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1.
Summary This study examines the organic matter and nutrient levels in soils under a 26-year old cocoa plantation and shifting cultivation farmlands cropped with cassava and maize, in Nigeria. The characteristics of soils under the two contrasting agricultural modes were compared with those of soils under rain forest, in order to infer the differential effects. Relative to the forest levels, the soil organic matter and nutrient levels were not substantially reduced in soils under plantations of cocoa. This is largely because cocoa plantations replicate forest conditions. In contrast, organic matter and nutrient levels were much lower in shifting cultivation farmlands. This is attributable to the fact that the crops of cassava and maize have a low ground cover, they generate relatively small amounts of litter and so do not replicate forest conditions. Measures which might be adopted to conserve soil organic matter and nutrient status during shifting cultivation methods are discussed.Dr A.O. Aweto is a Senior Lecturer in the Department of Geography where Mr O.A. Obe was, until recently, a research worker.  相似文献   

2.
Summary Nigerian efforts in agricultural development over the past three decades have failed to improve the country's economy. A review of the sector depicts a gloomy picture. Performance is reflected in environmental degradation, mounting food deficits, and decline in both gross domestic product and export earnings, while retail food prices and import bills have been increasing. These effects have further impoverished the smallholder farmers, locking them into a poverty web. The Government must seek to establish agricultural strategies which promote political stability, self reliance, public participation, sustained production and environmental security.Dr Gbadebo J. Osemeobo is a land use and conservation specialist working for the Nigerian Tropical Forestry Action Programme. He received from the University of Ibadan, Nigeria, a BSc in 1976, an MSc in 1982 and a PhD in 1985. His research interests are in rural land use, habitat/biotic preservation, and environmental conservation. He has worked in various capacities with the Federal Department of Forestry; as Head of the Zugurma Sector of Kainji Lake National Park, 1978–1980; as Head, Regional Offices of the Federal Department of Forestry in Benin and Abeokuta, 1981–1989; and as a specialist in the Tropical Forestry Action Programme from 1990 to the present time.  相似文献   

3.
Summary This overview paper examines past Australian conservation controversies and experiences to identify prospective means of ameliorating environmental conflict in the future. Since all community disputes should be resolved by means of political and administrative actions, emphasis is placed on federalism and intergovernmental relations, and measures are suggested which might improve environmental policy and practices in the future.Dr Bruce W. Davis is currently Head of the Department of Political Science, Dean of the Faculty of Arts, and member of the Council of the University of Tasmania. He possesses qualifications and professional experience in engineering, economics and administration. He has numerous publications within the fields of public sector planning and natural resources management, and acts in an advisory and consulting capacity to State and Federal agencies involved in national parks administration, heritage conservation and land-use planning.In addition to University commitments, Dr Davis holds the following appointments: Commissioner, Australian Heritage Commission; Member, Australian National Commission for UNESCO, Man and Biosphere Program; Trustee, World Wildlife Fund Australia; Councillor, Australian Conservation Foundation; and Consultant to IUCN, Gland, Switzerland.  相似文献   

4.
Summary This paper draws the attention to the major threats to nature conservation in Nigeria, and reviews critically the measures adopted for the protection of wildlife. The major problems include habitat degradation (through uncontrolled logging, agricultural projects, industrial plantations, highway and urban development, and exploitation for fuelwood), over-hunting and poachingSteps taken so far to protect wildlife include the creation of one national park and eighteen game reserves, enactment of wildlife laws, signing of international treaties, and manpower development. These measures have however failed to produce the desired effect owing largely to public apathy, low level of funding, inadequate game laws and weak enforcement of existing legal provisions.It is suggested that the Federal Government should intervene more positively in favour of conservation by creating more national parks and assuming joint responsibility with the states for formulating wildlife laws. Furthermore, the role of non-governmental organizations in influencing conservation policies and mobilizing public opinion will be crucial in the difficult years ahead.Dr. P. A. Anadu, although recently on secondment to the Department of Zoology, University of Oxford, UK; is currently on the staff of the Department of Forestry and Wildlife in the Faculty of Agriculture at the University of Benin.  相似文献   

5.
/ In southern Bahia, Brazil, the traditional cocoa agroecosystem with a dense shade canopy of native trees is now recognized as a secondary conservation route for highly endangered Atlantic Rainforest species. This "chocolate forest" of the densely shaded farms persists despite a massive 20-year Brazilian government modernization program in which shade was seen as a chief impediment to raising cocoa production. The objective of this study was to determine how this traditional agroecosystem endured. Although dense shade limits cocoa yield, it provides several agroecological benefits: control of insect pests and weeds, microclimate stability, and soil fertility maintenance. A keycomponent of modernization efforts was a shade-tree removal program designed to maximize cocoa production by using low shade and fertilizer while substituting agrochemicals for many beneficial roles of the overhead trees. This research found that many farmers rejected, or only partially accepted, the shade reduction process although it promised much higher cocoa yield and profit. Farmers employing a wide range of shading were interviewed, and it was found that decisions to remove or maintain the shade trees were linked to both agroecological and risk-minimization factors. Farmers' perceptions of the agroecological functions of the shade trees and individual willingness to entertain the economic risk associated with substituting agrochemicals for these were important. A less-profitable, but lower-risk approach of occasional fertilizer and agrochemical use with the traditional shade intact was a rational and widespread choice. Policies designed to maintain the traditional agroecosystem through the current economic crisis should heed the multiple functions of the overhead trees. KEY WORDS: Conservation; Brazil; Atlantic Rainforest; Cocoa; Agroecology; Risk; Agroforestry  相似文献   

6.
Summary The depletion of the world's natural resources continues relentlessly. Plants and animals alike are being trapped into ever more numerous shrinking pockets, as man advances to incorporate virgin estates into areas of productivity. The immediate consequence of such an all-out attack in the tropical areas of under-developed countries is the destruction of habitats and the likely break-up of food webs. The attendant disastrous effects on the reproduction of species, hence, puts natural selection at a premium. This scenario has distinctly impressed different people in different places. This suggests diverse sensitivity even for causes voiced in public as matters of sheer truism. The study concentrates on the examination of the dialectic nature/nurture controversy to see whether this may account for the state of disharmony recorded between man and nature. Conversion of nature is traditionally considered a realm of the scientific establishment. The study tries to suggest that the humanities cannot be left out in any debate on the interpretation of the environment. The synthesis reveals a blatant refusal of social determinism as causal agent and, with some reservation, projects biological determinism into sharp focus for pertinent consideration. The cautious reconciliation with parts of sociobiological tenets was regarded as inevitable once grasped that will, knowledge, and sensitivity, were interpreted as the foundation of the main teleological argument.Dr Antonio Allem is trained as a plant taxonomist. His research has focused on the collection of plant genetic resources germ plasm. He has recently written (with J.F.M. Valls) a book entitledRecursos Forrageiros Nativos do Pantanal Mato-Grossense, published by the Departamento de Difusão de Tecnologia, EMBRAPA, Brasilia. He has an interest in the taxonomy of cultivated plants and has recently solved the origin of the cassava plant (Manihot esculenta, Euphorbiaceae). Dr Allem is a member of staff of thein situ conservation unit at Centro Nacional de Recursos Genéticos e Biotecnologia da Empresa Brasileira de Pesquisa Agropecuária.  相似文献   

7.
Summary Though strong concern over the rapid conversion of moist tropical forests may justifiably arise from any discipline, a growing interdisciplinary tide of voices is expressing its alarm over a particularly disturbing consequence of forest alteration and destruction: the reduction of species diversity through the extinction of numerous plant and animal species. Consequently, an array of ecologists land-use planners, botanists, zoologists and conservationsts are searching for means to enhance the protection and preservation of tropical forests' biotic diversity. Management schemes aimed at achieving this particular end are being investigated, particularly by UNESCO's Man and Biosphere (MAB) Project 8 of Biosphere Reserves Projects, by the International Union for the Conservation of Nature and Natural Resources (IUCN) tropical forests conservation program (UNEP, 1980) and by the World Wildlife Fund. In addition, many countries with a significant area of moist tropical forest (MTF) are beginning to pursue some form of conservation strategy. Currently Robert T. Perry is a full-time teacher of biology at a private school for a cademically gifted students in the Brooklyn area. In addition he has designed and is teaching courses in environmental chemistry and ethology to advanced high-schoolers. He is also an adjunct instructor for the City College of the City University of New York, where he is teaching graduate students in the Environmental Studies Programme. He graduated in Environmental Conservation from Cornell University, and has a Masters Degree in Environmental Biology from City University, New York.  相似文献   

8.
Summary This, The First World Conservation Lecture, was presented at the Royal Institution, London, UK, on 12 March 1981. The Lecture celebrated the 20th anniversary of the World Wildlife Fund, and the first anniversary of the World Conservation Strategy. The Lecture was organized by the World Wildlife Fund, UK.Published with the kind permission of the World Wildlife Fund, UK.Edward Max Nicholson, CB, CVO, Commandeur (Netherlands), Order of the Golden Ark, holds honorary doctorates from the University of Aberdeen, and The Royal College of Art London. He was educated at the University of Oxford, and was a member of the University's expeditions to Greenland (1928) and to British Guiana (1929). He was General Secretary (until 1940), later Chairman of PEP (Political and Economic Planning): now Vice-President of its successor body, the Policy Studies Institute. From 1945 to 1952 he was Secretary of the Office of the Lord President of the Council, then Deputy Prime Minister of the United Kingdom. He was member of the Advisory Council on Scientific Policy from 1948–1964. In 1952 he was leader of the joint UN/FAO Development Team in Baluchistan. Charter Member from 1949, and Director-General (1952–1966) of the Nature Conservancy, London, UK. From 1963 to 1974 he was Convenor of the Conservation Section of the International Council of Scientific Unions' International Biological Programme. President of the IUCN Technical Meeting in Edinburgh in 1956, concerned with rehabilitation of areas biologically devastated by human disturbance, and relation of ecology to landscape planning. Member, Panel on Landscape Action Program, The White House Conference (USA) on Natural Beauty (1965). Secretary, HRH The Duke of Edinburgh's Study Conference on The Countryside in 1970 (1963 and 1965). Council and Board Member of IIED. Godman-Salvin Medallist British Ornithologist Unions. Phillips Medallist and Member of Honour IUCN, Geoffroy St. Hilaire Gold Medal, Société Nationale de Protection de Nature de France, Premio Europeo Cortina-Ulisse (1971), Europa Preis für Landespflege (1972), Hon Member of World Wildlife Fund, Chairman Ecological Parks Trust, President RSPB, 1980. Principal Consultant and Chairman of Land Use Consultants Ltd (London) since 1966. Author of many books,Birds and Men (1951);Britain's Nature Reserves (1958),The System (1967);The Environmental Revolution (1970).  相似文献   

9.
Summary Any attempts to preserve Third World ecosystems must recognize that the ultimate decisions lie with the governments of these sovereign states, which have to deal with widespread demands for higher living standards as well as growing populations. To deal with the powerful pressures of economic growth, the most promising strategy for conservationists is to press the Western industrialized states, where the conservation movement is relatively strong, to join with the Third World in an international agreement whereby the latter would preserve portions of threatened ecosystems in exchange for compensation provided from the industralized countries, most plausibly through an agreement to reduce Third World countries' debt. To reinforce this protection, the industrialized states could agree to purchase tropical ecosystem products only from those states which agree to preserve certain portions of their ecosystems. While there would be great problems both in working out the levels of compensation and in persuading the industrialized states to participate in such a scheme, intensive lobbying by conservation groups might be enough to bring it to fruition.Dr. John Cartwright, who teaches courses in environmental politics and African politics at the University of Western Ontario, took degrees from Queen's University in Kingston, Canada, and the University of Toronto. From 1963 to 1966 he taught at the University of Sierra Leone in Freetown. He has produced three books on African politics, his most recent beingPolitical Leadership in Africa (1983). He has also been interested for many years in natural history and conservation issues, which have taken him on several visits to Latin America as well as to Africa.  相似文献   

10.
The Urban Cleaning Company of the City of Rio de Janeiro - COMLURB launched the Recycling Separation Center Project (Projeto Central de Separação de Recicláveis or CSR) in 2003. The objectives of the project were the adequate disposal of solid urban waste as well as the generation of employment and income. The COMLURB Project had economic, environmental and social facets, and the researchers sought to establish whether COMLURB had prepared reports that would enable evaluation of the investment made and the results obtained. In particular, the researchers sought to establish whether COMLURB financial statements set out the results of actions inherent to the CSR. We concluded from our analysis of the Project that the three elements of sustainability (social, environmental and economic), despite being fully present, were not adequately demonstrated. This study therefore proposes a model report with a view to enabling various information users to evaluate the results of the CSR Project.  相似文献   

11.
Summary Citing topical international instances the author demonstrates that environmental impoverishment is a major cause for tension and hostilities between nations. He makes a strong case that an assessment of security concepts should include a measure of environmental and resource-based stability.Few threats to peace and survival of the human community are greater than those posed by the prospects of cumulative and irreversible degradation of the biosphere on which human life depends. In a global context, true security cannot be achieved by mounting buildup of weapons (defense in a narrow sense), but only by providing basic conditions for solving non-military problems which threaten them. Our survival depends not only on military balance, but on global cooperation to ensure a sustainable biological environment.Report of the Brandt Commission, 1980Dr Norman Myers is a consultant in environment and development. He is a prolific author and served as the General Editor toThe GaiaAtlas of Planet Management (1985). In 1983, Dr Myers was awarded the World Wildlife Fund Gold Medal for his work on conservation.  相似文献   

12.
To facilitate forest planning and management on National Wildlife Refuges, we synthesized multiple data sources to describe land ownership patterns, land cover, landscape pattern, and changes in forest composition for four ecoregions and their associated refuges of the Upper Midwest. We related observed patterns to ecological processes important for forest conservation and restoration, with specific attention to refuge patterns of importance for forest landbirds of conservation priority. The large amount of public land within the ecoregions (31–80%) suggests that opportunities exist for coarse and meso-scale approaches to conserving and restoring ecological processes affecting the refuges, particularly historical fire regimes. Forests dominate both ecoregions and refuges, but refuge forest patches are generally larger and more aggregated than in associated ecoregions. Broadleaf taxa have increased in dominance in the ecoregions and displaced fire-dependent taxa such as pine (Pinus spp.) and other coniferous species; these changes in forest composition have likely also affected refuge forests. Despite compositional changes, larger forest patches on refuges suggests that they may provide better habitat for area-sensitive forest landbirds of mature, compositionally diverse forests than surrounding lands if management continues to promote increased patch size. We reason that although fine-scale research and monitoring for species of conservation priority is important, broad scale (ecoregional) assessments provide crucial context for effective forest and wildlife management in protected areas.  相似文献   

13.
In the present study, forest biomass (fuelwood, leaf fodder, leaf-litter and non-timber forest products) consumption patterns have been evaluated in the villages of Govind Wildlife Sanctuary, Uttarakhand, Western Himalaya, India. The average fuelwood consumption in the selected villages was estimated at 3.14 kg/capita/day and its energy equivalent was found 52.74 MJ/capita/day. The average leaf fodder and leaf-litter consumption was estimated at 2.70 and 2.40 kg/unit/day, respectively, and the same pattern was estimated for energy equivalent. People's perception on impacts of conservation measures and resources utilization rights were also analysed. Our results emphasized the need for regular assessment of forest resources, particularly in protected areas, where access to natural resources have been denied due to legal restrictions. The study could be a pilot to strengthen the conservation measures across the protected area network by understanding the dynamics of anthropocentric activities and their subsequent impacts on forest resources.  相似文献   

14.
Forest restoration at large scales, or landscapes, is an approach that is increasingly relevant to the practice of environmental conservation. However, implementation remains a challenge; poor monitoring and lesson learning lead to similar mistakes being repeated. The World Wildlife Fund (WWF), the global conservation organization, recently took stock of its 10 years of implementation of forest landscape restoration. A significant body of knowledge has emerged from the work of the WWF and its partners in the different countries, which can be of use to the wider conservation community, but for this to happen, lessons need to be systematically collected and disseminated in a coherent manner to the broader conservation and development communities and, importantly, to policy makers. We use this review of the WWF’s experiences and compare and contrast it with other relevant and recent literature to highlight 11 important lessons for future large-scale forest restoration interventions. These lessons are presented using a stepwise approach to the restoration of forested landscapes. We identify the need for long-term commitment and funding, and a concerted and collaborative effort for successful forest landscape restoration. Our review highlights that monitoring impact within landscape-scale forest restoration remains inadequate. We conclude that forest restoration within landscapes is a challenging yet important proposition that has a real but undervalued place in environmental conservation in the twenty-first century.  相似文献   

15.
Summary This paper explains why the identification of the increase of national income (or GNP) with economic growth, increase in welfare and economic success is theoretically wrong. This incorrect use of terms strengthens the one-sided orientation of economic policy on the growth of production, often at the expense of the environment. Two examples are given of how this course of affairs is blocking the social choices regarding a fundamental solution of the environmental problem. An overview is given of the possibilities of correcting the Gross National Product (GNP) figures for environmental losses. None of these are perfect, since shadow prices for environmental functions directly comparable with the market prices of goods produced can be construed only in exceptional cases. The conclusion is that the only way to arrive at national income figures corrected for environmental losses is to supplement the corrections for expenditures on preventive, restoratory and compensatory measures (defensive expenditures) with the estimated expenditures on measures required to meet physical standards, based on health and a sustainable economic development.Dr Roefie Hueting is Head of the Department of Environment Statistics at the Netherlands Central Bureau of Statistics and a Visiting Fellow at the International Institute for Environment and Society (IIUG). He is a previous contributor toThe Environmentalist (1985, pp.253–262). Dr Christian Leipert is a staff member at IIUG.  相似文献   

16.
The productivity of tropical agricultural commodities is affected by the health of the ecosystem. Shade tolerant crops such as coffee and cocoa benefit from environmental services provided by forested landscapes, enabling landscape design that meets biodiversity conservation and economic needs. What can motivate farmers to apply and maintain such landscape approaches? Rather than rely on a proliferation of externally funded projects new opportunities are emerging through the international market that buys these commodities. As part of their growing commitment to sustainable supply chains, major companies are supporting agroforestry approaches and requiring producers and traders to demonstrate that the source of their commodities complies with a set of principles that conserves forested landscapes and improves local livelihoods. The paper presents examples of international companies that are moving in this direction, analyzes why and how they are doing it and discusses the impact that has been measured in coffee and cocoa communities in Latin America and Africa. It particularly considers the role of standards and certification systems as a driver of this commitment to promote profitable operations, environmental conservation and social responsibility throughout the coffee and cocoa value chains. Such approaches are already being taken to scale and are no longer operating only in small niches of the market but the paper also considers the limitations to growth in this market-based approach.  相似文献   

17.
There are relatively few Federal environmental regulations that influence agricultural production in the US. However, many local and state environmental rules may influence the management practices on US farms as might interactions between urban population centers and agricultural producers. Detailed analysis of corn farms gives insight into these relationships and suggests that stringent environmental regulations could increase the likelihood of adoption of certain conservation practices, all else being constant, but that the interaction between urban populations has less of an effect on the adoption decisions.  相似文献   

18.
Summary Agro-ecosystems in many of the developing economies are coming under increased pressure, especially in areas where population demands, weak economic growth, and debt burdens, are resulting in mass rural poverty and assault on environmental resources. The loss of forests is a double-edge blow for most rural and agricultural systems. The forests provide the resource substitutes for the many manufactured products which are scarce or physically and economically inaccessible, and they also provide congenial environments which support rural food systems by way of productive agricultural land opportunities.In many of the rural areas of Africa, in particular, forest stability is more threatened, and this requires both local and external responses to make sustainable development a possibility. This paper, which is based on a field study in Ghana by the author, identifies emerging socio-economic constraints in woodfuel systems in environments where demands on forest ecosystems are high. The degree to which such local socio-economic processes affect stability of forest ecosystems, and the conditions within which the research information could assist planners and resource managers towards sustainable use of forest ecosystems are analysed.Dr William Y. Osei was born in Ghana where he obtained a BA (Hons) Geography from the University of Ghana. He subsequently obtained an MA from Carleton University, Ottawa, Canada and a PhD from the University of Western Ontario, London, Canada. With teaching experience in Geography at the Canadian universities of Western Ontario, Brandon and Victoria, he currently holds the position of Assistant Professor in the Department of Geography at Algoma University College.  相似文献   

19.
Summary The conventional economic accounting systems have not played an enlightening role in statistically revealing the actual damage to the environment. They can, however, be methodologically improved; and they must be complemented by assessments of the ecological costs of the production process.In this article statistical evidence is provided on the level and structure of environmental damage and protection expenditures in the Federal Republic of Germany,i.e. on the environmental damage itself and on the environmental protection investments by industry and government, the capital stock for environmental protection, the total costs of and expenditures for environmental protection.Dr Christian Leipert and Prof. Udo Simonis are both regular contributors toThe Environmentalist (see 1989, pp.171–183; 1990, pp.25–38). Prof. Simonis is Director of the International Institute for Environment and Society (Wissenschaftszentrum) and Dr Leipert a member of its research staff.  相似文献   

20.
Protected areas (PAs) are cornerstones of biodiversity conservation, but small parks alone cannot support wide-ranging species, such as the tiger. Hence, forest dynamics in the surrounding landscapes of PAs are also important to tiger conservation. Tiger landscapes often support considerable human population in proximity of the PA, sometimes within the core itself, and thus are subject to various land use activities (such as agricultural expansion and road development) driving habitat loss and fragmentation. We synthesize information from 27 journal articles in 24 tiger landscapes to assess forest-cover dynamics in tiger-range countries. Although 29% of the PAs considered in this study have negligible change in overall forest cover, approximately 71% are undergoing deforestation and fragmentation. Approximately 58% of the total case studies have human settlements within the core area. Most changes—including agricultural expansion, plantation, and farming (52%), fuelwood and fodder collection (43%), logging (38%), grazing (38%), and tourism and development (10%)—can be attributed to human impacts largely linked to the nature of the management regime. This study highlights the need for incorporating new perspectives, ideas, and lessons learned locally and across borders into management plans to ensure tiger conservation in landscapes dominated by human activities. Given the increasing isolation of most parks due to agricultural, infrastructural, and commercial developments at the periphery, it is imperative to conduct planning and evaluation at the landscape level, as well as incorporate multiple actors and institutions in planning, instead of focusing solely on conservation within the PAs as is currently the case in most tiger parks.  相似文献   

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