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1.
Investigations of land use/land cover (LULC) change and forest management are limited by a lack of understanding of how socioeconomic factors affect land use. This lack also constrains the predictions of future deforestation, which is especially important in the Amazon basin, where large tracts of natural forest are being converted to managed uses. Research presented in this article was conducted to address this lack of understanding. Its objectives are (a) to quantify deforestation in the Northern Ecuadorian Amazon (NEA) during the periods 1986–1996 and 1996–2002; and (b) to determine the significance and magnitude of the effects of socioeconomic factors on deforestation rates at both the parroquia (parish) and finca (farm) levels. Annual deforestation rates were quantified via satellite image processing and geographic information systems. Linear spatial lag regression analyses were then used to explore relationships between socioeconomic factors and deforestation. Socioeconomic factors were obtained, at the finca level, from a detailed household survey carried out in 1990 and 1999, and at the parroquia level from data in the 1990 and 2001 Ecuadorian censuses of population. We found that the average annual deforestation rate was 2.5% and 1.8%/year for 1986–1996 and 1996–2002, respectively. At the parroquia level, variables representing demographic factors (i.e., population density) and accessibility factors (i.e., road density), among others, were found to be significantly related to deforestation. At the farm level, the factors related to deforestation were household size, distance by road to main cities, education, and hired labor. The findings of this research demonstrate both the severity of deforestation in the Northern Ecuadorian Amazon and the array of factors affecting deforestation in the tropics.  相似文献   

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This study describes the deforestation impact from three settlements, 5 de Junio, El Tigre, and 30 de Agosto, near the Madidi National Park in Bolivia. First deforestation rates along the road that connects the settlements and then deforestation within each settlement are examined. Landsat Thematic Mapper (TM) imagery from 1987, 1997, and 2000 were used to measure the deforestation. Face-to-face interviews were also used to collect detailed social and land-use information. Road-building and farming have been the major causes of deforestation in this region. The TM measurements indicate a high increase in the deforestation rate along the road in the area of study. The results also show a rapidly escalating deforestation rate in 5 de Junio, a potential high future deforestation rate in El Tigre, and a gradual deforestation increase in 30 de Agosto. The information provided by the settlers about clearing was compared with the imagery analysis. Generally, the settlers estimates were lower than the deforestation as derived from the imagery.  相似文献   

4.
The policy intervention to enforce property rights and control deforestation frontiers is often undermined in the Brazilian Amazon, and this intervention problem is considered to be stemming from weak frontier governance. However, little has been understood how this governance can be strengthened in the context of social change. Drawing on a literature review of the Amazon development and sociological studies of space, this article argues that frontier governance is characterised by the co-generation of two territorial processes: the official settlement implementation (physical spacing) and the spontaneous settlers' shaping of the vernacular community (production of place). The co-generation process opens new deliberative space where both state and non-state actors claim authority over the intervention. Therefore, strengthening frontier governance involves empowering this emerging authority to be able to promote public engagement with sustainable development on the frontier. The article uses the regional history and ethnographic material collected in the southeast of Pará to illustrate the discussion.  相似文献   

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Long-term human impacts are considered to be the prime cause of unsustainable forest exploitation in Ethiopia. Yet there exist well-established systems and a wealth of local experience in maintaining and managing forests. This study explores the trends and driving forces of deforestation plus traditional practices regarding sustainable forest use and management in the Chencha and Arbaminch areas, Southern Ethiopia. Satellite image analysis (images from 1972, 1984 and 2006) combined with field surveys were used to detect and map changes in forest cover. Household interviews and group discussions with experienced and knowledgeable persons were also employed. The results show a 23 % decline in forest cover between 1972 and 2006 with the most significant change from 1986 to 2006. Change was greatest in the lowlands and remarkable episodic forest changes also occurred, suggesting nonlinear spatial and temporal forest cover dynamics. According to farmers, the main driver of deforestation is agricultural land expansion in response to local population increases and a decline in agricultural production. Growing local and regional fuel wood demand is another chief cause. Despite these issues, remarkable relicts of natural forests remain and trees on farmland, around homesteads and on fields in every village are basic elements of farm activities and social systems. This demonstrates the effect of cumulative traditional knowledge and long-term local experience with forest management and preservation. Therefore, these practices should be promoted and advanced through the integration of local knowledge and forest management practices in the design and implementation of sustainable environmental planning and management.  相似文献   

6.
Summary The land uses that now predominate in Brazil's Amazon Region are unlikely to produce sustainable yields. They also tend to close off potentially sustainable alternative uses. Cattle pasture — either productive or abandoned — now occupies most deforested land. Small farmers plant pasture after using the land for a year or two under annual crops, while large cattle ranches plant pasture directly after clearing. The principal motive for planting pasture is often its low cost and high effectiveness as a means of securing speculative land claims — not beef production.Pasture and cattle yields are low and, after use for about a decade, the planted grasses are out-competed by secondary forest species or inedible grasses. Depletion of available phosphorus in the soil is a major cause of yield decline; Brazil's relatively modest phosphorus deposits, virtually all of which are outside of Amazonia, make fertiliser use not feasible for the vast areas now rapidly being converted to pasture. Converting a substantial portion of Amazonia to pasture would have potential climatic effects. Areas that can be planted in annual and perennial crops are restrained by world markets, as well as by soil quality and Brazil's limited stocks of the inputs needed for intensive agriculture.Recent initiatives for agricultural-ecological in Brazil's Amaoznian states could be a first step toward more rational land use. Immediate measures are needed to slow deforestation, to discourage unsustainable uses and to make sustainable alternatives profitable.Professor Philip Fearnside is currently Research Professor in the Department of Ecology at the National Institute for Research in the Amazon. The paper has been modified from an earlier version presented at the International Symposium on Alternatives to Deforestation held in Belém, Pará, Brazil in January 1988.  相似文献   

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This article examines the relationship between increased metal mining and sustainable development in the eastern section of the Amazonian state of Pará in Brazil. Since the early 1980s, mining has grown rapidly in Pará and local mining operations have become global leaders in the production of iron, manganese, bauxite, aluminum, gold, copper and — in the near future — nickel. To stay in tune with global standards, these companies have committed themselves to the principles of sustainability and have obtained certification for both social and environmental aspects of their activities. The article looks into whether such certification is linked to sustainable development of the relatively poor regions where these companies operate. The main findings are that: (1) there is a visible association between certification and improved performance by the companies, but not with the development of nearby areas; and (2) social‐environmental certification processes place more emphasis on ecological variables than on social ones.  相似文献   

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Community forestry initiatives have been shown to reduce rural poverty while promoting the conservation and sustainable use of forests. However, a number of challenges face communities wanting to initiate or maintain formal, community-based forest management. Through a grounded theory approach, this paper uses three case studies of community forest management models in the eastern Amazon to create a framework showing challenges faced by communities at different phases of formal management. The framework shows that, in the development phase, four root problems (land ownership, knowledge acquisition, community organization, and adequate capital) need to be addressed to obtain legal management permission. With this permission in hand, further challenges to operationalization are presented (deterring illegal loggers, maintaining infrastructure, obtaining necessary managerial skills and accessing markets). The interrelatedness of these challenges emphasizes that all challenges need to be addressed in a holistic manner for communities to maintain a profitable and self-sufficient operation. This contradicts current development approaches that only address part of this framework. The framework proposed here can be used as a starting point for community forestry initiatives in other regions.  相似文献   

10.
Implementing effective conservation requires an understanding of factors affecting deforestation and forest degradation. Previous studies have investigated factors affecting deforestation, while few studies have examined the determinants of both of deforestation and forest degradation for more than one period. To address this gap, this study examined factors influencing deforestation and forest degradation during 1989–2000 and 2000–2005 in the Popa Mountain Park, Myanmar. We applied multinomial logistic regression (MNL) using land cover maps derived from Landsat images as the dependent variables as well as spatial and biophysical factors as the independent variables. The MNL models revealed influences of the determinants on deforestation and forest degradation changes over time. For example, during 1989–2000, deforestation from closed forest was positively correlated to the distance from the park boundary and was negatively correlated with distance from villages, roads, the park circular road, slope, western aspect and elevation. On the other hand, during 2000–2005, deforestation of closed forest was positively correlated with distance from villages, roads, the park circular road, slope and western aspect, and negatively correlated with distance from the park boundary and elevation. Similar scenarios were observed for the deforestation of open forest and forest degradation of closed forest. The study also found most of the determinants influenced deforestation and forest degradation differently. The changes in determinants of deforestation and forest degradation over time might be attributable to the general decrease in resource availability and to the effect of conservation measures conducted by the park.  相似文献   

11.
The management of small-scale freshwater fisheries in Amazon has been based usually on surveys of urban markets, while fisheries of rural villages have gone unnoticed. We compared the fishing characteristics (catch, effort and selectivity) between an urban market and five small villages in the Lower Tocantins River (Brazilian Amazon), downstream from a large reservoir. We recorded 86 and 601 fish landings in the urban market and villages, respectively, using the same methodology. The urban fishers showed higher catch per unit of effort, higher amount of ice (related to a higher fishing effort, as ice is used to store fish catches) and larger crew size per fishing trip, but village fishers had a higher estimated annual fish production. Conversely, urban and village fishers used similar fishing gear (gillnets) and the main fish species caught were the same. However, village fishers showed more diverse strategies regarding gear, habitats and fish caught. Therefore, although it underestimated the total amount of fish caught in the Lower Tocantins River region, the data from the urban market could be a reliable indicator of main fish species exploited and fishing gear used by village fishers. Monitoring and management should consider the differences and similarities between urban and rural fisheries, in Amazon and in other tropical regions.  相似文献   

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The modern gold rush in the Brazilian Amazon attracted millions of people to become artisanal miners in order to escape complete social marginalization. The rudimentary nature of artisanal mining activities often generates a legacy of extensive environmental degradation,both during operations and well after mining activities have ceased. One of the most significant environmental impacts is derived from the use of mercury (Hg), which is illegal for use in gold amalgamation in Brazil, but continues to be the preferred method employed by artisanal gold miners. The general population is unaware of the capricious nature of mercury and artisanal mining activities. Moreover, individuals in positions of political or economic infiuence tend to be negatively biased towards artisanal mining and government policies do not effectively address the realities of these activities. Affected communities have consequently been ignored,and mistrust towards outside parties is high. Not surprisingly, miners are suspicious of and unlikely to employ externally derived solutions to reduce mercury emissions. This article reviews the use of mercury in artisanal mining and highlights the role miners, governments and non-governmental organizations (NGOs) have played in communicating facts, perpetuating myths and deriving solutions for mercury pollution. This article also raises some key concerns that must be addressed to understand the behaviour of mercury in the environment and identifies solutions for problems facing communities where artisanal gold mining operations have been abandoned.  相似文献   

14.
Forest fires represent a major driver of change at the ecosystem and landscape levels in the Mediterranean region. Environmental features and vegetation are key factors to estimate the ecological vulnerability to fire; defined as the degree to which an ecosystem is susceptible to, and unable to cope with, adverse effects of fire (provided a fire occurs). Given the predicted climatic changes for the region, it is urgent to validate spatially explicit tools for assessing this vulnerability in order to support the design of new fire prevention and restoration strategies. This work presents an innovative GIS-based modelling approach to evaluate the ecological vulnerability to fire of an ecosystem, considering its main components (soil and vegetation) and different time scales. The evaluation was structured in three stages: short-term (focussed on soil degradation risk), medium-term (focussed on changes in vegetation), and coupling of the short- and medium-term vulnerabilities. The model was implemented in two regions: Aragón (inland North-eastern Spain) and Valencia (eastern Spain). Maps of the ecological vulnerability to fire were produced at a regional scale. We partially validated the model in a study site combining two complementary approaches that focused on testing the adequacy of model’s predictions in three ecosystems, all very common in fire-prone landscapes of eastern Spain: two shrublands and a pine forest. Both approaches were based on the comparison of model’s predictions with values of NDVI (Normalized Difference Vegetation Index), which is considered a good proxy for green biomass. Both methods showed that the model’s performance is satisfactory when applied to the three selected vegetation types.  相似文献   

15.
Tropical forest countries are struggling with the partially conflicting policy objectives of socioeconomic development, forest conservation, and safeguarding the livelihoods of local forest-dependent people. We worked with communities in the lower Tapajós region of the central Brazilian Amazon for over 10 years to understand their traditional and present land use practices, the constraints, and decision making processes imposed by their biophysical, socioeconomic, and political environment, and to facilitate development trajectories to improve the livelihoods of forest communities while conserving the forest on the farms and in the larger landscape. The work focused on riverine communities initially in the Tapajós National Forest and then in the Tapajós–Arapiuns Extractive Reserve. These communities have a century-old tradition of planting rubber agroforests which despite their abandonment during the 1990s still widely characterize the vegetation of the river banks, especially in the two protected areas where they are safe from the recent expansion of mechanized rice and soybean agriculture. The project evolved from the capacity-building of communities in techniques to increase the productivity of the rubber agroforests without breaking their low-input and low-risk logic, to the establishment of a community enterprise that allowed reserve inhabitants to reforest their own land with tree species of their choice and sell reforestation (not carbon) credits to local timber companies while retaining the ownership of the trees. By making land use practices economically more viable and ecologically more appropriate for protected areas, the project shows ways to strengthen the system of extractive and sustainable development reserves that protects millions of hectares of Amazon forest with the consent of the communities that inhabit them.  相似文献   

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Forest fires are an integral part of the ecology of the Mediterranean Basin; however, fire incidence has increased dramatically during the past decades and fire is expected to become more prevalent in the future due to climate change. Fuel modification by prescribed burning reduces the spread and intensity potential of subsequent wildfires. We used the most recently published data to calculate the average annual wildfire CO(2) emissions in France, Greece, Italy, Portugal and Spain following the IPCC guidelines. The effect of prescribed burning on emissions was calculated for four scenarios of prescribed burning effectiveness based on data from Portugal. Results show that prescribed burning could have a considerable effect on the carbon balance of the land use, land-use change and forestry (LULUCF) sector in Mediterranean countries. However, uncertainty in emission estimates remains large, and more accurate data is needed, especially regarding fuel load and fuel consumption in different vegetation types and fuel layers and the total area protected from wildfire per unit area treated by prescribed burning, i.e. the leverage of prescribed burning.  相似文献   

17.
当前,我国重点国有林区的经济处于调整发展结构的关键时期,林区家庭的生活水平正在逐步提高,人们对文化产品消费也发生了很大的变化。采用重点国有林区大规模连续跟踪入户调查数据,运用二元Logistic回归分析研究了我国国有林区家庭文化产品消费的影响因素。结果表明:户主年龄、精神层面是否满足对文化消费具有负向影响,而家庭收入、医疗保障水平对文化消费具有正向影响。基于研究结果,从4个方面提出对策建议:(1)转变我国国有林区居民文化消费观念。(2)完善国有林区文化基础设施建设。(3)提升文化消费层次,营造文化消费氛围。(4)推进国有林区文化产品供给侧结构性改革,激发市场活力。  相似文献   

18.
Pine plantations are an alternative to marginal agriculture in many countries, and are often presented as an option that improves biodiversity. However, these plantations can have adverse environmental effects if improperly managed. To evaluate the effect of forest management practices on biodiversity, the diversity, species richness, dominance and frequency of understory woody plant species in different forests of the Basque Country (northern Spain) were compared. Plantations of exotic conifers (Pinus radiata [D.] Don) of different ages were compared with deciduous forests of Quercus robur L. and Fagus sylvatica L. The effects of different types and intensities of management were taken into account. The differences observed were mainly conditioned by the intensity of forestry management, although the response varied according to forest type and age. In unmanaged pine plantations, the diversity and species richness of the understory increased rapidly after planting (while dominance decreased), remained stable in the intermediate age range, and reached a maximum in plantations more than 25 years of age. Management practices resulted in decreased understory diversity and species richness, as well as greater dominance. This was more pronounced in younger than in older stands. Moderate management, however, favored a greater diversity of the understory in deciduous forests. The species composition of the plantations and deciduous forests were different, the latter having a wider range of characteristic species. Knowledge of how forestry practices influence biodiversity (in terms of diversity, richness, dominance, and species composition) may allow predictions to be made about the diversity achievable with different management systems.  相似文献   

19.
Abstract: The forest shelterbelt (afforestation) project in northern China is the most significant ecosystem project initiated in China during the past three decades. It aims to improve and conserve the ecological environment in the project areas. The tree belt stands along the southern edge of the sandy lands, nearly paralleling to the Great Wall. This study used a regional climate model to simulate the potential of improving regional hydroclimate conditions resulting from the afforestation project. Two simulations with preafforestation and postafforestation land cover were performed over East Asia from January 1987 to February 1988. The model resolution is 60 km. The differences between the two simulations suggest that the northern China forest shelterbelt project is likely to improve overall hydroclimate conditions by increasing precipitation, relative humidity, and soil moisture, and by reducing prevailing winds and air temperature. The effects are more significant in spring and summer than fall and winter. Changes in many hydrologic properties (e.g., evapotranspiration, soil moisture, and water yield), however, differ between the dry Northeast China and the moist Northeast China. The hydroclimate effects are also found in the surrounding areas, featured by noticeably moister conditions in the area south of the afforestation project. The results imply that the shelterbelt project would reduce water yield in afforested Northwest and North China during spring, but increase water yield in the afforested Northeast China as well as in the southern surrounding area, offset some greenhouse effects, and reduce the severity of dust storms. Possible improvements of this study by using actual afforestation data, modeling with higher resolution, longer integration and more detailed processes, and analyzing the physical mechanisms are discussed.  相似文献   

20.
In the tropics and sub-tropics, where high levels of biodiversity co-exist with some of the greatest levels of population density, achieving complete exclusion in protected area contexts has proved close to impossible. There is a clear need to recognize that parks are significantly impacted by human–environment interactions in the larger landscape within which they are embedded, and to move the frontier of research beyond the boundaries of protected areas in order to examine larger landscapes where multiple forms of ownership and access are embedded. This research evaluates forest change and fragmentation between 1990 and 2000, in a landscape surrounding the Mahananda Wildlife Sanctuary in the Indian state of West Bengal. This protected forest is bounded to the south by a less intensively protected area, the Baikunthapur Reserve Forest, and surrounded by a mosaic of unprotected, largely private land holdings. Results indicate differences in the extent and spatial pattern of forest cover change in these three zones, corresponding to different levels of government protection, access and monitoring. The two protected areas experience a trend toward forest regrowth, relating to the cessation of commercial logging by park management during this period. Yet, there is still substantial clearing toward peripheral areas that are well connected to illegal timber markets by transportation networks. The surrounding landscape, although experiencing some forest regrowth within less intensively cultivated tea plantations, is also becoming increasingly fragmented, with potentially critical impacts on the maintenance of effective wildlife corridors in this ecologically critical region.  相似文献   

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