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 46 毫秒
1.
Further cropland expansion might be unavoidable to satisfy the growing demand for land-based products and ecosystem services. A crucial issue is thus to assess the trade-offs between social and ecological impacts and the benefits of converting additional land to cropland. In the former Soviet Union countries, where the transition from state-command to market-driven economies resulted in widespread agricultural land abandonment, cropland expansion may incur relatively low costs, especially compared with tropical regions.Our objectives were to quantify the drivers, constraints and trade-offs associated with recultivating abandoned cropland to assess the potentially available cropland in European Russia, western Siberia, Ukraine and Kazakhstan—the region where the vast majority of post-Soviet cropland abandonment took place. Using spatial panel regressions, we characterized the socio-economic determinants of cropland abandonment and recultivation. We then used recent maps of changes in cropland to (i) spatially characterize the socio-economic, accessibility and soil constraints associated with the recultivation of abandoned croplands and (ii) investigate the environmental trade-offs regarding carbon stocks and habitat for biodiversity.Less cropland abandonment and more recultivation after 2000 occurred in areas with an increasing rural population and a younger labor force, but also improved yields. Synergies were observed between cropland recultivation and intensification over the 2000s. From 47.3 million hectares (Mha) of cropland abandoned in 2009, we identified only 8.5 (7.1–17.4) Mha of potentially available cropland with low environmental trade-offs and low to moderate socio-economic or accessibility constraints that were located on high-quality soils (Chernozems). These areas represented an annual wheat production potential of ∼14.3 (9.6–19.5) million tons (Mt). Conversely, 8.5 (4.2–12.4) Mha had high carbon or biodiversity trade-offs, of which ∼10% might be attractive for cropland expansion and thus would require protection from recultivation. Agro-environmental, accessibility, and socio-economic constraints suggested that the remaining 30.6 (25.7–30.6) Mha of abandoned croplands were unlikely to provide important contributions to future crop production at current wheat prices but could provide various ecosystem services, and some could support extensive livestock production. Political and institutional support could foster recultivation by supporting investments in agriculture and rural demographic revitalization. Reclaiming potentially available cropland in the study region could provide a notable contribution to global grain production, with relatively low environmental trade-offs compared with tropical frontiers, but is not a panacea to address global issues of food security or reduce land-use pressure on tropical ecosystems.  相似文献   

2.
This empirical and interdisciplinary study investigates the contribution of deeply enrooted social-political factors to the accumulation of exposure and vulnerability and amplification of cascading impacts of disasters, with implications on the creation and reinforcement of path dependency maintaining social-ecological systems on a maladaptive trajectory. Applying the Trajectory of Exposure and Vulnerability approach to Saint-Martin (Caribbean), we more specifically highlight how the causal chain linking historical geopolitical and political-institutional drivers to legal, economic, demographic, sociocultural, planning-related and environmental drivers, created the accumulation of exposure and vulnerability over time and contributed to the propagation and amplification of the impacts of tropical cyclones Irma and José in 2017. We find that historical social-political dynamics involving unsustainable development and settlement patterns, the weakness of local institutions, population mistrust in public authorities, high social inequalities and environmental degradation maintained Saint-Martin on a maladaptive trajectory through powerful reinforcing mechanisms operating both between and during cyclonic events. This study demonstrates that long-term interdisciplinary approaches are required for a better understanding of path dependency and the identification of levers to break it in risk-prone contexts. In Saint-Martin, breaking path dependency requires the alignment of local institutional capacities with national risk reduction policies, the promotion of social justice and involvement of local communities in decision making. This study therefore confirms the relevance of backward-looking approaches to support forward-looking climate adaptation.  相似文献   

3.
Food insecurity, and the factors that determine it, are experienced at the level of the household and the individual. Food insecurity is also spatially varied across regions. In this paper meta-analysis is used to synthesize 49 household economy local-level studies that focus on community-level livelihood strategies to identify drivers of food insecurity in southern Africa. The results reveal entrenched cycles of vulnerability in southern Africa's food insecure communities, where socio-economic issues feature prominently. The direct causes of inadequate food access are poverty, environmental stressors and conflict: these account for 50% of the identified indirect drivers of food insecurity. Meta-analysis is used to suggest the common processes behind food insecurity that take specific forms in particular communities. The findings underscore the need to understand the multiple social and political dimensions of food insecurity, such as the breakdown in social capital associated with poverty, conflict and HIV/AIDS, that run deeper than environmental constraints to food production.  相似文献   

4.
Scientific evidence for global environmental change in Africa presents a prima facia case for increased human migration and displacement. Closer scrutiny of the evidence on demographic change, however, suggests that migration and displacement are less important variables in explaining the human dimensions of global environmental change on the continent than is commonly projected. Natural population growth in cities is a more important dynamic in the evolving system of human settlement in Africa and this significant shift in where people live, both now and in the future is overlooked by the emphasis on the potential impact of environmentally induced migration. Even without any movement from the countryside, cities represent the fastest growing sector of the sub-Saharan African population. The existing vulnerability of African cities, with their fast growing populations and weak management means any environmental change is likely to have significant consequences for cities. Taking the sub-Saharan African demographic evidence seriously means that the scholarly and policy emphasis currently directed to GEC migration and displacement might be more effectively redirected to questions of the interface between global environmental change and urban areas.  相似文献   

5.
Small islands are widely agreed to be vulnerable to human-induced sea-level rise during the 21st century and beyond, with forced abandonment of some low-lying oceanic islands being a real possibility. A regional abandonment of islands in the Chesapeake Bay, USA provides an historical analog of such vulnerability as this has been linked to a mid 19th Century acceleration in relative sea-level rise. Using a case study approach for Holland Island, Maryland, this hypothesis was tested using a range of physical and human historical data. While sea-level rise was the underlying driver, this analysis shows that the abandonment was more complex than a direct response to sea-level rise. Between 1850 and 1900, Holland Island was a booming community and population increased from 37 to 253, with immigration causing the majority of the increase. At the same time, the upland area where people made their homes was steadily diminishing, losing about 15 ha or 38% of the total. After 1900, the island experienced a decrease in population to 169 in 1916, with final abandonment in 1918, with the exception of one family who left by 1920. Final abandonment was triggered by this depopulation as the population fell below a level that could support critical community services, and the community lost faith in their future on Holland Island. It is likely that similar social processes determined the abandonment of the other Chesapeake Bay islands. Looking to the future, it shows that many small low-lying islands could be abandoned due to sea-level rise long before they become physically uninhabitable.  相似文献   

6.
After a short summary of the main current drivers of internal migration in the UK, the paper discusses likely future migration patterns and processes under different social scenarios. It then anticipates the effects of environmental change on these migration flows. The main conclusion is that the impacts will probably be relatively minor; the UK is considered to be extremely well placed to adjust to climate change without a major redistribution of its population. A minor exception to this is that greater river and coastal flooding is likely to render some areas hazardous to settlement and/or very costly to protect. And crucial to successful adaptation is good governance, specifically a strong state that can plan and execute major environmental infrastructures, and can respond quickly and decisively to environmental challenges.  相似文献   

7.
Empirical work on the relationship between environmental stress and human migration has blossomed over the last 10 years. While such work has provided important insights into this relationship, there has been, to date, limited effort expended on generating a generalisable framework for apprehending such interactions. This paper seeks to address this deficit. Based on semi-structured interviews in two sending and four receiving areas in northern Ethiopia, it explores dominant mobility narratives among populations whose livelihoods are exposed to a range of environmental stresses. Analysis of these narratives corroborates findings from other empirical studies on the subject, highlighting how the impact of environmental stress on human mobility can only be understood within the context in which it occurs. To this end the paper attempts to generate a typology of interactions between environmental and non-environmental factors shaping mobility. The typology is based on four effects: additive, enabling, vulnerability and barrier effects. It is thought to provide a generalisable conceptual language which is capable of describing the role of environmental stress in mobility decisions and thereby offering a systematic means for thinking through the processes by which environmental stress impacts upon mobility. While the framework is hypothesised to be suitably generalisable to account for other contexts and other environmental stresses, this still needs to be tested. In addition it is acknowledged that the framework suffers from some major limitations. Most notable is reliance on a conceptually false distinction between environmental and non-environmental factors, and the inability to account for the non-environmental features which shape perceptions of migration.  相似文献   

8.
Vulnerability, adaptation and resilience are concepts that are finding increasing currency in several fields of research as well as in various policy and practitioner communities engaged in global environmental change science, climate change, sustainability science, disaster risk-reduction and famine interventions. As scientists and practitioners increasingly work together in this arena a number of questions are emerging: What is credible, salient and legitimate knowledge, how is this knowledge generated and how is it used in decision making? Drawing on important science in this field, and including a case study from southern Africa, we suggest an alternative mode of interaction to the usual one-way interaction between science and practice often used. In this alternative approach, different experts, risk-bearers, and local communities are involved and knowledge and practice is contested, co-produced and reflected upon. Despite some successes in the use and negotiation of such knowledge for ‘real’ world issues, a number of problems persist that require further investigation including the difficulties of developing consensus on the methodologies used by a range of stakeholders usually across a wide region (as the case study of southern Africa shows, particularly in determining and identifying vulnerable groups, sectors, and systems); slow delivery of products that could enhance resilience to change that reflects not only a lack of data, and need for scientific credibility, but also the time-consuming process of coming to a negotiated understanding in science–practice interactions and, finally, the need to clarify the role of ‘external’ agencies, stakeholders, and scientists at the outset of the dialogue process and subsequent interactions. Such factors, we argue, all hinder the use of vulnerability and resilience ‘knowledge’ that is being generated and will require much more detailed investigation by both producers and users of such knowledge.  相似文献   

9.
Environmental governance research has discovered much about what drives collective action to address human-environment issues, including factors such as risk perceptions and self-efficacy. Yet the design of many studies limits our ability to draw conclusions about collective action under conditions of environmental change, especially across spatial or temporal scales. In this study, we integrate social and biophysical data—assessing data over time and examining the influence of space—to analyze efforts by community members to manage rapid environmental change in the form of an invasive plant (Mikania micrantha) in community forests in Chitwan, Nepal. Invasive species are an increasingly complex ethical, cultural, and ecological issue that is becoming more pressing with global environmental and social changes. We combine household surveys, ecological surveys, and spatial data in Bayesian hierarchical linear models to explore changes in the drivers of collective action since initial household surveys in 2014. We find that risk perceptions, reliance on forest resources, perceptions of forest safety, and M. micrantha abundance were the most influential factors in our models. Additionally, our findings suggest that the influence of M. micrantha abundance on collective action varies across spatial scales, indicating important interactions between social and biophysical drivers of collective action. Ultimately, our results highlight the importance of considering social and biophysical factors across space and time to inform the design of institutions that will be effective in addressing collection action problems tied to environmental change.  相似文献   

10.
A long history of household-level research has provided important local-level insights into climate adaptation strategies in the agricultural sector. It remains unclear to what extent these strategies are generalizable or vary across regions. In this study we ask about three potential key factors influencing farming households’ ability to adapt: access to weather information, household and agricultural production-related assets, and participation in local social institutions. We use a 12-country data set from sub-Saharan Africa and South Asia to explore the links between these three potential drivers of agricultural change and the likelihood that farmers made farm-associated changes, such as adopting improved crop varieties, increasing fertilizer use, investing in improved land management practices, and changing the timing of agricultural activities. We find evidence that access to weather information, assets, and participation in social institutions are associated with households that have reported making farming changes in recent years, although these results vary across countries and types of practices. Understanding these drivers and outcomes of farm-associated changes across different socio-economic and environmental conditions is critical for ongoing dialogues for climate-resilient strategies and policies for increasing the adaptive capacity of smallholders under climate change.  相似文献   

11.
Land use patterns influence the long-term productivity of agro-ecosystems and result from socio-economic as well as biophysical and climatic drivers. This paper qualitatively examines how past demographic and political-economic changes in southern Romania twice led to vulnerable socio-economic and agro-ecological systems. Drawing on this case study, we establish broad-brush hypotheses identifying some of the potential causes of vulnerability. We suggest that vulnerable systems appear more likely to occur when socio-political uncertainty combines with a lack of off-farm employment in regions where there are abundant natural capital stocks that can be quickly liquidated.  相似文献   

12.
Drawing attention to the production of vulnerability across scales in Sri Lanka, we contribute to knowledge of why certain people and social groups are vulnerable. We build our contribution on the theoretical application of ‘situated adaptation’. A situated analytical approach identifies, assesses, and responds to the everyday realities and politics of those living in climate changed environments. It highlights uneven geographies of vulnerability and opportunity, while identifying new imaginations and possibilities for transformative action that counter the production of vulnerability. We illustrate the utility of ‘situated adaptation’ by filling an empirical gap relating to experiences of political-economic and environmental change in Sri Lanka’s Dry Zone. We detail situated experiences by drawing on field research in the Anuradhapura District, revealing how the lives and livelihoods of farmer participants are structured by a productivity-vulnerability paradox. We demonstrate how a prevalent adaptation-development paradigm (whereby development and adaptation programs co-exist in theory and practice) is unable to address the structural drivers of vulnerability in Sri Lanka’s Dry Zone. A situated adaptation approach both explains why this is the case and highlights opportunities for alternative transformative actions, potentially identifying a more democratic and egalitarian politics of co-determining socionatural change.  相似文献   

13.
This study aimed to evaluate the impact of climate change on the geographical distribution of selected native species from two areas from West Asia and North Africa. Three species representing two genera were selected for assessment of their vulnerability to climate change. The first species was Salsola vermiculata L. which is common to both study areas. The second genus was represented by two species, Haloxylon salicornicum (Moq.) Bunge from the Syrian rangelands and H. schmittianum Pomel from southern Tunisia. To assess the vulnerability of these species to climate change we used ecological-based models. The data inputs were composed of the species occurrence data and the environmental data which included eight climatic layers, three soil property layers in addition to an altitude layer. Since environmental parameters only enable assessing the sensitivity of target species to climate change, a grazing pressure layer was used to assess the species vulnerability. Only climatic parameters were considered as changing across three periods; current situation, 2020 and 2050. The main results indicated that threatened range species, such as S. vermiculata which were subjected to continuous grazing pressure, showed high vulnerability to climate change as expressed by the predicted decrease in the areas of their distribution. However, species with low palatability and broad ecological niches (i.e. H. salicornicum and H. schmittianum) had an advantage due to the reduced competition for water and nutrients. An adaptation strategy to increase the resilience of the most vulnerable species should involve management of grazing pressure and the establishment of other mitigation measures.  相似文献   

14.
An environmental history of the Leliefontein community of Namaqualand, Northern Cape provides a detailed case of the nexus between social and ecological stresses shaping livelihood change. By combining an historical proxy precipitation data set with a livelihood change study the value of historical research in integrated studies of past human-environment systems is illustrated. The identification of effective livelihood adaptation to extreme climatic conditions is examined, illustrating the tradeoffs made between adaptation and ‘coping’ strategies which were unsuccessful over the long term. During the course of the 19th century the Namaqua Khoikhoi population changed from a sustainable nomadic pastoral community to a poverty stricken rural community with a diversity of livelihood strategies. For the Namaqua increased livelihood diversity – usually an effective adaptation in times of stress – instead of promoting resilience, contributed to their material decline. Widespread transhumance between different climatic regions is shown to have been a successful adaptation to climatic extremes, but external economic exposure and restricted access to land become drivers of decline. The ‘double exposure’ framework used in contemporary studies, proved useful in accounting for this decline as it can accommodate both environmental and economic stressors.  相似文献   

15.
Reindeer husbandry represents a major land use in the Barents region, and has been predicted to be adversely affected by climate change. This paper considers the likely response of reindeer husbandry to changes both in climate and in socio-economic circumstances in the four countries of the Barents region from 1990 to 2080. Key natural factors include vegetation distribution, and a range of meteorological variables including temperature, wind, snow cover and freezing of rivers. The potential impact of these factors is evaluated quantitatively using the tolerable windows method, the results of which indicate a general but spatially non-uniform decline in the suitability of the region for reindeer husbandry. Relevant socio-economic factors include regional patterns of politics, management and knowledge. A focus on herders’ own perceptions of environmental change and flexibility of response, derived particularly from study sites in Russia, suggests that models of vulnerability to climate change should be tempered by paying greater attention to changes in socio-economic factors. When compared with the potential effect of changing these socioeconomic factors, the vulnerability of reindeer husbandry to projected climate change appears to be comparatively small.  相似文献   

16.
Mountains are critical ecosystems that have a strong influence far beyond their topographic boundaries. More than 50 million people inhabit the Himalayas, and more than one billion people depend on the ecosystem services they provide. Anthropogenic activities have driven concurrent deforestation and regeneration in the Himalayas, and interventions to reduce forest loss and promote forest recovery require a synthetic understanding of the complex and interacting drivers of forest change. We conducted a systematic review of case studies from 1984 to 2020 (n = 137) and combined a system dynamics approach with a causal network analysis to identify, map and articulate the relationships between the drivers, actors and mechanisms of forest change across the entirety of the Himalayan mountain range. In total, the analysis revealed five proximate drivers, 12 underlying drivers, two institutional factors and five ‘other’ factors connected by a total of 221 linkages. Forest change dynamics have been dominated by widespread smallholder agriculture, extensive non-timber forest product extraction, widespread commercial and non-commercial timber extraction, and high rates of agricultural abandonment. Underlying drivers include population growth, poor agricultural productivity, international support for development projects, and successful community forest management systems. Contradictory linkages emerge from a combination of contextual factors, which can have negative impacts on conservation goals. Global processes such as shifts in governance, transnational infrastructure-development programs, economic slowdowns, labor migrations and climate change threaten to destabilize established dynamics and change forest trajectories. The underlying and proximate drivers interact through multiple pathways that can be utilized to achieve conservation goals. Based on this analysis, we highlight five thematic focus areas to curtail forest loss and promote recovery: (1) decreasing the population pressure, (2) sustainable increase of agricultural productivity, (3) strengthening of forest management institutions, (4) leveraging tourism growth and sustainable infrastructure expansion, and (5) fuel transition and establishing firewood plantations on degraded land. The broader adoption of systems thinking, and specifically a system dynamics approach and causal network analysis, will greatly enhance the rigour of policy development, help design site-specific interventions at multiple spatial scales which can respond to local and global changes, and guide deeper inquiry to enhance our understanding of driver-forest dynamics.  相似文献   

17.
In recent decades there has been a sustained and substantial shift in human diets across the globe towards including more livestock-derived foods. Continuing debates scrutinize how these dietary shifts affect human health, the natural environment, and livelihoods. However, amidst these debates there remain unanswered questions about how demand for livestock-derived foods may evolve over the upcoming decades for a range of scenarios for key drivers of change including human population, income, and consumer preferences. Future trends in human population and income in our scenarios were sourced from three of the shared socioeconomic pathways. We used scenario-based modeling to show that average protein demand for red meat (beef, sheep, goats, and pork), poultry, dairy milk, and eggs across the globe would increase by 14% per person and 38% in total between the year 2020 and the year 2050 if trends in income and population continue along a mid-range trajectory. The fastest per person rates of increase were 49% in South Asia and 55% in sub-Saharan Africa. We show that per person demand for red meat in high-income countries would decline by 2.8% if income elasticities of demand (a partial proxy for consumer preferences, based on the responsiveness of demand to income changes) in high-income countries decline by 100% by 2050 under a mid-range trajectory for per person income growth, compared to their current trajectory. Prices are an important driver of demand, and our results demonstrate that the result of a decline in red meat demand in high-income countries is strongly related to rising red meat prices, as projected by our scenario-based modeling. If the decline in the income elasticity of demand occurred in all countries rather than only in high-income countries, then per person red meat demand in high-income countries would actually increase in 2050 by 8.9% because the income elasticity-driven decline in global demand reduces prices, and the effect of lower prices outweighs the effect of a decline in the income elasticity of demand. Our results demonstrate the importance of interactions between income, prices, and the income elasticity of demand in projecting future demand for livestock-derived foods. We complement the existing literature on food systems and global change by providing quantitative evidence about the possible space for the future demand of livestock-derived foods, which has important implications for human health and the natural environment.  相似文献   

18.
The development of effective environmental management plans and policies requires a sound understanding of the driving forces involved in shaping and altering the structure and function of ecosystems. However, driving forces, especially anthropogenic ones, are defined and operate at multiple administrative levels, which do not always match ecological scales. This paper presents an innovative methodology of analysing drivers of change by developing a typology of scale sensitivity of drivers that classifies and describes the way they operate across multiple administrative levels. Scale sensitivity varies considerably among drivers, which can be classified into five broad categories depending on the response of ‘evenness’ and ‘intensity change’ when moving across administrative levels. Indirect drivers tend to show low scale sensitivity, whereas direct drivers show high scale sensitivity, as they operate in a non-linear way across the administrative scale. Thus policies addressing direct drivers of change, in particular, need to take scale into consideration during their formulation. Moreover, such policies must have a strong spatial focus, which can be achieved either by encouraging local–regional policy making or by introducing high flexibility in (inter)national policies to accommodate increased differentiation at lower administrative levels. High quality data is available for several drivers, however, the availability of consistent data at all levels for non-anthropogenic drivers is a major constraint to mapping and assessing their scale sensitivity. This lack of data may hinder effective policy making for environmental management, since it restricts the ability to fully account for scale sensitivity of natural drivers in policy design.  相似文献   

19.
In response to substantial deforestation over many decades, large scale reforestation programs are being implemented across many tropical developing countries. Examples include the United Nations Billion Trees Campaign, the National Greening Program in the Philippines, and the 5 million ha reforestation program in Vietnam. However, while substantial investments are being made in reforestation, little information exists on the drivers influencing reforestation success and how these interact to determine environmental and socio-economic outcomes. In this study we surveyed 43 reforestation projects on Leyte Island, The Philippines to identify the drivers that most influence reforestation success as measured by key indicators drawn from the literature, including interactions between drivers and between drivers and indicators. We investigated 98 potential success drivers, including technical and biophysical factors; socio-economic factors; institutional, policy and management factors; and reforestation project characteristics. We also measured 12 success indicators, including forest establishment, forest growth, environmental and socio-economic success indicators. Stepwise multiple regressions were used to identify significant relationships among drivers and indicators and this analysis was used to develop a system of driver and indicator relationships. Based on this we found that revegetation method, funding source, education and awareness campaigns, the dependence of local people on forests, reforestation incentives, project objectives, forest protection mechanisms and the condition of road infrastructure were highly connected drivers that influenced multiple success indicators either directly or indirectly. We conclude that policies targeting revegetation methods, socioeconomic incentives, forest protection mechanisms, sustainable livelihoods, diversification of funding and partnerships, technical support, and infrastructure development are likely to have a broad systemic and beneficial effect on the success of reforestation programs in tropical developing countries.  相似文献   

20.
The recent rise in agricultural commodity prices and the expectation that high price will persist have triggered a wave of farmland expansion in regions where land resources are still available. One such region is the former Soviet Union, where the collapse of socialism caused massive agricultural abandonment and where some of these lands are now being brought back into production. Yet, the extent and spatial patterns of recultivation, and what determines these patterns, remains unclear. We examined the extent of recultivation of abandoned agricultural land in Ukraine since 2007 using a new, satellite-based recultivation map and assessed the effect of biophysical and socioeconomic determinants on recultivation patterns using boosted regression trees. We found key predictors of recultivation to be related to the suitability of land for agriculture (i.e., soil quality, temperature). Accessibility to major cities was also important, with most recultivation happening closer to settlements, but this influence varied across Ukraine. Variables related to agricultural management (fertilizer input, mechanization) and demography were negligible in explaining recultivation in our analyses. These factors suggest that recultivation patterns were primarily driven by factors related to land productivity, with recultivation focusing on the most promising areas. Given the remaining large amount of unused agricultural land in Eastern Europe and the former Soviet Union, and considering that much abandonment occurred in areas only marginally suited to agriculture, our findings provide important insights into where recultivation can be expected to happen and thus for assessing the potential socioeconomic and environmental impacts of recultivation.  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