FIGURE 2 - uploaded by David Goyder
Content may be subject to copyright.
Open woodlands in Cusseque area, Bié Plateau, where the species was collected, dominated by Brachystegia spp., Julbernardia paniculata and Cryptosepalum exfoliatum subsp. pseudotaxus.
Source publication
Background: The African genus Schistostephium has eight species in southern and south
tropical Africa. The most widely distributed species, Schistostephium crataegifolium, occurs in
upland or montane areas towards the eastern side of the continent.
Objectives: The objective of this study was to document a new geographic distribution record
of this...
Context in source publication
Similar publications
Our project within the African Plants Initiative (API) covers two Portuguese Herbaria, LISC (Herbarium of the Instituto de Investigação Científica Tropical) and LISU (Herbarium of Jardim Botânico, MNHN). At LISU, Welwitsch's African collections hold c. 9400 specimens mainly from Angola. We will present a short biography of Friedrich Welwitsch (1806...
Citations
... Durante o desenvolvimento do trabalho foram incluídas na colecção novas espécies para Angola e para a ciência, a maioria colhida durante as expedições botânicas acima mencionadas. No total, registaram-se 38 espécies não constantes da Lista de Plantas de Angola, colhidas em diferentes províncias do país (Gonçalves et al., 2016;Revermann et al., 2017;Goyder et al., 2018) e 15 espécies novas para a ciência (Bergh & Nordenstam, 2010;Hind & Goyder, 2014;Swanepoel, 2012Swanepoel, , 2014Paton, 2014;Goyder et al., 2018;Darbyshire & Goyder, 2019;Tripp & Darbyshire, 2020). A revisão taxonómica de parte da colecção de Acanthaceae (Géneros Barleria, Justicia, Petalidium) conduzida por I. Darbyshire do Herbário de Kew, resultou na descrição de 5 novas espécies , que durante décadas se mantiveram "anónimas" nos armários do Herbário. ...
... Durante o desenvolvimento do trabalho foram incluídas na colecção novas espécies para Angola e para a ciência, a maioria colhida durante as expedições botânicas acima mencionadas. No total, registaram-se 38 espécies não constantes da Lista de Plantas de Angola, colhidas em diferentes províncias do país (Gonçalves et al., 2016;Revermann et al., 2017;Goyder et al., 2018) e 15 espécies novas para a ciência (Bergh & Nordenstam, 2010;Hind & Goyder, 2014;Swanepoel, 2012Swanepoel, , 2014Paton, 2014;Goyder et al., 2018;Darbyshire & Goyder, 2019;Tripp & Darbyshire, 2020). A revisão taxonómica de parte da colecção de Acanthaceae (Géneros Barleria, Justicia, Petalidium) conduzida por I. Darbyshire do Herbário de Kew, resultou na descrição de 5 novas espécies , que durante décadas se mantiveram "anónimas" nos armários do Herbário. ...
... Durante o desenvolvimento do trabalho foram incluídas na colecção novas espécies para Angola e para a ciência, a maioria colhida durante as expedições botânicas acima mencionadas. No total, registaram-se 38 espécies não constantes da Lista de Plantas de Angola, colhidas em diferentes províncias do país (Gonçalves et al., 2016;Revermann et al., 2017;Goyder et al., 2018) e 15 espécies novas para a ciência (Bergh & Nordenstam, 2010;Hind & Goyder, 2014;Swanepoel, 2012Swanepoel, , 2014Paton, 2014;Goyder et al., 2018;Darbyshire & Goyder, 2019;Tripp & Darbyshire, 2020). A revisão taxonómica de parte da colecção de Acanthaceae (Géneros Barleria, Justicia, Petalidium) conduzida por I. Darbyshire do Herbário de Kew, resultou na descrição de 5 novas espécies , que durante décadas se mantiveram "anónimas" nos armários do Herbário. ...
O trabalho teve como objectivo fazer a caracterização de um Ecossistema Florestal do Elundulua, localizado no Município sede do Huambo, em termo da sua biodiversidade. O estudo incidiu sobre 12 parcelas de 400 m2, cada. Em cada parcela foram classificadas botanicamente e contabilizados os indivíduos presentes. Com bases nestes foram calculados os parâmetros da Estrutura Horizontal. Os resultados obtidos indicam que o ecossistema florestal do Elundulua apresenta uma baixa biodiversidade, na medida em que apesar de apresentar uma grande riqueza, a abundância não está distribuída de forma uniforme. Com efeito, o Ecossistema Florestal do Elundulua apresenta uma grande riqueza, traduzida pelo número total de espécies, (25) e de indivíduos, 746 por hectare. Por outro lado, o ecossistema em questão apresenta uma fraca abundância, isto é, uma má distribuição dos indivíduos pelas diferentes espécies, havendo espécies com muitos indivíduos e outras com pouquíssimos indivíduos, facto que se traduz numa baixa diversidade. Neste ecossistema dominam as seguintes espécies: Brachystegia hocki, com 57 % do total dos indivíduos, Brachystegia sp., com 10%, Sapium ellipticum com 6%. Há espécies como por exemplo, Syzygium guineense, Brachystegia tamarindoides e Diplorhynchus condylocarpn com uma representatividade de 1%.
... Fenzl ex Harv. (Asteraceae,Figure 44) were collected and represent the first generic records from Angola(Gonçalves, Tchamba & Goyder 2016). Altogether, this indicates that the vegetation of Angola is clearly understudied and that new surveys, be they based on old herbarium specimen or new field surveys are likely to reveal range extensions of species formerly not known to occur in the country or even detect new species. ...
Summary
The Okavango Basin is situated in south central Africa and shared among the three
countries of Angola, Namibia and Botswana. The Okavango River has its source on the
sub-humid Angolan Central Plateau where 95% of the runoff is generated. The river
terminates in the endorheic Okavango Delta in the Kalahari Desert, forming a world
renowned wetland ecosystem highly dependent on the annual inflow of water of the
Okavango River. However, the upper reaches of the river in the Angolan Miombo belt are
highly understudied; ecological data and understanding of ecosystem functioning are
lacking. At the same time, the socio-ecological systems of the upper Basin are subject to
rapid transformations and are regarded as a hot spot of accelerating land use change.
However, the largely subsistence based economy of the rural communities is highly
dependent on the continued delivery of a wide range of ecosystem services. Thus, the
presented thesis aims to provide scientific data to contribute to a sustainable
development and to safeguard plant diversity in the Okavango Basin.
The thesis focuses on three general aspects: a) the analysis of plant species composition
and diversity and their underlying environmental drivers, b) the development of
methodological tools to combine field data and remote sensing information to provide
spatially explicit data, c) the investigation of the impact of land use on vegetation and
plant diversity. The thesis hence combines methods of traditional vegetation ecology with
the application of remote sensing information and the development of innovative
ecological modelling approaches to upscale the knowledge gained in field studies at the
local scale to the scale of the Okavango Basin.
The three core aspects are covered in six articles published in peer-reviewed journals and
two submitted manuscripts. Moreover, summaries of the results from four co-author
papers are presented and discussed in the synthesis chapter. Additionally, first results and
a preliminary vegetation map of the Okavango Basin were published in a series of several
short papers in a special issue of Biodiversity and Ecology. These articles are presented as
pdf-files in the electronic appendix of the thesis. In the following, the main achievements
of the thesis are summarised.
The thesis presented a comprehensive and quantitative account of the vegetation
composition and the plant diversity of the Angolan part of the Okavango Basin for the first
time. The established vegetation-plot database contains standardised plots of all
common vegetation types of the study area ranging from Miombo woodlands and
forests, Baikiaea woodlands, and geoxylic grasslands to the wetlands of the Angolan
Central Plateau (Chapter 2). During the vegetation survey carried out in the framework of
the thesis approximately over 2,600 plant specimens were collected and deposited in
herbaria of the host countries (Lubango, LUBA; Windhoek, WIND) and a new collection on
plants from southeast Angola was established at the Herbarium Hamburgense (HBG). As
reference for future studies, a check list of the woody species of the Cusseque study site
was produced (Chapter 2). Furthermore, the vegetation classifications in Chapter 3 and 7
contain detailed species lists. Thus, solid foundations for future work on the vegetation of
southeast Angola have been laid and made available. As such, the vegetation plots were
fed into the global vegetation-plot database sPlot and will be used in regional vegetation
mapping of south central Africa within the SASSCAL project.
The thesis provided a first classification scheme of the woody vegetation of the Cubango
Basin. One vegetation type, the Combretum celastroides-Baikiaea plurijuga community
represents a unique vegetation type found only in the Cuando Cubango Province of
Angola and was described for the first time in this thesis. Soil and other environmental
conditions of the derived vegetation communities were quantified and compared among
the different communities (Chapter 3).
A network of micro-climatic measurement stations was installed on the Angolan Central
Plateau and air and soil temperatures were recorded over three years. The measurements
provided insights in the role of night frost as a driving factor of current vegetation patterns
and also identified frost as potential evolutionary driver of the development of geoxylic
suffrutices in the Zambezian phytoregion (Chapter 4).
An ecological modelling framework was developed to provide spatially explicit data on
vascular plant α-diversity of the Okavango Basin. The approach combined the information
contained in the vegetation-plot database created during this thesis with landscape
phenology metrics derived from moderate resolution satellite imagery (Chapter 5). It was
shown that models using landscape phenology metrics produced more realistic maps and
were better capable of depicting azonal vegetation types than models including climatic
predictors. Instead, climate models predicted belts of homogenous plant α-diversity and
ignored landscape level heterogeneity.
Two case studies investigated the impact of land use on vegetation and plant diversity
(Chapter 6 and 7). The unique situation of two contrasting land use intensities paired with
similar physio-geographic settings and traditional land use practices along the Angolan
and Namibian border allowed to assess the impact of diffuse, i.e. spatially not explicit
land use, on plant diversity. The cross border study revealed a negative impact of diffuse
land use on plant diversity especially affecting woody species (Chapter 6).
In times of increasing shortage of agricultural land and increasing demand of agricultural
products it is of high importance to understand how longer duration of usage for cropping
in shifting cultivation affects diversity and regeneration of vegetation. The study in
Chapter 7 showed that nutrient contents are affected negatively by prolonged usage and
that fallows with shorter time spans of land usage exhibit species composition more
similar to the original state than fallows with longer spans of usage.
In Chapter 8 the results of the preceding chapters are discussed in a wider context
drawing also on knowledge gained in four co-authored studies and providing first insights
from two manuscripts that are currently in preparation. These studies investigated the
impact of road infrastructure on spatial dynamics of deforestation using chronosequences
of satellite imagery, analysed the spatiotemporal patterns of the fire regime in the
Okavango Basin and modelled the potential and realised distribution of the important
timber species Pterocarpus angolensis DC. One highlight of the thesis was the discovery
of a hitherto unknown grass species. Its placement in the subfamily of the Chloridoideae
could be shown based on the anatomy and on molecular data. Further investigations will
show weather it needs to be placed in a new genus or should be incorporated in an
existing one.
In conclusion, the thesis filled important data gaps and produced new knowledge on
vegetation composition and diversity patterns in southeast Angola. In combination with
the studies on the impact of land use and the provision of spatial data the presented
thesis hopes to make a strong contribution to allow spatial planning for a sustainable
future of the Okavango Basin.
Angola is a tropical country with many biogeographical units and, therefore, has a high floristic diversity. Although an increasing number of floristic studies has been carried out in Angola in recent years, the country is still considered to be underinvestigated as many species being collected were previously unknown there. Several scientific groups working in different parts of Angola contributed to this paper their data from biodiversity assessments. With this we can add 67 species newly recorded for Angola, including two new generic records and five alien species, to the almost 7,300 vascular plant taxa known so far for Angola. Most of the new records for Angola are also present in different neighbouring countries, but they are little known, and their IUCN threat status has not been assessed yet. However, ongoing fieldwork and exploration are needed to complete the floristic knowledge of the understudied country.
Angola is botanically rich and floristically diverse, but is still very unevenly explored with very few collections from the eastern half of the country. We present an overview of historical and current botanical activity in Angola, and point to some areas of future research. Approximately 6850 species are native to Angola and the level of endemism is around 14.8%. An additional 230 naturalised species have been recorded, four of which are regarded as highly invasive. We draw attention to the paucity of IUCN Red List assessments of extinction risk for Angolan vascular plants and note that the endemic aquatic genus Angolaea (Podostemaceae), not currently assessed, is at high risk of extinction as a result of dams built on the Cuanza river for hydroelectric power generation. Recent initiatives to document areas of high conservation concern have added many new country and provincial records and are starting to fill geographic gaps in collections coverage.
Angola is botanically rich and floristically diverse, but is still very unevenly explored with very few collections from the eastern half of the country. We present an overview of historical and current botanical activity in Angola, and point to some areas of future research. Approximately 6850 species are native to Angola and the level of endemism is around 14.8%. An additional 230 naturalised species have been recorded, four of which are regarded as highly invasive. We draw attention to the paucity of IUCN Red List assessments of extinction risk for Angolan vascular plants and note that the endemic aquatic genus Angolaea (Podostemaceae), not currently assessed, is at high risk of extinction as a result of dams built on the Cuanza river for hydro-electric power generation. Recent initiatives to document areas of high conservation concern have added many new country and provincial records and are starting to fill geographic gaps in collections coverage.
This paper aims to provide a baseline for conservation planning by documenting patterns of plant diversity and vegetation in the upper catchment of the Cuito River. 417 species are recorded from this region. Nine of these are species potentially new to science. Ten species are newly recorded from Angola, with an additional species only recorded previously within Angola from the northern enclave of Cabinda. The 108 new provincial records for Moxico clearly indicate the lack of collections from Angola's largest province. We note the existence of extensive peat deposits in the Cuito river system for the first time and suggest that one of Barbosa's vegetation types in the area needs to be reassessed.
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.
