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1.
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   

2.
The assessment of agriculture at a regional scale is necessary to better guide regional agricultural planning. To improve the contribution of agriculture to sustainable regional development, assessments must take account of the locations and diversity of cropping systems. We have therefore developed a method based on a set of multi-scale indicators to assess the contribution of agriculture to the sustainable development of regions, and its evolution over time. This method can identify: i) sustainability issues, ii) relevant indicators that will provide information on impacts at the field scale, iii) a method to aggregate indicators, iv) data on cropping systems, and v) a database containing spatial units to analyse the whole region. Application of this method to Guadeloupe (2004–2010) enabled the definition of ten issues and 16 indicators, with three procedures to aggregate information from 36 cropping systems allocated to 11,908 fields between 2004 and 2010. Economic, social and environmental sustainability was poor in 2004, with high dependency on subsidies (47.3 M€ yr−1), low agricultural added value (48.5 M€ yr−1), low employment (only 1799 workers), significant risks of crop contamination and pressure on water quality. The total value of subsidies and the risks of river pollution tended to decrease between 2004 and 2010 because of a reduction in intensive banana cropping systems. In parallel, we were able to see that sugar cane, the most widespread crop in Guadeloupe, made only a small contribution to employment and food self-sufficiency during the studied period. The spatial representation revealed that improvements have been seen in southern Guadeloupe due to reductions in banana cultivation. This method was therefore helpful in identifying the most critical agricultural development issues and helping to highlight areas where relevant agricultural land use policies could be formulated.  相似文献   

3.
Successfully integrating human activities with ecosystem conservation forms the foundation of sustainability and is key to maintaining biological diversity. This is especially important in privately-owned lands in the U.S., which harbor high levels of biodiversity yet are often vulnerable to habitat degradation and loss. This study analyzes recreation as a sustainable use on private property, focusing on wildlife-associated recreation, defined here as fishing, hunting and wildlife watching. Eighteen national surveys implemented by three U.S. government agencies spanning 1999–2013 were analyzed to provide baseline information and an assessment of the conservation impact of recreation. Results show that approximately 440.1 million acres of private land, ∼22% of the contiguous land area of the U.S., are either leased or owned for wildlife-associated recreation. Land utilized for hunting accounts for 81% of that total. Approximately 33% of private forestland, 18% of private grazing land and 4% of private cropland is used to earn revenue from recreational activities. Annual spending for wildlife-associated recreation on private land is estimated at $814 million in day-use fees, $1.48 billion for long-term leases, and $14.8 billion to own land primarily for recreation (2011 dollars). Hunters own or lease properties of larger size classes than anglers or wildlife-watchers, indicating that hunting may provide a greater economic incentive for maintaining large unfragmented properties that provide a variety of conservation benefits. On grazing and cropland, landowners who earn income from recreation are significantly more likely to participate in government conservation programs (p < 0.001) and to pay for private conservation practices (p = 0.08). This provides support that recreation incentivizes conservation at higher rates than agricultural activities alone. Three policy measures that could further enhance conservation benefits of recreation are discussed.  相似文献   

4.
Cultivated land productivity potential improvement (CLPPI) assessment is the fundamental basis to launch land consolidation, which is one of the most important way to increase the grain productive capacity. Previous studies on CLPPI assessment have focused on factors related to natural conditions of cultivated land, but they ignored the impacts of utilization conditions, including plot characteristics and agricultural infrastructure, which account for substantial CLPPI from land consolidation. Based on the crop-growth model and Agro-ecological Zoning (AEZ) methodology, this paper proposed a modified CLPPI assessment model to estimate the improvement of land productivity potential via land consolidation. Meanwhile, the contribute rates of different factors involved in determining the CLPPI were also analysed to reveal the ideal work focus and policy direction for land consolidation. Results showed that the calculated CLPPI values had obvious spatial variety in Shenyang, of which the average was 326.18. For the consolidation case, total crop production in Shenyang could be increased by as much as 149.89 × 107 kg, 20% of the current yield. CLPPI is the comprehensive outcome of both natural and utilization qualities of land use, and the current productivity potential of cultivated land in Shenyang relied much less on natural conditions such as soil than on utilization conditions such as agricultural infrastructure. In addition, medium-productivity lands were most appropriate target areas for the implication of land consolidation projects. Actually, the arrangement of land consolidation projects should not only consider CLPPI as in the past, but also add the theoretical productivity potential into consideration. Moreover, the realization of estimated CLPPI also calls for active changes of the whole land management system. An integrated institution for the full implementation of land consolidation, proper regulations and laws on the follow-up protection of cultivated land productivity potential, economic policies to stimulate the willingness of farmers, and a transfer mechanism for cultivated land are all needed policy changes.  相似文献   

5.
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   

6.
Urban river rehabilitation aims to enhance the ecological status of urban watercourses and promote measures for the local population to increase their well-being by making a direct or indirect use of the services these ecosystems may provide. The social and economic feasibility is evaluated by contrasting the resources used in the rehabilitation process with the benefits derived from it through the Cost-Benefit Analysis (CBA). By means of a case study, this work not only introduces the most innovative CBA approaches in environmental projects, but also implements probabilistic simulation methods in order to increase the robustness of the assessment indicators.The case study encompasses two projects, whose global costs total €46 M in 50 years, for the environmental rehabilitation of the stretch of the River Segura that flows through the city of Murcia. The benefits have been obtained by a contingent valuation exercise: €3.3 M/year (€0.6 M/year of use benefits, and €2.7 M/year of non-use benefits). Three different CBA approaches (economic, extended and dual) are applied to contrast these costs and benefits, conducting the analyses of uncertainty and sensitivity of the benefit items through a Monte Carlo simulation. The results highlight the importance of environmental benefits for this kind of projects to be socioeconomically feasible thanks to the profitability indicators they provide.  相似文献   

7.
In sub-Saharan Africa, many people depend on natural resources for their livelihoods. While urbanisation causes landscape changes, little is known of how this process affects the use of wild plant resources by urban populations. This study contributes to addressing this knowledge gap by exploring the prevalence and determinants of urban collectors of wild plants in Kampala, Uganda. During February to August 2015, 93 structured interviews were conducted in inner, outer, and peri-urban areas of the city. The findings in this study show that urban wild plants are used by almost half (47%) of the respondents, mainly for medicinal purposes but also as a complement to diets. The findings further indicate that residents with lower income, of younger age (<51 years old), and predominantly living in peri-urban areas are more likely to be urban collectors. Seasonality appears to be of greater importance in collection of food plants than of medicinal plants. Overall, these findings indicate that wild plants occupy an important role in the livelihoods and traditions of Kampala’s residents, and we argue that this should be taken into account in urban planning projects.  相似文献   

8.
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   

9.
In the Genil River Basin (southern Spain), agriculture is the greatest pressure on freshwater demand. Furthermore, water degradation caused by soil erosion is becoming a key environmental concern. This study aims to assess the water-related impacts of agriculture combining the use of an ecohydrological model (SWAT) with a spatiotemporal water footprint assessment to evaluate the current status of streamflow (blue water), soil water (green water) and the assimilability of sediments by streamflow (grey water footprint). The Common Agricultural Policy (CAP) requires farmers to adopt certain agricultural practices that are beneficial for the environment. Such practices could affect the conditions of available land and water resources. Because of the importance of applying the best land management practices for the maintenance of sustainable water resources, the study also infers probable water availability and water pollution level changes under different post-2013 CAP scenarios. The Genil streamflow is highly regulated, and, as a result, it is hard to discern significant changes (p < 0.05) under the proposed scenarios. However, there is a shift with afforestation measures from unproductive (i.e., direct soil evaporation) to productive water (i.e., evapotranspired water from agricultural and natural areas, excluding non-growing periods) consumption. The probability of annual evapotranspiration from natural areas being greater in afforestation scenarios than in the baseline scenario is 0.70 to 0.88, whereas the likelihood of soil water evaporation being lower is 0.60. Evapotranspiration in natural areas increases by about 521% from September to May under afforestation measures compared with the baseline scenario, whereas soil water evaporation decreases by 30% in winter. The grey water footprint and water pollution level decrease by 19% and 9%, respectively, with the highest streamflow conditions under afforestation as opposed to current conditions. However, water pollution levels of suspended solids greater than 1 indicate that the river flow is not capable of assimilating the existing sediment loads. Since land use changes and agricultural practices have a major impact on water resources, the post-2013 CAP reform can provide environmental benefits for water allocation and mitigation of water pollution. However, further efforts are required to better align the policy goals of the CAP and the Water Framework Directive.  相似文献   

10.
In many countries, electricity transmission networks are being upgraded and developed arising from policies aiming to decarbonise energy systems. However, new power lines are often controversial, due to their perceived negative impacts on rural landscapes. Despite the fact that visual impacts are an important element of public objections, to date, little research has analysed public preferences for alternative pylon designs, as well as investigating the social and psychological factors that might explain such preferences. This paper sought to address this gap, informed by research on public acceptance of renewable energy technologies, using a survey conducted with a representative sample of UK adults (n = 1519). The findings indicate that the ‘T-pylon’ design, winner of a recent competition, was most strongly preferred and the one most perceived to fit with a rural landscape, by comparison to the conventional ‘A frame’ design and a ‘Totem’ design shortlisted in the competition. Linear regression analyses indicated three factors that explained perceived fit, regardless of the designs: lower levels of educational attainment, positive general attitudes towards transmission lines and higher levels of trust in National Grid were associated with positive perceptions of fit of the pylons in a rural landscape. Finally, findings concerning public support for diverse mitigation measures indicated that the use of alternative designs was less supported than burying new powerlines underground and routing pylons away from homes and schools. The implications of these results for more sustainable grid networks are discussed.  相似文献   

11.
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   

12.
This paper examines the potential and the cost of promoting forest carbon sequestration through a tax/subsidy to land owners for reducing/increasing carbon storage in their forests. We use a partial equilibrium model based on intertemporal optimization to estimate the impacts of carbon price (the tax/subsidy rate) on timber harvest volume and price in different time periods and on the change of forest carbon stock over time. The results show that a higher carbon price would lead to higher forest carbon stocks. The tax/subsidy induced annual net carbon sequestration is declining over time. The net carbon sequestration during 2015–2050 would increase by 30.2 to 218.3 million tonnes of CO2, when carbon price increases from 170 SEK to 1428 SEK per tonne of CO2. The associated cost, in terms of reduced total benefits of timber and other non-timber goods, ranges from 80 SEK to 105.8 SEK per tonne of CO2. The change in carbon sequestration (as compared with the baseline case) beyond 2050 is small when carbon price is 680 SEK per tonne of CO2 or lower. With a carbon price of 1428 SEK per tonne of CO2, carbon sequestration will increase by 70 million tonnes of CO2 from the baseline level during 2050-2070, and by 64 million tonnes during 2070–2170.  相似文献   

13.
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   

14.
The aim in this paper was to evaluate the spatial distribution of protected areas defined by law and their importance as structural corridors. The study area was 7,559,783.69 ha located in Western Bahia (Northeast Brazil), restricted to the limits of the Urucuia Group (Upper Cretaceous), where there is strong agribusiness growth. Currently, a major dilemma in Brazilian public policy arises from the conflicting interests of environmental conservation and increased food production. Brazilian environmental protection policies include the implantation of Protected Areas (Full Protection Units and Sustainable Use Units) and the adoption of the National Forest Act (Permanent Preservation Areas and Legal Reserves). In this context, we delimited illegal land-use in Permanent Preservation Areas (PPAs) adopting the intersection between land-use/land-cover data from PRISM/ALOS image classification for the years 2007–2010 and PPA vectors. We performed the temporal analysis in PAs considering land-use/land-cover data from Landsat TM image classification for the years 1988, 1992, 1996, 2000, 2004, 2008 and 2011. Finally, we performed a Morphological Spatial Pattern Analysis (MSPA) to evaluate whether PPAs alone are sufficient as structural corridors. Hypothetical scenarios were simulated to increase the potential of PPAs as structural corridors. The calculation of MSPA attributes was conducted considering 3 edge widths: 15 m (1 pixel), 510 m (34 pixels), and 1005 m (67 pixels). Four scenarios were simulated, considering a gradual increase in preserved areas. The results show that illegal land use is contained within PPA and protected areas. The scenario simulations present alternatives to increase the connectivity of the fragments and ensure the maintenance of ecological and hydrological services. Rapid agricultural expansion without proper landscape planning can compromise the sustainability of ecosystem services and the recharge zone of the Urucuia aquifer.  相似文献   

15.
Objectives(1) To quantify the contribution of the French forest-wood product chain in terms of carbon sequestration and substitution when accounting for both the physical impacts (shifts in tree growth and mortality rates) and the market impacts (increased demand of harvested wood products (HWP)) of climate change (cc) and the subsequent forest managers adaptations; (2) To assess the uncertainty of the impacts on the above carbon balance and on forest allocation; and (3) To assess the role of managers’ expectations toward these future, uncertain but highly anticipated, impacts.MethodologyWe used a bio-economic model of the French Forest Sector (FFSM++) that is able to consider and integrate: (a) the effects of climate change over forest dynamics; (b) forest investment decisions (among groups of species) according to expected profitability; and (c) market effects in terms of regionalised supply, consumption and trade of HWP, depending on the forest resource stocks and international prices. By including both forest dynamics and forest products, we can evaluate the carbon balance taking the following elements into consideration: (a) carbon sequestered in live and dead biomass in the forest; (b) carbon sequestered in HWP; (c) carbon substituted when wood is used in place of fossil fuels or more energy-intensive materials; and (d) carbon released by forest operations.ResultsWhen the model is run at constant conditions for the next century, the average carbon potential of French forests is 66.2–125.3 Mt CO2 y−1, depending on whether we consider only inventoried wood resources, HWP pools and direct energy substitution, or if we also account for the carbon stored in tree branches and roots and if we consider the more indirect, but also largely more subjective, material substitution. These values correspond to 18.3% and 34.7%, respectively, of the French 2010 emissions (361 Mt CO2). However, when we consider both the probable increment of coniferous mortality and changes in forest growth, plus the rise in HWP demand worldwide, the average sequestration rate of the French forest decreases by 6.6–5.8% to 61.8–118.0 Mt CO2 y−1. Running partial scenarios, we can assess the relative interplay of these two factors, where the price factor increases the HWP stock while decreasing the forest stocks (where the latter effect prevails), while the physical impact of climate change reduces both, but to a lesser extent. Considering short-sighted forest managers, whose behaviour is based uniquely on the observed conditions at the time decisions are made, we obtain a limited effect of the overall carbon balance but a relatively large impact on the area allocation of broadleaved vs. coniferous species.  相似文献   

16.
The “polluter pays principle” (PPP) has been looked at from the perspective of legal values and technical principles, namely of soil science, to evaluate the acceleration of soil erosion and the consequent development of degraded areas in the Uberaba River basin (area: 2419 km2), state of Minas Gerais, Brazil. Having accomplished this goal, the study highlights the importance of PPP for the conservation of soil and development of an ecologically equilibrated environment. The diagnosis of degraded areas was based on the coupling of a Geographic Information System with soil loss, land use conflict and tolerance to soil loss models, and revealed a preoccupying situation because an extension of approximately 905 km2 (1/3 of the basin) has been considered in advanced state of degradation potentially causing environmental damage (e.g., decline of soil fertility and hence crop production, negative impacts of soil particles export on stream and lake water quality and biodiversity of riverine ecosystems). Facing this problem, a legal framework standing on doctrinaire principles, federal laws and the Brazilian Constitution has been proposed whereby the protagonists of soil degradation are called to assume responsibility as well as the costs of repairing this negative condition. Although the study has been carried out on a specific country under pre-defined settings, the rationale behind the proposals can easily be transposed to other scenarios because the scientific methods on which soil degradation has been defined and mapped are generally applicable, while the suggested legal values are currently applied to many regions on the planet.  相似文献   

17.
Forest Transition Theory (FTT) suggests that reforestation may follow deforestation as a result of and interplay between changing social, economic and ecological conditions. We develop a simplistic but empirically data driven land use transition agent-based modeling platform, interactive land use transition agent-based model (ILUTABM), that is able to reproduce the observed land use patterns and link the forest transition to parcel-level heuristic-based land use decisions and ecosystem service (ES). The ILUTABM endogenously links landowners’ land use decisions with ecosystem services (ES) provided by the lands by treating both lands and landowners as interacting agents. The ILUTABM simulates both the land use changes resulting from farmers’ decision behaviors as well as the recursive effects of changing land uses on farmers’ decision behaviors. The ILUTABM is calibrated and validated at 30 m × 30 m spatial resolution using National Land Cover Data (NLCD) 1992, 2001 and 2006 across the western Missisquoi watershed, which is located in the north-eastern US with an estimated area of 283 square kilometers and 312 farmers farming on 16% of the total Missisquoi watershed area. This study hypothesizes that farmers’ land use decisions are made primarily based on their summed expected utilities and that impacts of exogenous socio-economic factors, such as natural disasters, public policies and institutional/social reforms, on farmers’ expected utilities can significantly influence the land use transitions between agricultural and forested lands. Monte Carlo experiments under six various socio-economic conditions combined with different ES valuation schemes are used to assess the sensitivities of the ILUTABM. Goodness-of-fit measures confirm that the ILUTABM is able to reproduce 62% of the observed land use transitions. However, the spatial patterns of the observed land used transitions are more clustered than the simulated counterparts. We find that, when farmers value food provisioning Ecosystem Services (ES) more than other ES (e.g., soil and water regulation), deforestation is observed. However, when farmers value less food provisioning than other ES or they value food provisioning and other ES equally, the forest transition is observed. The ILUTABM advances the Forest Transition Theory (FTT) framework by endogenizing the interactions of socio-ecological feedbacks and socio-economic factors in a generalizable model that can be calibrated with empirical data.  相似文献   

18.
Sub-Saharan Africa is likely going to experience more intense and frequent droughts with high parallel possibilities of ramifications on maize yields. While there is a lot of scholarship dwelling on the ramifications of droughts on maize yields at the level of Africa, little has been researched at lower scales. This study presents past (1960–2014) vulnerability of maize yields to droughts based on a previous study (Epule et al., 2017) and projects the future vulnerability of maize yields to droughts by calculating the sensitivity, exposure and adaptive capacity of maize yields to droughts for the period 2015–2050. The results show that maize yields are more vulnerable in the north of Uganda for the period 1960–2014. However, adaptive capacity is higher in the south. Maize yields also record higher levels of sensitivity and exposure in the north with the latter patterns explained by variations in precipitation, temperature, rich volcanic soils, access to rivers and lakes. In terms of future vulnerability for the period 2015–2050, this study shows that the level of vulnerability of maize yields to droughts in Uganda will increase to levels higher than what currently obtains. For example, the vulnerability index will increase from 0.54 under the 1.5 °C to 0.70 under the 2.0 °C and to 1.54 under the 2.5 °C scenario. Sensitivity is also likely to increase while exposure and adaptive capacity are most likely to remain the same. Overall, it can be said that the future of maize production in Uganda under present and future circumstances remains very bleak without concrete actions. As a way forward, land use policy designers will have to integrate water management, agroforestry, climatic information diffusion, training and indigenous knowledge into land use planning decisions in the context of agriculture.  相似文献   

19.
Forest fragmentation is continued to be widespread in the tropics resulting in reduced ecosystem services including carbon storage. However, the effect of forest fragmentation is not considered in the current carbon policy. We investigated the effect of forest fragmentation on tree biomass carbon and soil organic carbon (SOC) storage in a moist tropical forest in Bangladesh. Above and below-ground tree biomass carbon were calculated by using widely accepted allometric equations and SOC was measured by sampling soils up to 10 cm depth and analyzing them in a soil laboratory. Results showed that carbon storage in tree biomass was significantly lower in fragmented forests (16.3 ± 1.37 t C ha−1) than in contiguous forests (31.21 ± 2.75 t C ha−1) (p < 0.001). Likewise, a significantly lower SOC was contained in the soils of fragmented forests (17.26 ± 0.83 t C ha−1) than in contiguous forests (21.62 ± 0.78 t C ha−1) (p < 0.001). Thus a total of 36% less carbon retained in tree biomass and soils in fragmented forests than in contiguous forests. Backward multiple linear regression analysis revealed tree density, tree height, tree DBH, height-diameter ratio (H/D) and tree species richness as influential factors of carbon variation in fragmented forests. All these structural parameters except tree species richness were significantly lower in fragmented forests, were positively associated with carbon storage and explained together 69% of the carbon storage variation. These findings suggest that the altered stand structure and tree allometry likely caused reduced carbon storage in fragmented forests and highlight the importance of landscape scale management intervention in the tropics. Here, we provided with the evidence of strong negative impact of forest fragmentation on carbon storage and argue that this effect should be in consideration which is currently overlooked in existing carbon accounting systems for tropical forests.  相似文献   

20.
Identification, analysis and assessment of changes in the urbanised landscape, one of the most conspicuous transforming parts of earth surfaces, has become the topic of numerous research projects. However, there is still a lack of compatible data suitable for the generation of topical information about the urbanised landscape and its changes at different scales. An important contribution in this sense is the Urban Atlas (UA) Project pursued under the GMES (Global Monitoring for Environment and Security)/Copernicus Land (GIO land) Programme auspiced by the European Commission. The aim of this study is to document, examine and compare land use/cover change (LUCC) of the LUZs (Large Urban Zones) of Bratislava and Prague in 2006–2012 by means of the UA data and show how these changes are captured in official statistical data. Results confirmed the present trends in modern industrial cities dominating by transforming the agricultural land into residential and industrial areas. Dispersion of the urban fabric into locations previously used for agriculture was mostly widespread in LUZ Prague (1,718 ha). This trend has also been partially confirmed by the change of agricultural land in favour of construction sites, the most pronounced one in LUZ Bratislava (580 ha). Assessment and comparisons of LUCC changes of LUZs Bratislava and Prague proved that combining the UA data and official statistical data has a great potential for insight into the dynamics of the urbanised landscape of Europe.  相似文献   

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