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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Stochastic Geometry-Based Analysis of Aerial-Aided Vehicular Communications

Abu Zaid, Abdullah 04 April 2022 (has links)
Vehicular ad hoc networks (VANETs) will require improved communications, especially for critical scenarios. The improvement of these communications will be more crucial in dense urban environments where urban air mobility (UAM) is expected to witness significant growth during the next decade. We propose the use of networked tethered flying platforms (NTFPs) to enhance VANET communications. NTFPs are unmanned aerial platforms that are secured to the ground via a tether that supplies the platform with continuous power and data. To improve the spectral efficiency of communications, we implement non-orthogonal multiple access (NOMA) scheme. Additionally, to increase the bandwidth and data rates of communications, we use millimeter-wave (mmWave) frequencies. In UAM, NTFPs will coexist with other flying platforms, such as unmanned aerial vehicles (UAVs) and electric vertical takeoff and landing (eVTOL) aircraft. Hence, we study the performance of vehicular communications in the presence of interfering UAVs/eVTOLs and other road vehicles, and we compare the use of NTFPs with traditional terrestrial roadside units (RSUs).
2

Political Economy of Compensatory Conservation: A Case Study of proposed Omkareshwar National Park Complex, India

Goel, Abhineety 16 December 2013 (has links)
Proposed Omkareshwar National Park Complex (ONPC), is a planned park in Madhya Pradesh (central India) that is being designed as a compensatory conservation plan to overcome the loss of wildlife and forest by the construction and submergence from nearby Indira-Sagar and Omkareshwar dams, part of the infamous multi-purpose Narmada dam project. All the village communities in the ONPC largely depend on the forest resources for their daily sustenance, particularly fuel-wood and non-timber forest products such as tendupatta, mahua, kullu and dhavda gums. The local people typically engage as gatherers of non-timber forest resources, farmers or work as labors on other agricultural farms. Enclosing, this forest commons, threatens the livelihood opportunities of adivasis. Hence, this dissertation questions how compensatory conservation transforms the forest governance and the economic activities of the local communities. I examine how rules-in-use control spatial actions alter economic, political and social relationships within proposed ONPC in central India. I gathered the economic, social and political data through interviews, case-studies and surveys. Farmers benefit from the creation of the ONPC as a biodiversity offset, while other villagers engaged in off-farm and NTFP extraction labor, are more economically vulnerable. Adivasi depend mostly on the forest resource extraction for their income generation. Therefore, with increasing restrictions placed on the resource access and control, resource users are forced to travel outside their villages in search of wage labor.
3

Tradition, kultur och kunskapsöverföring : En studie om användningen och betydelsen avskogens ätliga resurser bland personer med polsk bakgrund boende i Stockholmsregionen

Edelman, Ida January 2013 (has links)
Det övergripande syftet med denna studie är att bidra till kunskap om hur dagens urbanamänniska använder sig av skogens ätliga resurser, såsom svamp och bär. Dessa resurser kallas iforskningssammanhang ofta för non-timber forest products (NTFP). Användningen av NTFP harbelysts ur ett kulturellt perspektiv och undersökts som tradition, det vill säga kunskap somtraderas mellan generationer. Fokus har legat på hur vanor förändras över tid och rum, vad debetyder för personer i gruppen och hur de vidareförmedlas. För att avgränsa studien är detgruppen Personer med polsk bakgrund boende i Stockholm (PPBS) som har undersökts. Studienär indelad i tre huvudteman: (1) Vad som plockas, hur mycket och varför? (2) Den kulturellabetydelsen och tradition (3) Kunskapsöverföring till nästa generation. Både kvantitativ liksomkvalitativ metod har använts, detta i form av en enkätundersökning samt ett antal intervjuer.Kunskap om hur människor använder sig av tätortsnära naturområden är viktig för att kunnafatta goda beslut inom bland annat stadsplanering och skogsutveckling. Studien har visat att främst svampplockning är av stor kulturell betydelse för många i gruppenPPBS, men att vanorna varierat på olika platser och tider i livet. Traditionen att plocka ochkunskaperna knutna till detta förs till viss mån vidare mellan generationer och kommertroligtvis fortskrida även i framtiden. Dels som rekreationsaktivitet men kanske även inom en”ny” trend av självhushållning och rena råvaror. Studien visar även att vistelse i skogsområden,för allmän rekreation eller svamp- och bärplockning, är en populär och viktig aktivitet förmänniskor i gruppen.
4

Enjeux et dynamiques de l’exploitation des Produits Forestiers Non-Ligneux au Cameroun / Challenges and dynamics in Non-Timber Forest Products exploitation in Cameroon

Awono, Abdon 22 November 2016 (has links)
Les produits forestiers non ligneux constituent l’une des richesses des écosystèmes forestiers du Bassin du Congo. A ce titre, nombre de chercheurs y ont vu un gage de lutte contre la pauvreté parce que capables de relancer la croissance à travers les revenus, l’alimentation et la santé dont ces produits sont tributaires. La crise économique des années 1980 qui a durement frappé la plupart des pays de la région, a également contribué à renforcer cette confiance dans le rôle économique des PFNL. Avec la crise, l’agriculture ne pouvait plus être la seule référence lorsqu’il s’agissait d’assurer les revenus des ménages. En fait, les chocs économiques successifs des années 1980 s’étant traduits par la baisse du pouvoir d’achat des ménages face aux effets conjugués de la chute brutale des produits de base tels le cacao, le café et la banane d’une part et la dévaluation du franc CFA en 1994 d’autre part, les populations se sont ruées sur des sources de revenus alternatives. L’exploitation plus intensive des PFNL s’inscrit dans cette dynamique. Au plan environnemental, de nombreux auteurs ont affirmé que, contrairement au bois, l’exploitation des PFNL aurait pour effet de retarder la conversion des forêts tropicales, grâce à son impact faible et surtout la volonté des populations à les conserver en connaissance de cause. Aussi, plus de deux décennies après, il y a lieu de se demander si ce mouvement des populations vers les PFNL a produits tous les effets escomptés. En d’autres termes, les PFNL ont-ils comblé les attentes des populations par rapport à la lutte contre la pauvreté et la création d’emplois en Afrique centrale ? L’objectif général de cette étude consiste à évaluer la contribution effective des PFNL à l’économie des ménages et l’impact de leur gestion sur l’environnement, en se limitant au Bassin du Congo et en insistant sur les expériences conduites dans la région au cours des 2-3 dernières décennies. / The involvement of rural people in forest management is determinant in sustainable management of forests. These people are relying on forest products, especially Non timber forest products they have been collecting for centuries. A good understanding of the valuing conditions of these products is essential in the Congo Basin. The implication of the private sector in adding value to NTFP is another challenge that will be analyzed in my thesis. By giving more attention to NTFP we create the conditions of equity in forest management. Overall the work attached to this thesis is important for sustainable forest management in Cameroon. Many articles, books and book chapters were published on the issue and number of presentations has been given during international conferences related to forests.
5

Socio-economic impact of Prunus africana management in the Mount Cameroon region : A case study of the Bokwoango community

Ekane, Bellewang Nelson January 2006 (has links)
<p>In most developing countries, forest resources are a major source of livelihood for forest dwellers. Forests provide fuel wood, farm products, meat, timber and plants of high medicinal value, including Prunus africana. The collection of medicinal plants is also an important source of cash income for some forest communities, and widely relied on to cure illnesses (Poffenberger, 1993). Because of this, the poor forest dwellers in particular are forced to exert pressure on their surrounding environment to make ends meet. Indiscriminate exploitation of forest resources has cost some forest dwellers dearly as they are now experiencing marked reduction of wildlife, forest cover, soil fertility and most importantly water supply, which is a key to life. Prunus africana has a very high economic and medicinal value locally as well as internationally. The exploitation of this species is a very profitable activity in most parts of Africa where it occurs, including the Mount Cameroon region. In recent years, most youths and young men in the Mount Cameroon region have seemingly become less interested in their usual income generating activities (farming, hunting, etc.) because of reduced productivity and have taken up Prunus harvesting as their major source of income. Increase in demand for this species by the French pharmaceutical company (Plantecam), weak institutional capacity to control exploitation, uncontrolled access into the forest, scramble for diminished stock by legal and illegal exploiters, destruction of wild stock by unsustainable practices, and insufficient regeneration of the species in the past have almost driven this species to extinction in certain parts of Cameroon and made it severely threatened in others. Prunus africana is presently threatened with extinction in the entire Mount Cameroon region. In response to this, the Mount Cameroon Project (MCP) and the Ministry of Environment and Forests (MINEF) helped some communities (Bokwoango and Mapanja) in the Mount Cameroon region to form Prunus africana harvesters’ unions with the aim of preserving the resource and improving the socio-economic benefits. The principal aim of the Bokwoango Prunus africana harvesters’ union is to ensure sustainable exploitation of Prunus africana while saving money for important development projects for individual members, their families and the entire community. This piece of work highlights the different facets of Prunus africana management in Cameroon in general and the Bokwoango community in particular. The study examines the socio-economic impact of Prunus africana management in the Bokwoango community and shows specifically the management role played by the Bokwoango Prunus africana harvesters’ union to reduce the rate of exploitation of Prunus africana and also to ensure benefit sharing of the earnings from sales of Prunus bark. It at the same time brings out the constraints encountered by harvesters as well as the opportunities that can make the union become more viable to the socio-economic development of the Bokwoango community. Results of this study show that for the short period that the Bokwoango Prunus africana harvesters’ union has existed, the socio-economic changes in this community are encouraging if one compares the present situation with that before the formation of the union. Most importantly, there has been increased awareness on the great need to conserve not only the threatened Prunus africana species but also other threatened plant and animal species in the region through sustainable hunting, harvesting and regeneration. Some proposals are made for efficient natural resource management and improvements on livelihood through alternative income generating activities. The study ends with recommendations for policy and institutional reforms as well as suggestions for further research in sustainable management of Prunus africana.</p>
6

Etudes écologique, floristique, phytosociologique et ethnobotanique de la forêt marécageuse de Lokoli (Zogbodomey – Bénin): Ecological, floristic, phytosociological and ethnobotanical studies of the swamp forest of Lokoli (Zogbodomey - Benin)

Dan, Bai 29 June 2009 (has links)
La forêt marécageuse de Lokoli, située dans le sud du Bénin est une formation non protégée, bien qu’elle soit la seule forêt marécageuse avec un cours d’eau permanent connue en Afrique de l’Ouest. Pour envisager une prise de décision de conservation et de protection de cet écosystème forestier, il est important de disposer d’une meilleure connaissance de sa flore, de sa végétation et de son fonctionnement. C’est dans ce cadre que la présente étude a été envisagée. Les données collectées concernent le milieu naturel, la structure de la forêt, la régénération naturelle des espèces et les usages faits des Produits Forestiers Non Ligneux (PFNL). Le milieu naturel se compose d’un substratum acide (pH variant de 3,5 à 5,5) et argilo-sableux. Le cortège floristique de cette forêt est composé de 241 espèces réparties en 185 genres et 70 familles dont des espèces endémiques (Uapaca paludosa) ou en danger (Hallea ledermannii), Nauclea xanthoxylon, etc. Sept groupements végétaux ont été identifiés (forêt primaire inondée à Alstonia congensis et Xylopia rubescens, forêt secondaire inondée à Ficus trichopoda et Spondianthus preussii et raphiale à Raphia hookeri et Anthocleista vogelii en forêt ;forêt ripicole à Alchornea cordifolia et Mitragyna inermis, savane marécageuse à Ficus asperifolia et Paullinia pinnata ;prairie marécageuse à Cyclosorus gongylodes et Polygonum pulchrum et enfin prairie marécageuse à Rhynchospora corymbosa et Ludwigia abyssinica en lisière) avec des précisions sur leurs caractéristiques floristiques, biologiques, phytogéographiques et écosociologiques. Les mésophanérophytes sont abondants en forêt alors qu’en lisière, ce sont les microphanérophytes qui sont les plus nombreux. Ces groupements constituent un refuge pour de nombreuses espèces animales dont Barboides britzi, poisson déterminé pour la première fois en 2006. D’après cette étude, on note une bonne régénération des espèces forestières malgré une recrudescence des trouées liées à l’installation de champs de Colocasia esculenta. Parmi les 75 espèces, source de PFNL recensées, les produits et sous-produits issus de Raphia hookeri sont les plus exploités car ils constituent pour les populations riveraines d’importantes sources de revenus. Ces PFNL sont exploités à Lokoli pour plusieurs usages à savoir l’alimentation, l’emballage, boisson alcoolisée, recettes médicinales, construction, etc. Le nombre de pieds de Raphia hookeri saignés par an est de 15.452 par 320 exploitants dont 148 cueilleurs, 81 transformateurs et 91 commerçants ;ce qui fournit aux exploitants des revenus de l’ordre de 28.000 à 159.000 FCFA (42,7 à 242,4 euros) par mois et par exploitant, sans oublier les autres activités menées par les riverains dans cet écosystème. On note une forte pression anthropique sur cette formation qu’il est donc urgent de protéger. En effet, elle dispose d’importants atouts qui militent en faveur de sa conservation. Elle abrite des espèces végétales et animales rares, endémiques, vulnérables et en danger (inscrites sur la liste rouge de l’UICN), telles que :Hallea ledermannii, Uapaca paludosa, Nauclea xanthoxylon, Cercopithecus erythrogaster erythrogaster, Cercopithecus mona, Colobus vellerosus, Ceriagrion citrinum Campion, Barboides britzi, etc. La forêt marécageuse de Lokoli joue un rôle de refuge pour toutes ces espèces qui y trouvent leur niche écologique. Sur le plan socio-économique, la FML fournit aux populations riveraines des revenus pour leur subsistance. Toutes ces potentialités font d’elle une Forêt à Haute Valeur pour la Conservation (FHVC) et elle pourrait constituer une véritable réserve de biosphère dans le Sud-Bénin. / The swamp forest of Lokoli, located in the south of Benin, is a non-protected area, although it is the only swamp forest in West Africa accompanied by a river which always contains water. To be able to make decisions concerning the conservation and protection of this forest ecosystem, it is important to have a better knowledge of its flora, its vegetation and its ecology and dynamics. It is within this framework that the present study was considered. The data that were collected relate to the natural environment, the structure of the forest, the natural regeneration of the species and the uses of the Non Timber Forest Products (NTFP). The natural environment is composed of a substratum which is acid (pH varying from 3.5 to 5.5) and loamy-sandy. The floristic composition of this forest is composed of 241 plant species from 185 genera and 70 families. Seven vegetation types were identified: 1. Inundated primary forest with Alstonia congensis and Xylopia rubescens; 2. Inundated secondary forest with Ficus trichopoda and Spondianthus preussii; 3. Raphia forest with Raphia hookeri and Anthocleista vogelii; 4. Riparian forest with Alchornea cordifolia and Mitragyna inermis; 5. Marshy savanna with Ficus asperifolia and Paullinia pinnata; 6. Marshy savanna with Cyclosorus gongylodes and Polygonum pulchrum; and 7. Marshy savanna with Rhynchospora corymbosa and Ludwigia abyssinica. Precise details are given on their floristic, biological, phytogeographical and phytosociological characteristics. The mesophanerophytes are abundant in forest whereas at forest edges the microphanerophytes are most numerous. These vegetation types constitute a refuge for many animal species, for example Barboides britzi, a species of fish first identified in 2006. This study noted a good regeneration of forest species, in spite of disturbance related to the installation of fields of Colocasia esculenta. About 75 investigated NTFP are exploited in Lokoli for many purposes, among which food, packaging, alcoholic drinks, medicines, construction, etc. Among the listed NTFP, the products and by-products made from Raphia hookeri are the most important because they are important sources of revenue for the inhabitants of the area. The number of stems of Raphia used per year for palm wine production is 15.452 by the 320 inhabitants, including 148 gatherers, 81 transformers and 91 tradesmen. This provides to the inhabitants an income of about 28,000 to 159,000 FCFA per month and per inhabitant, without forgetting the other activities undertaken by these inhabitants. This results in a strong human pressure on the vegetation of the area which is therefore in urgent need of protection. The vegetation of the Lokoli forest has important values which indicate its conservation concern. It shelters plant and animal species that are endemic and/or endangered or vulnerable according to the red list of the IUCN, such as: Hallea ledermannii, Uapaca paludosa, Nauclea xanthoxylon, Cercopithecus erythrogaster erythrogaster, Cercopithecus mona, Colobus vellerosus, Ceriagrion citrinum Campion, Barboides britzi, etc. The swamp forest of Lokoli is a refuge for all these species who find here their ecological niche. On the socio-economic level, the Lokoli forest provides to the inhabitants an income for their subsistence. The Lokoli forest in southern Benin is a forest with a high conservation value and it has the potential to become a “biosphere reserve”. / Doctorat en Sciences / info:eu-repo/semantics/nonPublished
7

Socio-economic impact of Prunus africana management in the Mount Cameroon region : A case study of the Bokwoango community

Ekane, Bellewang Nelson January 2006 (has links)
In most developing countries, forest resources are a major source of livelihood for forest dwellers. Forests provide fuel wood, farm products, meat, timber and plants of high medicinal value, including Prunus africana. The collection of medicinal plants is also an important source of cash income for some forest communities, and widely relied on to cure illnesses (Poffenberger, 1993). Because of this, the poor forest dwellers in particular are forced to exert pressure on their surrounding environment to make ends meet. Indiscriminate exploitation of forest resources has cost some forest dwellers dearly as they are now experiencing marked reduction of wildlife, forest cover, soil fertility and most importantly water supply, which is a key to life. Prunus africana has a very high economic and medicinal value locally as well as internationally. The exploitation of this species is a very profitable activity in most parts of Africa where it occurs, including the Mount Cameroon region. In recent years, most youths and young men in the Mount Cameroon region have seemingly become less interested in their usual income generating activities (farming, hunting, etc.) because of reduced productivity and have taken up Prunus harvesting as their major source of income. Increase in demand for this species by the French pharmaceutical company (Plantecam), weak institutional capacity to control exploitation, uncontrolled access into the forest, scramble for diminished stock by legal and illegal exploiters, destruction of wild stock by unsustainable practices, and insufficient regeneration of the species in the past have almost driven this species to extinction in certain parts of Cameroon and made it severely threatened in others. Prunus africana is presently threatened with extinction in the entire Mount Cameroon region. In response to this, the Mount Cameroon Project (MCP) and the Ministry of Environment and Forests (MINEF) helped some communities (Bokwoango and Mapanja) in the Mount Cameroon region to form Prunus africana harvesters’ unions with the aim of preserving the resource and improving the socio-economic benefits. The principal aim of the Bokwoango Prunus africana harvesters’ union is to ensure sustainable exploitation of Prunus africana while saving money for important development projects for individual members, their families and the entire community. This piece of work highlights the different facets of Prunus africana management in Cameroon in general and the Bokwoango community in particular. The study examines the socio-economic impact of Prunus africana management in the Bokwoango community and shows specifically the management role played by the Bokwoango Prunus africana harvesters’ union to reduce the rate of exploitation of Prunus africana and also to ensure benefit sharing of the earnings from sales of Prunus bark. It at the same time brings out the constraints encountered by harvesters as well as the opportunities that can make the union become more viable to the socio-economic development of the Bokwoango community. Results of this study show that for the short period that the Bokwoango Prunus africana harvesters’ union has existed, the socio-economic changes in this community are encouraging if one compares the present situation with that before the formation of the union. Most importantly, there has been increased awareness on the great need to conserve not only the threatened Prunus africana species but also other threatened plant and animal species in the region through sustainable hunting, harvesting and regeneration. Some proposals are made for efficient natural resource management and improvements on livelihood through alternative income generating activities. The study ends with recommendations for policy and institutional reforms as well as suggestions for further research in sustainable management of Prunus africana.
8

Policy Brief for realizing green/bio economy with high value Non-Timber Forest Products commercialization in Ethiopia and Sudan

Bekele, Tsegaye, Auch, Eckhard, Eshete Wassie, Abeje, Tadesse, Wubalem, Woldeamanuel, Teshale, Mahagaub Elnasri, Hagir, Nigatu, Teklehaymanot, Pretzsch, Jürgen, Alemu, Asmamaw, Elsheikh Mahmoud, Tarig, El Nour Taha, Mohamed 20 March 2017 (has links) (PDF)
This policy brief deals with the research findings of the collaborative research project “CHAnces IN Sustainability – promoting natural resource based product chains in East Africa” (CHAINS) funded by the Federal Ministry of Education and Research, and the DLR Project Management Agency. It presents the studies investigating the value chains of highland BAMBOO and NATURAL GUM AND RESIN products in Ethiopia as well as GUM ARABIC value chains in Sudan. These products possess high eco¬nomic, social and environ¬mental benefits and untapped potentials. However, their pro-duction and commercialization are con¬strained seriously by various challenges limiting the realization of their potentials. Identified policy options are: • strengthen institutional capacity; • improve infrastructure and support services; • organize necessary information for sustainable utilization planning; • facilitate actors’ communication, innovation and fair partnership. This calls for forest product value chain development that is supported by policy, training, research, technology development and transfer, market linkage that consider private sectors, state, civic organizations, universities and research institutes.
9

INFLUÊNCIA DE VARIÁVEIS DENDROMÉTRICAS, ANATÔMICAS E AMBIENTAIS NA PRODUÇÃO DE FRUTOS E SEMENTES DE Bertholletia excelsa H.B.K. / INFLUENCE OF DENDROMETRIC, ANATOMIC AND ENVIRONMENTAL VARIABLES IN THE PRODUCTION OF FRUITS AND SEEDS OF BRAZILIAN NUT (Bertholletia excelsa H.B.K.)

Ivanov, Guilherme Boeira 26 November 2011 (has links)
Conselho Nacional de Desenvolvimento Científico e Tecnológico / Bertholletia excelsa H.B.K. is a semi-deciduous species, heliophyle, characteristic of forest land and usually emerging, which collects on the fruits and seeds for use in feed. However, knowledge about the factors that influence the production of the trees is weak. This work aimed to evaluate the influence of rainfall, soil (texture, depth and hydromorphic) dendrometric variables (diameter at breast height and insertion of the crown, tapering, coefficient of taper artificially and taper artificially), qualitative variables (canopy shape and position), competition, sapwood area and size classes and grouping of vessels in the production of fruits and seeds of the species. It was observed that the same number of fruit generate seed yields in kg with significant differences. Rainfall for the month of September shows a positive correlation with the production. The deep soil and with texture sandy clay loam or sandy-clay have a higher yield potential than the shallow and clayey. Trees with less taper (more cylindrical) tended to produce more than trees with greater taper (more conical). Trees with full crowns (circular and irregular) have the same productive potential, and in turn greater potential than those who had half crown. The expected maximum sapwood area decreases exponentially with increasing competition. Trees with sapwood area less than 0.030 m² were not productive and less than 0,075 m² always produce less than 5 kg. Trees that have large solitary vessels are more abundant and have a tendency to produce less than those of other classes. The greatest production potential is expected to trees growing and deep soil, with texture sandy clay loam or clay-sandy, with complete canopies in areas subject to competition for Bertholletia index (IB) below 33, with sapwood area between 0.37450 and 0.29961 square meters and preferably not have large solitary vessels. The proposed model for prediction of seed fresh weight (kg) is Peso=-11.16+0.103636·PPSet +11.699216·galb in soils with texture clayey, in soils with texture sandy clay loam or sandy-clay are level difference with an increase of 7.40 kg of seeds per tree. / Bertholletia excelsa H.B.K. é uma espécie semidecídua, heliófila, característica da mata de terra firme e, normalmente emergente, da qual se coleta os frutos e as sementes para utilização na alimentação. Todavia, o conhecimento sobre os fatores que influenciam a produção de frutos e sementes das árvores é incipiente. Neste trabalho, buscou-se avaliar a influência da precipitação, do solo (textura, hidromorfia e profundidade), variáveis dendrométricas (diâmetro à altura do peito e na inserção da copa, afilamento, coeficiente de forma artificial e forma artificial), variáveis qualitativas (forma e posição de copa), competição, área de alburno e classes de tamanho e agrupamento dos vasos na produção de frutos e sementes da espécie. Observou-se que o número de frutos iguais gera produções de sementes em kg com diferenças significativas. A precipitação do mês de setembro demonstrou correlação positiva com a produção. Os solos profundos e de textura franco argilosa-arenosa ou argilo-arenosa evidenciaram maior potencial produtivo que os rasos e de textura argilosa. Árvores com menor afilamento (mais cilíndricas) revelaram uma tendência a produzirem mais que árvores com maior afilamento (mais cônicas). Árvores com copa completa (circular ou irregular) assinalam mesmo potencial produtivo e, por sua vez, maior potencial que as que apresentam metade da copa. A máxima área de alburno esperada decresce exponencialmente com o aumento da competição. Árvores com área de alburno inferior a 0,030 m² não foram produtivas e as inferiores a 0,075 m² produzem sempre menos de 5 kg. Árvores que possuem vasos largos solitários são mais abundantes e apresentam uma tendência a produzirem menos que as de outras classes. O maior potencial produtivo é esperado para árvores crescendo e solos profundos de texturas francoargilosa- arenosa ou argilo-arenosa, com copa completa, em áreas submetidas à competição pelo Índice de Bertholletia (IB) inferior a 33, com área de alburno entre 0,29961 e 0,37450 m² e preferencialmente não apresentem vasos largos solitários. O modelo proposto para predição do peso fresco de sementes (kg) é: Peso=- 11,16+0,103636·PPSet +11,699216·galb para solos de textura argilosa, em solos de textura franco argilosa-arenosa ou argilo-arenosa há diferença de nível com acréscimo de 7,40 kg de sementes por árvore.
10

Bases para o manejo sustentável de populações silvestres de Heliconia velloziana Emygdio /

Souza, Saulo Eduardo Xavier Franco de, 1983- January 2009 (has links)
Orientador: Vera Lex Engel / Banca: Edson José Vidal da Silva / Banca: Raquel Rejano Bonato Negrelle / Resumo: Muitos estudos têm estimado limites de colheita de produtos florestais não-madeireiros (PFNMs) baseados em dados demográficos das espécies fontes. Heliconia velloziana Emygdio (Zingiberales: Heliconiaceae) é utilizada como flor de corte e no paisagismo, e já foi alvo do extrativismo na comunidade rural na região do estudo (Distrito de Taiaçupeba, Mogi das Cruzes, SP). Nosso objetivo geral foi fornecer bases para a elaboração de planos de manejo sustentável para populações silvestres de Heliconia velloziana, através de: avaliação do conhecimento etnobotânico sobre H. velloziana; análise de sua fenologia reprodutiva em relação as variáveis climáticas; avaliação do rendimento e dos efeitos ecológicos do extrativismo sobre taxas vitais de populações silvestres da espécie alvo em diferentes micro-hábitats. Objetivou-se também verificar o potencial para manejo sustentável da espécie e sugerir um regime de rendimento sustentado específico. Para acessar o conhecimento local sobre H. velloziana, foram realizadas entrevistas informais e semiestruturadas, além de observação participante. Os efeitos ecológicos da colheita experimental sobre taxas vitais e a fenologia reprodutiva foram avaliados através de amostragem aleatória estratificada, em uma área total amostral de 0,12ha (12 parcelas de 10x10m) em seis sítios amostrais abrangendo dois estratos (planície e encosta). Em cada sítio, uma população foi submetida à colheita experimental e outra foi mantida como controle. Os aspectos melhor conhecidos pela comunidade local sobre a espécie alvo foram: nome popular, variação intraespecífica, reprodução clonal, visitantes florais, atrativos florais, floração seqüencial, distribuição e abundância local. A espécie foi considerada útil pelos entrevistados para complementação... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Many studies have estimated harvesting limits for non-timber forest products (NTFPs) based on demographic data of the source species. Heliconia velloziana Emygdio (Zingiberales: Heliconiaceae) is used as a cut flower and gardening, and has already been targeted for extractivism by the rural community of the study region. Our general goal was to provide bases for the elaboration of Heliconia velloziana wild populations sustainable management plans, through: assessing ethnobotanical knowledge about H. velloziana; analyzing its reproductive phenology in relation to climatic variables; assessing the yield and ecological effects of harvesting on vital rates of wild populations of the target species in different micro-habitats. We also aimed to verify sustainable management potential of the species and suggest a specific sustained yield regime. To access local knowledge on H. velloziana, informal and semi-structured interviews were done, besides participant observation. The experimental harvesting ecological effects on vital rates and the reproductive phenology were assessed through stratified random sampling, in a total sampling area of 0,12ha (12 10x10m plots) in six sampling sites enclosing two strata (lowland and hillside). At each site, one population was submitted to experimental harvesting and the other was kept as control. The best known aspects by local community about the target species were: common name, intra-specific variation, clonal growth, flower visitors, floral attractants, sequential flowering, local distribution and abundance. The species was considered useful by the interviewed as familiar income complementation through extractivism, besides other secondary uses. It was identified a rich knowledge about the species' management system, once used, that was considered simple and consisted of two to three... (Complete abstract click electronic access below) / Mestre

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