192 results on '"Pterocarpus angolensis"'
Search Results
52. Assessing the sustainability of harvest of Pterocarpus angolensis in Rukwa Region, Tanzania.
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Schwartz, M.W., Caro, T.M., and Banda-Sakala, T.
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PTEROCARPUS angolensis ,FOREST degradation - Abstract
Pterocarpus angolensis is being cut for construction and medicinal purposes through much of southern Africa. To assess the sustainability of this offtake, we estimated current harvest practice, population size structure, growth rates and seed production in protected and unprotected areas of Rukwa Region, western Tanzania. Results showed that adult P. angolensis are being removed very rapidly given its slow growth rate as determined from tree ring data, and that regeneration both inside and outside the protected area is very low. A simple model indicates that current harvest is unsustainable raising serious concerns about the long-term viability of this important hardwood species in miombo woodland. [Copyright &y& Elsevier] more...
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- 2002
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53. Growth patterns of Pterocarpus angolensis in savannas of the South African lowveld.
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Shackleton, Charlie M.
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PTEROCARPUS angolensis ,PLANT populations ,ALLOMETRY - Abstract
Pterocarpus angolensis D.C. is one of the most valuable indigenous timber species on the African continent south of the equator. Because of its high value, it is actively sought after in a number of countries, and wild populations are diminishing. However, attempts at artificial germination and growth trials have yielded poor results, thus, emphasis needs to be placed on sustainable management of existing populations. Success of in situ management will be enhanced if based on reliable data and knowledge regarding the growth patterns of this species within specific localities and countries. Such comprehensive data are lacking for several countries, including South Africa. This paper presents empirical data on a number of studies investigating the growth patterns of P. angolensis in the central lowveld savannas of South Africa, including phenology, annual diameter increment, size class structure, size of reproductive maturity, and morphometric relationships. The size class profile indicated that there was adequate recruitment of P. angolensis, but with constricted through growth from the suffrutex stage to the sapling stage. A small proportion of individuals attained reproductive maturity at 8 cm diameter, but most were bigger. All stems were reproductively mature by 26 cm diameter. This is below the minimum size for harvesting which is dictated by the need for a well developed heartwood. Annual growth was strongly related to stem size and rainfall during the growing season. Basal area increment of small stems was approximately four times greater than mature stems, and declined with increasing stem size. Over the 6-year-period and across all stem sizes, mean diameter increment was 4.5 mm per year. This rate is towards the lower end of the range of reported growth rates from other countries, and poses particular challenges for the sustainable management of this species in South African savannas. [Copyright &y& Elsevier] more...
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- 2002
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54. Annual diameter growth of Pterocarpus angolensis (Kiaat) and other woodland species in Namibia
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Hans Beeckman, Sam Van Holsbeeck, Esther Fichtler, Maaike De Ridder, Vera De Cauwer, and Jan Mertens
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0106 biological sciences ,Terminalia sericea ,Range (biology) ,Ecology ,Forest management ,Forestry ,Pterocarpus angolensis ,Woodland ,15. Life on land ,Management, Monitoring, Policy and Law ,Biology ,biology.organism_classification ,Baikiaea plurijuga ,010603 evolutionary biology ,01 natural sciences ,Burkea africana ,010606 plant biology & botany ,Nature and Landscape Conservation ,Woody plant - Abstract
Pterocarpus angolensis DC. (Kiaat) is one of the most preferred timber species that occurs in most southern African countries, including Namibia. In Namibia, the species mainly occurs across the five regions in the north-eastern part of the country where commercial timber harvesting has taken place since the 1940s. Information about the growth rates of the species is currently lacking, yet this information is required to determine a sustainable harvesting regime in Namibia. Therefore, more data about diameter increment is needed. This study aims to (1) determine annual diameter increment of P. angolensis in order to assist in planning for sustainable harvesting levels in the northern regions of Namibia, (2) compare growth of P. angolensis with other woodland species (Burkea africana, Baikiaea plurijuga, Terminalia sericea and Schinziophyton rautanenii) and (3) compare P. angolensis growth rates found in northern Namibia with those found in other countries within its distribution range. A total of 111 increment cores and 73 stem discs were collected for tree-ring analysis. The results showed that the average diameter increment of P. angolensis was higher in the Kavango regions (0.71–0.80 cm yr−1) than in neighbouring regions (0.35–0.41 cm yr−1). The northern Namibian growth rate is estimated as 0.50 cm yr−1 and lies within the growth range reported for southern Africa. Growth rates of P. angolensis were more than 0.10 cm yr−1 lower than rates of T. sericea and S. rautanenii, but 0.10 cm yr−1 higher than B. africana and B. plurijuga. Age–diameter relationships of P. angolensis may be a good indicator of tree age if a sufficient number of samples are obtained. Our results revealed a rotation cycle of 95–100 years to reach the minimum harvesting diameter of 45 cm in the Kavango regions. This rotation cycle should be a good guideline for sustainable management of this species. This study suggests that simple ring counting on increment cores and stem discs with additional diameter data can provide valuable information on growth rates and rotation cycles. Additional data and work on older trees (>100 years) is required to complete the age–diameter framework. more...
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- 2016
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55. Ecological characterization of anex situconservation plantation in south-eastern Mozambique
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Julieta L. Jetimane, Cacilda Chirizane, Elias Militão, Natasha Ribeiro, Ivete Maquia, Ana I. Ribeiro-Barros, Tereza Alves, Luis F. Goulao, Maria Manuela Veloso, and Camila de Sousa
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0106 biological sciences ,Germplasm ,biology ,Ecology ,Biodiversity ,Pterocarpus angolensis ,04 agricultural and veterinary sciences ,Afzelia quanzensis ,biology.organism_classification ,Forest genetic resources ,Ex situ conservation ,01 natural sciences ,Geography ,040103 agronomy & agriculture ,0401 agriculture, forestry, and fisheries ,Genetic erosion ,Ecology, Evolution, Behavior and Systematics ,Albizia adianthifolia ,010606 plant biology & botany - Abstract
Mozambican forests are exposed to risks that contribute to the loss of biodiversity and associated ecosystem services. Thus, ex situ conservation represents a key strategy to reduce genetic erosion. In this study, we evaluated the ecological status of the ex situ conservation plantation in Michafutene, Maputo province, one of the most important repositories of forest genetic resources in the country. Thirty plots were established in which all trees, shrubs and grass species were identified. A total of 2092 individuals spanning 39 species were scored. Afzelia quanzensis was the most important species (Importance Value Index – IVI = 203), but with a low silvicultural performance. Other important trees were Albizia adianthifolia (IVI = 32), Albizia versicolor (IVI = 16) and Pterocarpus angolensis (IVI = 12). A complementary genotyping analysis of A. quanzensis was conducted by intersimple sequence repeats, indicating that the germplasm collection has different provenances and represents a wide genetic pool. Thus, despite the poor management, there is a considerable potential for the conservation of A. quanzensis provided immediate and appropriate management activities are implemented to improve its ecological performance. Resume Mozambican forests are exposed to risks that contribute to the loss of biodiversity and associated ecosystem services. Thus, ex situ conservation represents a key strategy to reduce genetic erosion. In this study, we evaluated the ecological status of the ex situ conservation plantation in Michafutene, Maputo province, one of the most important repositories of forest genetic resources in the country. Thirty plots were established in which all trees, shrubs and grass species were identified. A total of 2092 individuals spanning 39 species were scored. Afzelia quanzensis was the most important species (Importance Value Index – IVI = 203), but with a low silvicultural performance. Other important trees were Albizia adianthifolia (IVI = 32), Albizia versicolor (IVI = 16) and Pterocarpus angolensis (IVI = 12). A complementary genotyping analysis of A. quanzensis was conducted by Inter-Simple Sequence Repeats, indicating that the germplasm collection has different provenances and represents a wide genetic pool. Thus, despite the poor management there is a considerable potential for the conservation of A. quanzensis provided immediate and appropriate management activities are implemented to improve its ecological performance. Les forets mozambicaines sont exposees a des risques qui peuvent contribuer a la perte de leur biodiversite et des services ecosystemiques qui y sont associes. La conservation ex situ constitue donc une strategie cle pour reduire cette erosion genetique. Dans cette etude, nous avons evalue le statut ecologique de la plantation ex situ de Michafutene, dans la province de Maputo, qui compte parmi les plus importants depositaires des ressources genetiques forestieres du pays. Trente parcelles ont ete etablies, ou toutes les especes d'arbres, arbustes et herbes ont ete identifiees. Au total, 2092 individus appartenant a 39 especes ont ete denombres. L'espece la plus importante etait Afzelia quanzensis (Indice de valeur d'importance – IVI = 32), mais avec une faible performance sylvicole. Parmi les autres arbres importants, citons Albizia adianthifolia (IVI = 32), Albizia versicolor (IVI = 16) et Pterocarpus angolensis (IVI = 12). Une analyse genotypique complementaire d’A. quanzensis a ete realisee au niveau des microsatellites (Inter-Simple Sequence Repeats – ISSR), qui indique que la collection de germoplasmes vient de differentes provenances et represente un large pool genetique. Donc, malgre une gestion mediocre, la conservation d’A. quanzensis garde un potentiel considerable pour autant que des activites de gestion appropriees soient realisees immediatement pour en ameliorer les performances ecologiques. . more...
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- 2016
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56. Miombo woodland under threat: Consequences for tree diversity and carbon storage
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Susannah M. Sallu, Jerome O'Connell, Andrew J. Dougill, Tim G. Benton, and Eleanor K.K. Jew
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0106 biological sciences ,Brachystegia ,010504 meteorology & atmospheric sciences ,Biodiversity ,Woodland ,Management, Monitoring, Policy and Law ,010603 evolutionary biology ,01 natural sciences ,Tanzania ,Ecosystem services ,IUCN Red List ,0105 earth and related environmental sciences ,Nature and Landscape Conservation ,biology ,Agroforestry ,fungi ,Diameter at breast height ,Pterocarpus angolensis ,Forestry ,Disturbance ,biology.organism_classification ,Geography ,Land use management ,Species richness - Abstract
Agriculture is expanding rapidly in the miombo woodlands of sub-Saharan Africa. Clear felling results in the loss of species and ecosystem services. The remaining woodland is used as a vital support system for the farming communities, and the impact of this utilisation on biodiversity and ecosystem service provision is not clear. Understanding these effects will aid the development of effective, sustainable land management strategies for multiple outcomes, including biodiversity conservation and resource utilisation. This study provides new data on miombo woodland tree species diversity, structure and carbon storage from a 8766 km2 landscape in south-western Tanzania, which is undergoing rapid conversion to tobacco cultivation. Human utilisation of the woodland was classified by ground surveys which recorded evidence of use (e.g. cut poles and timber, removal of bark and roots, access routes). Nine sites were surveyed and categorised into three groups: high, medium and low utilisation. To determine the effect of utilisation on the tree community stem density, diameter at breast height, tree species richness and carbon storage were recorded. In the low utilisation sites carbon storage was similar to that found in other miombo woodlands (28 t Ha−1), and the Shannon Wiener diversity score for tree species diversity was 3.44. However, in the high utilisation sites, tree species diversity (2.86) and carbon storage declined (14.6 t Ha−1). In areas of moderate utilisation diversity and carbon storage were maintained, but the structure of the woodland was affected, with a reduction of Class 1 (Diameter at Breast Height (DBH) < 10 cm) stems, demonstrating low recruitment which leads to a reduction in sustainability. Tree species richness and abundance demonstrated an intermediate disturbance effect in relation to utilisation, with highest levels at medium utilisation sites. Key miombo woodland species from the subfamily Caesalpinioideae in the two genera Brachystegia and Julbernardia were present in all sites, but the frequency of Brachystegia species declined by 60% from low to high utilisation. The IUCN near-threatened timber species Pterocarpus angolensis, highly protected in Tanzania, was harvested throughout the study site, and the majority of trees recorded were immature (DBH ⩽ 20 cm), suggesting that it is commercially extinct for the foreseeable future. These findings illustrate that in miombo woodlands with low to medium utilisation levels key miombo species are retained, and tree species diversity and carbon storage remains optimal. Sustainable land management plans need to regulate utilisation within miombo landscapes and retain areas of woodland. This will ensure their long term viability, and continue to support the 100 million people who are reliant on miombo woodlands for their goods and services. more...
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- 2016
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57. A Review of Pterocarpus angolensis DC. (Mukwa) an Important and Threatened Timber Species of the Miombo Woodlands
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Admus Uyapo Lumbile and Witness Mojeremane
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0106 biological sciences ,010504 meteorology & atmospheric sciences ,biology ,Agroforestry ,Pterocarpus angolensis ,General Medicine ,Woodland ,biology.organism_classification ,010603 evolutionary biology ,01 natural sciences ,Geography ,Botany ,Threatened species ,0105 earth and related environmental sciences - Published
- 2016
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58. Management implications of annual growth rings in Pterocarpus angolensis from Zimbabwe.
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Stahle, D.W., Mushove, P.T., Cleaveland, M.K., Roig, F., and Haynes, G.A.
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PTEROCARPUS angolensis ,FOREST management - Abstract
Discusses the forest management implications of the annual growth rings in Pterocarpus angolensis from Zimbabwe. Phenology; Ring anatomy; Cross-dating; Correlation between tree growth and climate; Diameter growth. more...
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- 1999
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59. The anatomy as a tool for the identification of the bark of Pterocarpus angolensis and Terminalia sericea
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Natasha Ribeiro, Fernanda Bessa, Ana I. Ribeiro-Barros, and Teresa Quilhó
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Terminalia sericea ,biology ,Astringent ,Pterocarpus angolensis ,Plant anatomy ,Anatomy ,biology.organism_classification ,complex mixtures ,Sclereid ,visual_art ,Automotive Engineering ,visual_art.visual_art_medium ,Bark ,Phloem ,Medicinal plants - Abstract
Pterocarpus angolensis and Terminalia sericea are two African species with medicinal potential. Despite the importance of their bark as a powerful astringent to treat various diseases it is poor described. In order to provide referential information for correct identification and standardization of the plant material, bark samples from each two species were collected and analyzed under light and electron microscopy. Some important anatomical features to identification were: the sclerenchyma tissue mostly in form of fibre-sclereids and the large secretory cells arranged in conspicuous rows or tangential bands in the conducting phloem in P. angolensis; the crystalliferous cells arranged in very regular tangential rows (druses) and the occurrence of large crystal cells near or including the tangential fibre bundles in T. sericea bark.The results obtained show that the anatomy of the bark can be used as an important subsidy in identification and standardization of the studied species contributing the scientific knowledge for more effective forms of scrutiny in preventing commercial adulteration of species. more...
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- 2020
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60. Data on dendrometric parameters, basic wood density, below- and aboveground biomass of tree species from Mangrove, Miombo, Mopane, and Mecrusse woodlands
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Tarquinio Mateus Magalhães, Rosta Mate, and Victoria Norberto Cossa
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ved/biology.organism_classification_rank.species ,Miombo ,lcsh:Computer applications to medicine. Medical informatics ,Mopane ,Mecrusse ,03 medical and health sciences ,0302 clinical medicine ,Agricultural and Biological Science ,Brachystegia spiciformis ,lcsh:Science (General) ,Mangrove ,030304 developmental biology ,0303 health sciences ,Multidisciplinary ,biology ,ved/biology ,Diameter at breast height ,Pterocarpus angolensis ,Forestry ,Afzelia quanzensis ,biology.organism_classification ,Julbernardia globiflora ,Avicennia marina ,Mozambique's forest ecosystems ,Tree and forest biomass ,lcsh:R858-859.7 ,Millettia stuhlmannii ,030217 neurology & neurosurgery ,lcsh:Q1-390 - Abstract
Mozambique is composed by the following forest types: Miombo, Mopane, Mecrusse, and Mangrove. Data on basic wood density at different height levels, tree component dry-mass, and other dendrometric parameters (root collar diameter, diameter at breast height, crown height, crown diameter, live crown length, and stem volume) for eight species typical of Miombo (Afzelia quanzensis Welw., Millettia stuhlmannii Taub., Pterocarpus angolensis DC., Brachystegia spiciformis Benth., and Julbernardia globiflora (Benth.) Troupin), Mopane (Colophospermum mopane Kirk ex J. Léonard), Mecrusse (Androstachys johnsonii Prain), and Mangrove (Avicennia marina (Forssk.)) forests collected from five provinces (Maputo, Gaza, Inhambane, Sofala, and Manica) of Mozambique are presented in this article. Biomass data of Miombo, Mecrusse, and Mopane woodlands were collected destructively, whereas those of Mangrove forests were collected using non-destructive methods. Keywords: Mozambique's forest ecosystems, Tree and forest biomass, Miombo, Mopane, Mecrusse, Mangrove more...
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- 2020
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61. The population dynamics and life-history attributes of a Pterocarpus angolensis DC. population in...
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Desmet, P.G. and Shackleton, C.M.
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PTEROCARPUS angolensis - Abstract
Examines the population dynamics and life-history attributes of a single Pterocarpus angolensis population in the Northern Province, South Africa. Use of matrix models in population biology; Elasticity values of life-history stages; Long-term survival greater than the life-span of a stem. more...
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- 1996
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62. Efficacy of Pterocarpus angolensis crude extracts against Candida krusei, Staphylococcus aureus, Streptococcus agalactiae and Escherichia coli
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Jones Victor Chipinga
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2. Zero hunger ,Minimum bactericidal concentration ,biology ,Traditional medicine ,010405 organic chemistry ,business.industry ,Pterocarpus angolensis ,General Medicine ,biology.organism_classification ,Antimicrobial ,medicine.disease_cause ,01 natural sciences ,3. Good health ,0104 chemical sciences ,010404 medicinal & biomolecular chemistry ,Streptococcus agalactiae ,Phytochemical ,Staphylococcus aureus ,Candida krusei ,Efficacy, Crude Extracts, Minimum Bactericidal Concentration (MBC), Minimum Inhibitory Concentration (MIC), Minimum Fungicidal Concentration (MFC), phytochemical ,medicine ,Medicinal plants ,business - Abstract
Background The medicinal plants used to treat different ailments in Malawi contain important phytochemicals which have bactericidal and anti-fungal properties. Pterocarpus angolensis, locally known as mlombwa tree, which is found in many parts of Malawi, is one such a plant and was studied. Aims In vitro analysis of the antimicrobial properties of Pterocarpus angolensis crude extracts on Staphylococcus aureus, Escherichia coli, Streptococcus agalactiae, Candida krusei and determination of the phytochemicals there in. Methods In this study, different organs of P. angolensis, a medicinal plant which is locally used to treat skin diseases, were qualitatively screened for the presence of phytochemical constituents and quantitatively assayed for the antimicrobial activity to ascertain their pharmaceutical potential. The aqueous, dichloromethane and methanolic extracts of the leaves, stem-bark, fruits and roots of the plant were tested against Escherichia coli, Staphylococcus aureus, Streptococcus agalactiae and Candida krusei by the macro tube dilution method. These pathogens were selected due to their significant contribution to infectious disease burden of most hospitals and also the fact that of late, they have shown signs of resistance to conventional antibiotics. Results The study revealed that P. angolensis contained tannins, flavonoids, saponins and terpenoids. All the extracts exhibited some antimicrobial activity against the test organisms. However, the activity of the extracts depended on concentration and microbial species. The minimum inhibition concentration (MIC) values of the extracts ranged from 0.166 g/ml to 0.01046 g/ml with the dichloromethane and methanolic extracts exhibiting more activity than the aqueous extracts. The minimum bactericidal concentration and minimum fungicidal concentration (MBC and MFC respectively) values of the extracts ranged from 0.166 g/ml to 0.0417 g/ml. Conclusion The results obtained indicate that Pterocarpus angolensis has both antibacterial and antifungal properties and could be used for the treatment of Taenia capitis (ring worm) and other ailments. Use of the isolated and purified compounds from P. angolensis could increase the susceptibility of the tested pathogenic microorganisms in this study. more...
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- 2018
63. PTEROCARPUS ANGOLENSIS CRUDE EXTRACTS INDUCE THE EXPRESSION OF COLLAGEN TYPE II IN ARTICULAR CARTILAGE IN VITRO
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Mapula Razwinani, Cornelius Cano Ssemakalu, Makwese Johannes Maepa, and Keolebogile Shirley Motaung
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biology ,Cartilage ,Histology ,Pterocarpus angolensis ,biology.organism_classification ,Molecular biology ,In vitro ,Chondrocyte ,03 medical and health sciences ,0302 clinical medicine ,medicine.anatomical_structure ,Complementary and alternative medicine ,Tissue engineering ,030220 oncology & carcinogenesis ,visual_art ,P. angolensis, medical plants, chondrocytes, collagen type II, arthritis ,Drug Discovery ,Botany ,medicine ,visual_art.visual_art_medium ,030211 gastroenterology & hepatology ,Bark ,Explant culture - Abstract
Background: Pterocarpus angolensis (P. angolensis) is a large deciduous tree native to Sub-Saharan Africa. This tree has traditionally been used to treat malaria, gonorrhoea, inflammation and wounds. The use of P. angolensis for tissue engineering has not been explored. This study investigated the potential of the bark and root water extracts of P. angolensis to induce the expression of collagen type II protein in the articular chondrocytes. Materials and Methods: Surface and middle zone chondrocytes, as well as explants, were stimulated with crude root and bark plant extracts at different concentrations. After 96 hours of stimulation, microscopic observation, XCELLigence assay and collagen type II ELISA, histology and immunohistochemistry assays were done. Results and Conclusion: Results showed no significant difference in the cell index between the controls and chondrocytes that had been treated with the plant extracts at concentrations of 15 and 30 μg/ml. A significant increase in the expression of collagen type II protein by the chondrocytes was observed and found to be optimal at a concentration of 30 μg/ml. There was an increase in the production of proteoglycans. However, the plant extracts at a concentration of 50 μg/ml induced apoptosis in the middle zone chondrocytes. These results show the potential of P. angolensis extracts in chondrocyte tissue regeneration. This potential could be exploited in the treatment of osteoarthritis. more...
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- 2015
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64. Simulation of Tropical Hardwood Processing – Sawing Methods, Log Positioning, and Outer Shape
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Dick Sandberg, Peter Bomark, Pedro Ah Shenga, and Olof Broman
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Engineering ,Engineering drawing ,Yield ,Environmental Engineering ,Yield (engineering) ,lcsh:Biotechnology ,ved/biology.organism_classification_rank.species ,Point cloud ,Bioengineering ,Saw method ,lcsh:TP248.13-248.65 ,Statistics ,Hardwood ,Waste Management and Disposal ,ved/biology ,business.industry ,Millettia stuhlmannii ,Skew ,Percentage point ,Pterocarpus angolensis ,business ,Rotation (mathematics) ,Positioning ,Volume (compression) ,Value - Abstract
To increase understanding of breakdown strategies for Mozambican timber, simulations were carried out using different sawing patterns that can be alternatives to the low degree of refinement performed for export today. For the simulations, 3D models of 10 Jambirre and 5 Umbila logs were used. The log shape was described as a point cloud and was acquired by 3D-laser scanning of real logs. Three sawing patterns (cant-sawing, through-and-through sawing, and square-sawing) were studied in combination with the log positioning variables skew and rotation. The results showed that both positioning and choice of sawing pattern had a great influence on the volume yield. The results also showed that the log grade had an impact on the sawing pattern that should be used for a high volume yield. The volume yield could be increased by 3 percentage points by choosing alternative sawing patterns for fairly straight logs and by 6 percentage points for crooked logs, compared to the worst choice of sawing pattern. more...
- Published
- 2015
65. Stem Volume Equations for Valuable Timber Species in Mozambique
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Rosta Mate, Almeida Sitoe, and Tord Johansson
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biology ,Renewable Energy, Sustainability and the Environment ,ved/biology ,Geography, Planning and Development ,ved/biology.organism_classification_rank.species ,Crown (botany) ,Potential candidate ,Forestry ,Pterocarpus angolensis ,Afzelia quanzensis ,Management, Monitoring, Policy and Law ,biology.organism_classification ,Volume equations ,Botany ,Millettia stuhlmannii ,Tree species ,Food Science ,Mathematics ,Volume (compression) - Abstract
Development of stem volume for umbrella-shaped crown trees remains a big challenge for efficient use of forest resources in Mozambique. In this study, species-specific stem volume equations were developed for the first time for three of the most important timber species in Mozambique: Afzelia quanzensis Welw. (Chanfuta), Millettia stuhlmannii Taub. (Jambire), and Pterocarpus angolensis D.C. (Umbila). The study was carried out at three locations in Mozambique: Inhaminga, Mavume, and Tome covering 58 trees from which, 24 of Chanfuta, 15 of Jambire, and 19 of Umbila. The volume of the sampled stem sections (logs) was calculated using Smalian’s formula, where stem volume total was obtained through the sum of the respective defined sections. Using a nonlinear procedure, different volume models were tested for each tree species independently. The coefficient of the determination of the tested equations in the tree species ranged from .90 to .95, making the equations potential candidate models for the stem volum... more...
- Published
- 2015
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66. Predicting site productivity of the timber tree Pterocarpus angolensis
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Bart Muys, F. Patrick Graz, Jan Mertens, Vera De Cauwer, Esther Fichtler, Hans Beeckman, and Sam Van Holsbeeck
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0106 biological sciences ,Abiotic component ,Forest inventory ,Biotic component ,010504 meteorology & atmospheric sciences ,biology ,Agroforestry ,Forestry ,Pterocarpus angolensis ,Woodland ,15. Life on land ,Seasonality ,biology.organism_classification ,medicine.disease ,010603 evolutionary biology ,01 natural sciences ,Basal area ,Productivity (ecology) ,medicine ,Environmental science ,basal area, boosted regression trees, diameter growth, miombo, site form ,0105 earth and related environmental sciences - Abstract
Pterocarpus angolensis is an important timber tree of the miombo woodlands of sub-Saharan Africa. The species only grows in natural mixed forests and little is known about is productivity potential. This study aimed at investigating productivity of P. angolensis on a local scale in Namibia and Angola and on a regional scale in southern Africa. The most commonly accepted productivity indicator is stem diameter increment and this was used to study productivity at a regional scale. Indicators of productivity used at the local scale were basal area, proportional basal area and site form, which were derived from 217 forest inventory plots in Namibia and Angola. The productivity measures were modelled with abiotic site factors; biotic factors were added for the local scale. Results indicated that the most consistent site factors at local and regional scale were not related to climate but to forest cover, with the species having a competitive advantage in more open forests. Mean annual diameter increment in the open forests of Namibia was 0.51 cm after 50 years. Boosted regression tree models at a local scale showed that species presence can be modelled more successfully than species basal area, proportional basal area (correlation of 0.72 vs 0.56 and 0.45, respectively) and site form. The sites with the highest productivity of P. angolensis at the local scale had a temperature seasonality below 34.5 °C, a slope of less than 1.5°, tree cover less than 20% and stand basal area higher than 9 m2 ha−1. The results can assist in establishing a site-dependent growth model for the species and direct forest and fire management towards the most productive areas. Keywords: basal area, boosted regression trees, diameter growth, miombo, site form more...
- Published
- 2017
67. DESPERDÍCIO DE MADEIRA NA CONCESSÃO FLORESTAL DA INDÚSTRIA SOTOMANE NA PROVÍNCIA DA ZAMBÉZIA, MOÇAMBIQUE
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Salvador José António Nanvonamuquitxo, Fidel Góngora Rojas, and Noé dos Santos Ananias Hofiço
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Wood waste ,Swartzia ,biology ,Manejo de Florestas Nativas ,Ecologia Florestal ,Mensuração Florestal ,Mineralogy ,Pterocarpus angolensis ,Forestry ,biology.organism_classification ,Miombo woodland - Abstract
O objetivo desta pesquisa foi avaliar a viabilidade do reaproveitamento de desperdicio de madeira no processo de corte na concessao florestal da industria Sotomane na provincia da Zambezia em Mocambique. Para tal, na area de corte demarcou-se 2,0 ha onde foram mensurados desperdicio de madeira de duas especies nomeadamente Pterocarpus angolensis DC., e Swartzia madagascariensis Desv., tambem foi determinado o rendimento volumetrico por cada arvore abatida pela industria. Cerca de 85% da madeira desperdicada no cepo e 36% desperdicada em galhos de Swartzia madagascariensis apresentaram diâmetro acima de 30 cm. Mais de 60% de madeira desperdicada no cepo e galhos de Pterocarpus angolensis apresentaram diâmetro acima de 50 cm. Em geral os comprimentos das pecas de madeira desperdicadas para ambas especies excederam 200 cm, exceto os desperdicios de cepos de Swartzia madagascariensis , que apresentaram-se nas classes de 10 a 50 cm. Tambem observou-se que apenas 44,32% de madeira cortada pela industria e aproveitada, e os restantes 55,68% permanecem na floresta como desperdicio. As dimensoes dos desperdicios de madeira permitem que a industria reaproveite como forma de criar oportunidades lucrativas e melhorar a rentabilidade do produto principal. Palavras-chave: Floresta de Miombo; Corte de madeira; Industria Sotomane; Mocuba WOOD WASTE OF THE SOTOMANE LOGGING CONCESSION IN ZAMBEZIA PROVINCE, MOZAMBIQUE ABSTRACT The aim of this study was to evaluate the viability of reuse wood waste from logging of the Sotomane logging concession in Zambezia province, Mozambique. For this purpose, in a demarcated area of 2.0 ha the wood waste was measured from two species namely Pterocarpus angolensis DC., and Swartzia madagascariensis Desv. The volumetric efficiency per unit of tree that was harvest by the company was calculated. About 85% of the wood wasted on stocks and 36% of the branch of Swartzia madagascariensis presented a diameter above 30 cm. More than 60% of wood wasted on stocks and branch of Pterocarpus angolensis had diameters above 50 cm. In general the lengths of wood waste for both species have exceeding 200 cm, excluding wood waste from stocks of Swartzia madagascariensis where showed between 10 to 50 cm. It also was observed that only 44.32% of all wood harvest by the company was used for product and another 55.68% remained in the forest as wood waste. The size of the wood wasted allows that the company can reuse them, creating lucrative opportunities and improving the profitability of the main industry product. Keywords: Miombo woodland, Logging, Sotomane Company, Mocuba. DOI: http://dx.doi.org/10.5935/2318-7670.v05n03a09 more...
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- 2017
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68. Alternative remedies and approaches used by resources-challenged farmers in the management of cattle black-leg disease in Umzingwane district, Matabeleland South, Zimbabwe
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V. Maphosa, Voster Muchenje, Daud Nyosi Ndhlovu, S. Moyo, Patrick J. Masika, S. L. Ndlovu, and B. Moyo
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Veterinary medicine ,biology ,business.industry ,Clostridium chauvoei ,Blackleg ,Pterocarpus angolensis ,Beef cattle ,medicine.disease ,biology.organism_classification ,Lumpy skin disease ,Diospyros mespiliformis ,medicine ,Herd ,business ,Sclerocarya birrea - Abstract
Cattle productivity has been minimized by the occurrence of diseases such as blackleg. This study was conducted to determine and document how resource-challenged farmers of Umzingwane district of Zimbabwe use alternative remedies to manage cattle blackleg cases. Random sampling was used to select 90 beef cattle farmers who were interviewed using a structured questionnaire. Results of the study revealed that cattle owners (86%) reported blackleg disease to be the most important disease followed by ehrlichiosis (23%) and lumpy skin disease (5%). Almost 71% of the respondents reported having experienced cases of blackleg in their herd in the past three years. Few farmers (22%) used conventional vaccines, whereas the majority (78%) used alternative remedies to manage the disease, which included; hot water (80%), hot iron (78%), Potassium permanganate (10%), Ihlwili (60%), Ricinis communis (5%), Pterocarpus angolensis (7%), Sclerocarya birrea (8%), Diospyros mespiliformis (3%), Gardenia spatulifolia (2%). Some of these remedies (P. angolensis, S. birrea, D. mespiliforms, G. spatulifolia) were believed to prevent the occurrence of the diseases, while hot water and hot iron were used for treatment of infected animals. The study revealed that most resource-challenged farmers in Umzingwane district of Zimbabwe used alternative remedies to manage blackleg infections in cattle. Key words: Alternative remedies, blackleg, cattle, Clostridium chauvoei. more...
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- 2014
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69. Potential, realised, future distribution and environmental suitability for Pterocarpus angolensis DC in southern Africa
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Rasmus Revermann, Vera De Cauwer, Antonio Trabucco, and Bart Muys
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Ecological niche ,biology ,Ecology ,Range (biology) ,Species distribution ,Climate change ,Forestry ,Pterocarpus angolensis ,Management, Monitoring, Policy and Law ,biology.organism_classification ,Environmental data ,Deforestation ,Threatened species ,Environmental science ,Physical geography ,Nature and Landscape Conservation - Abstract
The deciduous tree species Pterocarpus angolensis occurs in the dry woodlands of southern Africa and grows under a broad range of environmental conditions. It is threatened by overharvesting due to its valuable timber (Blood wood, Kiaat) and by land use changes. Information on the most suitable environmental conditions for the species is often old and anecdotal, while available data on its occurrence refer to range extent and not to distribution. Species distribution models (SDM) could provide more accurate information on distribution and environmental requirements and thereby assist sustainable management of this tree species. Maxent models were developed to estimate the potential, realised and future distribution of P. angolensis and to identify detailed environmental requirements. Occurrences data of the species were sourced from herbaria and other published sources; environmental data from global GIS databases. Relevant environmental predictors were selected through a jack-knife test of the first model runs. The addition of information on competing species, fires and deforestation was tested to determine realised distribution. Model quality was evaluated with an independent presence-absence dataset. The model was projected with two different climate change scenarios to study their effect on the distribution by 2080. Results show that a potential distribution map can be obtained with good discrimination of the presence of the species (AUC 0.83) and fairly good calibration (correlation coefficient 0.61). Range extent and environmental requirements are more detailed than those described in literature. The distribution of the species is mainly influenced by the amount of summer rainfall, by the minimum temperature in winter and by temperature seasonality. Potential and realised distributions are very similar, with Madagascar as major exception where the species can grow but does not occur. Adding the fire history of the last 13 years or the distribution maps of potentially competing species as predictor variables did not improve the distribution model. It did illustrate that P. angolensis is mainly found in areas with annual fire frequency below 45% and that only a few of the tested species show signs of competition. Using a forest cover map improved the realised distribution slightly (Kappa coefficient 0.64). Climate change can decrease the species range considerably, especially in the west, threatening species existence in Namibia and Botswana. On the other hand, the species’ occurrence is predicted to increase in Zambia. more...
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- 2014
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70. The Characterization of Wood Species from Mozambique as a Fuel
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Inácio Lhate, Carlos Alberto Cuvilas, Nasko Terziev, and R. Jirjis
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biology ,Renewable Energy, Sustainability and the Environment ,ved/biology ,ved/biology.organism_classification_rank.species ,Energy Engineering and Power Technology ,Acacia ,Biomass ,Pterocarpus angolensis ,Afzelia quanzensis ,biology.organism_classification ,Horticulture ,Fuel Technology ,Nuclear Energy and Engineering ,Dry weight ,Bioenergy ,Botany ,Hardwood ,Millettia stuhlmannii - Abstract
The efficient utilization of fuelwood as a source of energy is strongly dependent on the properties of the biomass. This study characterizes common hardwood species from Mozambique and evaluates their quality as a fuel. Disc samples, taken at breast height, from Afzelia quanzensis Welwn, Millettia stuhlmannii Taub, Pterocarpus angolensis DC, Sterculia appendiculata K. Schum, Pericopsis angolensis Meeuwen, Acacia nigrescens Oliv., Pseudolachostylis maprounaefolia Pax, and Icuria dunensis Wieringa, were collected from three provinces in Mozambique. Chemical and physical properties were analyzed. The raking of the species as fuel was performed using fuelwood value index. The higher heating value varied between 19.38 and 21.50 MJ/kg dry weight. The concentration of lignin ranged from 21.96 up to 36.69% weight dry basis (wt% d.b.), and ash free. All studied species showed very low concentrations of Si, S, and Cl. Ash content varied between 0.76–3.71 wt% (d.b.), while the basic density ranged from 536 to 1,111 ... more...
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- 2014
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71. Evaluation of antimicrobial activity of Pterocarpus extracts
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Rui Cao, Cai Mengke, Bin Xu, Liping Zhang, Cong Cao, and Huangfei Lv
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Ethanol ,biology ,Traditional medicine ,Pterocarpus angolensis ,Pterocarpus soyauxii ,biology.organism_classification ,Antimicrobial ,chemistry.chemical_compound ,chemistry ,Pterocarpus ,Gloeophyllum trabeum ,Ethanol fuel ,Phenols ,Agronomy and Crop Science - Abstract
Pterocarpus is one of the most widely used timber resources on the market. But the utilization rate has been low. In order to improve the utilization of Pterocarpus processing residue, as well as explore the reason of its good decay-resistance. In this study, the antifungal mechanism of Peterocarpes spp., aqueous extracts and ethanol extracts of three Pterocarpus species were studied. The antimicrobial active factors were analyzed by gas chromatography-mass spectrometry. Italian poplar (Populus euramevicana cv. ‘I-214’) wood was immersed in the extracts and then inoculated with both Coriolus versicolor and Gloeophyllum trabeum. The antimicrobial properties of the extracts were studied, and the mechanism underlying these properties were analyzed using gas chromatography-mass spectrometry. The results showed that the yield of ethanol extracts from the three Pterocarpus species was significantly higher than that of aqueous extracts. Pterocarpus soyauxii and Pterocarpus macarocarpus produced the highest yield of ethanol extracts (28.59%) and aqueous extracts (14.31%), respectively. With increasing concentrations, the antimicrobial activities of aqueous extracts of Pterocarpus angolensis and Pterocarpus macarocarpus gradually increased, while the antimicrobial activity of other extracts remained constant. Gas chromatography-mass spectrometry analysis identified a considerable number of phenols, ketones, amines, and aromatic compounds in all extracts, which is consistent with their antimicrobial activity and suggests synergism among the chemicals. more...
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- 2019
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72. Climate change threatens some miombo tree species of sub-Saharan Africa
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Mary V. Ashley and Percy Jinga
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0106 biological sciences ,Brachystegia ,Ecology ,biology ,Brachystegia boehmii ,Forestry ,Pterocarpus angolensis ,Plant Science ,Afzelia quanzensis ,biology.organism_classification ,Albizia ,Baikiaea plurijuga ,010603 evolutionary biology ,01 natural sciences ,Pterocarpus rotundifolius ,Brachystegia spiciformis ,Ecology, Evolution, Behavior and Systematics ,010606 plant biology & botany - Abstract
Climate change is affecting the distribution of species globally. Predicting the distribution of species under climate change is important for conservation of biodiversity. The aim of this research was to model the current distribution of miombo woodlands of sub-Saharan Africa using seventeen miombo tree species, and to project their distributions under different climate change scenarios. A maximum entropy method, Maxent, was used to model the distributions of the seventeen representative tree species, Albizia antunesiana, Afzelia quanzensis , Baikiaea plurijuga , Brachystegia bakeriana, Brachystegia boehmii, Brachystegia longifolia, Brachystegia microphylla, Brachystegia spiciformis, Brachystegia utilis, Cryptosepalum exfoliatum, Guibourtia coleosperma, Isoberlinia angolensis , Julbernadia globiflora , Julbernadia paniculata , Pericopsis angolensis Pterocarpus angolensis , and Pterocarpus rotundifolius . A total of 3 429 occurrence records, nineteen bioclimatic variables, monthly precipitation, minimum and maximum temperatures, soil characteristics and altitude were used in modeling. Distributions were hindcasted to the Mid-Holocene and forecasted to 2050 and 2070 under all four Representative Concentration Pathways (RCPs). Hindcasting showed that ranges for A. antunesiana , B. bakeriana , B. boehmii , C. exfoliatum , G. coleosperma and Pterocarpus angolensis were larger in the Mid-Holocene than they are currently, while the ranges of the other species were constricted during this period. When forecasted, range contraction was observed for nine species, A. quanzensis , A. antunesiana , B. microphylla , B. spiciformis , B utilis , C. exfoliatum , J. globiflora , Pericopsis angolensis and P. rotundifolius . Range expansion was observed in the other eight species. Range contraction was acute in 2070 under RCP8.5 for A. quanzensis (-13%), A. antunesiana (-15%) and B. microphylla (-14%). Species whose forecasted ranges contracted should be prioritized for mitigation against climate change. All species should be protected from anthropogenic threats since most are unsustainably harvested. more...
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- 2019
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73. Julbernardia paniculata and Pterocarpus angolensis: From Ethnobotanical Surveys to Phytochemical Characterization and Bioactivities Evaluation.
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Santos, Eugénia Solange, Luís, Ângelo, Gonçalves, Joana, Rosado, Tiago, Pereira, Luísa, Gallardo, Eugenia, Duarte, Ana Paula, Silva, Artur M. S., and Pinto, Diana Cláudia
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- *
AFRICAN traditional medicine , *HIGH performance liquid chromatography , *GRANULATION tissue , *BARK , *DIGESTIVE organs , *PLANT species , *TERPENES , *PHENOLS - Abstract
Julbernardia paniculata and Pterocarpus angolensis are two plant species with important application in African traditional medicine, particularly in Angola, in the treatment of several diseases. However, scientific studies concerning these species are scarce. The goal of this work was to know better which medicinal approaches are used by the Huíla population in Angola by means of ethnobotanical surveys. Furthermore, extracts of both plants were phytochemically characterized. Antioxidant, anti-inflammatory, wound-healing activities, and potential cytotoxicity were also studied. With this study it was possible to verify that 67% of the individuals that use medicinal plants are women, and their main therapeutic uses are the treatment of problems of the digestive system and skin disorders. Barks of J. paniculata and leaves of P. angolensis are the most often used plant parts. Through high-performance liquid chromatography coupled to diode-array detector (HPLC-DAD) and GC-MS it was possible to characterize the chemical composition of the two species, which are rich in phenolic compounds, terpenes, terpenoids, sesquiterpenoids and fatty acids. Both plants showed to possess antioxidant, anti-inflammatory proprieties, and wound-healing activity. To the best of our knowledge, this is the most comprehensive study of these two species and the first ethnobotanical and ethnopharmacological study of medicinal plants from this region of Angola. [ABSTRACT FROM AUTHOR] more...
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- 2020
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74. A tree-ring based comparison of Terminalia superba climate–growth relationships in West and Central Africa
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Wannes Hubau, Jan Van den Bulcke, Joris Van Acker, Maaike De Ridder, Hans Beeckman, and Valerie Trouet
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Wet season ,Ecology ,biology ,Physiology ,Forestry ,Pterocarpus angolensis ,Plant Science ,Dendroclimatology ,biology.organism_classification ,Terminalia superba ,La Niña ,Geography ,Brachystegia spiciformis ,Dry season ,Dendrochronology - Abstract
Tropical lowland forests are characterized by humid climate conditions with interannual variations in amount of precipitation, length of dry season, and relative humidity. The African tree species, Terminalia superba Engl. & Diels has a large distribution area and potentially incorporates these variations in its tree rings. Tree ring analysis was performed on 60 plantation trees (increment cores) and 41 natural trees (stem disks) from Ivory Coast and the Congolese Mayombe Forest. Natural forests and old plantations (50–55 years) showed similar growth patterns. Regional chronologies were developed for the two sample regions and showed a long-distance relationship for the period 1959–2008. Growth in the Mayombe was associated with early rainy season precipitation, but no relation was found between tree growth and precipitation in Ivory Coast. Congolese trees possibly show a higher climate-sensitivity than Ivorian trees, because precipitation in the Mayombe is more limiting, and Congolese T. superba trees are found closer to the margins of their distribution. Likewise, tree growth in the Mayombe was also influenced by the SSTs of the Gulf of Guinea and the South Atlantic Ocean during the early rainy season. However, tree growth was influenced by ENSO in both regions. In the Mayombe, La Nina years were associated with stronger tree growth whereas in Ivory Coast, El Nino years corresponded with stronger tree growth. The presented relation between ENSO, precipitation and tree growth is original for equatorial African forests, suggesting an influence of global climate variability on tree growth. more...
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- 2013
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75. The Isoflavonoids
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Wong, E., Harborne, J. B., editor, Mabry, T. J., editor, and Mabry, Helga, editor
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- 1975
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76. The Effect of Log Position Accuracy on the Volume Yield in Sawmilling of Tropical Hardwood
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Dick Sandberg, Peter Bomark, Pedro Ah Shenga, and Olof Broman
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0106 biological sciences ,Engineering drawing ,Environmental Engineering ,Offset (computer science) ,Yield (engineering) ,Rotation ,lcsh:Biotechnology ,Bioengineering ,Soil science ,Skew ,01 natural sciences ,Offset ,Position (vector) ,lcsh:TP248.13-248.65 ,010608 biotechnology ,Hardwood ,Waste Management and Disposal ,Mathematics ,040101 forestry ,Annan maskinteknik ,biology ,Pterocarpus angolensis ,04 agricultural and veterinary sciences ,biology.organism_classification ,Volume (thermodynamics) ,0401 agriculture, forestry, and fisheries ,Log positioning error ,Other Mechanical Engineering ,Tropical species ,Rotation (mathematics) - Abstract
This study investigated the effect of the positioning of the log before sawing on the volume yield of sawn timber from tropical hardwood species. Three positioning parameters were studied, the offset, skew, and rotation, combined with two sawing patterns of cant-sawing and through-and-through sawing. A database consisting of two tropical hardwood species with very different outer shapes, jambirre (Millettia stuhllmannii Taub.) and umbila (Pterocarpus angolensis DC.), was used to simulate the sawing process. The result of the simulation revealed that, according to the combined effect of offset, skew, and rotation positioning, the positioning of the log before sawing is extremely important to achieve a high volume yield of sawn timber. The positioning parameter that has the highest effect on the volume yield is the rotation, and the variation in the volume yield associated with a deviation in the positioning can reduce the volume yield of sawn timber by between 7.7% and 12.5%. Validerad; 2016; Nivå 2; 2016-11-23 (andbra) more...
- Published
- 2016
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77. Community Knowledge in Restoring Trees in Controversial Forest Hot Spots: Case of Nkanya-Lusewa rivers catchment area in Zomba-Malosa Forest Reserve, Malawi
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Gift Gladson Moyo, Sosten Chiotha, and Marlene Chikuni
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Geography ,Eucalyptus camaldulensis ,biology ,Agroforestry ,Tree planting ,Reforestation ,Pterocarpus angolensis ,Forestry ,Catchment area ,Firewood ,biology.organism_classification ,Uapaca kirkiana ,Forest restoration - Abstract
Trees planted by the Forestry Department and other institutions in Nkanya-Lusewa river hotspot in Zomba-Malosa forest reserve in Domasi area in Malawi have not been surviving because villagers have been defiantly encroaching the forest reserve and this has led to many problems such as intermittent piped water supply in dry season. The study was done to investigate the community’s knowledge on better forest restoration strategies in the hotspot and it involved 591 interviewees selected from 2,111 households in 25 villages. Several sampling methods were used such as cluster, purposeful, snowballing and accessibility methods. The majority of people in the area know the importance of forests and impacts of deforestation mostly citing direct-use values such as firewood, rainfall, construction materials, medicine, and water catchment conservation. Many villagers (56%) view previous reforestation efforts in the area as being unsuccessful while 34% considered them as successful. Seedling uprooting, bush fires and lack of post-planting care are the key activities that lead to high mortality of young trees. Most respondents (28%) indicated that yearly tree planting must fully involve the community and that garden owners must provide post-planting care (19%) in their prohibited gardens. Khaya anthotheca, Senna siamea, Eucalyptus camaldulensis, Pterocarpus angolensis, Mangifera indica, Toona ciliata, Breonadia salicina, Uapaca kirkiana, and Albizia lebbeck were highly preferred for their various characteristics and purposes. Most villagers (96.1%) are willing to participate in forestry activities as long as their views are appreciated while 3.4% of them indicated unwillingness because they are busy with personal work, are aged and/or sickly. more...
- Published
- 2016
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78. Patterns of forest composition and their long term environmental drivers in the tropical dry forest transition zone of southern Africa
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Bart Muys, Miya Kabajani, Vera De Cauwer, Raf Aerts, and Coert J. Geldenhuys
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0106 biological sciences ,Tropical and subtropical dry broadleaf forests ,Baikiaea woodland ,010504 meteorology & atmospheric sciences ,ved/biology.organism_classification_rank.species ,boosted regression trees ,Ochna pulchra ,Ecological succession ,Woodland ,Baikiaea plurijuga ,010603 evolutionary biology ,01 natural sciences ,Shrub ,Basal area ,lcsh:QH540-549.5 ,Miombo Ecoregion ,Climate change ,Ecology, Evolution, Behavior and Systematics ,0105 earth and related environmental sciences ,Nature and Landscape Conservation ,Ecology ,biology ,ved/biology ,Agroforestry ,Tree community ,Forestry ,Pterocarpus angolensis ,Disturbance ,biology.organism_classification ,Namibia ,Geography ,lcsh:Ecology - Abstract
Background: Tropical dry forests cover less than 13 % of the world’s tropical forests and their area and biodiversity are declining. In southern Africa, the major threat is increasing population pressure, while drought caused by climate change is a potential threat in the drier transition zones to shrub land. Monitoring climate change impacts in these transition zones is difficult as there is inadequate information on forest composition to allow disentanglement from other environmental drivers. Methods: This study combined historical and modern forest inventories covering an area of 21,000 km2 in a transition zone in Namibia and Angola to distinguish late succession tree communities, to understand their dependence on site factors, and to detect trends in the forest composition over the last 40 years. Results: The woodlands were dominated by six tree species that represented 84 % of the total basal area and can be referred to as Baikiaea - Pterocarpus woodlands. A boosted regression tree analysis revealed that late succession tree communities are primarily determined by climate and topography. The Schinziophyton rautanenii and Baikiaea plurijuga communities are common on slightly inclined dune or valley slopes and had the highest basal area (5.5 – 6.2 m2 ha−1). The Burkea africana - Guibourtia coleosperma and Pterocarpus angolensis – Dialium englerianum communities are typical for the sandy plateaux and have a higher proportion of smaller stems caused by a higher fire frequency. A decrease in overall basal area or a trend of increasing domination by the more drought and cold resilient B. africana community was not confirmed by the historical data, but there were significant decreases in basal area for Ochna pulchra and the valuable fruit tree D. englerianum. Conclusions: The slope communities are more sheltered from fire, frost and drought but are more susceptible to human expansion. The community with the important timber tree P. angolensis can best withstand high fire frequency but shows signs of a higher vulnerability to climate change. Conservation and climate adaptation strategies should include protection of the slope communities through refuges. Follow-up studies are needed on short term dynamics, especially near the edges of the transition zone towards shrub land. ispartof: Forest Ecosystems vol:3 issue:1 status: published more...
- Published
- 2016
79. GC-MS Analysis and Preliminary Antimicrobial Activity of Albizia adianthifolia (Schumach) and Pterocarpus angolensis (DC)
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Runner R. T. Majinda and Mustapha N Abubakar
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0301 basic medicine ,Friedelin ,lcsh:Medicine ,01 natural sciences ,GC-MS ,NMR ,antimicrobial activity ,A. adianthifolia ,P. angolensis ,Palmitic acid ,03 medical and health sciences ,chemistry.chemical_compound ,General Environmental Science ,Lupeol ,Stigmasterol ,biology ,Traditional medicine ,010405 organic chemistry ,Chemistry ,lcsh:R ,General Engineering ,Pterocarpus angolensis ,biology.organism_classification ,Antimicrobial ,0104 chemical sciences ,Oleic acid ,030104 developmental biology ,Biochemistry ,General Earth and Planetary Sciences ,Albizia adianthifolia - Abstract
The non-polar components of two leguminoceae species Albizia adianthifolia (Schumach), and Pterocarpus angolensis (DC) were investigated. GC-MS analysis of the crude n-hexane and chloroform extracts together with several chromatographic separation techniques led to the identification and characterization (using NMR) of sixteen known compounds from the heartwood and stem bark of Albizia adianthifolia and Pterocarpus angolensis respectively. These constituents include, n-hexadecanoic acid (palmitic acid) 1, oleic acid 2, chondrillasterol 3, stigmasterol 4, 24S 5α-stigmast-7-en-3β-ol 5, 9,12-octadecadienoic acid (Z,Z)-, methyl ester 6, trans-13-octadecanoic acid, methyl ester 7, tetradecanoic acid 8, hexadecanoic acid, methyl ester 9, octadecanoic acid 10, tetratriacontane 11, 7-dehydrodiosgenin 12, lupeol 13, stigmasta-3,5-diene-7-one 14, friedelan-3-one (friedelin) 15, and 1-octacosanol 16. Using agar over lay method, the preliminary antimicrobial assay for the extracts was carried out against bacterial (E. coli, P. aeruginosa, B. subtilis, S. aueus) and a fungus/yeast (C. albicans) strains. The n-hexane and chloroform extracts of A. adianthifolia showed the best activity against E. coli with minimum inhibition quantity (MIQ) of 1 µg each while the remaining exhibited moderate-to-weak activity against the test microorganisms. more...
- Published
- 2016
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80. Ethno-veterinary control of bovine dermatophilosis and ticks in Zhombe, Njelele and Shamrock resettlement in Zimbabwe
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Patrick J. Masika and Daud Nyosi Ndhlovu
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Adult ,Male ,Veterinary Medicine ,Zimbabwe ,Health Knowledge, Attitudes, Practice ,Veterinary medicine ,food.ingredient ,Dichrostachys cinerea ,Ethnobotany ,Ximenia caffra ,Cattle Diseases ,Catunaregam spinosa ,Young Adult ,Ticks ,food ,Food Animals ,Surveys and Questionnaires ,Actinomycetales ,Animals ,Humans ,Medicine ,Tick Control ,Animal Husbandry ,Medicinal plants ,Aged ,Plants, Medicinal ,biology ,business.industry ,Pterocarpus angolensis ,Skin Diseases, Bacterial ,Middle Aged ,Animal husbandry ,biology.organism_classification ,Tick Infestations ,Cattle ,Female ,Animal Science and Zoology ,Livestock ,Plant Preparations ,business ,Actinomycetales Infections ,Phytotherapy - Abstract
A structured questionnaire survey was conducted to determine the ethno-veterinary practices and other control methods used by smallholder farmers for the management of bovine dermatophilosis and ticks. A total of 153 farmers were interviewed from Njelele, Zhombe communal and Shamrock resettlement areas. Crop production contributed most to livelihoods (83.2 %) while livestock contributed 9.0 %. Over 90 % of the respondents had attended school up to primary level, with 11.4 % undergoing animal health and husbandry training. Treatment of livestock diseases was practised by 96 % of the farmers, and 49.7 % of these farmers used ethno-veterinary medicines. Across the study sites, dermatophilosis was controlled using the following plants: Cissus quadrangularis (59.7 %), Catunaregam spinosa (10.5 %), Pterocarpus angolensis (10.5 %), Kalanchoe lanceolata (5.3 %), Aloe chabaudii (3.5 %), Cassia abbreviata (1.8 %), Dichrostachys cinerea (1.8 %), Urginea sanguinea (1.8 %), Ximenia caffra (1.8 %) and a plant locally called umfanawembila (1.8 %). Carica papaya and two plants, locally called mugimbura and umdungudungu, were used for tick control, and these were reported once from Njelele communal. Other control methods, besides plants or conventional drugs, were used by 28 % of the farmers for the treatment of dermatophilosis and ticks. Some farmers (14.4 %) claimed that ethno-veterinary medicines performed better than conventional drugs. The study revealed that farmers used ethno-veterinary medical practices for the treatment of dermatophilosis but rarely for tick control. more...
- Published
- 2012
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81. Genetic Diversity in Pterocarpus angolensis Populations Detected by Random Amplified Polymorphic DNA Markers
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Ezekiel Amri and Florence Mamboya
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Genetics ,Genetic diversity ,biology ,Genetic marker ,Pterocarpus angolensis ,biology.organism_classification - Published
- 2012
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82. Botryosphaeriaceae associated withPterocarpus angolensis(kiaat) in South Africa
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James William Montague Mehl, Bernard Slippers, Michael J. Wingfield, and Jolanda Roux
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0106 biological sciences ,0301 basic medicine ,Fusicoccum ,Lasiodiplodia ,Pterocarpus ,Physiology ,Polymerase Chain Reaction ,010603 evolutionary biology ,01 natural sciences ,Endophyte ,Trees ,South Africa ,03 medical and health sciences ,Peptide Elongation Factor 1 ,Ascomycota ,DNA, Ribosomal Spacer ,Botany ,Genetics ,DNA, Fungal ,Molecular Biology ,Phylogeny ,Ecology, Evolution, Behavior and Systematics ,Plant Diseases ,Base Sequence ,Virulence ,biology ,Pterocarpus angolensis ,Sequence Analysis, DNA ,Cell Biology ,General Medicine ,030108 mycology & parasitology ,Botryosphaeriaceae ,biology.organism_classification ,Diplodia ,Taxon ,DNA, Intergenic ,Lasiodiplodia theobromae - Abstract
There have been several recent reports of Pterocarpus angolensis (kiaat) trees dying in South Africa, Zambia and Zimbabwe, where this tree is used in traditional medicine and is a valuable source of timber for woodcarving and furniture. A survey of material from diseased P. angolensis trees in South Africa yielded isolates of the Botryosphaeriaceae, an important fungal family known to cause a number of tree diseases. The aim of this study was to identify these Botryosphaeriaceae and to determine their pathogenicity to P. angolensis with branch inocula- tions. Seven species of the Botryosphaeriaceae were identified based on a combination of morphological characteristics and sequences from the ITS and EF-1a gene regions. Four of these represent undescribed taxa for which the names Pseudofusicoccum violaceum, P. olivaceum, Diplodia alatafructa and Fusicoccum atrovirens are provided. The remaining three species collected include Lasiodiplodia theobromae, L. pseu- dotheobromae and L. crassispora. Inoculation trials on tree branches showed that L. pseudotheobromae and one isolate of D. alatafructa differed significantly from control inoculations. The high levels of viru- lence and common occurrence of L. pseudotheobromae suggest that this species could play a role in tree dieback and death. more...
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- 2011
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83. Dendrochronology in the dry tropics: the Ethiopian case
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Keith R. Briffa, Hans Beeckman, Camille Couralet, Aster Gebrekirstos, Iain Robertson, Ute Sass-Klaassen, Achim Bräuning, Tommy H. G. Wils, Marcin Koprowski, Declan Conway, Ramzi Touchan, and Zewdu Eshetu more...
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Mediterranean climate ,reconstruction ,Physiology ,Plant Science ,Juniperus procera ,isotope ratios ,Dendrochronology ,Temperate climate ,Bosecologie en Bosbeheer ,Precipitation ,stable carbon ,forests ,rhizophora-mucronata ,Ecology ,biology ,climate-growth relationships ,Tropics ,Forestry ,Pterocarpus angolensis ,dynamics ,PE&RC ,biology.organism_classification ,Forest Ecology and Forest Management ,Geography ,africa ,Boreal ,pterocarpus-angolensis ,tree-ring analysis - Abstract
Dendrochronology is developing outside temperate and boreal regions. Over the past decade substantial progress has been made in Mediterranean and wet tropical regions. However, research in dry tropical regions, notably those of sub-Saharan Africa, has remained fragmentary. Here, we try to identify the unique challenges and opportunities of dendrochronology in the dry tropics. First, we briefly review the status of dendrochronology outside temperate and boreal regions with an emphasis on sub- Saharan Africa. Subsequently, we focus upon one of those areas where dendrochronology in the dry tropics is at the forefront of scientific advance: Ethiopia. A detailed review of tree ring studies in the lowlands and highlands highlights the complexity of ring formation and made us identify four major types of growth ring expression: anatomically notdistinct rings, multiple rings per year, annual rings and multiple missing rings. This complex tree growth behaviour is associated with large-scale variations in precipitation regime (unimodal to multimodal) and relatively small-scale variations in tree sensitivity to water availability. Literature results are used to develop a scheme that can be used to predict differences in growth ring formation along gradients in these two factors. Because of the exceptional growth sensitivity of and the importance of local site conditions (topography, biological factors, etc.) for most trees sampled, those growing at the limits of their ecological amplitude are prone to possess multiple rings per year or multiple missing rings. In such circumstances, site selection should not always take place at the limits of the ecological amplitude of a species, but may sometimes have to be diverted to more mesic environments. Successful studies are now appearing, such as those reporting correlations between tree ring chronologies and Blue Nile river flows. more...
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- 2010
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84. Die-back of kiaat (Pterocarpus angolensis) in southern Africa: a cause for concern?
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Jolanda Roux, Michael J. Wingfield, Coert J. Geldenhuys, and James William Montague Mehl
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Vegetation types ,Altitude ,biology ,Ecology ,Range (biology) ,Forestry ,Ecosystem ,Pterocarpus angolensis ,Woodland ,biology.organism_classification ,Endemism ,Lasiodiplodia theobromae - Abstract
Pterocarpus angolensis (kiaat) is a well-known southern African tree species of commercial importance that occurs in several vegetation types in the Zambezian regional centre of endemism. The most prominent of these vegetation types are the Zambezian miombo woodland and undifferentiated woodland. A diverse range of ecosystems within these vegetation types necessitate adaptation by tree species to survive extremes of drought, temperature, altitude, soil nutrition and tolerate fire in order to compete with other plant species. There are several reports of a die-back disease of P. angolensis in Zambia, Zimbabwe and South Africa, but very little is known regarding the cause or significance of this problem. In this review, we provide details regarding the history of the disease and consider its possible causal agents. A pathology study conducted at three locations in South Africa on diseased and dying trees resulted in the collection of 199 fungal isolates; comprising saprophytic species such as Candida, Penicillium and Humicola, and potentially pathogenic species such as Lasiodiplodia theobromae, Cytospora spp. and Fusarium spp. Drought, during several years preceding disease, along with a lack of fire management may have contributed to both the present and past reports of tree die-back and death. Finally, an analysis is made of the importance of the problem and actions that might be taken to alleviate it.Keywords: Cytospora, drought, fire management, Fusarium, Fusarium oxysporum, Lasiodiplodia theobromae, mukwa disease, stand-level die-backSouthern Forests 2010, 72(3/4): 121–132 more...
- Published
- 2010
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85. Chemical composition of traditionally and lesser used wood species from Mozambique
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Nasko Terziev, Raida Jirjis, Carlos Alberto Cuvilas, and Inácio Lhate
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Sterculia appendiculata ,biology ,Dry basis ,Acacia ,Pterocarpus angolensis ,Afzelia quanzensis ,Pseudolachnostylis ,biology.organism_classification ,chemistry.chemical_compound ,chemistry ,Botany ,Lignin ,General Materials Science ,Chemical composition - Abstract
The main objective of this study was to determine the chemical composition of some lesser used Mozambican native wood species, such as Acacia nigrescens Oliv., Icuria dunensis Wieringa, Pseudolachnostylis maprounaefolia Pax and Sterculia appendiculata K. Schum. Another aim was to compare these species with traditionally used species, namely, Afzelia quanzensis Welwn, Milletia stuhlmannii Taub, Pericopsis angolensis Meeuwen and Pterocarpus angolensis DC. Wood samples for analysis were taken from sapwood, outer and inner heartwood. All chemical analyses were performed according to standard methods. The contents of carbohydrates, extractives and ash were in ranges considered normal for tropical species. The contents of lignin and minerals were unexpectedly high in Pseudolachnostylis (ntholo), reaching 37.51% and 2.2% (wt% extractive-free) on a dry basis, respectively. Based on the determined chemical features, it was concluded that Acacia and Pseudolachnostylis were similar to well-known species, wh... more...
- Published
- 2010
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86. The ethnobotany of Pterocarpus angolensis DC.: A reflection of rural Venda speaking community of Gundani in Limpopo Province, South Africa
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T.S. Sadiki and M.P. Tshisikhawe
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Geography ,biology ,010405 organic chemistry ,Agroforestry ,Ethnobotany ,Pterocarpus angolensis ,Plant Science ,010402 general chemistry ,Reflection (computer graphics) ,biology.organism_classification ,01 natural sciences ,0104 chemical sciences - Published
- 2018
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87. Crude extracts of, and purified compounds from,Pterocarpus angolensis, and the essential oil ofLippia javanica: their in-vitro cytotoxicities and activities against selected bacteria andEntamoeba histolytica
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A. Housein, Namrita Lall, Amidou Samie, and J.J.M. Meyer
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Pterocarpus ,Microbial Sensitivity Tests ,medicine.disease_cause ,Catechin ,Microbiology ,law.invention ,Inhibitory Concentration 50 ,Entamoeba histolytica ,law ,Oils, Volatile ,medicine ,Humans ,Medicinal plants ,Essential oil ,Bacteria ,biology ,Traditional medicine ,Plant Extracts ,Pterocarpus angolensis ,Biological activity ,biology.organism_classification ,Anti-Bacterial Agents ,Infectious Diseases ,Staphylococcus aureus ,Parasitology ,Lippia ,Enterobacter cloacae - Abstract
In a recent study, various extracts of Pterocarpus angolensis were prepared and tested against bacteria. The acetone extract was found to be the most active against all the bacteria investigated, with minimum inhibitory concentrations varying from 0.0156 mg/ml against Staphylococcus aureus to 2 mg/ml against Enterobacter cloacae. Seven pure compounds were subsequently isolated from the ethanol extract of P. angolensis. Using several chromatographic and spectroscopic methods, the structures of five of these compounds - phthalate and four derivatives of epicatechin [(-)-epicatechin, epicatechin-3-O-galate, epicatechin (4beta-8)-epicatechin (B2), and a hexamer of epicatechin] - were successfully determined. The seven purified compounds were then further tested, in vitro, against Staphylococcus aureus and Entamoeba histolytica, and for their in-vitro cytotoxic activity. Although all seven were active against S. aureus, just one of the purified compounds from P. angolensis and piperitenone, a pure compound isolated from Lippia javanica essential oil, were found to have marked activity against Entamoeba histolytica, with median inhibitory concentrations (IC(50)) of 25 and 100 microg/ml, respectively. The other P. angolensis compounds were either weakly active or showed no activity against the amoebae when tested at concentrations up to 400 microg/ml. All seven compounds isolated from P. angolensis showed less toxicity against cultures of human (HCT-8) cells than piperitenone, with IC(50) of 175-375 microg/ml. The presence of epichatechin and derivatives (with strong antibacterial activities but generally weak activities against Entamoeba histolytica) in the stem bark of P. angolensis has thus been demonstrated. Further investigation of the activities of these compounds and their potential use in the treatment of bacterial diseases appears justified. more...
- Published
- 2009
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88. Phenotypic variation among five provenances ofPterocarpus angolensisin Zimbabwe and Zambia
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E. Chisha-Kasumu, Stephen Woodward, and Adam H. Price
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Horticulture ,Biomass (ecology) ,Recovery period ,biology ,Inoculation ,Germination ,Mycorrhizal fungi ,Shoot ,Botany ,Forestry ,Pterocarpus angolensis ,biology.organism_classification - Abstract
The feasibility of utilising morphological markers for determining existing provenance variation in the African savanna tree Pterocarpus angolensis was assessed. Five provenances were used: Mtao, Gokwe, Nyazura, Chesa (Zimbabwe) and Kapirimposhi (Zambia). Two weeks after germination, seedlings were inoculated with mycorrhizal inoculum and raised in a glasshouse. Height and collar diameter were measured at one, three and five months of age (before stem dieback), and at 14 months (after stem dieback). At the time of dieback, percentage of seedlings losing leaves, stem dieback and mortality were recorded; numbers of new shoots produced in the recovery period were also determined. To further assess growth, leaf, stem and root dry biomass were measured after stem dieback at 14 months. At one month, Chesa seedlings were the tallest and Kapirimposhi seedlings were significantly shorter (p < 0.05) than the rest of the provenances. However, at three and five months of height growth no significant differences were ... more...
- Published
- 2009
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89. RAPD markers demonstrate genetic diversity inPterocarpus angolensisfrom Zimbabwe and Zambia
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E. Chisha-Kasumu, Adam H. Price, and Stephen Woodward
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education.field_of_study ,Genetic diversity ,biology ,Ecology ,Population ,Zoology ,Population genetics ,Forestry ,Pterocarpus angolensis ,biology.organism_classification ,RAPD ,Genetic variation ,Genetic variability ,education ,Domestication - Abstract
Understanding the availability, extent and apportionment of genetic variability in natural populations of the southern African savanna tree Pterocarpus angolensis can provide reliable information on the evolutionary history and phylogenetic relationships of P. angolensis populations. This information will aid strategies for successful domestication, conservation and sustainable exploitation of the species. In this study random amplified polymorphic DNA (RAPD) analysis was employed to assess genetic diversity of P. angolensis, characterising 60 genotypes originating from four Zimbabwean and two Zambian provenances. Four RAPD primers each generated 11 to 15 scorable bands, with a total of 50 reproducible bands of which 88% were polymorphic. Analysis of molecular variance partitioned the greatest proportion of variability to within population (80.82%). Euclidean distance gave a phiST value of 0.192, indicating a moderately high level of population differentiation. The degree of population diversity found in this study, with two clear strong population structures for most genotypes from Nyazura and Gokwe and the rest of the populations with slight weak structures, suggests that all provenances tested could be beneficially utilised in a domestication programme for P. angolensis. Keywords: domestication, genetic variation, population diversity, Pterocarpus angolensis , RAPD more...
- Published
- 2009
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90. Heritability of shoot die-back and root biomass in sixteenPterocarpus angolensis(Fabaceae) half-sib families from Malawi, Namibia and Zambia
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G. Van Wyk, Cry Munthali, and JP Mwitwa
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Biomass (ecology) ,biology ,Dying back ,food and beverages ,Die back ,Forestry ,Pterocarpus angolensis ,Taproot ,social sciences ,Fabaceae ,Heritability ,equipment and supplies ,biology.organism_classification ,Horticulture ,Shoot ,Botany ,human activities ,health care economics and organizations - Abstract
The experiment was conducted to ascertain narrow-sense heritability ( h 2 ) and the family-within-provenance variation in shoot die-back, taproot length and root biomass of half-sib Pterocarpus angolensis families from Malawi, Namibia and Zambia. Provenances differed significantly in shoot die-back for both shoot die-back seasons. A within provenance family effect was not significant in the first shoot die-back season but was significant in the second shoot die-back season. An increase in proportion of seedlings dying back, to 91%, for a Malawi family was observed in the second shoot die-back season. Provenance and within provenance family effects may be due to latitudinal differences between the provenances. The h 2 of shoot die-back was 0.07 (SE = 0.07) in the first shoot die-back season and 0.42 (SE = 0.27) in the second shoot die-back season. Narrow-sense heritability for root biomass was 0.81 (SE = 0.45). The h 2 for the second die-back season and root biomass suggest the traits are heritable. Random selection of individual families for assessing shoot die-back is important since this trait is only restricted to seedlings and saplings and not mature trees. Within provenance family effects for root biomass were significant, indicating differences between families. Two families from the most northerly provenances of Phalombe and Skull Rock in Malawi were significantly different from other southern families. Non-significant phenotypic correlation between shoot die-back and root biomass shows that shoot die-back is not likely to be determined by root size nor taproot depth. Although a non-significant negative phenotypic correlation (–0.15) between the second shoot die-back season and root biomass was obtained, a family from Malawi that had the highest mean shoot die-back in the second shoot die-back season had the smallest root biomass. Half-sib families with post shoot die-back growth potential, in the first shoot die-back season, are likely to have a better chance of post shoot die-back growth later. Keywords: half-sib families; narrow-sense heritability; phenotypic correlation; Pterocarpus angolensis ; root biomass; shoot die-back; taproot extensibility Southern Forests 2008, 70(3): 221–226 more...
- Published
- 2008
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91. Leaf phenology and carbon dynamics in six leguminous trees
- Author
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Renee Richer
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Julbernardia globiflora ,Annual growth cycle of grapevines ,biology ,Burkea africana ,Phenology ,Botany ,Carbohydrate storage ,Pterocarpus angolensis ,biology.organism_classification ,Baikiaea plurijuga ,Erythrophleum africanum ,Ecology, Evolution, Behavior and Systematics - Abstract
I documented photosynthetic rates and seasonal stem total nonstructural carbohydrates (TNC) in six leguminous tree species Burkea africana, Baikiaea plurijuga, Erythrophleum africanum, Guibourtia coleosperma, Julbernardia globiflora and Pterocarpus angolensis exhibiting a range of leaf phenological patterns. My goal was to (i) measure photosynthetic characteristics and levels of stored stem carbohydrates in species with varying patterns of leaf phenology and (ii) determine seasonal patterns of stem carbohydrate storage. Despite significant differences in the timing of bud break and leaf cover between the six species, there were no significant differences in maximum photosynthetic rate, quantum efficiency or light saturation point between species. Similarly, there was no significant difference in seasonal mean stem TNC levels despite significant differences in the timing of bud break and leaf cover both between species and within a single species. However, while the average amount of TNC does not seem to be related to leaf phenology, the patterns of carbohydrate use and storage do seem to be related to leaf phenology. Resume J’ai documente les taux photosynthetiques et les hydrates de carbone non structurels totaux (total nonstructural carbohydrates - TNC) des pousses saisonnieres chez six especes d’arbres de l’ordre des legumineuses : Burkea africana, Baikiaea plurijuga, Erythrophleum africanum, Guibourtia coleosperma, Julbernardia globiflora et Pterocarpus angolensis, qui presentent des patterns varies dans la phenologie des feuilles. Mon but etait de: 1) mesurer les caracteristiques photosynthetiques et le taux d’hydrates de carbone stockes dans les pousses de chaque espece selon le pattern de phenologie des feuilles et 2) determiner le schema saisonnier de stockage d’hydrates de carbone dans les pousses. Malgre des differences significatives entre les six especes dans le timing de l’eclatement des bourgeons et de la poussee des feuilles, il n’y avait pas de difference significative du taux maximal de photosynthese, du rendement quantique ou du point de saturation de lumiere entre les especes. De meme, il n’y avait pas de difference significative des taux saisonniers moyens de TNC dans les pousses, malgre la difference observee dans le timing de l’eclatement des bourgeons et de l’apparition des feuilles entre les especes et au sein d’une meme espece. Toutefois, si la quantite moyenne de TNC ne semble pas liee a la phenologie des feuilles, le schema de l’utilisation et du stockage des hydrates de carbone semble y etre lie. more...
- Published
- 2008
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92. Anatomical characteristics, properties and use of traditionally used and lesser-known wood species from Mozambique: a literature review
- Author
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Inácio Lhate, Nasko Terziev, Ernesto Uetimane, and Alexandre Charifo Ali
- Subjects
Engineering ,Sterculia appendiculata ,biology ,Agroforestry ,business.industry ,Androstachys ,Forestry ,Pterocarpus angolensis ,Plant Science ,Afzelia quanzensis ,Sterculia quinqueloba ,biology.organism_classification ,Industrial and Manufacturing Engineering ,Pericopsis angolensis ,Khaya ,Botany ,Mechanical strength ,General Materials Science ,business - Abstract
Mozambique is a country with vast forestry resources that include native wood species with high commercial value. Thus, the trade of timber as raw material, as well as wooden finished products are commercial options of considerable valuable for the country. This work presents information about anatomical characteristics, physical and mechanical properties and use of some native wood species from Mozambique, namely, Afzelia quanzensis, Androstachys johnsonii, Erytrophleoum suaveolens, Khaya nyasica, Pterocarpus angolensis, Milletia stuhlmannii and the emerging lesser-known species Pericopsis angolensis, Sterculia appendiculata and Sterculia quinqueloba. The study concludes that these Mozambican wood species are similar in several aspects. They are generally described as very hard, dense, having high mechanical strength and durable. The study also concludes that although the lesser-known wood species, S. quinqueloba, has similar properties to the traditionally used one, A. quanzensis, it is less used because of its poorly known properties and potential uses. Thus, further research to determine the properties and suitable end uses of other lesser know species is likely to be beneficial to the country. more...
- Published
- 2008
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93. Vegetation of the central Kavango woodlands in Namibia: An example from the Mile 46 Livestock Development Centre
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A. Petersen and Ben J. Strohbach
- Subjects
biology ,business.industry ,ved/biology ,Agroforestry ,ved/biology.organism_classification_rank.species ,Acacia ,Pterocarpus angolensis ,Vegetation ,Woodland ,Understory ,Plant Science ,Kavango woodlands ,biology.organism_classification ,Fire ,Shrub ,Namibia ,Geography ,Land-use impact ,Livestock ,Arenosols ,Zambesian Baikiaea woodlands ecoregion ,business ,Thicket - Abstract
No detailed vegetation descriptions are available for the Kavango woodlands — recent descriptions have all been at the broad landscape level without describing any vegetation communities. With this paper the vegetation associations found at and around the Mile 46 Livestock Development Centre (LDC) are described. Two broad classes are recognised: the Acacietea are represented by three Acacia species-dominated associations on nutrient-richer eutric Arenosols, whilst the Burkeo–Pterocarpetea are represented by three associations dominated by broad-leafed phanerophytic species on dystri-ferralic Arenosols. The, for the Kavango woodlands typical, Pterocarpus angolensis – Guibourtia coleosperma bushlands and thickets are further divided into four variants. Fire has been found to be an important factor in determining the structure of the vegetation — exclusion of fire on the LDC itself seems to lead to an increase in shrub (understory) density. more...
- Published
- 2007
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94. Age, and radial growth dynamics of Pterocarpus angolensis in southern Africa
- Author
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David W. Stahle, Herman H. Shugart, Mukufute M. Mukelabai, and Matthew D. Therrell
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biology ,Range (biology) ,Ecology ,Growth data ,Forest management ,Forestry ,Pterocarpus angolensis ,Management, Monitoring, Policy and Law ,biology.organism_classification ,Radial growth ,Dendrochronology ,Growth rate ,Arbol ,computer ,Nature and Landscape Conservation ,computer.programming_language - Abstract
Pterocarpus angolensis D.C. is a highly valuable and sought after timber species across much of its range in southern Africa. Attempts at plantation cultivation of this species have not been successful, suggesting that sustainable management of natural populations is necessary for the continued utilization of this resource. Such management will require reliable age and long-term growth data. Despite the value of P. angolensis, few long-term studies of the species’ growth rate have been conducted, and some of these studies indicate that current harvest schemes may be inappropriate. This paper presents results of tree-ring analyses of P. angolensis from nine locations across southern Africa. The analyses include estimates of: (1) tree age, (2) diameter increment, (3) the relationship between tree diameter and the percentage of heartwood, and (4) the relationship between mean diameter increment and local rainfall. The mean annual diameter increment averaged over all nine sites was generally lower than other published values, though the range of values was within that of published figures. Cumulative diameter as a function of age indicates that radial growth can be quite variable, both within and among stands. These variable age–diameter relationships within and across the nine sites suggest that diameter may be a reasonable indicator of tree age at the stand level but not across the species’ range. The relationship between stem diameter and percentage heartwood is significantly positive, suggesting that optimal harvesting diameters may be reliably determined. Average annual diameter increment is significantly positively correlated with mean seasonal rainfall, which explains about half of the variance in mean diameter increment. These findings should be helpful for the sustainable management of this important species. more...
- Published
- 2007
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95. Influência da classe diamétrica no rendimento em madeira serrada de duas espécies nativas de Moçambique
- Author
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Juizo, Cláudio Gumane Francisco, Loiola, Pedro Lício, Marchesan, Raquel, Josséfa, Celio Gregório, Chaóra, Inoque João, Pereira da Rocha, Márcio, and Klitzke, Ricardo Jorge
- Subjects
Serraria ,Sawmill ,Wood unfolding ,Pterocarpus angolensis ,Combretum imberbe ,Desdobro da madeira - Abstract
In a technical bulletin designed by the Food and Agriculture Organization, the importance of studies in Mozambique to assist in decision-making techniques that aim to improve incomes of sawmills in the country was emphasized. Because of the species used and the industry’s low technological level, this study was carried out in order to assess the lumber yield of two tropical species, in a sawmill in Chimoio, Manica Province, in the central region of Mozambique. We used trees of Combretum imberbe (mondzo) and Pterocarpus angolensis (umbila), selecting 12 logs from each species. The logs were divided into three diameter classes (four logs in each class). Logs were sawed with band saw, in successive tangential unfolding model. Lumber yielding for both species increased depending on the diameter class, with statistical differences of lumber yielding between the two species and in the three diameter classes. C. imberbe had higher yield compared to P. angolensis, with results considered satisfactory for wood unfold of both native species from Mozambique. Em um boletim técnico idealizado pela Organização das Nações Unidas para Alimentação e Agricultura foi ressaltada a importância de estudos em Moçambique para auxiliar as tomadas de decisões técnicas que visem à melhoria dos rendimentos nas serrarias do país. Em virtude das espécies utilizadas, bem como do baixo nível tecnológico do setor, desenvolveu-se este trabalho com o objetivo de avaliar o rendimento em madeira serrada de duas espécies tropicais, em uma serraria localizada na Província de Manica, cidade de Chimoio na região central de Moçambique. Para tanto, foram utilizadas árvores de Combretum imberbe (mondzo) e Pterocarpus angolensis (umbila), sendo selecionadas 12 toras para cada espécie. As toras de cada espécie foram classificadas em três classes diamétricas (quatro toras em cada classe). O desdobro das toras foi efetuado com serra fita, em modelo de desdobro tangencial sucessivo. O rendimento em madeira serrada, para as duas espécies avaliadas, aumentou em função da classe diamétrica, tendo diferenças estatísticas no rendimento em madeira serrada entre as duas espécies nas três classes diamétricas. C. imberbe apresentou maior rendimento em comparação a P. angolensis, sendo que os resultados considerados satisfatórios para o desdobro destas duas espécies de madeira nativas de Moçambique. more...
- Published
- 2015
96. In vitroshoot multiplication and rooting from seedling explants ofPterocarpus angolensisin Zambia
- Author
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Adam H. Price, Steve Woodward, and Exildah Chisha-Kasumu
- Subjects
chemistry.chemical_classification ,biology ,Forestry ,Pterocarpus angolensis ,Plant Science ,biology.organism_classification ,chemistry.chemical_compound ,Cutting ,chemistry ,Micropropagation ,Auxin ,Axillary bud ,Cytokinin ,Botany ,Shoot ,Explant culture - Abstract
Pterocarpus angolensis is a savanna tree species growing mostly in the southern part of Africa. Exploitation for its medicinal and commercial uses has led to diminishing of wild populations. Developing reliable in vitro protocols for propagation would enable mass production of desired genotypes for domestication and conservation of P. angolensis . In this study, the effect of 6-benzylaminopurine (BAP), isopentenyl-adenine (2-iP) and thidiazuron (TDZ) were tested for shoot induction on cuttings from four weeks old P. angolensis seedlings. BAP at 5 mg/l gave higher shoot multiplication compared with 0 – 2 mg/l BAP. Although axillary buds opened on cuttings treated with 0.1 to 2 mg/l TDZ, no elongation occurred. Shoots placed on 0.5 – 5 mg/l 2-iP produced roots but no axillary shoots. Indole-3-butyric acid (IBA) and indole-3-acetic acid (IAA) were tested for ability to induce rooting of micropropagated shoots. IAA at 1 mg/l and IBA at 1 - 4 mg/l induced higher percent rooting than other auxin concentrations. Shoots on media lacking auxins also rooted well (48%), suggesting that no growth regulator was required for rooting of 4 weeks old P. angolensis shoots. Southern African Forestry Journal Vol. 208, 2006: 31-37 more...
- Published
- 2006
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97. Effects of fire on germination of Pterocarpus angolensis
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Tim Caro, Tasila Banda, and Mark W. Schwartz
- Subjects
media_common.quotation_subject ,Longevity ,food and beverages ,Forestry ,Pterocarpus angolensis ,Fabaceae ,Management, Monitoring, Policy and Law ,Biology ,biology.organism_classification ,Husk ,Horticulture ,Germination ,Botany ,Soil water ,Dormancy ,Ecosystem ,Nature and Landscape Conservation ,media_common - Abstract
Pterocarpus angolensis (Fabaceae) is a leguminous tree species of the miombo region of sub-Saharan Africa that is highly prized for its wood value. We use both experimental exposure to fire, as well as classification of field burned seeds, to predict germination rates in seeds from both husked and unhusked fruits. We find that seed germination and seed persistence in unhusked fruits are maximized by moderate exposure to fire. Germinating seeds had heavier fruit and seeds than those that did not. Finally, seeds without husks persisted in the soil yet continued to germinate even after 18 months in wet soil, indicating potentially long soil longevity. Using these results, we support an intermediate fire exposure model wherein repeated moderate exposure to fire enhances the capability of seeds to emerge from fruits. Seeds from unburned and unhusked fruits were never observed to germinate and had poorer soil longevity than those exposed to moderate fire. Similarly, extreme exposure to fire resulted in poor seed germination rates, often as a consequence of direct fire mortality of seeds. We suggest that early burning resulting in cool fires may augment germination and recruitment in wild populations. more...
- Published
- 2006
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98. Tree communities and structural dynamics in miombo (Brachystegia–Julbernardia) woodland, Tanzania
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Ingvar Backéus, Lennart Strömquist, C. Ruffo, and Börge Pettersson
- Subjects
Brachystegia ,Brachystegia boehmii ,biology ,Ecology ,Forestry ,Pterocarpus angolensis ,Plant community ,Woodland ,Management, Monitoring, Policy and Law ,biology.organism_classification ,Julbernardia ,Tanzania ,Geography ,Brachystegia spiciformis ,Nature and Landscape Conservation - Abstract
Tree vegetation and size structure was sampled in a miombo woodland area in E Tanzania and related to environmental factors, particularly soil and disturbance history. A total of 86 tree species wa ... more...
- Published
- 2006
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99. Annual Growth Ring Patterns in Brachystegia spiciformis Reveal Influence of Precipitation on Tree Growth1
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Hans Beeckman, Valerie Trouet, and Pol Coppin
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Wet season ,biology ,Ecology ,Tropics ,Pterocarpus angolensis ,Dendroclimatology ,Woodland ,biology.organism_classification ,Geography ,Brachystegia spiciformis ,Vegetation type ,Physical geography ,Ecology, Evolution, Behavior and Systematics ,Chronology - Abstract
The availability of exactly dated tree-ring chronologies is limited in tropical regions. However, these chronologies could contribute widely to studies of the influence of natural and human-induced factors on tropical forests. We examine the potential for building a chronology based on three sites in the miombo woodland of western Zambia. Brachystegia spiciformis Benth., a dominant species from this vegetation type, is used. Response of the chronology to several climatic factors is examined. All specimens showed very clear growth rings, and cross-dating between radii of a tree was successful for all trees. Site chronologies could be constructed after cross-dating of growth ring series of individual trees. The mean growth ring curves of the three sites were significantly similar, allowing for the construction of a regional chronology. Correlation function analysis between the tree-ring chronology and regional climatic variables revealed that climate at the core of the rainy season, in December and January, has an explicit influence on tree growth. Where precipitation and relative humidity in these months influence tree growth positively, temperature correlates in a negative way. Some 20 percent of the variance in the B. spiciformis tree-ring chronology is accounted for by wet season rainfall. The successful cross-dating and correlation between a tree-ring chronology and climate demonstrated in this study indicate annual ring formation in B. spiciformis trees and sensitivity to climatic conditions. more...
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- 2006
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100. Savanna trees in Namibia—Factors controlling their distribution at the arid end of the spectrum
- Author
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Antje Burke
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Ecology ,biology ,Agroforestry ,Pterocarpus angolensis ,Edaphic ,Plant Science ,Baikiaea plurijuga ,biology.organism_classification ,Mopane ,Arid ,Boscia albitrunca ,Geography ,Burkea africana ,Faidherbia albida ,Ecology, Evolution, Behavior and Systematics - Abstract
This study reviewed the distribution of ten common savanna trees in Namibia. Tree distributions were investigated in relation to bioclimatic, topographic and edaphic variables at a national scale. The factors of importance at these broad geographic scales appeared to be rainfall, substrate and, likely, the incidence of frost. Baikiaea plurijuga, Burkea africana, Guibourtia coleosperma and Pterocarpus angolensis seem to reach their bioclimatic limits in Namibia. At the local level, plant traits become important and contribute to explaining distribution patterns. High water and/or nitrogen use efficiency (Acacia erioloba, Colophospermum mopane), dual water obtaining strategies (Faidherbia albida), fire tolerance (e.g. Acacia species, Burkea africana and Pterocarpus angolensis) and drought tolerance (Boscia albitrunca) are some key attributes providing additional explanations for current distributions. Amongst the selected trees and at broad geographic scales, below-ground adaptations are governed by rainfall regime in combination with coarse-textured soils, whereby shallow-rooted trees prevail in the Kalahari sandveld. Deep-rooted species are found largely on non-sandy soils. Physiological performance of many trees appears to be directly linked to rainfall regime and trees may hence show varying performance throughout their distribution range. Insight into plant functional attributes of trees in Namibia is required to develop appropriate management strategies in the light of climate change. Modelling climate change impacts should consider the relative contribution of bioclimatic versus local environmental factors that explain the current distribution patterns of the selected trees. more...
- Published
- 2006
- Full Text
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