Luís Catarino

Exploring the floristic diversity of tropical Africa

BackgroundUnderstanding the patterns of biodiversity distribution and what influences them is a fundamental pre-requisite for effective conservation and sustainable utilisation of biodiversity. Such knowledge is increasingly urgent as biodiversity responds to the ongoing effects of global climate change. Nowhere is this more acute than in species-rich tropical Africa, where so little is known about plant diversity and its distribution. In this paper, we use RAINBIO – one of the largest mega-databases of tropical African vascular plant species distributions ever compiled – to address questions about plant and growth form diversity across tropical Africa.ResultsThe filtered RAINBIO dataset contains 609,776 georeferenced records representing 22,577 species. Growth form data are recorded for 97% of all species. Records are well distributed, but heterogeneous across the continent. Overall, tropical Africa remains poorly sampled. When using sampling units (SU) of 0.5°, just 21 reach appropriate collection density and sampling completeness, and the average number of records per species per SU is only 1.84. Species richness (observed and estimated) and endemism figures per country are provided. Benin, Cameroon, Gabon, Ivory Coast and Liberia appear as the botanically best-explored countries, but none are optimally explored. Forests in the region contain 15,387 vascular plant species, of which 3013 are trees, representing 5–7% of the estimated world’s tropical tree flora. The central African forests have the highest endemism rate across Africa, with approximately 30% of species being endemic.ConclusionsThe botanical exploration of tropical Africa is far from complete, underlining the need for intensified inventories and digitization. We propose priority target areas for future sampling efforts, mainly focused on Tanzania, Atlantic Central Africa and West Africa. The observed number of tree species for African forests is smaller than those estimated from global tree data, suggesting that a significant number of species are yet to be discovered. Our data provide a solid basis for a more sustainable management and improved conservation of tropical Africa’s unique flora, and is important for achieving Objective 1 of the Global Strategy for Plant Conservation 2011–2020.

RAINBIO: a mega-database of tropical African vascular plants distributions

Abstract The tropical vegetation of Africa is characterized by high levels of species diversity but is undergoing important shifts in response to ongoing climate change and increasing anthropogenic pressures. Although our knowledge of plant species distribution patterns in the African tropics has been improving over the years, it remains limited. Here we present RAINBIO, a unique comprehensive mega-database of georeferenced records for vascular plants in continental tropical Africa. The geographic focus of the database is the region south of the Sahel and north of Southern Africa, and the majority of data originate from tropical forest regions. RAINBIO is a compilation of 13 datasets either publicly available or personal ones. Numerous in depth data quality checks, automatic and manual via several African flora experts, were undertaken for georeferencing, standardization of taxonomic names and identification and merging of duplicated records. The resulting RAINBIO data allows exploration and extraction of distribution data for 25,356 native tropical African vascular plant species, which represents ca. 89% of all known plant species in the area of interest. Habit information is also provided for 91% of these species.

Medicinal plants of Guinea-Bissau: Therapeutic applications, ethnic diversity and knowledge transfer

ETHNOPHARMACOLOGICAL RELEVANCE The rich flora of Guinea-Bissau, and the widespread use of medicinal plants for the treatment of various diseases, constitutes an important local healthcare resource with significant potential for research and development of phytomedicines. The goal of this study is to prepare a comprehensive documentation of Guinea-Bissaus medicinal plants, including their distribution, local vernacular names and their therapeutic and other applications, based upon local notions of disease and illness. MATERIALS AND METHODS Ethnobotanical data was collected by means of field research in Guinea-Bissau, study of herbarium specimens, and a comprehensive review of published works. Relevant data were included from open interviews conducted with healers and from observations in the field during the last two decades. RESULTS A total of 218 medicinal plants were documented, belonging to 63 families, of which 195 are native. Over half of these species are found in all regions of the country. The medicinal plants are used to treat 18 major diseases categories; the greatest number of species are used to treat intestinal disorders (67 species). More than thirty ethnic groups were identified within the Guinea-Bissau population; 40% of the medicinal plants have been recorded in the countrys principal ethnic languages (i.e. Fula and Balanta). CONCLUSIONS This multi-disciplinary, country-wide study identifies a great diversity of plants used by indigenous communities as medicinal, which constitute an important common reservoir of botanical species and therapeutic knowledge. The regional overlap of many indigenous species, the consensual nature of disease groups based upon local perceptions of health conditions, and the relevance of local vernacular including Guinean Creole are key factors specific to the country which enhance the potential for the circulation and transmission of ethno-botanical and therapeutic knowledge.

Cashew cultivation in Guinea-Bissau – risks and challenges of the success of a cash crop

In recent decades a boom in cashew (Anacardium occidentale)cultivation has taken place in Guinea-Bissau, leading to the replacement of traditional slash-and-burn agriculture by a cash crop. As a result, the country is currently one of the world’s largest producers of raw cashew nuts and the cashew sector has acquired enormous importance in Guinea-Bissau’s economy. Changes induced by the cashew boom at social and environmental levels are yet to be analyzed and understood. The present study provides an account of the process of cashew expansion in Guinea-Bissau, reviews the current situation and discusses its future prospects. The cashew tree was introduced into the country by the Portuguese in the XIXth century, but only effectively expanded in the mid-1980s. It is largely cultivated by small farmers around villages and also plays a role in land ownership, since land tenure practices are linked to the planting of trees. The effects of this cashew boom on habitat fragmentation, fire regimes and biodiversity are still to be assessed. On the other hand, the spread of pests and diseases is becoming a problem. Strong dependence on a single cash crop also renders the country vulnerable to market fluctuations, entailing risks to local producers and the national economy. In the medium term, losses of export earnings can occur, which may impact the living standards and food security of Bissau-Guineans both in urban and rural areas.

Land cover/land use multiclass classification using GP with geometric semantic operators

Multiclass classification is a common requirement of many land cover/land use applications, one of the pillars of land science studies. Even though genetic programming has been applied with success to a large number of applications, it is not particularly suited for multiclass classification, thus limiting its use on such studies. In this paper we take a step forward towards filling this gap, investigating the performance of recently defined geometric semantic operators on two land cover/land use multiclass classification problems and also on a benchmark problem. Our results clearly indicate that genetic programming using the new geometric semantic operators outperforms standard genetic programming for all the studied problems, both on training and test data.

Tracking cashew economically important diseases in the West African region using metagenomics

During the last decades, agricultural land-uses in West Africa were marked by dramatic shifts in the coverage of individual crops. Nowadays, cashew (Anacardium occidentale L.) is one of the most export-oriented horticulture crops, notably in Guinea-Bissau. Relying heavily on agriculture to increase their income, developing countries have been following a strong trend of moving on from traditional farming systems toward commercial production. Emerging infectious diseases, driven either by adaptation to local conditions or inadvertent importation of plant pathogens, are able to cause tremendous cashew production losses, with economic and social impact of which, in developing countries is often underestimated. Presently, plant genomics with metagenomics as an emergent tool, presents an enormous potential to better characterize diseases by providing extensive knowledge on plant pathogens at a large scale. In this perspective, we address metagenomics as a promising genomic tool to identify cashew fungal associated diseases as well as to discriminate the causal pathogens, aiming at obtaining tools to help design effective strategies for disease control and thus promote the sustainable production of cashew in West African Region.

Chorological and taxonomic notes on African plants

Abstract The taxonomy of complicated native African taxa, Biscutella maritima (Brassicaceae) and annual species of Sesuvium (Aizoaceae) is discussed. The distribution of B. maritima is widened to the most of the coastal areas of NE Algeria and N Tunisia. Morphological differences with regard to other North African members of Biscutella ser. Biscutella are reported to facilitate the identification of B. maritima. We propose to accept four annual Sesuvium species (instead of the one previously accepted species, S. sesuvioides sensu amplissimo) with different distributions in Africa: S. digynum, S. hydaspicum, S. sesuvioides s.str. and S. nyasicum. A delimitation key based on morphological and carpological characters is provided. Lectotypes of S. digynum, S. digynum var. angustifolium, S. hydaspicum, S. nyasicum, Diplochonium sesuvioides (Sesuvium sesuvioides) and Trianthema polysperma (synonym of Sesuvium hydaspicum) are selected. Other discussed taxa belong to the alien elements of the flora. Atriplex semibaccata (Amaranthaceae-Chenopodiaceae) is reported as a new species for Cape Verde. Gaillardia × grandiflora (Asteraceae) is discovered as a new species for Africa found in Morocco. Prosopis velutina (Fabaceae) is collected for the first time in Northern Africa (Morocco). Mollugo verticillata (Molluginaceae) is recorded as a new species for DR Congo. Its morphology, including seed ornamentation, is discussed in reference to other similar-looking Molluginaceae. Incidence of American species Heterotheca subaxillaris (Asteraceae) in North Africa is discussed. Vernonanthura polyanthes (Asteraceae) is recorded as a naturalized invasive species in eastern Zimbabwe. It seems to be the first documented discovery of this ergasiophyte in Africa.

New records of insect pest species associated with cashew, Anacardium occidentale L. (Anacardiaceae), in Guinea-Bissau.

The cashew tree, Anacardium occidentale L., is a small to medium-sized evergreen perennial native to northeast Brazil (Jaffee 1994; Asogwa et al. 2008). The species was introduced to distant regions such as India and East Africa as early as the 16th century (Malhotra 2008), and is now an important crop cultivated in tropical regions worldwide (Maruthadurai et al. 2012). Cashew is generally grown for its fruit, which has two connected parts: (i) the kidney-shaped nut containing the nutritious edible kernel, and (ii) the false fruit or cashew apple (the fleshy edible stalk) which can be eaten raw, used to make jam, juiced or fermented into wine (Jaffee 1994; Asogwa et al. 2008; Lundy 2012). The nut shell contains a corrosive liquid known as cashew nut shell liquid, which is widely used in automobile brake linings, paints, varnishes and insecticides, among others (Malhotra 2008).

Ecological data in support of an analysis of Guinea-Bissau׳s medicinal flora

This dataset presents an annotated list of medicinal plants used by local communities in Guinea-Bissau (West Africa), in a total of 218 species. Data was gathered by means of herbarium and bibliographic research, as well as fieldwork. Biological and ecological information is provided for each species, including in-country distribution, geographical range, growth form and main vegetation types. The dataset was used to prepare a paper on the medicinal plants of Guinea-Bissau “Medicinal plants of Guinea-Bissau: therapeutic applications, ethnic diversity and knowledge transfer” (Catarino et al., 2016) [1]. The table and figures provide a unique database for Guinea-Bissau in support of ethno-medical and ethno-pharmacological research, and their ecological dimensions.

New species of Maerua (Capparaceae) from Angola

Genus Maerua has around 60 species represented on the African continent, of which three have been reported for Angola. Two new species of Maerua (Capparaceae) from Angola are here described. Both are closely similar to M. juncea subsp. juncea, being distinguished by floral traits such as the receptacle, androphore and gynophore (M. pintobastoae) or leaf traits such as venation, as well as size and shape of the ovary and disc shape (M. mendesii). A key for Maerua species occurring in Angola is provided, as well as a table summarizing and comparing the morphological characters for the new species and similar African species. With the description of these two new species, the genus Maerua comprises five species in Angola. Resumo O genero Maerua tem cerca de 60 especies representadas no continente Africano, das quais 3 foram ja reportadas para Angola. Sao aqui descritas duas novas especies de Maerua (Capparaceae) de Angola, ambas estreitamente semelhantes com M. juncea subsp. juncea, da qual diferem por carateres florais como o recetaculo, androforo e ginoforo (M. pintobastoae) ou por caracteres foliares como nervacao, bem como tamanho e forma do ovario e forma do disco (M. mendesii). Apresenta-se uma chave das especies de Maerua que ocorrem em Angola, bem como uma tabela comparativa das caracteristicas morfologicas de cada uma das novas especies com especies africanas similares. Considerando as novas especies descritas, o genero Maerua compreende cinco especies com ocorrencia confirmada em Angola.