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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.
61

Regeneration potential and habitat suitability modeling of three imperiled Southeastern U.S. woody plants

Hale, Clayton Warren 06 August 2021 (has links)
Presented within this thesis are three studies on three rare and imperiled Southeastern woody plant species: mountain stewartia (Stewartia ovata), Atlantic white-cedar (Chamaecyparis thyoides), and Miller's witch-alder (Fothergilla milleri). This work contributes to the ecological understanding of these three species allowing for better-informed conservation decision-making. Machine learning habitat suitability models are presented for mountain stewartia and Miller's witch-alder. These models can direct limited conservation dollars and manpower towards areas of the highest habitat suitability. This work also utilizes field-based data to assess the habitat needs, species associations, and regeneration potential of both Atlantic white-cedar and Miller's witch-alder. Understanding the habitat and regeneration potential of these species allows conservationists to make more tailored land management decisions for the species. As plant species continue to be threatened with extinction, more basic and applied research is needed to lessen the impacts of the 6th mass extinction on native flora.
62

Medicinal plant trade and opportunities for sustainable management in the Cape Peninsula, South Africa

Loundou, Paul-Marie 12 1900 (has links)
Thesis (MScConsEcol (Conservation Ecology and Entomology))--Stellenbosch University, 2008. / Medicinal plants represent an important asset to the livelihoods of many people in developing countries. This is the case for South Africa where most of the rural and also urban communities rely on medicinal plants for their primary healthcare needs and income generation. Harvesting for domestic usage is not generally detrimental to the wild populations of medicinal plants. However, the shift from subsistence to commercial harvesting is posing unprecedented extinction threat to the wild populations of medicinal plants. The purpose of this investigation was to: (1) document the most traded/used species of medicinal plants in the Cape Peninsula, including parts used, sourcing regions, harvesting frequencies and seasons as well as the conservation status of these species; (2) to profile and investigate the rationales for the involvement of stakeholders in medicinal plants related-activities; and to (3) assess constraints and opportunities for sustainable management of medicinal plants in the Cape Peninsula. Triangulation techniques such as semi-structured questionnaires, formal and informal interactions with key informants from the Cape Peninsula and surroundings, personal observations and field visits were used to gather relevant data for this investigation. Accordingly, about 170 medicinal plant species were found to be actively traded or used in the study area. These species were mostly traded/used for their underground parts; shoot, barks and in many cases the whole plant is uprooted. The bulk of traded/used species were from the wild populations, harvested on monthly basis and the Western and Eastern Cape provinces acted as the main source regions. Some of the traded/used species are rare, vulnerable, endangered, critically endangered and are declining from the wild. Nonetheless, there are subtitutes for some of these medicinal plant species. Traders and collectors were mainly men in the Cape Peninsula. Cultural considerations, economic conditions and the burden imposed by the number of dependents were the factors influencing local communities to engage in medicinal plants related-activities. Despite the fact that the majority of the informants acknowledged the decline of medicinal plants from wild stocks, an overwhelming number of them expected an upsurge in the future demand for natural remedy due to its popularity among South Africans. Similarly, the majority of the respondents were aware of the conservation status of the plants that they were using, but this did not prevent them from trading/using some protected species. Encouragingly, an overwhelming number of the informants were willing to use cultivated species and cultivate some of the most used medicinal plant species if seeds and land were freely provided. It is noteworthy that these results were influenced by the gender, age, category and time of involvement in medicinal plants, ethnicity and residence status of the respondents as well as the source of supply of medicinal plants. It is recommended that species that have been identified of concern should be prevented from further commercial harvesting. Competent conservation organizations like CapeNature should focus on practical skills development of people who have expressed willingness to cultivate medicinal plants or are already doing so, especially in plant propagation and basic gardening techniques.
63

Bark in traditional healthcare in KwaZulu-Natal, South Africa : usage, authentication and sustainability.

Grace, Olwen Megan. January 2002 (has links)
Healthcare in South Africa is polarised between western and traditional African systems of therapy. The latter is consulted by the majority of the population and therefore plays an integral role in the delivery of healthcare to South Africans. Traditional medicines are primarily plant products with long storage lives, among which the dominance of bark is typical of southern African traditional healthcare systems. Expansion of the traditional healthcare sector during the twentieth century, in response to rising consumer demands, stimulated a lucrative trade in medicinal plants that is centred in KwaZulu-Natal. Since herbal medicines are sourced almost exclusively from indigenous vegetation, harvesting pressures exerted on the indigenous flora to meet demands for traditional medicines have rendered such resources non-sustainable. Although trees comprise a small fraction of South African medicinal plant species, bark from them constitutes a substantial proportion of the plant products used medicinally. Trees are among the most threatened medicinal plants in South African due to their limited abundance, the ecological sensitivity of the vegetation in which they occur, and destructive methods of commercial bark harvesting that frequently take place within protected areas. In KwaZulu-Natal, bark is harvested primarily from forests that occupy an extent of only 0.1 % in the province. Conservation of economically valuable tree species is particularly problematic since data necessary for the establishment of sustainable usage systems are absent or inaccessible. Alternatives to in situ conservation for renewable bark resources include propagation, multi-use timber systems and reintroduction of locally extinct species. To facilitate appropriate management of bark resources, there is a need for specialist publications and consolidated data with which sustainable usage levels may be determined. The importance of bark in South African traditional healthcare is poorly reflected by the ethno botanical literature. In this study, 180 bark species used in traditional healthcare in KwaZulu-Natal were inventoried from thorough literature surveys, but this number is anticipated to be a conservative reflection of actual statistics. Where trade data were recorded in the literature, they indicated intensive exploitation of bark resources in KwaZulu-Natal and throughout South Africa, but conservation and management data were lacking for 72 % of the species inventoried. A number of problems were encountered in the literature, of which vague information and the documentation of local vernacular nomenclature were the most troublesome. Despite the importance of traditional medicine, the country's political history led to the prevailing situation, where the traditional healthcare sector is largely unregulated. Coupled with increasingly limited availability of medicinal plants, the quality and appropriate use of traditional medicines is negatively affected by growing numbers of inadequately trained practitioners, herbalist retailers and plant gatherers. Possibilities of misidentification or purposeful adulteration of medicinal bark products therefore lead to concerns for patient safety, since dried bark is difficult or impossible to identify. Whilst bark characters are useful for field identifications, many useful diagnostic characters are lost through desiccation, and anatomy and morphology of bark are variable. Additionally, medicinal bark products used in KwaZulu-Natal, and their identification, are largely undocumented. This study focussed on eight bark species used medicinally in the province, elected by an esteemed traditional medical practitioner as having problematic identity. Monograph-type characterisation profiles were drawn up for reference specimens collected from various localities, and their medicinal bark products traded under vernacular names recorded in the literature. In the absence of standardised traditional medicines, there is a need for reliable and affordable methods for their authentication. Phytochemical bark characters identified by Thin Layer Chromatography (TLC) have proved useful in chemotaxonomic studies, and the technique is widely used for herbal drug authentication. TLC was tested here for authentication of medicinal bark products from the aforementioned study species. Three reference samples of each species were collected, and TLC-generated fingerprints compared. At the intraspecific level, TLC was useful in confirming the relationship of ethanol and hexane bark extracts, but was less meaningful in distinguishing between fingerprints of different species. Three medicinal bark products of each study species were purchased and fingerprints compared to a reference. The technique proved useful in confirming the identity of several medicinal bark products. Authentication of medicinal bark products may be useful in toxicology cases and in the accurate documentation of their trade. This research identified a complexity of issues surrounding the use of bark in traditional healthcare in KwaZulu-Natal, and indeed South Africa. A multi-faceted approach is required to secure their sustainability. Critical, however, to factors such as effective conservation and regulation of the traditional healthcare sector, is recognition of the importance, and documentation, of traditional bark medicines. The integrity of traditional healthcare, and the future of the South African flora, hinge upon the sustainable use of medicinal products such as bark. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 2002.
64

Ecologia, conservação e aspectos taxonômicos do gênero neotropical Davilla Vand. (Dilleniaceae) / Distribution Modeling and Conservation of Davilla Vand. (Dilleniaceae Salisb.).

Pereira, Ismael Martins 06 June 2014 (has links)
Neste trabalho realizou-se o estudo de distribuição, riqueza e conservação do gênero Davilla Vand. (Dilleniaceae) no Neotrópico. Para tal utilizou-se a modelagem de distribuição de espécies com o algoritmo Maxent. Este produz distribuição das espécies no espaço geográfico a partir de dados ambiental e de ocorrência. Foram estudadas as espécies de acordo com o bioma de ocorrência: Mata Atlântica; Cerrado; e Amazônia. Este grupo está representado no Neotrópico por 25 espécies. Para o Cerrado incluiu-se além das espécies do gênero Davilla as demais espécies da família Dilleniaceae. Os resultados indicaram que no Cerrado o grupo está representado por nove espécies de Davilla, além de Curatella americana L. e três espécies de Doliocarpus Rol., destas cinco são endêmicas (Doliocarpus elegans Eichler e 4 Davilla spp.). Para a Mata Atlântica ocorrem 12 espécies de Davilla, oito delas são endêmicas, incluindo uma espécie ameaçada de extinção. Para a Floresta Amazônica são conhecidas nove espécies, cinco delas endêmicas. Duas outras espécies são Neotropicais, portanto, compartilhadas por todos os biomas citados anteriormente. As demais espécies são de ocorrência em pelo menos dois biomas. Para estes três biomas produziu-se a distribuição e a riqueza de espécies visando comparar os resultados com as unidades de conservação, objetivando discutir questões relativas à conservação deste grupo. Os parâmetros conservacionistas como espécies raras, zonas de endemismo, zonas de alta riqueza, áreas de preservação ambiental, foram confrontados objetivando indicar áreas prioritárias para a conservação do grupo e da biodiversidade. Os resultados indicaram existir três centros de diversidade para este grupo. O principal deles está localizado na Mata Atlântica, principalmente nas florestas litorâneas do estado da Bahia. Outro centro de diversidade localiza-se na região central do Cerrado, especialmente nos estados de Goiás e Bahia. A outra área de diversidade localiza-se próximo à foz do Rio Amazonas e ao longo de seu curso. Devido ao hábito predominante das espécies serem lianas, estas são importantes componentes das florestas, das quais usamos este referencial para discutir questões relativas à conservação destes habitats, de suas espécies e da biodiversidade. As informações completas estão apresentadas nos capítulos de acordo com os respectivos biomas abordados. / In this study was realized to study the distribution, richness and conservation of the Davilla Vand. (Dilleniaceae) in the neotropics. For this purpose was used to distribution model of species with Maxent algorithm. This produces species distribution in geographic in space based on environmental and occurrence data. Species in accordance with biome of occurrence were studied: Atlantic Forest; Cerrado; and the Amazon. This group is represented by 25 species in the neotropics. For the Cerrado was included in addition to the Davilla species all species of Dilleniaceae family. The results indicated that in the Cerrado this group is represented by nine species of Davilla, and Curatella americana L. and three species of Doliocarpus Rol., to these five are endemic (Doliocarpus elegans Eichler and 4 Davilla spp.). For Atlantic Forest occur 12 Davilla species, eight of which are endemic, including an endangered species. For the Amazon are known nine species, five of these endemic. Two other neotropical species are therefore shared by all biomes mentioned above. The other species are occurring in at least two biomes. For these three biomes produced the distribution and species richness in order to compare the results with the protected areas, aiming to discuss issues relating to the conservation of this group. Conservationists parameters as rare species, areas of endemism, areas of high species richness, conservation areas, were confronted aiming indicate priority areas for conservation of biodiversity and too this group. The results indicated three centers of diversity for this group. The main one is located in the Atlantic Forest in coastal forests of Bahia. Another center of diversity is located in central region of Cerrado, especially in the states of Goias and Bahia. The other area of diversity is located near the mouth of the Amazon River and along its course. Due to the prevailing habit of the species are lianas, these are important components of forests, of which we use this framework to discuss issues relating to the conservation of these habitats, their species and biodiversity. Full details are presented in chapters according to their biomes addressed.
65

Dendrologia, anatomia do lenho e "status" de conservação das espécies lenhosas dos gêneros Cinchona, Croton e Uncaria no estado do Acre, Brasil. / Dendrology, wood anatomy and “status” conservation of species of the Cinchona, Croton and Uncaria’s genus from Acre state, Brasil.

Pollito, Percy Amilcar Zevallos 19 April 2004 (has links)
No presente trabalho foram estudadas 8 espécies lenhosas dos gêneros Cinchona (C. amazonica Standl.), Croton (C. billbergianus Müll.Arg., C. floribundus Spreng., C. lechleri, Müell.Arg., C. matourensis Aubl., C. palanostigma Klotzsch) e Uncaria (U. guianensis (Aubl.) J.F. Gmel. e U. tomentosa (Willd. ex Roem. & Schult.) DC.) de interesse medicinal e ocorrentes no Estado do Acre, Brasil. Dessas plantas foram analisadas as características dendrológicas, a estrutura anatômica do lenho, sua distribuição geográfica e "status" de conservação. A pesquisa consistiu de visitas de campo a diferentes regiões do Estado, coleta de material botânico e do lenho das plantas, levantamento e estudo das exsicatas das espécies em herbários nacionais e internacionais da América do Sul, revisão bibliográfica das espécies na literatura e "sites" especializados, descrição dos parâmetros dendrológicos e da estrutura antômica do lenho das espécies em laboratório, possibilitando a identificação das espécies dos 3 gêneros. As características dendrológicas vegetativas das plantas mostraram variações, resultado das adaptações ao meio ambiente, da idade e de sua ampla distribuição geográfica. A estrutura anatomica do lenho foi mais distinta entre famílias (Euphorbiaceae e Rubiaceae) e gêneros (Cinchona, Croton, Uncaria) e menos nas espécies, constituindose em parâmetro importante e auxiliar na sua identificação. As plantas de Cinchona amazonica apresentaram baixa intensidade populacional, embora com ampla distribuição no Estado do Acre, em outros estados brasileiros e nos países amazônicos. No gênero Croton, as plantas de C.palanostigma mostraram distribuição quase pontual no Acre e extensa na Amazônia e menos ampla na América Latina; C. floribundus com ocorrência pontual no Acre, distribuição concentrada no Estado de São Paulo e em outros estados brasileiros e no Paraguai; C. matourensis encontram-se bem distribuídas no Acre e em outros estados brasileiros e países amazônicos, até o Panamá; C. lechleri ocorrem somente no sudeste do Estado do Acre, na Bolívia, Colômbia, Peru e Equador; C. billbergianus encontram-se bem distribuídas no Estado do Acre, escassa em outros estados amazônicos, ocorrendo em outros países da América Latina até o México. As plantas de Uncaria guianensis e U. tomentosa foram as de maior abundância no Estado do Acre e em toda a Amazônia brasileira, sendo U. tomentosa de menor abundância e distribuição muito ampla ocorrendo, inclusive, até a América Central. Com respeito ao "status" de conservação, as plantas de Croton billergianus, C. matourensis e Uncaria guianensis foram incluídas na categoria LC (comuns e abundantes ou fora de perigo), Cinchona amazonica, Croton lechleri e C. palanostigma em CR (perigo crítico), Uncaria tomentosa em VU (perigo a médio prazo) e Croton floribundus em DD (informação insuficiente). A presença destas espécies não foi constatada nas unidades de conservação do Estado do Acre e, no momento, as florestas onde ocorrem estão sendo exploradas para a extração da madeira, de fármacos e para a ampliação da fronteira agropecuária. Nos herbários das instituições de pesquisa e de ensino do Estado do Acre as coleções de plantas das espécies de Cinchona, Croton e Uncaria são escassas em comparação com as de outros Estados do Brasil e dos países visitados. / This research studied eight wood species of the genus Cinchona (C. amazonica Standl.), Croton (C. billbergianus Müll.Arg. C. floribundus Spreng.; C. lechleri, Müll.Arg.; C. matourensis Aubl. and C. palanostigma Klotzsch) and Uncaria (U. guianensis (Aubl.)J.F. Gmel. and U. tomentosa (Willd. ex Roem. & Schult.)DC.). All of them with medicinal interest, grown in the state of Acre (Brazil). The research consisted mainly in: field work in different regions of the state of Acre and botanical and plants collections, raising the exsiccates of the mentioned species in the most important national and international herbariums of South America, a wide bibliographical review concerning these species, dendrology description and the macro and microscopy description of the wood. The ve getative dendrological characteristics of these species showed variations with age adaptations and geographical distribution. The anatomy structures were different between families (Euphorbiaceae and Rubiaceae) and genus (Cinchona, Croton, Uncaria) and less within species. These results can be used for identification of these genus. In the order hand, this study shows that Cinchona amazonica had low distribution in Acre State, other Brazilian states and Amazonian countries. For Croton genus as C. palanostigma showed an almost punctual distribution in Acre, although had high distribution on the Amazon region and lowest on Latin America; C. floribundus with punctual occurrence on the Acre State and concentrated distribution in Sao Paulo State, other Brazilian States and in Paraguay; C. matourensis had high distribution in Acre, other Brazilian states and Amazonian countries, reaching up to Panama; C. lechleri grew only in the south east of Acre, Bolivia, Colombia, Peru and Ecuador; C. billbergianus was found well distributed in Acre, less abundant in other Amazon states and Latin countries and reaching up to Mexico. Uncaria guianensis and U. tomentosa were the most abundant species in Acre state and in all the Brazilian Amazon, and the U. tomentosa in Brazil can be considered less abundant, although with a wider distribution reaching inclusive the Central America. Concerning the conservation "status", C billbergianus, C. matourensis and U. guianensis were included in the category LC (common and abundant or out of danger); Cinchona amazonica, Croton lechleri and C. palanostigma on CR (critical danger), Uncaria tomentosa on VU (medium term danger) and Croton floribundus on DD (insufficient information). One of the most important aspects to mention is that there were no evidence of any presence of these species in the conservation unites in the State of Acre, and in the forests where they occur. Also, they are cuttings for raw material for wood, pharmacological exploration and farm and cattle frontiers amplification.. This situation was verified in the State of Acre for the lower collection of plants of Cinchona, Croton and Uncaria in relation to other states in Brazil and in other countries visited.
66

Ecology and management of bushland in Australian cities

Stenhouse, Renae N. January 2005 (has links)
[Truncated abstract] Native vegetation (bushland) in urban areas remains in small, isolated patches embedded within a matrix of human-dominated land uses. Bushlands in urban areas have high biodiversity conservation and social values, and there has been a local-level movement towards protecting and managing urban bushlands in Australia. This thesis aims to test principles, theories and concepts relating to the ecology and management of bushland fragments in Australian cities ... A commonly used qualitative scale was compared with an ecologically based, quantitative technique developed in the research. The qualitative scale was found to be a reliable proxy for assessing vegetation condition, while also being more user-friendly for community groups and other bushland managers. The human-caused disturbances and weed cover in urban bushlands indicate a need for management intervention. Local government has an important role in local biodiversity management, yet there has been little research on this topic ... Positive partnerships developed where local governments have taken a ‘contract model’ approach to volunteer coordination, have a number of expectations of volunteer groups, and provide the groups with relatively high level of assistance. Also important is a local government that supports, respects, trusts and communicates with the community group, and recognises volunteers’ skills, knowledge and contributions. With increased resources allocated to local government bushland management and conservation, and coordination with community groups, the full potential of local bushland management would be realised.
67

Investigating the most favourable seed establishment methods for restoring sand plain fynbos on old fields

Cowell, Carly Ruth January 2013 (has links)
Thesis submitted in fulfilment of the requirements for the degree Master of Technology: Horticulture in the Faculty of Applied Sciences at the Cape Peninsula University of Technology, 2013 / Cape Flats Sand Fynbos (CFSF) is one of the most poorly conserved vegetation types in the Cape Floral Kingdom, and a large proportion of unconserved land is degraded, primarily as a result of transformation by agricultural, urban developments and invasion by alien plants. Fynbos restoration is one of the most important management interventions, both within the current conservation areas and in any future land remnants acquired for conservation. Many extant remnants are fragmented and isolated, and if successful restoration protocols are found, it may be possible to improve the conservation targets for this critically endangered vegetation type. On old fields, where indigenous soil seed banks have been lost due to alien plant invasion and anthropogenic action, it is essential to reintroduce the longer-lived fynbos components that contribute to vegetation structure, in order to facilitate the progress of the ecosystem on a more natural trajectory. This research is built on an earlier study of optimal ground-preparation treatments for restoring Sand Fynbos to old fields. This former study indicated that fossorial mammals (molerats and gerbils) may occur in dense colonies on old fields and present an obstacle to successful seedling establishment. The project aims to provide protocols for the establishment of indigenous seedlings from harvested seed onto old fields, in order to restore Sand Fynbos vegetation. Different pre-sowing treatments and sowing techniques were tested on large field plots to determine the most efficient protocol. The objectives of the research were: a) to investigate optimal pre-sowing treatments of indigenous seed for restoring degraded Sand Fynbos vegetation in old field sites; b) to investigate optimal sowing techniques on large field plots for restoring degraded Sand Fynbos vegetation in old field sites with depleted indigenous seed banks; c) to provide guidelines and disseminate information on optimal sowing protocols, and their costs, for restoring Sand Fynbos vegetation in degraded areas and old fields. A further component of the research was to calculate the costs of all treatments on a per hectare basis in order to assess the cost-effectiveness of the different options. Several different seed treatments may potentially increase the germination rate and promote fynbos restoration. These are scarifying, smoke, smoke water, chemical, light and temperature pre-sowing treatments. In order to keep the number of treatments (including their interactions) to a manageable level, only soaking in smoke water extract and seed coat scarification with course sand and grit were tested. A seed sample of each species was x-rayed at the Millennium Seed Bank in the United Kingdom, to test for viability in the seed samples, 52 % of the seed collected were empty, a typical indication of wild harvested seed. All species were germinated at 10/25 °C and 16/8 hours light/dark respectively. Scarification had a larger overall germination success, smoke water had very little effect on CFSF species, it is rather that germination is related to temperatures during a fire that result in seed coat splitting. It was recommended that further investigation using more species across the Sand Fynbos vegetation be conducted on pre-germination effects of heat and scarification. The study site had been cleared of woody invasive alien vegetation and additional site preparation included the application of a systemic herbicide to kill undesirable herbaceous weeds, prescribed fire to clear the site of woody debris and destroy weed seeds, and the local control of fossorial mammals (gerbils and molerats) by placing raptor perches and owl nesting boxes around the site. This research found that the use of herbicide shortly after the prescribed fire and once again prior to sowing was successful in controlling herbaceous weeds and the indigenous grass Cynodon dactylon. The challenge to using prescribed burning on old fields was low fuel loads, which resulted in a cool patchy. It is suggested that cutting and spreading of alien plant biomass is tested as a solution, however, the material must be evenly spread across the site and not stacked into piles which can cause excessively hot fires and scorching of the soil. In order to better understand soil conditions across the site, soil samples were collected prior to sowing, to analyse for soil macronutrients, organic matter and pH. It was established that all the excess nutrients added to the site from agriculture and pasturage over the years had leached from the soil. However, the organic matter content of the soil was extremely low and research needs to be done on the organic carbon content of the soils, how these relate to soil micro biota (which species are present and their relationship with CFSF species) and how best to enrich the site with humic matter for restoration and establishment of Cape Flats Sand Fynbos. The field trial was set up in the Blaauwberg Nature Reserve, a random split-plot block design, was replicated five times and used to investigate the selected seedbed preparation and sowing techniques, namely: broadcast sowing onto unprepared seedbed, broadcast with plank embedding of seed onto disked seedbed, broadcast onto disked seedbed and hydro-seed with disked seedbed. Results from the research found that the most successful methods for sowing seeds were the hydro-seeding and broadcast with plank embed. These methods may have provided better contact between the soil and seeds and better protection from predation and wind. Economically the broadcast and embed was better as machinery was more efficient and effective than manual labour. This study recommended that these two methods be combined with the additional planting of rare and threatened species in clumps to determine the benefits and interactions of each technique over the long term.
68

Dendrologia, anatomia do lenho e "status" de conservação das espécies lenhosas dos gêneros Cinchona, Croton e Uncaria no estado do Acre, Brasil. / Dendrology, wood anatomy and “status” conservation of species of the Cinchona, Croton and Uncaria’s genus from Acre state, Brasil.

Percy Amilcar Zevallos Pollito 19 April 2004 (has links)
No presente trabalho foram estudadas 8 espécies lenhosas dos gêneros Cinchona (C. amazonica Standl.), Croton (C. billbergianus Müll.Arg., C. floribundus Spreng., C. lechleri, Müell.Arg., C. matourensis Aubl., C. palanostigma Klotzsch) e Uncaria (U. guianensis (Aubl.) J.F. Gmel. e U. tomentosa (Willd. ex Roem. & Schult.) DC.) de interesse medicinal e ocorrentes no Estado do Acre, Brasil. Dessas plantas foram analisadas as características dendrológicas, a estrutura anatômica do lenho, sua distribuição geográfica e “status” de conservação. A pesquisa consistiu de visitas de campo a diferentes regiões do Estado, coleta de material botânico e do lenho das plantas, levantamento e estudo das exsicatas das espécies em herbários nacionais e internacionais da América do Sul, revisão bibliográfica das espécies na literatura e “sites” especializados, descrição dos parâmetros dendrológicos e da estrutura antômica do lenho das espécies em laboratório, possibilitando a identificação das espécies dos 3 gêneros. As características dendrológicas vegetativas das plantas mostraram variações, resultado das adaptações ao meio ambiente, da idade e de sua ampla distribuição geográfica. A estrutura anatomica do lenho foi mais distinta entre famílias (Euphorbiaceae e Rubiaceae) e gêneros (Cinchona, Croton, Uncaria) e menos nas espécies, constituindose em parâmetro importante e auxiliar na sua identificação. As plantas de Cinchona amazonica apresentaram baixa intensidade populacional, embora com ampla distribuição no Estado do Acre, em outros estados brasileiros e nos países amazônicos. No gênero Croton, as plantas de C.palanostigma mostraram distribuição quase pontual no Acre e extensa na Amazônia e menos ampla na América Latina; C. floribundus com ocorrência pontual no Acre, distribuição concentrada no Estado de São Paulo e em outros estados brasileiros e no Paraguai; C. matourensis encontram-se bem distribuídas no Acre e em outros estados brasileiros e países amazônicos, até o Panamá; C. lechleri ocorrem somente no sudeste do Estado do Acre, na Bolívia, Colômbia, Peru e Equador; C. billbergianus encontram-se bem distribuídas no Estado do Acre, escassa em outros estados amazônicos, ocorrendo em outros países da América Latina até o México. As plantas de Uncaria guianensis e U. tomentosa foram as de maior abundância no Estado do Acre e em toda a Amazônia brasileira, sendo U. tomentosa de menor abundância e distribuição muito ampla ocorrendo, inclusive, até a América Central. Com respeito ao “status” de conservação, as plantas de Croton billergianus, C. matourensis e Uncaria guianensis foram incluídas na categoria LC (comuns e abundantes ou fora de perigo), Cinchona amazonica, Croton lechleri e C. palanostigma em CR (perigo crítico), Uncaria tomentosa em VU (perigo a médio prazo) e Croton floribundus em DD (informação insuficiente). A presença destas espécies não foi constatada nas unidades de conservação do Estado do Acre e, no momento, as florestas onde ocorrem estão sendo exploradas para a extração da madeira, de fármacos e para a ampliação da fronteira agropecuária. Nos herbários das instituições de pesquisa e de ensino do Estado do Acre as coleções de plantas das espécies de Cinchona, Croton e Uncaria são escassas em comparação com as de outros Estados do Brasil e dos países visitados. / This research studied eight wood species of the genus Cinchona (C. amazonica Standl.), Croton (C. billbergianus Müll.Arg. C. floribundus Spreng.; C. lechleri, Müll.Arg.; C. matourensis Aubl. and C. palanostigma Klotzsch) and Uncaria (U. guianensis (Aubl.)J.F. Gmel. and U. tomentosa (Willd. ex Roem. & Schult.)DC.). All of them with medicinal interest, grown in the state of Acre (Brazil). The research consisted mainly in: field work in different regions of the state of Acre and botanical and plants collections, raising the exsiccates of the mentioned species in the most important national and international herbariums of South America, a wide bibliographical review concerning these species, dendrology description and the macro and microscopy description of the wood. The ve getative dendrological characteristics of these species showed variations with age adaptations and geographical distribution. The anatomy structures were different between families (Euphorbiaceae and Rubiaceae) and genus (Cinchona, Croton, Uncaria) and less within species. These results can be used for identification of these genus. In the order hand, this study shows that Cinchona amazonica had low distribution in Acre State, other Brazilian states and Amazonian countries. For Croton genus as C. palanostigma showed an almost punctual distribution in Acre, although had high distribution on the Amazon region and lowest on Latin America; C. floribundus with punctual occurrence on the Acre State and concentrated distribution in Sao Paulo State, other Brazilian States and in Paraguay; C. matourensis had high distribution in Acre, other Brazilian states and Amazonian countries, reaching up to Panama; C. lechleri grew only in the south east of Acre, Bolivia, Colombia, Peru and Ecuador; C. billbergianus was found well distributed in Acre, less abundant in other Amazon states and Latin countries and reaching up to Mexico. Uncaria guianensis and U. tomentosa were the most abundant species in Acre state and in all the Brazilian Amazon, and the U. tomentosa in Brazil can be considered less abundant, although with a wider distribution reaching inclusive the Central America. Concerning the conservation “status”, C billbergianus, C. matourensis and U. guianensis were included in the category LC (common and abundant or out of danger); Cinchona amazonica, Croton lechleri and C. palanostigma on CR (critical danger), Uncaria tomentosa on VU (medium term danger) and Croton floribundus on DD (insufficient information). One of the most important aspects to mention is that there were no evidence of any presence of these species in the conservation unites in the State of Acre, and in the forests where they occur. Also, they are cuttings for raw material for wood, pharmacological exploration and farm and cattle frontiers amplification.. This situation was verified in the State of Acre for the lower collection of plants of Cinchona, Croton and Uncaria in relation to other states in Brazil and in other countries visited.
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Conservation incentives for private commercial farmers in the thicket biome, Eastern Cape, South Africa

Cumming, Tracey Lyn January 2007 (has links)
This study sought opportunities to mitigate the pressures of land transformation and alien invader plants on commercial farm land in the thicket biome in the lower reaches of the Fish Kowie Corridor. It had two aims. Firstly, to determine the role incentives could play in mitigating these pressures. Secondly, to determine the characteristics of an incentive programme that would most effectively achieve this. In order to do this, an understanding of landowner activities, needs, opinions and barriers to behaviour; the nature of the pressures on thicket and the nature of the required behaviour to reduce these pressures; and current and past institutional arrangements needed to be achieved. This was done predominantly through a current literature review and personal interviews with landowners and key informants. These findings were used to make recommendations for an effective incentive programme. Landowners showed a preference towards tangible incentives, in particular management assistance, financial compensation and law enforcement. They indicated an aversion to an incentive programme implemented by a government agency, particularly district and provincial government. Rather, landowners showed a propensity towards a nongovernment organisation (NGO) or a farmers group implementing an incentive programme. It was recommended that the two major pressures, namely land transformation and alien invader plants, required different interventions by different agencies in order to be mitigated. The pressure of land transformation required a stewardship model response, with the primary drive being a non-contractual environmental extension service to landowners. The extension service should focus on promoting pro-conservation practises, raising awareness and disseminating information. It should also build a relationship of trust between landowners and the implementing agency. The pressure of alien invader plants would be most effectively addressed through the Working for Water programme. Tangible incentives must be provided to the landowner to induce the costly exercise of alien invader plant control. In particular, the high cost of labour must be addressed. The regulatory incentive of applying laws requiring landowners to control alien invader plants on their land should also be enforced.
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Comparative Reproductive Biology of a Rare Endemic Orchid and its Sympatric Congeners in Southwestern China

Lin, Wuying 22 March 2012 (has links)
Comparative studies on endangered species and their more common congeners can shed light on the mechanism of species rarity, and enable conservationists to formulate effective management strategies. I compared the breeding and pollination systems of the endangered Geodorum eulophioides and its two more common sympatric congeners in subtropical China. Geodorum eulophioides and G. recurvum were self-compatible, both depending on Ceratina cognata for fruit production, while G. densiflorum can autonomously self. Although the floral visitation frequency of G. eulophioides was the highest among the three, its natural fruit set was similar to that of G. recurvum, but both lower than that of G. densiflorum. These results partially explain the difference in species abundance. Coupled with severe habitat loss and degradation, the extremely low pollinator visitation and natural fruit set of G. eulophioides calls for rapid establishment of ex-situ collection, in conjunction with improving in-situ habitat. Natural hybridization tendencies were also studied among species.

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