuels (plus cement) near 120 Pg of carbon (1 Pg = 1015 g) from 1860 to 1970 were assumed to equal the prompt plus delayed releases due to forest clearing. Limits of exploitable forest area and biomass were evaluated and found to contribute much less future CO2 than usable fossil fuels. Ultimate release from the latter (7500±2500 Pg C) could increase atmospheric CO2 manyfold: doubling the assumed 1860 levels as early as (1) the year 2032 for assumed early fossil-use scenarios and (2) the year 2045 for late fossil-use scenarios. Depending on the poorly known parametes that were programmed to constrain the organic production rates, cumulative storage, and the response of plants and soils to enhanced atmospheric CO2, biospheric storage might reach higher levels for all scenarios than the estimates given here. However, maximizing such storage in real life would require much closer understanding and wiser management of ecosystems than history has shown.  相似文献   

3.
The objective of this paper is to analyse the impacts of climate change on a pine forest stand in Central Siberia (Zotino) to assess benefits and risks for such forests in the future. We use the regional statistical climate model STARS to develop a set of climate change scenarios assuming a temperature increase by mid-century of 1, 2, 3 and 4 K. The process-based forest growth model 4C is applied to a 200-year-old pine forest to analyse impacts on carbon and water balance as well as the risk of fire under these climate change scenarios. The climate scenarios indicate precipitation increases mainly during winter and decreases during summer with increasing temperature trend. They cause rising forest productivity up to about 20 % in spite of increasing respiration losses. At the same time, the water-use efficiency increases slightly from 2.0 g C l?1 H2O under current climate to 2.1 g C l?1 H2O under 4 K scenario indicating that higher water losses from increasing evapotranspiration do not appear to lead to water limitations for the productivity at this site. The simulated actual evaporation increases by up to 32 %, but the climatic water balance decreases by up to 20 % with increasing temperature trend. In contrast, the risk of fire indicated by the Nesterov index clearly increases. Our analysis confirms increasing productivity of the boreal pine stand but also highlights increasing drought stress and risks from abiotic disturbances which could cancel out productivity gains.  相似文献   

4.
Governments in the Lower Mekong Basin (LMB) face decisions that involve trade-offs between the economic benefits from hydropower generation and potentially irreversible negative impacts on the ecosystems that provide livelihoods and food security to the rural poor. As a means of comparing these trade-offs, a sensitivity analysis of the benefit-cost analysis of certain Basin Development Plan (BDP) scenarios was undertaken. By changing some key assumptions in the BDP about discount rates, the value of lost capture fisheries, future aquaculture production in the LMB, and the value of lost ecosystem services from wetlands to reflect the full range of uncertainty, at the extremes, there could be a reversal of the Net Present Value (NPV) estimates of the scenarios from a positive $33 billion to negative $274 billion. This report recommends when dealing with large-scale, complex projects: a more comprehensive, integrated human and natural systems framework and adaptive management approach to LMB planning and development that deals with the entire watershed; a more comprehensive analysis and treatment of risk and uncertainty; a more thorough assessment of the value of direct and indirect ecosystem services; a broader set of scenarios that embody alternative models of development, broader stakeholder participation; and better treatment of the effects of infrastructure construction on local cultures and the poor.  相似文献   

5.
This study addresses the impact of climate change and management approach on the provision of four ecosystem services (ES) (timber production, protection against gravitational hazards, carbon sequestration and biodiversity) in Valsaín forest in central Spain. The hybrid forest patch model PICUS v1.6 was used to simulate the development of 24 representative stand types over 100 years (2010–2110) in a full factorial simulation experiment combining three management regimes [“business as usual” management (BAU) and two alternatives to BAU (AM1 and AM2)], a no-management scenario (NOM) and six climate scenarios (historic climate represented by the period 1961–1990 and five transient climate change scenarios). Simulations indicated relatively small differences as regards the impact of the different management alternatives (BAU, AM1 and AM2) on the provision of ES as well as a clear improvement in biodiversity, protection and carbon storage under the no-management regime (NOM). Although timber production indicators were the most sensitive to climate change scenarios, biodiversity-related indicators responded fastest to the management regimes applied. Indicators of protection against rockfall and landslides were affected by both management and climate change. The results indicate substantial vulnerability of ES provisioning under the more extreme climate change scenarios at low elevations (1250 m). At higher elevations, the productivity of Scots pine stands may show a moderate decrease or increase, depending on the climate change scenario.  相似文献   

6.
Multiple production and demand side measures are needed to improve food system sustainability. This study quantified the theoretical minimum agricultural land requirements to supply Western Europe with food in 2050 from its own land base, together with GHG emissions arising. Assuming that crop yield gaps in agriculture are closed, livestock production efficiencies increased and waste at all stages reduced, a range of food consumption scenarios were modelled each based on different ‘protein futures’. The scenarios were as follows: intensive and efficient livestock production using today’s species mix; intensive efficient poultry–dairy production; intensive efficient aquaculture–dairy; artificial meat and dairy; livestock on ‘ecological leftovers’ (livestock reared only on land unsuited to cropping, agricultural residues and food waste, with consumption capped at that level of availability); and a ‘plant-based eating’ scenario. For each scenario, ‘projected diet’ and ‘healthy diet’ variants were modelled. Finally, we quantified the theoretical maximum carbon sequestration potential from afforestation of spared agricultural land. Results indicate that land use could be cut by 14–86 % and GHG emissions reduced by up to approximately 90 %. The yearly carbon storage potential arising from spared agricultural land ranged from 90 to 700 Mt CO2 in 2050. The artificial meat and plant-based scenarios achieved the greatest land use and GHG reductions and the greatest carbon sequestration potential. The ‘ecological leftover’ scenario required the least cropland as compared with the other meat-containing scenarios, but all available pasture was used, and GHG emissions were higher if meat consumption was not capped at healthy levels.  相似文献   

7.
湖北省具有发展森林资源的良好条件,但目前的森林覆盖率不高,林种结构不合理,森林生产力相当低。应在保护和经营好现有森林资源的基础上,以扩大森林面积和提高森林质量为中心,统筹规划,合理布局,增加投入,加速发展,科学经营,永续利用,不断提高其经济、社会、生态效益,造福于人民。  相似文献   

8.
Eco-certification has been used as a tool to mitigate adverse effects of aquaculture production and might thus be understood as a private approach to sustainable ecosystem management. In production forests in Ca Mau, Vietnam, where mangrove have suffered degradation despite legal protection, different projects have targeted reversing this trend by means of private certification using the ‘Naturland’ organic standard as a reference. So far the outcomes have, however, been proven unsatisfactory. With the aim to better understand the reasons for these poor outcomes, a survey of forty households was conducted in a production forest in Rach Goc commune, Ngoc Hien District. We evaluated farmers’ perceptions on mangrove management, the drivers guiding shrimp farming, and whether there was a difference between participants and non-participants in a former ‘Naturland’ organic project. To complement the survey, a range of stakeholders involved in shrimp value chains were interviewed to better understand the terms and benefits of certification. The results of this survey suggested that, when applied to shrimp–mangrove farming systems in production forests in Ca Mau, ‘eco-certification’ and associated benefits are not very satisfactory. The survey results revealed that certified farms do not show significant differences to non-certified farms in terms of social and environmental benefits. As far as the implementation process was concerned, the survey results showed that a failure to integrate local farmers as participants consequently resulted in households becoming ‘objects’ for certification and not project partners with equal weight and power. It appears that rather than being a tool for improvement, ‘Naturland’ certification for shrimp–mangrove farming systems in Ca Mau’s production forests has become an end in itself.  相似文献   

9.
Returning farmland to forests is important for the protection of ecological values. Eucommia ulmoides is considered to be a suitable species for reforestation in the hilly red soil region of southern China. The objective of this study was to investigate the relationship between the water supply and demand of an E. ulmoides plantation to provide insights into the feasibility of large-scale planting for ecological restoration and forest management activities in the hilly red soil region of southern China. With the measured precipitation, surface runoff and interflow and actual evapotranspiration (ETc) estimated by the modified P–M model, soil water storage (SWS) was estimated based on the water balance equation. Monthly variations of SWS were then compared with in situ measured SWS. The results showed that the estimated mean monthly water losses (the sum of the surface runoff, interflow and ETc) were 139.8 mm in a wet year and 120.0 mm in a dry year, while the measured mean monthly water input values (net precipitation) were 131.2 mm in a wet year and 70.8 mm in a dry year. Net soil water storage (ΔSWS) was negative in each month of the growing season in a dry year, but the soil water deficit was replenished during the following season. The model performance showed that the modified P–M model can be adapted to estimate the soil water storage in other forest catchments where no adequate in situ data are available. As a result of estimating the water balance and observing soil water storage in two different hydrological years, E. ulmoides is recommended as a suitable forest rehabilitation species in the study area, and a suitable plant region has been defined by the GIS technique based on the water balance model.  相似文献   

10.
Invasive species alter the functioning of natural ecosystems, creating “novel ecosystems” comprising species occurring in combinations with no analogs within a given biome. This poses major challenges for managers who cannot rely exclusively on previous experiences. Multiple factors that drive invasion and which interact in complex ways demand innovative management approaches. We show the utility of scenario planning in considering options for management in a region with substantial problems with invasive alien plants: South Africa’s Cape Floristic Region. The approach allows us to identify the driving forces that shape the status and trajectories of major woody invasive plants and to identify sensible strategies by considering a set of scenarios based on the main uncertainties that encapsulate the linkages between the various components of the management of biological invasions. Attitudes of landowners and management capacity are shown to be the crucial uncertainties influencing the spread of major invasive species; axes based on these factors define our scenarios. Mapping current management projects onto scenario axes highlighted key differences among areas. These insights can assist in directing particular management units toward more desirable futures. Our study highlights the need to link social, political and legal constraints with ecological processes to assure the effectiveness of management operations in controlling biological invasions.  相似文献   

11.
In Brazil’s semi-arid Northeast, most rural dwellers derive income from the dry Caatinga forest through livestock farming, fruit collection, and firewood extraction. However, recurring droughts and inadequate land use practices jeopardize farmers’ livelihoods. The drought-resistant, endemic Umbuzeiro tree provides fruit for direct consumption and allows for the creation of transformed products. The planting of this native species can enhance the well-being of the ecosystem and establish future benefits for smallholdings. However, it is crucial that when taking up innovative practices to cope with environmental change, a willingness to apply them should be fostered among local farmers. We used constellation analysis as a transdisciplinary approach to identify elements of current land management which subsequently defined the nodes of a Bayesian network (BN). We developed probabilities of practice uptake that strengthen success, namely the conservation of natural resources while securing the incomes of smallholders. In collaboration with stakeholders and experts, 25 identified nodes for the BN were tested under various scenarios. Adopting all suggested innovative practices secures the final objectives—ecosystem health and farmer benefits (approx. 90%). The analysis quantified the relevance of single issues that may impede farmers to adopt the practices, such as having to cultivate seedlings or avoiding long-term investments. Further crucial actions include the fencing-off of livestock and marketing pathways. Affordable credit, research, and supportive farmers’ institutions can encourage farmers to implement innovative practices. The use of modeled scenarios can provide evidence, which might encourage sustainable land management.  相似文献   

12.
This paper identifies the factors that influence perception of program benefit of the recipients when a hypothetical public program is implemented in reality. We compare pre- and post-program Willingness to pay (WTP) estimates for improved waste management in Bally Municipality, India, and find that post-program predicted WTP falls by more than 50 % even when if there are substantial improvements in urban environment. We show that this can be explained by the relative strength of leisure cost of effort to participate in the waste management program vis-à-vis the benefit derived from cleaner environment. Our study shows that mismatch between expected and offered service attributes might be a source of disutility and could also dampen households’ perceived value of the program benefits. In such cases, the reduction in WTP might act as an indication of the local bodies regarding the scale of outreach and expansion of the program needed to finance the operation and maintenance expenses by supplementing the property tax bases through user fees.  相似文献   

13.
Deforestation and oil palm expansion in Central Kalimantan province are among the highest in Indonesia. This study examines the physical and monetary impacts of oil palm expansion in Central Kalimantan up to 2025 under three policy scenarios. Our modelling approach combines a spatial logistic regression model with a set of rules governing land use change as a function of the policy scenario. Our physical and monetary analyses include palm oil expansion and five other ecosystem services: timber, rattan, paddy rice, carbon sequestration, and orangutan habitat (the last service is analysed in physical units only). In monetary terms, our analysis comprises the contribution of land and ecosystems to economic production, as measured according to the valuation approach of the System of National Accounts. We focus our analysis on government-owned land which covers around 97 % of the province, where the main policy issues are. We show that, in the business-as-usual scenario, the societal costs of carbon emissions and the loss of other ecosystem services far exceed the benefits from increased oil palm production. This is, in particular, related to the conversion of peatlands. We also show that, for Central Kalimantan, the moratorium scenario, which is modelled based on the moratorium currently in place in Indonesia, generates important economic benefits compared to the business-as-usual scenario. In the moratorium scenario, however, there is still conversion of forest to plantation and associated loss of ecosystem services. We developed an alternative, sustainable production scenario based on an ecosystem services approach and show that this policy scenario leads to higher net social benefits including some more space for oil palm expansion.  相似文献   

14.
Greece is included among the most vulnerable regions of Europe by climate change on account of higher temperature and reduced rainfall in areas already facing water scarcity. With respect to wetland systems, many ephemeral ones are expected to disappear and several permanent to shrink due to climate change. As regards two specific wetlands of Greece, the change in hydroperiod of Cheimaditida and Kerkini lakes due to climate change was studied. Lakes’ water balance was simulated using historical climate data and the emission scenarios Α1Β for the period 2020–2050 and Α1Β and Α2 for the period 2070–2100. Future climate scenarios, based on emission scenarios A1B and A2, were provided in the context of the study of Climate Change Impacts Study Committee. The surface area of Lake Cheimaditida will undergo a substantial decrease, initially by 20 % during the period 2020–2050 and later until 37 % during the period 2070–2100. In Lake Kerkini, the surface area will decrease, initially by 5 % during the period 2020–2050 and later until 14 % during the period 2070–2100. Climate change is anticipated to impact the hydroperiod of the two wetlands, and the sustainable water management is essential to prevent the wetland’s biodiversity loss.  相似文献   

15.
Fuelwood is one of the major sources of energy in the domestic sector across the rural areas, especially in the developing regions across the world. The Northeastern Himalayan state of Manipur is dominated by the tribal population that largely depends on fuelwood from the nearby forest area. The entire dependence on forests for energy resources is affecting the sustainability of the forest ecosystem in the region, thus indicating the livelihood conditions. Since land-use land-cover change is the key driver to the change in resource availability of a region, the present study has tried to analyze the land-cover changes over a period 28 years. The second major component affecting resource availability is the increasing population pressure that leads to changes in the land dynamics, which directly affect the resource production. Based on the existing consumption pattern, the total consumption of fuelwood in the watershed ranges from a minimum of 289.992 tons/year to a maximum of 3545.719 tons/year with an average of 1561.956 tons/year in the year 2009 and simulated fuelwood consumption for the year 2021 is around 1469.260 tons/year. Nine different probable scenarios of resource are proposed to calculate the stress value that can be used by the policy-makers and planners for suitable policy implementation at the micro level with a complex social system.  相似文献   

16.

In tropical areas, pioneer occupation fronts steer the rapid expansion of deforestation, contributing to carbon emissions. Up-to-date carbon emission estimates covering the long-term development of such frontiers depend on the availability of high spatial–temporal resolution data. In this paper, we provide a detailed assessment of carbon losses from deforestation and potential forest degradation from fragmentation for one expanding frontier in the Brazilian Amazon. We focused on one of the Amazonia’s hot-spots of forest loss, the BR-163 highway that connects the high productivity agricultural landscapes in Mato Grosso with the exporting harbors of the Amazon. We used multi-decadal (1984–2012) Landsat-based time series on forested and non-forested area in combination with a carbon book-keeping model. We show a 36% reduction in 1984s biomass carbon stocks, which led to the emission of 611.5 TgCO2 between 1985 and 1998 (43.6 TgCO2 year−1) and 959.8 TgCO2 over 1999–2012 (68.5 TgCO2 year−1). Overall, fragmentation-related carbon losses represented 1.88% of total emissions by 2012, with an increasing relevance since 2004. We compared the Brazilian Space Agency deforestation assessment (PRODES) with our data and found that small deforestation polygons not captured by PRODES had increasing importance on estimated deforestation carbon losses since 2000. The comparative analysis improved the understanding of data-source-related uncertainties on carbon estimates and indicated disagreement areas between datasets that could be subject of future research. Furthermore, spatially explicit, annual deforestation and emission estimates like the ones derived from this study are important for setting regional baselines for REDD+ or similar payment for ecosystem services frameworks.

  相似文献   

17.
Water security is an integral aspect of the socio-economic development in China. Nevertheless, water resources are under persistent pressures because of the growing population, heavy irrigation, climate change effects and short-term policies. Traditional management approaches narrowly focus on increasing supply and reducing demand without considering the complex interactions and feedback loops that govern water resource behaviour. Whereas these approaches may provide quick fix solutions, they often lead to unanticipated, sometimes catastrophic, delayed outcomes. Therefore, water management needs to take a holistic approach that caters to the interdependent physical (e.g. water inflows, outflows) and behavioural (e.g. decision rules, perceptions) processes in the system. Unlike reductionist approaches, System Dynamics (SD) takes a system-level view for modelling and analysing the complex structure (cause–effect relationships, feedback loops, delays) that generates the systemic behaviour. Simulating the SD model allows assessing long-term system-wide impacts, exploring leverage points and communicating results to decision makers. In this paper, we follow an SD modelling approach to examine the future of water security in Yulin City. First, we present a conceptual model for integrating water supply and demand. Based on this, we build an SD model to simulate and analyse the dynamics of water resource over time. The model output is tested to ensure that it satisfactorily replicates the historical behaviour of the system. The model is used to quantitatively assess the effectiveness of various supply/demand management options. Three scenarios are designed and examined: business-as-usual, supply management, and demand management. Results show that current management regime cannot effectively meet the future water demand. Whereas supply acquisition provides short-term benefits, it cannot cope with the growing population. A combination of conservation measures and demand-management instruments is regarded the most effective strategy for balancing supply and demand.  相似文献   

18.
In this study, a multi-criteria methodology is proposed to identify and prioritize interventions for water quality improvement with the aid of computer simulation models. The methodology can be used to elaborate and compare future socio-economic development scenarios to select the best interventions based on three criteria: (1) ideas of experts and stakeholders about the importance of scenarios, (2) impacts of each scenario on surface water quality in watershed, and (3) benefit–cost analysis for each scenario. A score is computed for each scenario based on a weighted sum technique which enables to take into consideration different level of importance for the three criteria. The methodology is applied to Cau River basin in Vietnam, with the aid of a computer tool, to assess interventions for river water quality improvement within the context of population growth and urbanization. The results show that fast future population growth in upstream has significant impacts. In 2020, an increase of 116 % of the population in Bac Kan town can lead to an increase of 120 and 135 % in BOD5 and NH4 + median concentrations, respectively, with the implementation of a treatment plant for 10,000 people in Bac Kan town. Therefore, the increase of the domestic wastewater treatment plant’s capacity in Bac Kan town, at least twice as the projection of local government, is necessary. These results will help decision makers to select the best interventions for Cau River basin management.  相似文献   

19.
The vulnerability of forest ecosystem services to climate change is expected to depend on landscape characteristic and management history, but may also be influenced by the proximity to the southern range limit of constituent tree species. In the Western Rhodopes in South Bulgaria, Norway spruce is an important commercial species, but is approaching its current southern limit. Using climate sensitive forest models, we projected the impact of climate change on timber production, carbon storage, biodiversity and soil retention in two representative landscapes in the Western Rhodopes; a lower elevation landscape (1000–1450 m a.s.l) dominated by mixed species forests, and a higher elevation landscape (1550–2100 m a.s.l.) currently dominated by spruce. In both landscapes climate change is projected to induce a shift in forest composition, with drought-sensitive species, such as Norway spruce, being replaced by more drought-tolerant species such as Scots pine and black pine at lower elevations. In the higher elevation landscape a reduction in spruce growth is projected, particularly under the more severe climate change scenarios. Under most climate scenarios a reduction in growing stock is projected to occur, but under some scenarios a moderate increase in higher elevation stands (>1500 m a.s.l.) is expected. Climate change is projected to negatively influence carbon storage potential across landscapes with the magnitude depending on the severity of the climate change scenario. The impact of climate change on forest diversity and habitat availability is projected to differ considerably between the two landscapes, with diversity and habitat quality generally increasing at higher elevations, and being reduced at lower elevations. Our results suggest that if currently management practices are maintained the sensitivity of forests and forest ecosystem services in the Western Rhodopes to climate change will differ between low and higher elevation sites and will depend strongly on current forest composition.  相似文献   

20.
This paper summarizes studies of carbon mitigation potential (MP) and costs of forestry options in seven developing countries with a focus on the role of agroforestry. A common methodological approach known as comprehensive mitigation assessment process (COMAP) was used in each study to estimate the potential and costs between 2000 and 2030. The approach requires the projection of baseline and mitigation land-use scenarios derived from the demand for forest products and forestland for other uses such as agriculture and pasture. By using data on estimated carbon sequestration, emission avoidance, costs and benefits, the model enables one to estimate cost effectiveness indicators based on monetary benefit per t C, as well as estimates of total mitigation costs and potential when the activities are implemented at equilibrium level. The results show that about half the MP of 6.9 Gt C (an average of 223 Mt C per year) between 2000 and 2030 in the seven countries could be achieved at a negative cost, and the other half at costs not exceeding $100 per t C. Negative cost indicates that non-carbon revenue is sufficient to offset direct costs of about half of the options. The agroforestry options analyzed bear a significant proportion of the potential at medium to low cost per t C when compared to other options. The role of agroforestry in these countries varied between 6% and 21% of the MP, though the options are much more cost effective than most due to the low wage or opportunity cost of rural labor. Agroforestry options are attractive due to the large number of people and potential area currently engaged in agriculture, but they pose unique challenges for carbon and cost accounting due to the dispersed nature of agricultural activities in the tropics, as well as specific difficulties arising from requirements for monitoring, verification, leakage assessment and the establishment of credible baselines.  相似文献   

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