scholarly journals First vegetation-plot database of woody species from Huíla province, SW Angola

2021 ◽  
Vol 2 ◽  
pp. 109-116
Author(s):  
Francisco M.P. Gonçalves ◽  
António V. Chisingui ◽  
José C. Luís ◽  
Marina F.F. Rafael ◽  
José J. Tchamba ◽  
...  
Keyword(s):  
Vegetation Change ◽  
Central Africa ◽  
Woody Species ◽  
Vegetation Survey ◽  
Size Classes ◽  
South Central ◽  
Key Species ◽  
Plant Families ◽  
Abundance And Diversity ◽  
Almost All

Angola is a country in south-central Africa, particularly rich in biodiversity. Despite the efforts recently made to document its biodiversity, there is a need for standardized sampling methods to document and compare the variety of ecosystems and plants occurring in the country. With this database report we aim to document the abundance and diversity of woody species in the woodlands of Huíla province. The database hosts the results of a standardised plot-based vegetation survey, consisting of 448 vegetation plots distributed throughout the 14 municipalities and Bicuar National Park. In total, 40,009 individuals belonging to 44 plant families were recorded and measured, belonging to 193 woody species. Species richness per municipality ranged from 32 to 126. The mean stem diameter (DBH) was 10.9 cm ± 7.5 cm. Small-size classes are increasingly dominated by few species, while the largest trees come from a wider range of species; miombo key-species dominated almost all size classes. Our study represents the first plot-based vegetation survey of any Angolan province and constitutes a useful source of information for conservation and management. Additionally, may constitute a powerful dataset to support future studies on biodiversity patterns and vegetation change over time and facilitate the elaboration of vegetation maps. Taxonomic reference: Checklist of Angolan Plants (Figueiredo and Smith 2008), The African Plant Database (version 3.4.0) and A new classification of Leguminosae (LPWG 2017). Abbreviations: DBH = Diameter at Breast Height; GIVD = Global Index of Vegetation-Plot Databases; LUBA = Acronym of the Herbarium of Lubango

scholarly journals Woody species of the Miombo woodlands and geoxylic grasslands of the Cusseque area, south-central Angola

Check List ◽  
2017 ◽  
Vol 13 (1) ◽  
pp. 2030 ◽  
Author(s):  
Rasmus Revermann ◽  
Francisco Maiato Gonçalves ◽  
Amândio Luis Gomes ◽  
Manfred Finckh
Keyword(s):  
Species Composition ◽  
Woody Species ◽  
Woody Vegetation ◽  
Growth Forms ◽  
Miombo Woodlands ◽  
Vegetation Survey ◽  
Central Plateau ◽  
South Central ◽  
Independence Era ◽  
Plant Families

The species composition of the vegetation in most regions of Angola has been poorly studied and most studies date back to the pre-independence era. In this study, we provide a detailed account of the woody flora of the Miombo woodlands and geoxylic grasslands of the Cusseque study site of “The Future Okavango” (TFO) project, situated on the Angolan Central Plateau. The checklist is based on a vegetation survey using vegetation plots of 1,000 m² and also includes records from botanical collections made elsewhere at the study site. In total, we documented 154 woody species belonging to 99 genera of 37 plant families in 100 km². The study represents the first comprehensive account of the woody vegetation of the area including all habitats and growth forms.

scholarly journals Tree Species Diversity and Composition of Miombo Woodlands in South-Central Angola: A Chronosequence of Forest Recovery after Shifting Cultivation

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Francisco M. P. Gonçalves ◽  
Rasmus Revermann ◽  
Amândio L. Gomes ◽  
Marcos P. M. Aidar ◽  
Manfred Finckh ◽  
...  
Keyword(s):  
Shifting Cultivation ◽  
Stand Structure ◽  
Woody Species ◽  
Distinct Group ◽  
Forest Recovery ◽  
Miombo Woodlands ◽  
Principal Coordinates Analysis ◽  
South Central ◽  
Principal Coordinates ◽  
Management Plans

The study was carried out in the Cusseque area of the Municipality of Chitembo in south-central Angola. Our objectives were to assess the floristic diversity, the species composition, and stand structure of Miombo woodlands during regeneration after shifting cultivation. A total of 40 plots of 1000 m2were surveyed and analyzed, corresponding to mature forests/woodlands and three fallow types of different age. The analyses were based on plot inventories of all trees with DBH ≥ 5 cm. A total of 51 woody species, 38 genera, and 19 families were recorded. The dominant family was Fabaceae, with subfamily Caesalpinioideae being very abundant. Shannon Diversity and Evenness were highest in mature forests and young fallows, while the mature forest stands showed the highest species richness. A Principal Coordinates Analysis (PCoA) showed many species shared between the intermediate fallow types, but only few species were shared with young fallows. Mature forests formed a clearly distinct group. This study shows potential pathways of forest recovery in terms of faster regeneration after agricultural abandonment and, thus, the results presented here can be used in future conservation and management plans in order to reduce the pressure on mature forests.

scholarly journals Structure et Régénération des Peuplements naturels de Balanites Aegyptiaca (L.) Del. et Ziziphus Mauritiana Lam. suivant un Gradient écologique dans la Région de Maradi au Niger

Afrika Focus ◽  
2020 ◽  
Vol 33 (1) ◽  
Author(s):  
Rabiou Habou ◽  
Moussa Massaoudou ◽  
Tougiani Abasse ◽  
Mahamane Ali ◽  
Mahamane Larwanou ◽  
...  
Keyword(s):  
Stand Structure ◽  
Woody Species ◽  
Food Sources ◽  
Ziziphus Mauritiana ◽  
Balanites Aegyptiaca ◽  
Total Height ◽  
South Central ◽  
Consequent Reduction ◽  
Agrosilvopastoral System ◽  
Sahelian Zone

Les espèces ligneuses jouent un rôle important dans la vie des populations locales. Parmi les espèces couramment utilisées au Niger figurent Balanites aegyptiaca et Ziziphus mauritiana. Ces deux espèces sont exploitées comme sources alimentaires et pour divers produits médicinaux, avec comme conséquence une réduction de leurs peuplements. La présente étude vise à analyser la structure des peuplements et les modes de régénération des deux espèces dans deux secteurs agro-écologiques contrastées de la région de Maradi au centre sud du Niger. Au total, 60 relevés ont été délimités, d’une part dans des formations naturelles dominées par ces espèces, et d’autre part dans les systèmes agrosylvopastoraux des secteurs sahélien et sahélo-soudanien. Dans chaque placette et sur chaque arbre, le diamètre à 1,30 m au rasdu sol , la hauteur totale et deux diamètres perpendiculaires de houppier ont été mesurés. L’inventaire de la régénération a été effectué dans 5 placeaux. La nature de la régénération (drageon, marcotte, semis naturel), la hauteur totale et le nombre de tiges de chaque plantule ont été notés. La densité de B. aegyptiaca ne varie significativement entre sites et entre secteurs. Par contre, la densité de Z. mauritiana varie significativement entre sites et entre secteurs. En effet, le site de Birni Lallé, situé dans le secteur sahélien strict, et le site de Kegil dans le secteur sahélo-soudanien ont les densités les plus élevées de Z. mauritiana avec respectivement 66,4 ± 52,5 et 77,5 ± 61,4 arbres/ha. L’analyse de la distribution des tiges par classe de diamètre montre que pour les deux espèces, les individus jeunes sont bien représentés. Cela suggère une bonne régénération de ces espèces. L’analyse de la densité et nature de régénération montre que les deux espèces se régénèrent essentiellement par drageonnage. En réponse au ramassage des fruits pour diverses utilisations, les espèces B. aegyptiaca et Z. mauritiana ont développé des stratégies alternatives de propagation en zone sahélienne. Cette aptitude à la propagation végétative permet aux deux espèces de s’adapter en zones arides caractérisées par la sécheresse et les hautes températures. MOTS CLÉS : DISTRIBUTION DES ESPÈCES LIGNEUSES, B. AEGYPTIACA, Z. MAURITIANA, MARADI, NIGER, SAHÉLO-SOUDANIEN [83] afrika focus — Volume 33, Nr. 1, 2020 — pp. 83-104 RABIOU HABOU, MOUSSA MASSAOUDOU, TOUGIANI ABASSE, MAHAMANE ALI, MAHAMANE LARWANOU & PATRICK VAN DAMME Wood species play an important role in the life of local communities. Among the species commonly used in Niger, are Balanites aegyptiaca and Ziziphus mauritiana. This species are exploited as food sources and as various medicinal products, with a consequent reduction in their populations. The present study aims to analyze the stand structure and the regeneration modes of the two species in two contrasting agro-ecological sectors of the Maradi region in south central Niger. A total of 60 surveys were delineated in natural formations dominated by these species and in agrosilvopastoral system in the Sahelian and Sahelo-Sudanian zones. On each tree, the diameter at 1.30 m from the ground, the total height and two perpendicular tree crown diameters were measured. The inventory of natural regeneration was carried out in 5 plots delineated in each plot. The mode of reproduction of the regeneration (suckers, marcots, natural seedlings) was recorded as well as the total height and the number of stems of each juvenile were. The density of B. aegyptiaca does not vary significantly between sites and between sectors. The Birni Lallé site, located in the strict Sahelian zone, and the Kegil site in the Sahelo-Sudanese sector stand out in terms of Z. mauritiana density with respectively 66.4 ± 52.5 and 77.5 ± 61.4 trees. /Ha. The analysis of the diameter class structure shows that for both species, young individuals are well represented. This suggests strong regeneration among these species. The analysis of the density and nature of regeneration shows that the two species regenerate mainly by suckering. In response to the collection of fruits for various uses by local populations, B. aegyptiaca and Z. mauritiana have developed alternative propagation strategies in the Sahelian zone. This ability to propagate vegetatively allows these two species to adapt to arid areas characterized by drought and high temperatures. KEY WORDS: DISTRIBUTION OF WOODY SPECIES, B. AEGYPTIACA, Z. MAURITIANA, MARADI, NIGER, SAHELO-SUDANESE

scholarly journals RESTORATION OF FORMER GRASSLAND IN SOUTH-CENTRAL TEXAS

2019 ◽  
Vol 71 (1) ◽  
Author(s):  
Wendy J. Leonard ◽  
O. W. Van Auken
Keyword(s):  
San Antonio ◽  
Plant Cover ◽  
Woody Species ◽  
Bare Soil ◽  
Grass Species ◽  
Herbaceous Plant ◽  
Percent Cover ◽  
Juniperus Ashei ◽  
South Central ◽  
Central Texas

Abstract In the past, grasslands and savannas were common in many areas of south-central Texas, including the San Antonio area. With the advent of European settlers and their livestock, much of this area was converted to agriculture and rangeland. Today, most of San Antonio is developed, but some preservation has occurred. Restored grassland, mechanically cleared of Juniperus ashei (juniper, Ashe juniper) and other woody species in 2013, was examined and compared to adjacent non-cleared woodland. The woodland examined was dominated by Diospyros texana (Texas persimmon) and Juniperus ashei. Richness in the woodland canopy was 15 species. The understory below the canopy had 25 woody species. In the restored grassland area, herbaceous plant cover was 41.8%, woody plant cover 5.8%, bare soil 2.9%, and litter cover 49.5%. Species richness was 71, with 60 herbaceous and 11 woody species (percent cover of each from <0.1–7.1%). The most common species in the restored grassland in descending order were Nassella leucotricha (Texas winter grass), Calyptocarpus vialis (straggler daisy), Carex planostachys (cedar sedge), Sporobolus crypandrus (sand dropseed), D. texana, and Verbesina virginica (frost weed). Several C4 grass species were present with low cover but may increase in abundance over time. Four of the six most common restored grassland species were present below the woodland canopy and 12 woody species were present in the restored grassland as juveniles. Cost of restoration was approximately $38,500 ($7,500 supplies, $31,000 labor).

scholarly journals Analysis of lithofacies cyclicity in the Miocene Coal Complex of the Bełchatów lignite deposit, south-central Poland

Geologos ◽  
2015 ◽  
Vol 21 (4) ◽  
pp. 285-302 ◽  
Author(s):  
Wojciech Mastej ◽  
Tomasz Bartuś ◽  
Jerzy Rydlewski
Keyword(s):  
Statistical Tests ◽  
Surface Flow ◽  
Alluvial Fan ◽  
Statistical Testing ◽  
New Approach ◽  
Sedimentary Environments ◽  
Carbonate Sedimentation ◽  
South Central ◽  
Sedimentation Model ◽  
Almost All

Abstract Markov chain analysis was applied to studies of cyclic sedimentation in the Coal Complex of the Bełchatów mining field (part of the Bełchatów lignite deposit). The majority of ambiguous results of statistical testing that were caused by weak, statistically undetectable advantage of either cyclicity over environmental barriers or vice versa, could be explained if only the above-mentioned advantages appeared in the neighbourhood. Therefore, in order to enhance the credibility of statistical tests, a new approach is proposed here in that matrices of observed transition numbers from different boreholes should be added to increase statistical reliability if they originated in a homogeneous area. A second new approach, which consists of revealing statistically undetectable cyclicity of lithofacies alternations, is proposed as well. All data were derived from the mining data base in which differentiation between lithology and sedimentary environments was rather weak. For this reason, the methodological proposals are much more important than details of the sedimentation model in the present paper. Nevertheless, they did reveal some interesting phenomena which may prove important in the reconstruction of peat/lignite environmental conditions. First of all, the presence of cyclicity in the sedimentation model, i.e., cyclic alternation of channel and overbank deposits, represents a fluvial environment. It was also confirmed that the lacustrine subenvironment was cut off from a supply of clastic material by various types of mire barriers. Additionally, our analysis revealed new facts: (i) these barriers also existed between lakes in which either carbonate or clay sedimentation predominated; (ii) there was no barrier between rivers and lakes in which clay sedimentation predominated; (iii) barriers were less efficient in alluvial fan areas but were perfectly tight in regions of phytogenic or carbonate sedimentation; (iv) groundwater, rather than surface flow, was the main source of CaCO3 in lakes in which carbonate sedimentation predominated; (v) a lack of cyclic alternation between abandoned channels and pools with clayey sedimentation; (vi) strong evidence for autocyclic alternation of phytogenic subenvironments and lakes in which carbonate sedimentation predominated was found in almost all areas studied.

An 18 ka to present pollen- and phytolith-based vegetation reconstruction from Hall's Cave, south-central Texas, USA

2019 ◽  
Vol 92 (2) ◽  
pp. 497-518 ◽  
Author(s):  
Carlos E. Cordova ◽  
William C. Johnson
Keyword(s):  
Vegetation Change ◽  
Last Deglaciation ◽  
Sedimentary Records ◽  
South Central ◽  
Drought Tolerant ◽  
Arboreal Pollen ◽  
Central Texas ◽  
Scattered Trees ◽  
Sizable Proportion ◽  
Drying Trend

AbstractPollen, spores, phytoliths, and microscopic charcoal from a sedimentary column in Hall's Cave, south-central Texas, provide information for local and regional vegetation change during the last deglaciation and the Holocene in the context of broader regional and global climatic changes. The combination of paleoenvironmental proxy data from the cave indicates that between about 18,000 and 16,500 cal yr BP the cave area was dominated by an open plant community consisting of herbaceous vegetation, dominated by C3 grasses, and scattered trees, primarily Quercus and Pinus species. After about 16,500 cal yr BP, the arboreal component fluctuated, attaining a peak between 14,000 and 13,000 cal yr BP with relatively equal proportions of C3 and C4 grasses, including a sizable proportion of Panicoideae grasses. The Younger Dryas is marked by a conspicuous decrease in arboreal pollen with an apparent increase of C4 grasses toward its termination. Early Holocene recovery of arboreal vegetation is followed by a drying trend marked by the increasing dominance of C4 drought-tolerant Chloridoideae grasses. Increasing human use of the cave in middle to late Holocene times creates noise in the climatic significance of pollen, phytolith, and other proxies, a factor to consider when interpreting paleoenvironmental proxies in other cave sedimentary records.

Sign in / Sign up

Export Citation Format

Share Document