首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 546 毫秒
1.
Although many different forest certification standards exist, harvest adjacency and green-up regulations are common to most certifying bodies. This study develops a means for evaluating trade-offs associated with implementation of nth-order adjacency and green-up constraints on a 1.7 million ha landscape in Oregon in the US. Depending on the type of adjacency structure and delay between harvests, the opportunity cost of the restrictions, estimated by the change in discounted sum of producer and consumer surplus in the regional log market, ranged from 0.25% to 66% (or US $60 million to $15.3 billion) of the unconstrained value. Increasing green-up delays beyond 30–40 years had little effect on estimated opportunity cost of the modeled restrictions.  相似文献   

2.
Why are organised shoots involving birds that are farm-reared and subsequently released a dividing issue in several countries? As a contribution to answering this question the paper reports a national survey of landowners (n = 1207), hunters (n = 1130) and the general public (n = 1001) in Denmark. While there was broad agreement across all three groups that recreational hunting of naturally occurring “surplus” wildlife is acceptable, the release of farm-reared game birds for shooting was a dividing issue, both within the groups and between them. The majority of participants (51%) in the survey representing the general public were against the practice; a majority of hunters (61%) were in favour of it; and landowner approval rates lay between these two poles. Respondents with a “mutualist” or “distanced” wildlife value orientation according to the definitions by Teel et al. (2005) consistently displayed a more negative attitude to rear and release shooting than those with a “utilitarian” orientation. The differences in attitude could not be explained in terms solely of underlying concerns about nature conservation and biodiversity protection. Concerns about the behaviour of the released birds, and about hunting “culture” and regulatory measures, also informed the participants’ attitudes. The regulatory framework governing shooting based on the release of farm-reared birds could reflect a wider range of concerns than those hitherto acknowledged.  相似文献   

3.
We examine dramatic cropland expansion in Karamoja, Uganda by investigating the links between biophysical and political historical events leading to the current state of agricultural land use. Our objective was to quantify agricultural expansion, uncover the dominant drivers leading to the current state of agricultural land use and its impacts on livelihoods. Region wide analysis of remotely sensed data, land use policy and history as well as farmer interviews were undertaken. We posit that government programs instituting sedentary agriculture are the most significant drivers of cropland expansion in Karamoja. We show a 299% increase in cropland area between 2000 and 2011 with most expansion occurring in Moroto District (from 706 ha to 23,328 ha). We found no evidence of an increase in overall crop production or food security and food aid continues to be essential due to recurrent crop failures. Due to lack of resources for inputs (e.g., seeds and labor) cultivated fields remain very small in size and over 55% of once cultivated land is left fallow. Our findings bring into question whether continued promotion of rain-fed agriculture in Karamoja serves the best interests of the people. Current cropland expansion is directly competing and compromising pasture areas critical for livestock-based livelihoods. Without strong agricultural extension programs and major investments in climate-smart options, cropland expansion will continue to have a net negative impact, especially in the context of current climate projections which indicate a future decrease in rainfall, increase in temperature and an increase in the frequency and magnitude of extreme events.  相似文献   

4.
This study evaluated the potential effectiveness of future carbon reserve scenarios, where U.S. forest landowners would hypothetically be paid to sequester carbon on their timberland and forego timber harvests for 100 years. Scenarios featured direct payments to landowners of $0 (baseline), $5, $10, or $15 per metric ton of additional forest carbon sequestered on the set aside lands, with maximum annual expenditures of $3 billion. Results indicated that from 1513 to 6837 Tg (Teragrams) of additional carbon (as carbon dioxide equivalent, CO2e) would be sequestered on U.S. timberlands relative to the baseline case over the next 50 years (30–137 Tg CO2e annually). These projected amounts of sequestered carbon on timberlands take into account projected increases in timber removal and forest carbon losses on other timberlands (carbon leakage effects). Net effectiveness of carbon reserve scenarios in terms of overall net gain in timberland carbon stocks from 2010 to 2060 ranged from 0.29 tCO2e net carbon increase for a payment of $5/tCO2e to the landowner (71% leakage), to 0.15 tCO2e net carbon increase for a payment of $15/tCO2e to the landowner (85% leakage). A policy or program to buy carbon credits from landowners would need to discount additions to the carbon reserve by the estimated amount of leakage. In the scenarios evaluated, the timber set-asides reduced timberland area available for harvest up to 35% and available timber inventory up to 55%, relative to the baseline scenario over the next 50 years, resulting in projected changes in timber prices, harvest levels, and forest product revenues for the forest products sector.  相似文献   

5.
Studies of land use policies are commonly based on the environmental impacts or on people's direct responses to the policies. However, research on the impact of policy implementation on people's livelihood and activities and the subsequent economic development of an area is incomplete. We selected Yanchang County as an example to track land use changes and their effects on the livelihood of the local population following the implementation of a new land use policy known as the Grain for Green Project (GGP). The data were collected from statistical yearbooks, questionnaire surveys, and satellite imagery from 1990, 2000, and 2008. We found that dramatic land use changes have occurred in Yanchang County. The vegetation coverage improved significantly from 1990 to 2008, as the grassland and forest areas increased from 44.1% to 60.1% and from 17.7% to 18.4% of the total land area, respectively. The cultivated land declined from 37.3% to 20.7%. With the agricultural area and grain production decreasing from 64 × 103 tons to slightly over 20 × 103 tons per year, an increasing number of local people sought employment in towns and cities. The non-farm income increased, and the local income structure shifted. Migrant and orchard worker income contributed the most to the balance of the total household income. We narrowed our focus to discuss how the GGP accelerated the changes in the participants’ lifestyles and what might be done to sustain the long-term effects of the GGP. While the GGP has brought about considerable environmental benefits, a comprehensive study of environmental–social systems is still needed to achieve a more efficient land use policy. The research results presented in this paper demonstrate that changes in land use and people's activities were triggered by policy changes. We aim to pave the way for studies on the “policy-land-use-social development” chain and to provide references for new policies.  相似文献   

6.
Being fertile lands, wetlands have been managed for traditional agriculture over millennia. However, the integrity and ecosystem services of wetlands are being jeopardized by intensive land-use comprising of drainage and excessive disturbance. An adhoc and intensive use of wetlands, without preserving ecological integrity is causing ecosystem disservices and threatening conversion of a large soil organic carbon (SOC) sink into a net source. Wetlands in the tropical parts of the world are distributed unevenly and represent ∼3% of the total world land area. Due to stagnancy and even reduction in rice (Oryza sativa) yield of many agricultural regions, there is a need for additional and alternative land-uses which can raise the global rice production to ∼1 billion Mg (megagram = 106g = metric ton) by 2050 from ∼497 million Mg now. Wetlands can be a viable option to advance global food security because of high soil fertility and vast geographical distribution. A ‘3-tier rice production system’ is proposed herein based on specific hydrological niche to advance global food security without degrading the ecosystem services of wetlands. In addition to increasing agronomic yield, the proposed modus operandi can also improve the livelihood security of farmers through an additional income streams by: (i) trading of SOC credits generated through adoption of conservation agriculture in littoral zones, and (ii) promoting fish and duckery culture in conjunction with deepwater rice farming. Furthermore, the proposed strategies will also set in motion the process of restoration of wetlands while enhancing C sink capacity of the ecosystems.  相似文献   

7.
In this study, an interval fuzzy chance-constrained land-use allocation (IFCC-LUA) model is developed for sustainable urban land-use planning management and land use policy analysis under uncertainty. This method is based on an integration of interval parameter programming (IPP), fuzzy flexible linear programming (FFLP) and chance-constrained programming (CCP) techniques. Complexities in land-use planning management system can be systematically reflected, thus applicability of the modeling process can be highly enhanced. The developed method is applied to planning land-use allocation practice in Nanjing city, China. The objective of the IFCC-LUA is maximizing net benefit from LUA system and the main constraints include investment constraints, land suitability constraints, water/power consumption constraints and wastewater/solid waste capacity constraints. Modeling results indicate that desired system benefit will be between [1.34, 1.74] × 1012 yuan under the minimum violating probabilities; the optimized areas of commercial land, industrial land, agricultural land, transportation land, residential land, water land, green land, landfill land and unused land will be [290, 393] hm2, [176, 238] hm2, [3245, 4390] hm2, [126, 170] hm2, [49, 66] hm2, [1241, 1679] hm2, [102, 138] hm2, [7, 10] hm2 and [178, 241] hm2. They can be used for generating decision alternatives and thus help decision makers identify desired land use policies under various system-reliability constraints of economic development requirement and environmental capacity of pollutant. Tradeoffs between system benefits and constraint violation risks can also be tackled.  相似文献   

8.
Land use and cover (LUC) change is a major driver of ecosystem service loss worldwide. In response, policymakers have designed conservation strategies that incentivize the establishment and maintenance of LUC types associated with higher ecosystem service provision. Many of these policies also aim to promote social and economic goals such as reducing poverty. Attempts to measure the impact of policy-driven LUC change on stakeholders typically focus only on economic outcomes for landowning participants or aggregate the socio-economic outcomes of diverse groups. In this study, we applied local ecological knowledge (LEK) held by beekeepers in Costa Rica to understand the impact of policy-driven LUC change on this specific group of often non-landowning stakeholders. Beekeeping is a globally important rural livelihood and provides pollination services to crops and wild plants. We synthesized beekeeper LEK using a mixed-methods approach including apiary mapping exercises (n = 215 apiaries), questionnaires (n = 50 participants), and follow-up interviews (n = 21 participants). Our study revealed that some policy-driven LUC changes have limited beekeepers’ access to preferred land uses, such as secondary and mature forests with native trees. Participants reported concern for their livelihoods due to policy-driven spatial and temporal change of floral resources via the establishment of tree plantations, changes in pasture management, and laws that prohibit beekeeping in national parks and reserves. Our study provides evidence of unintended outcomes from land use policies, including Payment for Ecosystem Services, with disproportionate negative impacts on non-landowning residents who depend on natural resources in the landscape for their livelihoods. Our study illustrates potential inequality rising from current incentive mechanisms associated with Payments for Ecosystem Services and other conservation policies and calls for policymakers to consider LUC change impacts on non-landowning stakeholders.  相似文献   

9.
The bioeconomy is gaining growing attention as a perceived win-win strategy for environment and economy in the EU. However, the EU already has a disproportionately high global cropland footprint compared to the world average, and uses more cropland than domestically available to supply its demand for agricultural products. There is a risk that uncontrolled growth of the bioeconomy will increase land use pressures abroad. For that reason, a monitoring system is needed to account for the global land use of European consumption. The aim of this paper is to take a closer look at the tools needed to monitor global cropland footprints, as well as the targets needed to benchmark development. This paper reviews recent developments in land footprint accounting approaches and applies the method of global land use accounting to calculate the global cropland footprint of the EU-27 for the years between 2000 and 2011. It finds a slight decrease in per capita cropland footprints over the past decade (of around 1% annually, reaching 0.29 ha/cap in 2011) and advocates promoting a further decrease in per capita cropland requirements (of around 2% annually) to reach global land use targets for keeping consumption within the safe operating space of planetary boundaries by 2030. It argues that strategic land reduction targets may still go hand in hand with the growth of a smart, innovative and sustainable bioeconomy by reinforcing the need for policies that support greater efficiency across the life-cycle and reduce wasteful and excessive consumption practices. Recommendations for further improving land footprint accounting are given.  相似文献   

10.
Agriculture is the largest type of land use in the UK, accounting for about 77 per cent of the total area, compared with an average 50 per cent for the EU27. But in common with most high-income countries, agriculture's contribution to UK GDP and employment is low, at about 0.5 and 1.8 per cent, respectively, although the regional importance of the sector (and its associated food and farming industries) varies considerably.Of the 17.5 million ha used for agriculture, about 28 per cent is allocated to crops, and 67 per cent is grassland. The grassland includes 4.4 million ha of sole-owned rough grazing and 1.1 million ha of common land in mainly upland “disadvantaged areas,” primarily used for beef and sheep production. This has a major influence on land use, especially in the northern and western parts of the UK.From the 1930s until the mid-1980s, UK policy promoted increases in agricultural productivity to feed the nation from its own resources. An array of income and production support measures encouraged intensive farming, including a relative switch to arable farming in eastern areas. Since the early-1990s, policies have sought simultaneously to make UK agriculture internationally competitive and environmentally benign. These policies, evident in the Agenda 2000 Reforms of the Common Agricultural Policy, point the way forward for the future. It is likely that a greater distinction will emerge between policies to protect natural resources and enhance the flow of non-market ecosystem services from rural land, and agriculture and food policies intended to encourage an appropriate proportion of national food requirements to be met from domestic sources.It seems likely that over the next 50 years, the UK's land area will be required to deliver an increasingly diverse range of private and public goods to meet growing human needs and aspirations. This will require a balance of policy-driven goals and market forces. It will also need a much improved understanding of the trade-offs between food production and environmental goals and of the institutional arrangements required to achieve a balance of economic, social and environmental outcomes.  相似文献   

11.
Traditional rural biotopes (TRBs) are semi-natural farmland habitats of high nature value formed through traditional agricultural activities, such as grazing and fodder collection. The aims of this study were to 1) understand manager motivations for managing TRBs and their attitudes toward TRB conservation and 2) determine whether TRB managers differ in attitude, motivation for management, experiences or area under management depending on whether their managed TRBs are integrated or separate from their farming systems. Farmers and landowners (N = 27) managing TRBs in coastal Finland were interviewed. In addition to quantitative analysis, responses were mapped with DebateGraph for inductive analysis to discern patterns amongst the two groups and to explore a series of questions related to motivations. Although area under management and farming strategy varied amongst managers, they all had a positive view toward the existential value of TRBs. A small group of “TRB entrepreneurs”, whose farming strategy was based on grazing primarily rented TRBs was identified. Their farming income was dependent upon direct sale of meat and participation in agri-environmental scheme for TRB management. Desire for open landscape was the primary motivation for managing TRBs and strongly outweighed extrinsic values such as fodder production and AES. Higher TRB: farm ratio was associated with more positive attitude toward TRBs and TRB conservation. No difference was found in motivation for management between the two farmer groups. Although motivations were similar, improved and tailored extension services for TRB managers could promote their conservation management.  相似文献   

12.
Mexico is a megadiverse country with large agroclimatic diversity and socioeconomic inequality. These two factors result in strong diversity in diets and agricultural systems within the country. In this paper, we assess the impact of Mexican diets and production systems on the per capita land requirements for food. We estimate it for the extremes: from the very basic diet of the poorest share of the population to the affluent diet of the richest share of the population; and for extensive and intensive systems, with irrigation as the indicator of the intensity of the system. We show that the basic diet produced in rainfed systems requires 1620 m2/cap/yr and produced in irrigate systems requires 700 m2/cap/yr. The affluent diet produced in rainfed systems requires 2540 m2/cap/yr and produced in irrigated systems requires 1230 m2/cap/yr. Hence, differences in diets result in a requirement for 80% or 60% more land for an affluent diet; and differences in production systems result in more than twice the amount of land for extensive than for intensive systems. In 2050, it would be possible to feed the entire population with affluent diets only if all the present area of crop land had the productivity of intensive systems. In contrast, it would be possible to feed all people with a basic diet even if all present crop land area had only the productivity of extensive systems.  相似文献   

13.
Scenarios of future outcomes often provide context for policy decisions and can be a form of science communication, translating complex and uncertain relationships into stories for a broader audience. We conducted a survey experiment (n = 270) to test the effects of reading land use change scenarios on willingness to participate in land use planning activities. In the experiment, we tested three combinations of scenarios across two time periods, comparing survey responses of individuals reading a set of scenarios with individuals who did not read scenarios. Reading scenario narratives increased willingness to participate in land use planning activities and perceived self-efficacy. Measures of interest and sense of community also increased willingness to participate. Tests of an indirect mediation model found self-efficacy partially mediated the effect of reading scenarios on willingness to participate. This latter relationship may be a mechanistic explanation for the effect of reading scenarios. Envisioning the future with brief, bulleted scenarios of land use change in a print format appears to increase self-efficacy in planning for the future. Our results suggest scenarios can serve as a vehicle for changing public participation in land use planning.  相似文献   

14.
To assist pest management planning, the Canadian Forest Service developed the Spruce Budworm Decision Support System (SBW DSS), which quantifies the timber supply impacts of protecting stands against spruce budworm (Choristoneura fumiferana Clem.) defoliation. We incorporated protection costs and timber product values in this system to evaluate economic aspects of spruce budworm control. The analysis allows pest managers to evaluate the degree to which the traditional volume protection priority objective corresponds to three economic criteria, namely the volume protected per dollar protection program cost, the benefit–cost ratio of the protection program, and the net present value of the protection program. Twelve alternative spruce budworm protection strategies were analyzed on Crown License 1 in New Brunswick and Prince Albert Forest Management Area (PAFMA) in Saskatchewan, based on a number of protection program extents and intensities. For both landbases under base-case market conditions, the largest, most intensive protection scenario provided the highest amount of volume saved and net present value (at 3.94 Mm3 and $39.98 M for PAFMA, and 4.04 Mm3 and $41.49 M for License 1, respectively) while smaller, less-intensive programs provided the highest benefit–cost ratios and volume protected per present value dollar of protection cost (at 8.22 and 0.52 m3/$ for PAFMA, and 10.26 and 0.65 m3/$ for License 1, respectively). Sensitivity analysis on product values and protection costs revealed that smaller, less-intensive programs could also produce the highest net present values when costs are higher and/or product values lower. These results highlight the conditions under which pest managers should consider deviating from their traditional strategy of maximizing volume saved to one that maximizes the economic returns of protection.  相似文献   

15.
Zoning is one of the oldest policy tools for regulating private land use, but its effect on housing change is disputed. We define housing change as the difference over time in the number of housing units in a given jurisdiction. We conducted a cross-jurisdictional study of zoning effects on housing change, comparing zoned and unzoned townships in Michigan, USA (n = 709) after propensity score matching. Four-decade (1970–2010) panel models predicted zoned townships to have on average 2.2% fewer housing units a decade after zoning adoption compared to similar unzoned townships, but this effect was tempered by other variables. Higher-income townships had more housing units a decade after zoning adoption compared to higher-income unzoned townships, whereas lower-income townships with zoning had fewer housing units than similar unzoned townships. This study highlights the heterogeneous effects of zoning on rural and exurban housing change.  相似文献   

16.
A high level of fragmentation of farmland ownership is an important underlying cause of land degradation and, at the same time, an obstacle to sustainable land management. This study makes the first-ever analysis of long-term trends in the rate of fragmentation. Our study covers the period from the earliest stages of the current form of ownership patterns at the end of the 18th century until the present day. On the basis of significant predictors that have been identified (initial fragmentation, population growth, historical development of inheritance laws and of the land market, natural soil fertility and landscape type), we go on to project probable developments for the period from 2016 to 2045. A total of 102,984 land parcels in 56 cadastral units in the territory of Czechia have been analysed on the basis of data from four years (1785, 1840, 1950, 2015). Our study considers the development of two basic indicators of fragmentation – Mean Parcel Size and Number of Owners per 100 ha. The Mean Parcel Size has decreased over a period of 230 years from 1.08 ha to 0.64 ha, at a mean rate of −0.26% year−1. During the same period, the Number of Owners per 100 ha has risen from 17.50 to 79.66, at a mean rate of 0.61% year−1. A detailed analysis of the development trends confirms significant spatial variability and also time variability of the rates of the two indicators. The analysis also shows their mutual complementarity: growth in the rate of one of the indicators is usually accompanied by a drop in the other. The general trend that we project for the territory of Czechia in the upcoming 30 years is that there will be further diminution of the physical size of land parcels (continuing fragmentation of land parcels) accompanied by a reduction in the Number of Owners (defragmentation of land ownership).  相似文献   

17.
The study examines citizens’ opinions about one crucial factor: the fire that affects the Brazilian savannah “Cerrado”. The paper aims at introducing a new tool that facilitates the assessment of people’s behaviour in order to support practitioners and decision makers to develop management strategies that fostering the environmental conservation, economic growth and human wellbeing.The study applies the network analysis in order to analyse the citizens’ opinions about causes of fire ignition and suppression activities for firefighting evoked by local inhabitants during the face-to-face interviews.The main finding carried out in this work is the usefulness of a cognitive map for synthesising a variety of people’s beliefs. Furthermore, the study reveals the general lack of awareness among people concerning fire use and management and the careless use of fire in rural activities. The chi-square test reveals that natural and physical dimensions affect society’s beliefs with statistical significance p < 0.001.  相似文献   

18.
In a chestnut belt in the northern Apennines (Italy), we interviewed current (n = 52) and potential growers from a younger generation (n = 57), to assess what factors are likely to drive their willingness to continue chestnut culture. In 35 cases, local appraisals of chestnut stand disturbances were also contrasted with expert assessments. More than half of current growers were confident about the future of chestnut cultivation. This proportion decreased with grower’s age and experienced issues, while slightly increased in presence of multifunctional management and support from family members. Although most growers resulted highly capable of diagnosing problems, expert advice significantly contributed to driving positive perceptions. About half of the younger interviewees also expressed interest in growing chestnut. This proportion was higher for respondents who are exposed to chestnut culture within the family, and who value cultural services above other ecosystem services (ES) of forests. Overall, passion for the activity and attachment to local heritage were the most influential motivation for both categories of respondents. We outline policy actions that may encourage the continuation of chestnut management and, more generally, conservation of cultural landscapes in mountain areas. Possible measures include financial incentives (e.g., payments for ES), tighter integration of traditional and expert knowledge in the production chain, and public recognition of the value of local heritage in land management. Broader support to maintaining services and infrastructure in rural areas, however, will also be a pre-condition.  相似文献   

19.
Tropical forests potentially contribute to global climate change mitigation through carbon sequestration, hence a global carbon pool. In order to mitigate the global climate change impact, the Kyoto protocol developed the clean development mechanism (CDM) which supports carbon credits for plantation activities in developing countries. Unfortunately, none of the CDM forestry projects included bamboo as a carbon reservoir. Although bamboo is an integrating part of tropical forest ecosystems, it was overlooked in the initial negotiating process. The present study, therefore, investigated the carbon storage potential of a common bamboo species, Bambusa vulgaris at Lawachara forest reserve of Bangladesh. Results showed that five-year-old B. vulgaris stand stored in total 77.67 t C ha−1 of which 50.44 t C ha−1 were stored in the above ground biomass (culms, branches and leaves), 2.52 t C ha−1 in the below ground biomass and 24.71 t C ha−1 in the soils. This amount of carbon storage is much more promising than the carbon storage of many other tree species considered in the CDM projects. These findings demonstrate the potential of B. vulgaris to be considered in CDM projects as a plantation species and thereby mitigate climate change impact more efficiently.  相似文献   

20.
Oil palm plantations in Indonesia have been linked to substantial deforestation in the 1990s and 2000s, though recent studies suggest that new plantations are increasingly developed on non-forest land. Without nationwide data to establish recent baseline trends, the impact of commitments to eliminate deforestation from palm oil supply chains could therefore be overestimated. We examine the area and proportion of plantations replacing forests across Sumatra, Kalimantan, and Papua up to 2015, and map biophysically suitable areas for future deforestation-free expansion. We created new maps of oil palm plantations for the years 1995, 2000, 2005, 2010 and 2015, and examined land cover replaced in each period. Nationwide, oil palm plantation expansion occurred at an average rate of 450,000 ha yr−1, and resulted in an average of 117,000 ha yr−1 of deforestation, during 1995–2015. Our analysis of the most recent five-year period (2010–2015) shows that the rate of deforestation due to new plantations has remained relatively stable since 2005, despite large increases in the extent of plantations. As a result, the proportion of plantations replacing forests decreased from 54% during 1995–2000, to 18% during 2010–2015. In addition, we estimate there are 30.2 million hectares of non-forest land nationwide which meet biophysical suitability criteria for oil palm cultivation. Our findings suggest that recent zero-deforestation commitments may not have a large impact on deforestation in Sumatra, where plantations have increasingly expanded onto non-forest land over the past twenty years, and which hosts large potentially suitable areas for future deforestation-free expansion. On the other hand, these pledges could have more influence in Kalimantan, where oil palm driven deforestation increased over our study period, and in Papua, a new frontier of expansion with substantial remaining forest cover.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号