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Impact of fire on Finnish forest in the past and today. Texto completo
1996
Parviainen, Jari
Impact of fire on Finnish forest in the past and today. Texto completo
1996
Parviainen, Jari
Nearly every forest land in Finland has been burnt down by a wildfire at least once during the past 400â500 years. Slash and burn cultivation (1700â1920) was practised on 50â75 percent of Finland's forests, while prescribed burning (1920â1990) has been applied to 2â3 percent of the country's forests. Because of land-use changes and efficient fire prevention and control systems, the occurrence of wildfires in Finland has decreased considerably during the past few decades. Owing to the biodiversity and ecologically favourable influence of fire, the current tendency is to revive the use of controlled fire in forestry in Finland. Prescribed burning is used in forest regeneration and endeavours are being made to revert old conservation forests to the starting point of succession through forest fires.
Mostrar más [+] Menos [-]Impact of fire on Finnish forest in the past and today.
Impact of fire on Finnish forests in the past and today Texto completo
1996
Parviainen, Jari | Metsäntutkimuslaitos / Joensuu
Report of Working Group 1b on The relationship between historical land use, cultural landscape diversity and the conservation of biodiversity
1996
Hedberg, I.
Report of Working Group 1a on The relationship between historical land use, cultural landscape diversity and the conservation of biodiversity
1996
Almered Olsson, G.
Plant biodiversity conservation in Kenya: the plant conservation and propagation unit of the East African Hebarium -a case study
1996
Simiyu, S. W.
This paper shows that biodiversity is under threat in Kenya for the same underlying reasons as anywhere else in the world. Three-quarters of the population and 80% of the forests reside in the total land area. Biological resources wealth and alternative human use are strongly correlated creating potential conflict in interest. The East African Herbarium plant Conservation and Propagation unit was established in 1992 with objective of ensuring the survival and prolification of Kenya's endemic and threatened flora. The unit continued to focus on the conservation of the rare, field surveys and assessments, propagation of target species through preliminary data collection and validation, field surveys and associated research. This initiative is a complement to those of other national institutions and NGO's dealing with plant biodiversity issues in Kenya, and will provide a basis for sustainable development to enhance the future security of the nation
Mostrar más [+] Menos [-]Intensification of agriculture on Vertisols to minimize land degradation in parts of the Ethiopian highlands Texto completo
1996
El Wakeel, A. | Astatke, A.
This paper highlights some interventions which might alleviate agricultural pressures on steep slopes and reduce land degradation in parts of the Ethiopian Highlands. The Ethiopian highlands are losing alarming amounts of soils (estimated at more than one billion, 1000 million, tonnes) annually. This loss, which is associated with nutrient losses, is manifest in declining agricultural production and biodiversity. About 80 percent of the annual soil loss occurs from croplands during the rainy season. The nutrient imbalance is further accentuated by forest clearing, removal of crop residue from cultivated lands, and little use of chemical fertilizers or organic manure. Even where livestock are part of the production system, dung is preferentially used as a cooking fuel. Chemical fertilizers are costly, and therefore an alternative land-management scheme is suggested. This is based on a new land-shaping device for drainage which is called the BBM (broad-bed maker), and growing forage legumes to improve soil nutrients, which should allow intensive cultivation of Vertisols in the Ethiopian Highlands. Adoption of the broad bed and furrow land-management system would facilitate early planting and increase the yield of both grain and straw from the major crops relative to the yield from traditional cultivation in flat beds. While not decreasing the yield of grain, mixed cropping of grain and forage crops has been shown to give significantly greater total crop residue yields. The yield is even greater when fertilizers are applied. Supplementary irrigation can help in utilizing Vertisols on bottom lands, and this can be expedited by constructing water reservoirs.
Mostrar más [+] Menos [-]Large-scale logging in Suriname's interior: too few facts, to many uncertainties.
1996
Dijn de Bart P.E.
This paper discusses the conditions of Suriname's interior and the technical feasibility of large-scale logging in the light of the sustainability. It is uncertain if the CELOS Management System (CMS), a supposedly sustainable logging system developed in Suriname, is truly sustainable when applied to the forests of the interior. The land-scape types in the interior are considered difficult to work in with heavy equipment and can generally be considered erosion-prone. Large-scale logging in the Interior would be comparable in size and tempo with ecosystem changes by prehistoric climate changes; consequently special protective measures would be warranted and could be based on the Refuge Theory. Biodiversity would be effected and ought to be preserved in-situ. Indigenous peoples living in the forest could be affected through land-resource use conflicts. Current developments in the forestry sector in Suriname are not encouraging and call for caution with respect to future developments. It is suggested here that the best way to tackle new developments, such as large-scale forestry, is to subject them to an environmental impact assessment, preferably at an early, strategic stage. Finally, a set of rules and procedures is proposed in an attempt to define some modalities for large-scale logging in Suriname; some conditionalities are added.
Mostrar más [+] Menos [-]What drives deforestation in Sumatra? Texto completo
1996
.t.p tomich
Why a presentation about Sumatra at a symposium on mainland Southeast Asia? Aparalle1 rešearch programme is about to be replicated at sites in Northern Thailand and this is a good �?pportunity to share experience that may be relevant. The first phase of research in Sumatra has certainly deepened our appreciation of the complexity of the driving forces of land use change and forest conversion. This paper discusses the issues that have emerged from the initial work on these �??driving forces�??.Conversion of tropical forests, regardless of the technique used, leads to a loss of biodiversity and release of stored carbon. Slašh and burn agriculture contributes to a portion of this global problem of tropical deforestation (Bandy and others, 1993). The Alternatives to Slash_and_Burn project (ASB) was formulated to address these issues in various parts of the tropics, since slash-and-bum is practiced by different actors and deforestation is driven by different forces in different places | .T.P Tomich, 'What drives deforestation in Sumatra?', Proceedings of a conference on 'Montane Mainland Southeast Asia in Transition', 13-16 November, 1995, at Chiang Mai, Thailand, pp.120-149, 1996
Mostrar más [+] Menos [-]Recrûs forestiers post-agricoles : perceptions et usages chez les Mvae du sud Cameroun forestier Texto completo
1996
Dounias, Edmond
Chez les Mvae de la forêt littorale du Sud-Cameroun, les recrûs forestiers post-agricoles revêtent des formes et des fonctions diverses, suivant le cadre d'analyse choisi pour les appréhender. Partant de la perception des Mvae vis-à-vis du milieu qu'ils exploitent, plusieurs typologies émergent, suivant que l'on aborde ces recrûs post-agricoles en tant qu'espaces au sein de l'agroécosystème, en tant que terres en situation de déprise agricole dans le cadre de la rotation agricole, ou en tant qu'unités foncières à l'intérieur du système d'appropriation territoriale. Les notions dénaturées et réductrices de "friche" et de 'jachère" ne permettent plus de caractériser ces entités polymorphes à échelles de pertinence multiples. Une approche intégrée et dynamique des activités de production permet notamment de saisir l'importance du piégeage et de la collecte à l'intérieur de ces espaces. Une telle approche -moins restrictive - ouvre des perspectives intéressantes de gestion/conservation de la biodiversité des forêts tropicales, reposant sur l'exploitation traditionnelle des ressources fauniques et végétales à l'intérieur des recrûs forestiers post-agricoles. | Among the Mvae farmers of the coastal rain forest of southern Cameroon, postagricultural secondary regrowths cover different meanings and functions, depending of the conceptual frame retained for their study. Using Mvae perception of their environment as a web for analysis, distinct typologies emerge whether post-agricultural regrowths are considered as spatial components of agroecosystems, as fallows characterizing land rotation, or as land units among the whole system of territorial ownership. Notion of "fallowing" is no more suitable for describing kaleidoscopic entities which entail multiple levels of relevance. An integrative and dynamic approach of the land use system as a whole, raises the importance of trapping arid gathering inside regrowths. Such non restrictive approach opens new pathes for a sustainable management/conservation of the biodiversity of tropical rain forests, based on the traditional exploitation of faunal and plant resources inside postagricultural secondary regrowths.
Mostrar más [+] Menos [-]Recrûs forestiers post-agricoles : perceptions et usages chez les Mvae du Sud-Cameroun Texto completo
1996
Dounias, Edmond | Centre d’Ecologie Fonctionnelle et Evolutive (CEFE) ; Université Paul-Valéry - Montpellier 3 (UPVM)-Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-École Pratique des Hautes Études (EPHE) ; Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Université de Montpellier (UM)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD [Occitanie])-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro)
International audience | Among the Mvae farmers of the coastal rain forest of southern Cameroon, postagricultural secondary regrowths cover different meanings and functions, depending of the conceptual frame retained for their study. Using Mvae perception of their environment as a web for analysis, distinct typologies emerge whether post-agricultural regrowths are considered as spatial components of agroecosystems, as fallows characterizing land rotation, or as land units among the whole system of territorial ownership. Notion of "fallowing" is no more suitable for describing kaleidoscopic entities which entail multiple levels of relevance. An integrative and dynamic approach of the land use system as a whole, raises the importance of trapping arid gathering inside regrowths. Such non restrictive approach opens new pathes for a sustainable management/conservation of the biodiversity of tropical rain forests, based on the traditional exploitation of faunal and plant resources inside postagricultural secondary regrowths. | Chez les Mvae de la forêt littorale du Sud-Cameroun, les recrûs forestiers post-agricoles revêtent des formes et des fonctions diverses, suivant le cadre d'analyse choisi pour les appréhender. Partant de la perception des Mvae vis-à-vis du milieu qu'ils exploitent, plusieurs typologies émergent, suivant que l'on aborde ces recrûs post-agricoles en tant qu'espaces au sein de l'agroécosystème, en tant que terres en situation de déprise agricole dans le cadre de la rotation agricole, ou en tant qu'unités foncières à l'intérieur du système d'appropriation territoriale. Les notions dénaturées et réductrices de "friche" et de 'jachère" ne permettent plus de caractériser ces entités polymorphes à échelles de pertinence multiples. Une approche intégrée et dynamique des activités de production permet notamment de saisir l'importance du piégeage et de la collecte à l'intérieur de ces espaces. Une telle approche -moins restrictive - ouvre des perspectives intéressantes de gestion/conservation de la biodiversité des forêts tropicales, reposant sur l'exploitation traditionnelle des ressources fauniques et végétales à l'intérieur des recrûs forestiers post-agricoles.
Mostrar más [+] Menos [-]CIFOR’s strategy for collaborative forestry research Texto completo
1996
Center for International Forestry Research
Pressures on the remaining forests to provide ever-increasing volumes of fuelwood, timber, non-timber products, watershed protection and land for agriculture and other purposes keep growing. At the same time, the importance of tropical forests to the well-being of the rural poor, in regulating the global climate and as a reservoir of biodiversity is increasingly recognised. With growing social recognition of the many diverse values of forests, the dominant demand is likely to change from timber, to providing a much wider range of social, economic and environmental benefits, for a much wider range of beneficiaries. Some forests will be more valuable for environmental and watershed protection, or for provision of non- timber products to local communities, than for their capacity to produce industrial wood-fibres. CIFOR works through research partnerships, as a "Center without Walls" with a holistic, inter-disciplinary approach to solving general or widespread problems. CIFOR's strategic research is focused on policy issues that will enable more informed, productive, sustainable and equitable decisions about the management and use of forests. CIFOR will give priority to research at seven focal ecological regions: the tropical moist forests in central-west Africa and the Congo; the drier forests (like the Miombo woodlands) of eastern-southern Africa); the rainforest-dry forest continuum in southern India (such as the Western Ghats); the tropical moist forests in insular Southeast Asia (e.g. Borneo); the uplands of mainland Southeast Asia; the tropical moist forests of the western Amazon; and the mixed forest systems of Central America.
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