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 31 毫秒
1.
Anthropogenic disturbances have caused major landscape changes in the forests of northeastern China during the past 50 years. In particular, continuous over-deforestation has greatly decreased the region's forest quality. Ecological footprint analysis generates aggregated information about a population's demand on nature and the population regional biological capacity. To show the forest change and the population's ecological demand on the study area, this paper presents an ecological footprint time series for the Songling Forestry Bureau in northeastern China from 1965 to 2000. The paper shows conventional ecological footprint time series and area demand time series – under global, Chinese and local yearly yields – to study the biological productivity of Songling. In this study, biological capacity was calculated based on a conventional approach. The results demonstrate that the ecological footprint has increased slightly and continuously during the 35-year timespan, while the biological capacity has decreased dramatically. These effects have been caused mainly by the depletion of forest resources. The results also yield much information about natural changes and socioeconomic dynamics, as well as the driving factors for these changes, of which the most important is forest management policy.  相似文献   

2.
Administrative divisions in the Great Southern Watershed of the Himalaya are diverse in terms of population density and forest cover. This study analyzed the spatial patterns of different attributes in the different Indian states and Himalayan kingdoms, and explored the extent and patterns of forest fragmentation in a Himalayan landscape as a case study. Of the total landscape in the case study area (3167 km2), 41% was fragmented. Homogenous landscape (59%) includes either continuous natural vegetation or a village landscape. Presence of two forest patches (38% of the total fragmented area) at a unit scale of about 0.5 km2 (525 × 525 m) was the most commonly occurring pattern but, in some parts, up to 13 patches were observed. Fragmentation of vegetation was visible even at smaller scales of landscape analysis. At a scale of 75 × 75 m, land division into three patches was observed. With an increase in the unit area of landscape analysis the number of patches per unit land area and the total fragmented area also increased. The forests that escaped fragmentation were either inaccessible to humans or had rigorous legal protection. Anthropogenic activities appeared to be one of the factors responsible for fragmentation but, natural factors also contributed.  相似文献   

3.
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   

4.
The World Development Report 2000–2001 recommends action on three complementary and synergistic fronts for poverty alleviation – promoting opportunity, facilitating empowerment and enhancing security. This paper analyses the Tamilnadu Forestry Project, funded by US$100 million from the Japan Bank for International Cooperation, for community forestry. The project was launched in 1997–1998 in this southern state of India and has evolved into a comprehensive poverty alleviation programme for the forest abutting villages where the proportion of poor people is largest. It endeavours to explain how the project provides the above three elements at the local level for sustainable poverty alleviation. Regeneration of forests, improvement of basic infrastructure through integration of line departments and promotion of alternate livelihoods provide ample economic opportunities. Establishment of Village Forest Councils, and delegation of sufficient powers to these Councils, has empowered the poorest of the poor. Tree assets, promotion of alternate income generation activities and water harvesting structures have provided security by reducing vulnerability to natural vagaries, particularly drought. In this project, the restoration of biodiversity and people development go hand in hand in a synergistic way that makes the project worth replicating elsewhere in the country and other parts of the world, with suitable modifications.  相似文献   

5.
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   

6.
The head Bay region bordering the Bay of Bengal is highly vulnerable to tropical cyclones. Catastrophic risks from storm surge and associated inundation are quite high due to high population density in coastal areas, socio-economic conditions, and shallow bathymetry. It features the world’s largest deltaic system comprising of ‘Sunderbans’ bordered by West Bengal and Bangladesh. In a geomorphologic sense, the head Bay region is a low-lying belt comprising several barrier islands and river drainage systems, numerous tidal creeks, and mud flats having a high risk for widespread inundation. In addition, the high tidal range together with low-lying topography leads to high risk and vulnerability from storm surge inundation. During May 2009, a severe cyclonic storm Aila struck West Bengal causing enormous destruction to life and property along coastal belts of West Bengal and Bangladesh. It was the strongest pre-monsoon cyclone in the past two decades that had landfall in West Bengal. This work reports on a numerical study for hypothetical storm surge and associated inundation from Aila using the ADCIRC model. The study covers a comprehensive qualitative analysis on water level elevation and onshore inundation for West Bengal and Bangladesh regions. The estimated peak storm surge was about 4 m in the Sunderban region that propagated into all major riverine systems, inundating the river banks as well the inland areas. Numerical simulations indicate an average inland penetration distance of 350 m with a maximum of 600 m at various coastal locations in West Bengal and Bangladesh. The study emphasizes the need and importance of inundation modeling system required for emergency preparedness and disaster management.  相似文献   

7.
Forest policies that devolve forest-use rights to local people have undergone development over the past few years in Laos. As collaboration between local people and forestry officials is seen as indispensable to effective and sustainable local forest management, the objective of this study is to clarify the issues pertinent to the resolution of latent conflict between these two stakeholders. The issues are examined by presenting two case studies in terms of forest management as perceived by local people and forestry officials; the first in a rich forest area and the second in a degraded forest. Issues relating to land and borders and social capital are identified as the most important in the degraded forest area, while social capital is a very important issue in the rich forest area. Our studies show that the problems of land and border issues in the degraded forest area were caused by an inappropriate resettlement policy. This can be interpreted as the mismanagement of social capital, and for effective local forest management it is very important to overcome problems of this nature. The effective use of social capital has so far been overlooked, however, in the establishment of collaborative forest governance at the local level.  相似文献   

8.
Socio-economic surveys were carried out in the Malimba and Mouanko communities in the Sanaga delta region of the Douala-Edea Wildlife Reserve, Cameroon, on the exploitation, processing and marketing of bivalves, with emphasis on gender aspects and impacts on the surrounding forest resources. Sixty people from 16 villages were sampled using a structured questionnaire with field observations documented during the peak fishing period (November 2000–June 2001). Results indicated a strong gender differentiation in the activity, with males dominating bivalve harvesting and shell processing and women dominating the processing for meat. Monthly bivalve meat production of 32.9 tons (197.4 tons per year) generated revenues of 65.4 million FCFA (74.9 million per year). Monthly shell production was put at 1380 tons (8040 tons per year) generating a monthly revenue of 74 million FCFA (444 million per year). Problems faced during exploitation, processing and marketing stages include physical, health and socio-economic: use of very depreciable rudimentary tools, shell injuries, fire and hot water burns, insect pests; blindness, deafness; inadequate storage facilities, transport and remoteness of the area. Bivalve processing activities using wood contributed to a total annual harvest of 50 986 m3 from the surrounding forest. Sustainable conservation measures geared towards poverty alleviation are proposed.  相似文献   

9.
The participatory approach in management of forests is now well established in forest policies of many developing countries. Incentives for different groups to participate have been argued by many to be desirable characteristics to promote participation. A key challenge for government and donor agencies is to develop better understanding of the incentives for different groups to be able to achieve and sustain their participation. Based on a case study of a joint forest management (JFM) programme in the northern state of Haryana in India, this paper highlights the relevance of understanding people's perception of the incentives. It specifically examines three hypotheses related to perceptions of villagers about incentives offered under the JFM programme and relates them to their participation in joint management. It concludes that a better understanding is likely to help in improving project implementation at the local level and the design of participatory forest management programmes more generally.  相似文献   

10.
Urban forest is a very important part of urban ecosystems and provides significant ecosystem services. It benefits urban communities environmentally, aesthetically, recreationally and economically. This article reviews the development status, development patterns and influencing factors of urban forest in China. There are four typical development patterns of urban forest in China: the forest city, garden city, ecological economics and forest greenbelt. Social, climatic, economic and other factors influence urban forest development in China. Social factors include government behaviour, laws and regulations, science and technology, education and culture, public awareness and participation, ecological planning and management. Climatic factors include rainfall, temperature and sunlight. Economic factors include urban economic level and funding for urban forest. In future, government, NGOs and the private sector should be considered more in the planning and management of urban forest. The social, climatic and economic factors should be taken into account when improving urban forest management. Research on urban forest from the academic and the management viewpoint should be strengthened. This can improve the development and management of urban forest in China and in other developing countries.  相似文献   

11.
Many ponderosa pine and mixed-conifer forests of the western, interior United States have undergone substantial structural and compositional changes since settlement of the West by Euro-Americans. Historically, these forests consisted of widely spaced, fire-tolerant trees underlain by dense grass swards. Over the last 100 years they have developed into dense stands consisting of more fire-sensitive and disease-susceptible species. These changes, sometimes referred to as a decline in "forest health," have been attributed primarily to two factors: active suppression of low-intensity fires (which formerly reduced tree recruitment, especially of fire-sensitive, shade-tolerant species), and selective logging of larger, more fire-tolerant trees. A third factor, livestock grazing, is seldom discussed, although it may be as important as the other two factors. Livestock alter forest dynamics by (1) reducing the biomass and density of understory grasses and sedges, which otherwise outcompete conifer seedlings and prevent dense tree recruitment, and (2) reducing the abundance of fine fuels, which formerly carried low-intensity fires through forests. Grazing by domestic livestock has thereby contributed to increasingly dense western forests and to changes in tree species composition. In addition, exclosure studies have shown that livestock alter ecosystem processes by reducing the cover of herbaceous plants and litter, disturbing and compacting soils, reducing water infiltration rates, and increasing soil erosion.  相似文献   

12.
Bamboo forests, due to their special characteristics and ecological functions, play an important role in sustainable forest management and rural development in China. Over the past two decades, China has successfully established millions of hectares of bamboo forest, which has restored fragile ecosystems, provided benefits to local communities, alleviated rural poverty and eased timber shortages. However, there is potential for further improvements to the bamboo forest estate. This paper analyses the current state of bamboo forest resources and management, and the roles of the bamboo forest industry in social development, economic growth and ecosystem protection in China. We examine the main issues related to governance systems, local economic development and traditional management practices. Finally, we suggest some directions for future development.  相似文献   

13.
Soil desiccation is a major issue limiting development and sustainability of forest vegetation in the Loess Plateau of China. Better understanding of the mechanisms of soil desiccation in the Loess Plateau can help scientists and forest managers improve vegetation management practices. The arid soil layer is the ecological aftermath of intense soil desiccation due to disturbed plant succession and soil water reduction. The formation and types of arid soil layer in the Loess Plateau were investigated to determine major causes of soil desiccation and its impact on forest vegetation. The negative effects of soil desiccation on the ecological environment and forest vegetation mainly include drying microclimate, degrading soil quality, poor vegetation growth, difficult forest renewal from natural seed banks, making it even more difficult to reforest forest lands and grasslands following plant senescence. Low precipitation, high evaporation, soil and water losses, improper selection of vegetation types, and too high population density of trees are probably the major reasons for the arid soil layer. Proper selection of vegetation types, adjusting tree density and other management practices can reduce the negative effects of the arid soil layer on forest vegetation.  相似文献   

14.
The study examines mainstream efforts to rehabilitate and conserve forests in Cameroon, and concludes that technocratic blueprints will always flounder when they come face-to-face with the real world of complex human relations in poverty-stricken societies. These result from the failure to integrate concerns relating to rights, needs and priorities of rural communities, who are the local natural resource users. The paper argues that when rural livelihoods are affected negatively, the adjacent forest communities often respond in ways involving conflict, illegal exploitation of resources and apathy, which makes the realisation of conservation goals very remote. There is, therefore, need for a broader perspective that links environmental protection with human welfare. Consequently, the study advocates that Social Impact Assessment (SIA) be an integral part of such conservation projects if success is to be achieved.  相似文献   

15.
《Ecological modelling》2007,201(1):67-74
Translocation is a useful management option for conservation of threatened animal species. It can be used to increase the range of a species, augment the numbers in a critical population, or establish new populations and hence spread the risk of extinction through local catastrophes. As it is an important and expensive conservation tool, translocation management decisions must be carefully considered, with the objective of the translocation project in mind. By analysing the translocation problem within a decision-theory framework, we find optimal management decisions that are rational and transparent. We illustrate our approach using a case study of the bridled nailtail wallaby (Onychogalea fraenata). Our particular translocation question is: if we have a set number of wallabies to translocate in each time period and two translocation sites, how many wallabies should we put at each site given the state of each population to maximise the benefit to the species? We model the translocated populations with first-order Markov chain stochastic population models, and use stochastic dynamic programming to determine the optimal management decisions. We look at two sites with different growth rates – one increasing and one decreasing – and compare the optimal strategies for two different objective functions. The first is a long-term persistence objective function, which maximises the persistence of translocated populations a large number of time steps after the end of the translocation program. The second maximises total population size at the end of the translocation program. Although these objective functions are similar, they generate surprisingly different optimal translocation strategies. When maximising the long-term persistence of the translocated populations, translocation decisions are not important as long as an increasing population is established. This indicates that site quality – rather than the number and timing of translocations – primarily determines the long-term persistence of populations. When maximising total population size, the optimal strategy is to add to the increasing population unless it is above a size where it is likely to reach its carrying capacity over the planning timeframe. As translocation decisions are important in fulfilling the objective, this objective function is more useful in creating practical advice for translocation managers. The discrepancy between the optimal strategies given by the two objectives demonstrates the importance of careful consideration when specifying the goals of a project. This observation applies not only to translocation programs, but any project where clear decision-making is needed.  相似文献   

16.
The harvesting of Phragmites australis reeds in the Tembe Elephant Park has to be managed pro-actively. Solutions to potential problems should be sought before they arise. This paper offers a potential solution to the problem of instating a winter-only reed harvest in the Muzi Swamp. The potential for manufacturing finished products such as prefabricated huts from sustainably harvested reeds and forest timber is examined and a cost estimate is presented. A prefabricated reed hut is three-times cheaper than a similarly-sized house made of bricks and cement. The manufacturing of finished products from the harvested material will add secondary value to the resource and also offer an alternative employment to harvesting reeds in the summer. The higher prices obtained for a processed article will also, hopefully, reduce the demand for the resource in its raw form, thereby increasing the perceived value of the resource and reducing wastage from raw materials that are not sold.  相似文献   

17.
The road side plants are continuously exposed to the high levels of oxides of nitrogen and sulphur dioxide, emitted from automobile. Resistance to automobile exhaust pollution was studied with Nerium indicum Mill, Boerhaavia diffusa L., Amaranthus spinosus L., Cephalandra indica Naud., and Tabernaemontana divaricata L., growing on the edges of Delhi Road, National Highway 2 (NH 2) near Dankuni, West Bengal. By analysing the activities of a few enzymes like superoxide dismutase, catalase, ascorbate peroxidase, glutathione reductase and phenolic peroxidase, it appears that among the five plants examined,Amaranthus and Cephalandra are equipped with a very good scavenging system to combat effects of air pollution.  相似文献   

18.
Forest degradation in the tropics is often associated with roads built for selective logging. The protection of intact forest landscapes (IFL) that are not accessible by roads is high on the biodiversity conservation agenda and a challenge for logging concessions certified by the Forest Stewardship Council (FSC). A frequently advocated conservation objective is to maximize the retention of roadless space, a concept that is based on distance to the nearest road from any point. We developed a novel use of the empty‐space function – a general statistical tool based on stochastic geometry and random sets theory – to calculate roadless space in a part of the Congo Basin where road networks have been expanding rapidly. We compared the temporal development of roadless space in certified and uncertified logging concessions inside and outside areas declared IFL in 2000. Inside IFLs, road‐network expansion led to a decrease in roadless space by more than half from 1999 to 2007. After 2007, loss leveled out in most areas to close to 0 due to an equilibrium between newly built roads and abandoned roads that became revegetated. However, concessions in IFL certified by FSC since around 2007 continuously lost roadless space and reached a level comparable to all other concessions. Only national parks remained mostly roadless. We recommend that forest‐management policies make the preservation of large connected forest areas a top priority by effectively monitoring – and limiting – the occupation of space by roads that are permanently accessible.  相似文献   

19.
The United Nations Sustainable Development Goals (UN SDGs) contain a set of 17 measures to foster sustainable development across many areas. It offers a good opportunity to reinvigorate sustainable development research for two main reasons. First, it comprises many areas of SD research, which have become mainstream thanks to the UN SDGs. Second, the fact that the UN and its member countries have committed to attaining SDGs by 2030 has added a sense of urgency to the need to perform quality research on SD on the one hand, and reiterates the need to use the results of this research on the other. Even though the basic concept of sustainability goes back many centuries, it has only recently appeared on the international political agenda. This is partly due to an awakening of the fact that the human ecological pressure on the planet is still much larger than what nature can renew or compensate for. Based on this state of affairs, this paper presents an outline of the process leading to the agreement on the UN SDGs, and looks at some of the ecological aspects as a result of continued pressure of human activities on natural resources. Furthermore, a set of research needs is proposed – also based holistically on updated research trends – discussing the degree of urgency of some measures and explaining why the UN SDGs need to be accorded greater priority in international sustainable development research efforts.  相似文献   

20.
The nature of nutrient limitation in large areas of temperate forest may be changing due to human activities. As N availability in these forests increases, other nutrients could increasingly constrain productivity and other ecosystem processes. To determine the nature of nutrient limitation (N, P, and Ca) in forest soils exhibiting differing N availability, we conducted three field studies in the Fernow Experimental Forest, West Virginia, USA. The first used a ubiquitous herbaceous species, Viola rotundifolia, to compare indices of N availability to the activity of root-associated phosphomonoesterase (PME) activity at two spatial scales. The second study used fertilized, root in-growth cores to assess the extent of N, P, and Ca limitation. Finally, we measured the root-associated PME activity of V. rotundifolia growing in experimental plots that have received various combinations of nutrient additions and harvest treatments. For entire watersheds, stream water nitrate concentrations were positively related to PME activities (R2 = 0.986). For small plots, PME activities were positively associated with soil nitrate availability (R2 = 0.425), and to a lesser extent with the leaf N concentrations (R2 = 0.291). Root growth into microsites fertilized with P was greater than growth into microsites fertilized with either N or Ca, especially in watersheds with high N availability. Experimental additions of N increased the root-associated PME activity of V. rotundifolia, supporting the causality of the relationship between N availability and PME activity. Collectively, our results indicate that, as N availability increases, P becomes increasingly limiting at the sites examined. Understanding how nutrient limitations change during N saturation should improve ecosystem models and better inform our attempts to mitigate any undesired effects.  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