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1.
SUMMARY

Forests are fundamental and vital components of the world ecosystems. The essential links between forest and man are now receiving renewed and urgent attention, and there is increasing awareness that the value of forests to life on Earth is beyond economic value, and should be above political considerations. Tropical forests, generally marked out by richness in species, are found in more than 80 countries and account for roughly one-third of the world's forest cover. They encompass a wide variety of forest types found under diverse environmental conditions — from lush, constantly wet rain forests to arid thorn woodlands. These forests have been estimated to cover about 1715 million hectares in Africa alone. They have provided habitats for wildlife and wood, fibre, food and many other products to generations of mankind and are invaluable genetic resources of plants. Rapid population growth has, however, resulted in increasing the pressure on these forests, with a consequent decline in their qualitative and quantitative values. Throughout the world, forest lands have been cleared extensively for agriculture, and deforestation continues today. In the tropics, 10–25 million ha are being lost each year, with Africa alone losing 4–5 million ha annually. It has been estimated that, at this rate, the remaining tropical forest would disappear in 60–80 years; thereby leading to catastrophic environmental changes. The serious impact of these changes on the environment and on human needs is awakening world attention, and alarming consequences have sometimes been suggested. This paper highlights the major causes of tropical deforestation and its environmental consequences. Possible efforts to arrest the unpleasant trend are discussed.  相似文献   

2.
ABSTRACT

Rural communities worldwide face a decrease of critical ecosystem services caused by replacement of native forests by commercial plantations. Replacement of native forest by commercial plantations decreases water provisioning, with possible negative impacts over well-being. We tested this hypothesis in Central Chile. We assessed subjective well-being (SWB) and local perceptions of changes in forest cover and water provision among 78 rural families. We also assessed if the Shifting Baseline Syndrome (SBS) affects the perceptions of environmental changes and their implications in SWB. Individuals perceived less forest cover than 20 years ago, and this is seen as a factor of decreased livelihood, availability of forest products, and water provisioning for households. People also reported less water available than 20 years ago. The main drivers associated with decreased water provision were the establishment of pine plantations (44% of individuals) and drought (44%). A better-off SWB was associated with perception of lower rate of deforestation. The perceptions of forest degradation and its association to SWB are affected by SBS. Paradoxically, a better-off SWB was also associated with an improvement of water quality, although the quantity and quality of water have decreased according to biophysical data, which ought to decrease the SWB. Impacts of environmental degradation in SWB are masked by factors such as more infrastructure for drinking water, assisted by governments. This masking of environmental degradation reduces the opportunity to avoid negative impacts over well-being among rural communities that are dependent on assistance around the world.  相似文献   

3.
SUMMARY

In recent years, indigenous tenure over forest lands has emerged as a means to conserve forests while recognizing indigenous rights. There is concern, however, that indigenous reserves may not be an appropriate policy tool for sustained forest conservation. Our research examined how recognition of indigenous common-property rights has controlled agricultural expansion and conserved forests in Bosawas Biosphere Reserve, Nicaragua. We used satellite imagery with empirical data gathered in the field on land-use institutions, population pressures, and land-use practices to compare whether indigenous communities under territorial management or public management are better able to (1) control the ‘fast threat’ of frontier expansion and (2) address the long-term ecological threats posed by indigenous land-use practices and institutional changes in the region. Our findings are that indigenous residents who share common-property rights over their territories are better able to control agricultural expansion than are indigenous residents living on public lands. With respect to the long-term threats to the region, a series of simulations of possible land-use pressures demonstrate that the enforcement of territorial boundaries and further development of indigenous forest management rules will prove crucial in determining land-use capacity and deforestation over the next 50 years.  相似文献   

4.
SUMMARY

The Lesser Himalaya, as the most densely populated part of the tectonically active and ecologically sensitive Himalayan mountain ranges, deserves specific attention to the conservation of the environment and the sustainable development of natural resources. Rapid growth of the human population during recent years, and the absence of any viable means of livelihood other than uneconomic crop farming have led to the uncontrolled exploitation of land areas and the consequent degradation and depletion of critical biophysical resources in the region. The need for sustainable development in Himalaya, therefore, makes it imperative to adopt a comprehensive land-use policy based on land capacity analysis that is scientific and practical. The main objective of this paper is to evolve an optimal land-use framework for the Gomti Watershed, situated in Kumaon, Lesser Himalaya. A detailed study of the traditional land use, regional agricultural system and the areas prone to environmental hazards was made throughout the watershed, through the preparation of large scale topographical forest and land record maps, field surveys and mapping. The average slope was considered as the principal parameter of land capacity, the potential for landslides and the intensity of erosion. Recognising the drastic changes that have taken place in the traditional land use, the watershed area has been proposed to be defined as protected forests (33.41%), community forests (32.86%), cultivation (23.33%) and horticulture (8.30%).  相似文献   

5.
SUMMARY

Despite the declining volumes of biotic resources flowing from natural ecosystems, no sustainable rural-based programmes have been put in place to stabilize habitats and diversify products to meet the needs and livelihoods of forest-dependent communities. Nevertheless, there is increasing evidence that agricultural expansion and rising demands for forest resources are increasingly depleting the forests. Within these extremes, daily used wild plants that sustain rural communities are under threat of over-exploitation.

This study identified major daily used wild plants in rural environments, examined their use categories, and suggested suitable ways to conserve these plants in order to improve the biodiversity capital and stabilize rural livelihoods. Results of data analysis showed that: (i) about 96 species of wild plants were in daily use for food, energy, medicine, shelter and cultural festivals; (ii) the management and utilization of daily used wild plants were based on traditional knowledge that had become inefficient as a result of resource scarcity and loss of habitats. In these circumstances, resource utilisation is leading to the loss of species; (iii) the resource users were willing to conserve wild plants on private lands to meet their ways of life. The success of wild plant conservation however, hinges on the provision of infrastructures for smallholder farmers who are willing to plant trees on their lands. There is urgent need for those responsible for conserving the forests and the environment (Federal Ministry of Environment) to design and implement suitable programmes that will accommodate the needs of the rural people in conserving wild plants in daily use in the country.  相似文献   

6.
The Potential for Species Conservation in Tropical Secondary Forests   总被引:3,自引:0,他引:3  
Abstract: In the wake of widespread loss of old‐growth forests throughout the tropics, secondary forests will likely play a growing role in the conservation of forest biodiversity. We considered a complex hierarchy of factors that interact in space and time to determine the conservation potential of tropical secondary forests. Beyond the characteristics of local forest patches, spatial and temporal landscape dynamics influence the establishment, species composition, and persistence of secondary forests. Prospects for conservation of old‐growth species in secondary forests are maximized in regions where the ratio of secondary to old‐growth forest area is relatively low, older secondary forests have persisted, anthropogenic disturbance after abandonment is relatively low, seed‐dispersing fauna are present, and old‐growth forests are close to abandoned sites. The conservation value of a secondary forest is expected to increase over time, as species arriving from remaining old‐growth forest patches accumulate. Many studies are poorly replicated, which limits robust assessments of the number and abundance of old‐growth species present in secondary forests. Older secondary forests are not often studied and few long‐term studies are conducted in secondary forests. Available data indicate that both old‐growth and second‐growth forests are important to the persistence of forest species in tropical, human‐modified landscapes.  相似文献   

7.
SUMMARY

The contention is examined that forests can contribute to biodiversity conservation either as protected areas or as production forests, especially where the latter are managed for timber extraction. This notion is explored for the Peninsular Malaysian forests, and it is shown that biodiversity conservation would be optimized if the system of protected areas is located within a broader matrix of carefully managed production forests. A model is developed to illustrate how the biodiversity value of protected areas would be enhanced through interaction with production forests. In no way is the suggestion being made here that production forests could serve as critical centres for the conservation of biotic diversity, but then neither should they be dismissed as areas completely devoid of any contribution to the biodiversity cause. These findings are especially significant in Peninsular Malaysia where two-thirds of the forests legally set aside as Permanent Forest Estate is to be managed as production forests. If the incremental biodiversity value of these forests can be captured through improved management practices, then the overall biodiversity status of the country, and the globe, could be greatly increased. The extent to which any country is willing to set aside forests as protected areas, strictly for biodiversity conservation, is limited, hence the integrated approach to the management of protected and production forests advocated here could prove an attractive and feasible strategy. Where funding is limited, as in the case of the Global Environment Facility, it may be worthwhile to provide incentives for improved management of production forests as a means of conserving biodiversity.  相似文献   

8.
ABSTRACT

Conservation of protected areas requires understanding of the consumption of forest products by rural people who live near protected forests. Socioeconomic factors such as a better education, income, land holding size, have been used to understand the patterns of consumption of non-timber forest products (NTFPs). Ethnicity, and especially whether or not people are indigenous to the forested areas, may also change consumption patterns. In this study we analysed the socioeconomic factors, indigeneity and geographical locations of people living in the buffer zones of Vietnam’s Bu Gia Map National Park to better understand the key determinants of the consumption of NTFPs. We conducted 121 interviews with local households and found that indigeneity, education, family size, and the area of land used were statistically significant in explaining the amount of NTFPs consumed, while indigeneity and area of land used by local people had positive relationships with the diversity (measured in number of categories) of NTFPs consumed by local people. Interestingly, there were statistically significant effects of interactions between the area of land used and indigeneity on the consumption of NTFPs. The amount of these products is important for indigenous people who belong to the groups using small and medium areas of land. The medium land use group consumed significantly fewer categories of NTFPs than the small and large land use groups. This data may help local managers to develop interventions that support biodiversity conservation, promote sustainability of these important resources and improve the social welfare of marginal groups.  相似文献   

9.
The forests of southeastern Alaska remain largely intact and contain a substantial proportion of Earth's remaining old‐growth temperate rainforest. Nonetheless, industrial‐scale logging has occurred since the 1950s within a relatively narrow range of forest types that has never been quantified at a regional scale. We analyzed historical patterns of logging from 1954 through 2004 and compared the relative rates of change among forest types, landform associations, and biogeographic provinces. We found a consistent pattern of disproportionate logging at multiple scales, including large‐tree stands and landscapes with contiguous productive old‐growth forests. The highest rates of change were among landform associations and biogeographic provinces that originally contained the largest concentrations of productive old growth (i.e., timber volume >46.6 m3/ha). Although only 11.9% of productive old‐growth forests have been logged region wide, large‐tree stands have been reduced by at least 28.1%, karst forests by 37%, and landscapes with the highest volume of contiguous old growth by 66.5%. Within some island biogeographic provinces, loss of rare forest types may place local viability of species dependent on old growth at risk of extirpation. Examination of historical patterns of change among ecological forest types can facilitate planning for conservation of biodiversity and sustainable use of forest resources. El Uso de Patrones Históricos de Tala para Identificar Ecosistemas Talados Desproporcionadamente en Bosques Lluviosos Templados del Sureste de Alaska Albert & Schoen 11‐839  相似文献   

10.
Abstract: Unsustainable hunting of wildlife for food empties tropical forests of many species critical to forest maintenance and livelihoods of forest people. Extractive industries, including logging, can accelerate exploitation of wildlife by opening forests to hunters and creating markets for bushmeat. We monitored human demographics, bushmeat supply in markets, and household bushmeat consumption in five logging towns in the northern Republic of Congo. Over 6 years we recorded 29,570 animals in town markets and collected 48,920 household meal records. Development of industrial logging operations led to a 69% increase in the population of logging towns and a 64% increase in bushmeat supply. The immigration of workers, jobseekers, and their families altered hunting patterns and was associated with increased use of wire snares and increased diversity in the species hunted and consumed. Immigrants hunted 72% of all bushmeat, which suggests the short‐term benefits of hunting accrue disproportionately to “outsiders” to the detriment of indigenous peoples who have prior, legitimate claims to wildlife resources. Our results suggest that the greatest threat of logging to biodiversity may be the permanent urbanization of frontier forests. Although enforcement of hunting laws and promotion of alternative sources of protein may help curb the pressure on wildlife, the best strategy for biodiversity conservation may be to keep saw mills and the towns that develop around them out of forests.  相似文献   

11.
SUMMARY

A cross-section survey of five states in Nigeria was derived through a stratified random sampling technique in 1999–2000 to assess the contribution of traditional knowledge in environmental conservation. Data were collected through a combination of questionnaire survey and discussions with stakeholders, with field assessment of herb gardens. Interviews were held with 1953 respondents composed of women, men and youths drawn from 20 settlements in 10 local government areas in the savanna and rainforest ecological zones.

The results derived from data analysis indicated that: (i) the rural communities were willing to accept integrated rural land-use practices that would conserve species and habitats, sustain the rural economy and the socio-cultural lifestyles of the people; (ii) the people at the local level had some basic knowledge about species and habitats, and have been conserving the forests with traditional land tenure rights; and (iii) environmental projects acceptable to the rural communities must be beneficial to the people, participatory, integrated with traditional knowledge and based on local needs.  相似文献   

12.
ABSTRACT

Nepal is in the process of formulating its forest policies at the provincial level . Various community-managed forests have been designed in the past by the Nepal government to decentralize the forest for its sustainable management practice. This study facilitates the process of identifying appropriate forest management options in two of the provinces, namely Provinces Three and Gandaki. Four forest management options – passive, active, scientific and multiple – were identified following the existing management practices. For the evaluation of the overall performance of the options, a framework with three criteria, 10 indicators and 28 verifiers were designed. The framework followed the green economy perspective considering the improvement of the forest conditions, economic and social well-being, and low carbon emission. The Analytical Hierarchy Process was used to prioritize the best management option and analyse trade-offs to guide future decision-making and reduce the risk of unwanted consequences. Our results show that the elicitation of preferences for the evaluation criteria varied by stakeholder groups. Their preference was largely guided by improving the forest resource condition and economic well-being. Foresters prefer scientific and active forest management, policymakers prefer multiple-use forest management and scientific management, whereas community forest user groups prefer active forest management. We argue that a scientific management approach may contribute better to economic aspects, although it may often compromise the other aspects. The multiple forest management option seems to be the best for green economy considering ecological, economic and social consequences.  相似文献   

13.
ABSTRACT

The signing of Colombia’s peace agreement in 2016 signaled the end of a decades-long war between the government and the FARC (Las Fuerzas Armadas Revolucionarias de Colombia), but also an emerging assault against the country’s forests. This article aims to understand the interactions between forests and peace. In doing so, it traces landscape transformations of deforestation and possibilities for making landscapes livable in the midst of disturbance. Drawing on field research, including interviews and participant observation carried out in Colombia from 2016 to 2018, it reveals how deforestation is driven by ongoing colonization and land grabbing, mostly dedicated to extensive cattle ranching, coca cultivation, and campesinos’ transition to ‘licit’ agricultural alternatives. The article also shows how emerging coordination among farmers and forests following forest disturbance contributes to an interpretation of peace in which forests are integral. The article concludes with a call to incorporate forests in the construction of peace.  相似文献   

14.
Abstract: Current networks of protected areas are biased in many countries toward landscapes of low productivity. Voluntary conservation incentives have been suggested as a socially acceptable way to supplement existing networks with more productive, privately owned areas of high priority for nature conservation. The limited resources committed to nature conservation demand cost‐efficiency. Efficiency, however, depends not only on costs incurred to society from alternative ways of maintaining biodiversity but also on ecological values that can be captured. We examined the ecological efficiency of the new market‐based voluntary program to preserve forest habitats on private land in southwestern Finland. We compared sites that have become protected (10‐year contracts) in the program with managed forests, with sites that have been negotiated for protection for which no contract has been signed, and with the most ecologically valuable privately owned sites in the region that have not been offered for protection by forest owners. We surveyed sites for the amount of dead wood, wood‐decomposing fungi, and epiphytic lichens to evaluate their ecological quality. Contracted sites had more features important for overall biodiversity than managed forests and negotiated sites with no contract. These results indicate that procedures used during site selection and negotiations were appropriate and not opportunistic. The contracted sites were also as valuable in ecological terms as the best, still‐unprotected, privately owned forests in the region that have not been offered for protection. We conclude that voluntary conservation programs have the potential to yield ecologically valuable sites for protection if the site‐selection procedures are appropriate. Reliance on completely voluntary programs, however, may entail uncertainties and inadequacies, for example, in terms of spatial configuration and persistence of the ecological values. Thus, such programs may often need to be supplemented with alternative methods such as land purchase to achieve an ecologically effective network of protected sites.  相似文献   

15.
The study investigated the role of traditional institutions in the conservation of the East Usambara forests in Tanzania. It revealed that there had been institutional changes in management of forests, which had a negative impact on forest conservation. However, the presence of traditional institutions, which included among others traditional healers, traditional leaders, traditional taboos, sacred species and sites, had active roles in conserving the forest. More than 90% of the respondents had retained indigenous tree species on their farms and around households, with an average of six trees per household. This strategy is influenced by socio-economic factors whereby respondent age had a significant positive influence on the number of trees retained by a household. The study concludes by pointing out that traditional institutions have active roles in conserving the forests, and recommends that various strategies must be combined, including the use of traditional institutions, in Conservation of forests. Studying tradition institutions will give us knowledge on how they operate and how they can be combined with other strategies in government, NGOs and even the private sector in conservation of the forests. Socio-economic factors must be taken into account in the management of natural resources.  相似文献   

16.
Poaching has devastated forest elephant populations (Loxodonta cyclotis), and their habitat is dramatically changing. The long‐term effects of poaching and other anthropogenic threats have been well studied in savannah elephants (Loxodonta africana), but the impacts of these changes for Central Africa's forest elephants have not been discussed. We examined potential repercussions of these threats and the related consequences for forest elephants in Central Africa by summarizing the lessons learned from savannah elephants and small forest elephant populations in West Africa. Forest elephant social organization is less known than the social organization of savannah elephants, but the close evolutionary history of these species suggests that they will respond to anthropogenic threats in broadly similar ways. The loss of older, experienced individuals in an elephant population disrupts ecological, social, and population parameters. Severe reduction of elephant abundance within Central Africa's forests can alter plant communities and ecosystem functions. Poaching, habitat alterations, and human population increase are probably compressing forest elephants into protected areas and increasing human–elephant conflict, which negatively affects their conservation. We encourage conservationists to look beyond documenting forest elephant population decline and address the causes of these declines when developing conversation strategies. We suggest assessing the effectiveness of the existing protected‐area networks for landscape connectivity in light of current industrial and infrastructure development. Longitudinal assessments of the effects of landscape changes on forest elephant sociality and behavior are also needed. Finally, lessons learned from West African elephant population loss and habitat fragmentation should be used to inform strategies for land‐use planning and managing human–elephant interactions.  相似文献   

17.
The Tibetan sacred mountains (TSMs) cover a large area and may represent a landscape‐scale conservation opportunity. We compared the conservation value of forests in these mountains with the conservation value of government‐established nature reserves and unmanaged open‐access areas in Danba County, southwestern China. We used Landsat satellite images to map forest cover and to estimate forest loss in 1974–1989, 1989–1999, and 1999–2013. The TSMs (n = 41) and nature reserves (n = 4) accounted for 21.6% and 29.7% of the county's land area, respectively. Remaining land was open‐access areas (i.e., areas without any restrictions on resource use) (56.2%) and farmlands (2.2%). Within the elevation range suitable for forests, forest cover did not differ significantly between nature reserves (58.8%) and open‐access areas (58.4%), but was significantly higher in TSMs (65.5%) after controlling for environmental factors such as aspect, slope, and elevation. The TSMs of great cultural importance had higher forest cover, but patrols by monastery staff were not necessarily associated with increased forest cover. The annual deforestation rate in nonsacred areas almost tripled in 1989–1999 (111.4 ha/year) relative to 1974–1989 (40.4 ha/year), whereas the rate in TSMs decreased in the later period (19.7 ha/year vs. 17.2 ha/year). The reduced forest loss in TSMs in 1989–1999 was possibly due to the renaissance of TSM worship and strengthened management by the local Buddhist community since late 1980s. The annual deforestation rate in Danba decreased dramatically to 4.4 ha/year in 1999–2013, which coincided with the implementation of a national ban on logging in 1998. As the only form of protected area across the Tibetan region during much of its history, TSMs have positively contributed to conserving forest at a landscape scale. Conservation of TSM forests largely relied on the strength of local religious institutions. Integrating community‐based conservation of TSMs within the government conservation network would benefit the conservation of the Tibetan region.  相似文献   

18.
Abstract:  Research on local use values of forests across an ecological succession informs land-use decisions and conservation planning. I evaluated use values of three age classes of secondary forest: fallow fields (<5 years old, $8.20/ha/year), young secondary forest (5–20 years old, $20.60/ha/year), and old secondary forest (>20 years old, $6.80/ha/year). I quantified daily forest product use and calculated use values in dollars per hectare per year for three communities in the northern Peruvian Amazon. I made three comparisons between forest types: number of useful species, value based on different use categories, and overall use values. Old secondary forest had the greatest number of total species present and species collected. Wood, food, and medicine were the three most valuable use categories. The value different families extracted from local forests varied enormously, but median forest values were lower for all forest types than potential gains from agricultural land use (e.g., coffee $167/ha/year). Values of different-aged stands on privately owned lands in two communities did not differ significantly, whereas in the third community, young secondary forest had a significantly greater value than other forest types. Old secondary forests were the most valuable source of wood products, and wood was the only use category in which there was any difference in the value of products extracted from different-aged forest stands. The value of all three forest types on open-access (nonprivate) lands was minimal (mean in each forest type, $0/ha/year). Local people can utilize the valuation results to develop land-use strategies that balance forest product use, agricultural productivity, and biodiversity conservation.  相似文献   

19.
Abstract: We assessed quantitatively the woody species used for timber, medicine, and other products in 10 tropical wet-forest stands with different land-use histories in the Atlantic lowlands of northeastern Costa Rica. Species were classified into 20 use categories based on regional ethnobotanical studies. Three size classes of woody vegetation were sampled in nested, contiguous plots along transects: trees (≥5 cm diameter at breast height [dbh]), saplings (>1 m high, <5 cm dbh), and seedlings (>20 cm high, <1 m high). Our study included five second-growth stands, three old-growth stands, and two selectively logged stands. Of the 459 woody species surveyed, 70% of the species and 86% of the total number of individuals had at least one use. Overall, species richness was highest for medicinal species (167 species). Absolute and relative abundance of medicinal and timber trees was significantly higher in second-growth stands than in old-growth and selectively logged stands. For 8 of the 15 use categories examined statistically, stem density showed no significant differences across forest types for any stem size class. Young, tropical, second-growth forests and selectively logged forests have high utilitarian as well as conservation value and will likely become important sources of forest products. The success of secondary forest regeneration, however, depends critically upon conservation of genetically diverse source populations in forest fragments and protected old-growth stands.  相似文献   

20.
An historical generalization about forest cover change in which rapid deforestation gives way over time to forest restoration is called "the forest transition." Prior research on the forest transition leaves three important questions unanswered: (1) How does forest loss influence an individual landowner's incentives to reforest? (2) How does the forest recovery rate affect the likelihood of forest transition? (3) What happens after the forest transition occurs? The purpose of this paper is to develop a minimum model of the forest transition to answer these questions. We assume that deforestation caused by landowners' decisions and forest regeneration initiated by agricultural abandonment have aggregated effects that characterize entire landscapes. These effects include feedback mechanisms called the "forest scarcity" and "ecosystem service" hypotheses. In the forest scarcity hypothesis, forest losses make forest products scarcer, which increases the economic value of forests. In the ecosystem service hypothesis, the environmental degradation that accompanies the loss of forests causes the value of ecosystem services provided by forests to decline. We examined the impact of each mechanism on the likelihood of forest transition through an investigation of the equilibrium and stability of landscape dynamics. We found that the forest transition occurs only when landowners employ a low rate of future discounting. After the forest transition, regenerated forests are protected in a sustainable way if forests regenerate slowly. When forests regenerate rapidly, the forest scarcity hypothesis expects instability in which cycles of large-scale deforestation followed by forest regeneration repeatedly characterize the landscape. In contrast, the ecosystem service hypothesis predicts a catastrophic shift from a forested to an abandoned landscape when the amount of deforestation exceeds the critical level, which can lead to a resource degrading poverty trap. These findings imply that incentives for forest conservation seem stronger in settings where forests regenerate slowly as well as when decision makers value the future.  相似文献   

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