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- Cashew as a high agricultural commodity in West Africa: insights towards sustainable production in Guinea-BissauPublication . Monteiro, Filipa; Catarino, Luís; Batista, Dora; Indjai, Bucar; Duarte, Maria Cristina; Romeiras, MariaIn Sub-Saharan Africa, the West African region has highly diverse agro-climatic conditions, which grant the potential for a remarkable agricultural production of a great diversity of crops. Since the 1980s, the production volumes of most crops have grown vigorously for both domestic and export markets. Traditional food crops—such as rice, groundnuts and sorghum—have been replaced by cash crops, namely cashew. Among the main cashew production areas, West Africa is the most recent and dynamic in the world, accounting for 45% of the worldwide production of cashew nuts in 2015. In consequence, cashew cultivation has acquired an important position in West African smallholder farming, providing positive economic and social effects. In this paper, we provide an overview of the cashew production system in the West African region, using Guinea-Bissau as a case study. In particular, we present some viewpoints concerning the impact of cashew production and discuss how the strong dependence on a single cash crop can compromise the local livelihoods and food security. Finally, some insights are given towards the sustainable production of cashew in the face of the recent risks affecting the agricultural sector in West Africa
- Recovering plant data for Guinea-Bissau: implications for biodiversity knowledge of West AfricaPublication . Romeiras, Maria; Duarte, Maria Cristina; Francisco-Ortega, Javier; Catarino, Luís; Havik, PhilipThe rich plant diversity that characterizes the West African Region and the inherent knowledge of their flora and vegetation has been the backbone of scientific explorations during the past centuries. The evolution of botanical knowledge on Guinea-Bissau, throughout the 16th and 20th centuries is reviewed. We present and discuss floristic data collected by scientific expeditions between the mid-1700s to 1974, when the Portuguese colonial period ended. Expeditions undertaken by French naturalists provided some of the earliest plant collections. A list of herbarium specimens collected by the French naturalist Jardin, in the Bijagós Islands in ca. 1847–1858 is presented here for the first time, while in the late 1800s some Portuguese naturalists also explored Guinea-Bissau. During the colonial period (1915–1974), Gomes e Sousa published the first comprehensive study of the territory’s flora while Espírito Santo assembled the largest plant collection. Our review applies a multi-disciplinary perspective to fill important lacuna regarding biodiversity knowledge of this under-researchedWest African country. It constitutes the first study tracing the long term evolution of knowledge on Guinea Bissau's plant diversity, which provides the basis for understanding trends and research priorities, in particular in conservation and botanical fields
- Plant species richness in the Cape Verde islands - ecogeographical determinantsPublication . Duarte, Maria Cristina; Rego, Francisco Castro; Romeiras, Maria; Moreira, IlídioPlant species richness in the Cape Verde archipelago is examined relative to island eco-geographical factors. Species-area and species-area-habitat relationships are analysed using the classical species-area model and the recently proposed species-choros model. The number of Xoristic zones (used to estimate the choros parameter) provides an adequate estimate of the potential habitat diversity, and the species-choros model achieved a better Wt with both total Xora and endemic species. In addition to area and habitat diversity, longitude also emerges as an important determinant of species diversity, whereas latitude, minimum distance to the nearest island, and total rural population do not display any correlation. As in other insular ecosystems, the species richness (about 140 per 100 km2) is lower than in nearby mainland regions; the proximity to the desert areas of the Sahel can also be seen as related with this low value. The Xoristic heterogeneity in Cape Verde is high, as is usual in island ecosystems. In a comparative analysis of the species richness on the diVerent islands (using -values), Brava stands out as having the highest total Xora species densities, while for endemic Xora Brava and São Nicolau jointly occupy the leading position. The high diversity for both total and endemic species on Santo Antão, São Vicente, São Nicolau, Fogo and Brava reinforces their importance in conservation terms - in the case of most of them, something that is already recognized in the established network of protected areas