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- Present and future distribution of Faidherbia albida in Cabo Verde as revealed by climatic modelling and LULC analysisPublication . Varela, Danilson; Romeiras, Maria M.; Silva, LuísClimate change poses one of the most significant challenges to conserve biodiversity, especially in tropical dry islands, as is the case of Cabo Verde (northeast Atlantic Ocean). This archipelago has a low percentage of forest cover and hosts only seven native tree species, among them, Faidherbia albida (Delile) A.Chev. (Fabaceae). Therefore, protective afforestation is extremely important in Cabo Verde, one of the most vulnerable West African countries to climate change. With this work, we aimed to estimate the current distribution and potential shifts in suitable areas for F. albida under climate change, using species distribution models (i.e., random forest, generalized linear and additive models), covering its distribution range in Cabo Verde and mainland Africa. The best model was then projected for the studied area, at two different slice times, using Representative Concentration Pathway (RCP) 4.5 and 8.5 scenarios. Based on current bioclimatic variables, we estimated that almost two thirds of Cabo Verde’s territory is highly suitable for F. albida, which contrasts with its current occurrence. By overlaying the present habitat suitability with land use and land cover data, we concluded that habitat availability and suitability could be constrained by that factor. On average, the predicted suitable habitat for future distributions gradually decreases by 2080 under both scenarios compared with the current, with a smaller effect of RCP4.5 than of RCP8.5. Local authorities can benefit from this research and develop actions to promote sustainable reforestation in Cabo Verde, which should include native tree species that are best adapted to the local climate and could thus contribute to mitigate the effects of climate change.
- Insights into the cashew production system in Guinea-Bissau: implications for agroecosystem sustainabilityPublication . Sierra-Baquero, Paola Vanessa; Catarino, Sílvia; Costa, Gonçalo João; Barai, Amidu; Correia, Zinha; Ferreira, Maria Rosa; Varón-Devia, Edgar; Romeiras, Maria M.; Catarino, Luís; Duarte, Maria Cristina; Monteiro, FilipaIntroduction: West Africa, particularly Guinea-Bissau, heavily relies on cashew nut (Anacardium occidentale L.) production, which significantly impacts the countries’ economies. Cashew exhibits remarkable adaptability to impoverished and arid soils. Understanding producers’ socio-economic characteristics is crucial due to their potential influence on crop productivity and household income. Methods: This study aims to characterize the socio-economic, productive, and phytosanitary aspects of cashew production in Guinea-Bissau, through 151 interviews with producers across all administrative regions of the country. Results: Our findings reveal that cashew producers are mainly males aged 40 to 60, they typically manage plantations under 5 ha, with the smaller plantation areas located in Gabú, Cacheu, and Bolama. The age of the older trees averaged 31 years, with the highest age found in Biombo. Tree density averaged 286 trees per hectare, with higher values in Cacheu, Bafatá, and Bolama. Cashew nut yield in 2020 averaged less than 0.5 tons per hectare, with farmer-set prices generally lower than government determined prices. Oio, Tombali, and Bolama were the regions most affected by pests, while Oio and Cacheu (North) were the most affected by diseases. Top pests included termites, branch girdler, weaver ants, African grasshopper, and stem borer; while top diseases comprised gummosis, anthracnose, and dieback. Discussion: Characterization of cashew production system is crucial at both national and regional levels to identify region-specific limitations and strengths, aiding in the formulation of tailored strategies for sustainable production. Moreover, cashew production plays a crucial role in household incomes in Guinea-Bissau, underscoring the necessity of developing integrated management strategies.
- Assessing the conservation of Miombo timber species through an integrated index of anthropogenic and climatic threatsPublication . Catarino, Silvia; Romeiras, Maria M.; Pereira, José M. C.; Figueira, RuiAim: Angolan Miombo woodlands, rich in timber species of the Leguminosae family, go through one of the highest rates of deforestation in sub-Saharan Africa. This study presents, on the basis of updated information of the distribution of Leguminosae timber species native to Angola, an integrated index framing the main threats for trees, which aims to support new conservation measures. Location: Sub-Saharan Africa, Republic of Angola. Methods: The current distribution areas of six Leguminosae timber species (i.e., Afzelia quanzensis, Brachystegia spiciformis, Guibourtia coleosperma, Isoberlinia angolensis, Julbernardia paniculata, and Pterocarpus angolensis) were predicted through ensemble modeling techniques. The level of threat to each species was analyzed, comparing the species potential distribution with a threat index map and with the protected areas. The threat index of anthropogenic and climatic factors encompasses the effects of population density, agriculture, proximity to roads, loss of tree cover, overexploitation, trends in wildfires, and predicted changes in temperature and precipitation. Results: Our results revealed that about 0.5% of Angola's area is classified as of “Very high” threat, 23.9% as “High” threat, and 66.5% as “Moderate” threat. Three of the studied species require special conservation efforts, namely B. spiciformis and I. angolensis, which have a large fraction of predicted distribution in areas of high threat, and G. coleosperma since it has a restricted distribution area and is one of the most valuable species in international markets. The priority areas for the conservation of Leguminosae timber species were found in Benguela and Huíla.Main conclusions: This study provides updated data that should be applied to inform policymakers, contributing to national conservation planning and protection of native flora in Angola. Moreover, it presents a methodological approach for the predictions of species distribution and for the creation of a threat index map that can be applied in other poorly surveyed tropical regions.
- Editorial: Reconciling nature conservation and sustainability of tropical ecosystemsPublication . Duarte, Maria Cristina; Massante, Jhonny Capichoni; Bandeira, Salomão; Romeiras, Maria M.
- Agro-Economic Transitions in Guinea-Bissau (West Africa): Historical Trends and Current InsightsPublication . Havik, Philip; Monteiro, Filipa; Catarino, Silvia; Correia, A.; Catarino, Luís; Romeiras, Maria M.The present study provides a critical analysis of the introduction of exotic food crop species and their impact on agricultural transformations in Guinea-Bissau, based on survey data and a review of the literature from the 1800s to the present. It applies a multidisciplinary analysis to map historical and contemporary agrarian knowledge in Guinea-Bissau, presenting the first list of exotic cultivated species introduced in the country. Our results show that many introduced crops have gained widespread acceptance among local producers, with 63 exotic cultivated species native to America and Asia. The most representative families are Fabaceae, Solanaceae, and Anacardiaceae, including the country’s main former and current cash crops. First driven by peanuts in colonial times and by cashew after independence from 1980s onwards, Guinea-Bissau rapidly became one of Africa’s major exporters. The current cashew monoculture—like peanuts before it—relies almost exclusively on smallholder agriculture, raising concerns with regard to biodiversity, sustainability, and food security. The paper analyses historical trends in agro-economic transformations taking into account policies, programs, performance, and scientific research. Despite the existence of a long-standing single crop economy, further research is needed in this largely understudied country to assess the impact of long-term agrarian change.
- Mechanisms Implemented for the Sustainable Development of Agriculture: An Overview of Cabo Verde PerformancePublication . Varela, Danilson; Monteiro, Filipa; Vidigal, Patrícia; Silva, Luís; Romeiras, Maria M.In 2005, the Economic Community of West African States (ECOWAS) adopted the Common Agricultural Policy of ECOWAS (ECOWAP), as an instrument for implementing the Comprehensive Africa Agriculture Development Program (CAADP). The main goals of ECOWAP/CAADP were set to promote agriculture development and end hunger by 2025. In this study we focused on the Cabo Verde archipelago as one of the best performing countries within ECOWAS in terms of overall sustainable development. In this paper, the evolution of the ECOWAP implementation and of the Sustainable Development Goals (SDGs) associated with agriculture in Cabo Verde, were assessed by semi-quantitative (e.g., agricultural policies, agrarian periodical literature) and quantitative (modeling regression of ECOWAP implementation and Sustainable Development Goals—SDGs—performance) analyses. Our integrated results suggest that the agriculture development strategies, the signature of ECOWAP/CAADP by the national government, and political stability might explain the progress made towards poverty reduction and the improvement of food security. The results also show that agriculture-related SDGs in Cabo Verde are higher than the mean values obtained from the remaining West African countries, well above the top 25% WA countries. Nevertheless, Cabo Verde public expenditure into agriculture under the ECOWAP was generally below the targeted 10% of the national budget, with food import required to meet internal food demands.
- James Cook and Macaronesian Botany: Typification and nomenclature updates of the new species described by Johann R. Forster and J. Georg A. ForsterPublication . Francisco-Ortega, Javier; Gandhi, Kanchi N.; Duarte, Maria Cristina; Santos-Guerra, Arnoldo; Carine, Mark; Romeiras, Maria M.Johann Reinhold Forster and his teenaged son John Georg Adam Forster (then 17) joined James Cook’s second voyage (1772-1775), as botanist and artist, respectively. Upon their return they described six species that are pertinent to the study of the Macaronesian flora. Previous typifications are revisited and we designate lectotypes for Aytonia rupestris J.R. Forst. & G. Forst. (Aytoniaceae), Borago tristis G. Forst. (Boraginaceae), and Teucrium canescens G. Forst. (Lamiaceae). We designate epitypes for A. rupestris and Epibaterium pendulum J.R. Forst & G. Forst. Our study indicates that Teucrium betonicifolium Jacq. is the accepted name for this Madeiran endemic. Lectotypes, along with epitypes, are also designated for T. betonicifolium and T. betonicum L’Hér.
- The Role of Climate and Topography in Shaping the Diversity of Plant Communities in Cabo Verde IslandsPublication . Neto, Carlos; Costa, José Carlos; Figueiredo, Albano; Capelo, Jorge; Gomes, Isildo; Vitória, Sónia; Semedo, José Maria; Lopes, António; Dinis, Herculano; Correia, Ezequiel; Duarte, Maria Cristina; Romeiras, Maria M.The flora and vegetation of the archipelago of Cabo Verde is dominated by Macaronesian, Mediterranean, and particularly by African tropical elements, resulting from its southernmost location, when compared to the other islands of the Macaronesia (i.e., Azores, Madeira, Selvagens, and Canary Islands). Very likely, such a geographical position entailed higher susceptibility to extreme climatic fluctuations, namely those associated with the West African Monsoon oscillations. These fluctuations led to a continuous aridification, which is a clear trend shown by most recent studies based on continental shelf cores. Promoting important environmental shifts, such climatic fluctuations are accepted as determinant to explain the current spatial distribution patterns of taxa, as well as the composition of the plant communities. In this paper, we present a comprehensive characterization of the main plant communities in Cabo Verde, and we discuss the role of the climatic and topoclimatic diversity in shaping the vegetation composition and distribution of this archipelago. Our study reveals a strong variation in the diversity of plant communities across elevation gradients and distinct patterns of richness among plant communities. Moreover, we present an overview of the biogeographical relationships of the Cabo Verde flora and vegetation with the other Macaronesian Islands and northwestern Africa. We discuss how the distribution of plant communities and genetic patterns found among most of the endemic lineages can be related to Africa’s ongoing aridification, exploring the impacts of a process that marks northern Africa from the Late Miocene until the present.
- Diversification of Aeonium Species Across Macaronesian Archipelagos: Correlations Between Genome-Size Variation and Their Conservation StatusPublication . Brilhante, Miguel; Roxo, Guilherme; Catarino, Sílvia; Dos Santos, Patrícia; Reyes-Betancort, J. Alfredo; Caujapé-Castells, Juli; Sequeira, Miguel Menezes; Talhinhas, Pedro; Romeiras, Maria M.The rich endemic flora of the Macaronesian Islands places these oceanic archipelagos among the top biodiversity hotspots worldwide. The radiations that have determined the evolution of many of these insular lineages resulted in a wealth of endemic species, many of which occur in a wide range of ecological niches, but show small distribution areas in each of them. Aeonium (Crassulaceae) is the most speciose lineage in the Canary Islands (ca. 40 taxa), and as such can be considered a good model system to understand the diversification dynamics of oceanic endemic floras. The present study aims to assess the genome size variation within Aeonium distribution, i.e., the Macaronesian archipelagos of Madeira, Canaries and Cabo Verde, and analyse it together with information on distribution (i.e., geography and conservation status), taxonomy (i.e., sections), morphological traits (i.e., growth-form), geological data (i.e., island’s geological age), and environmental variables (i.e., altitude, annual mean temperature, and precipitation). Based on extensive fieldwork, a cytogeographic screening of 24 Aeonium species was performed. The conservation status of these species was assessed based on IUCN criteria. 61% of the taxa were found to be threatened (4% Endangered and 57% Vulnerable). For the first time, the genome size of a comprehensive sample of Aeonium across the Macaronesian archipelagos was estimated, and considerable differences in Cx-values were found, ranging from0.984 pg (A. dodrantale) to 2.768 pg (A. gorgoneum). An overall positive correlation between genome size and conservation status was found, with the more endangered species having the larger genomes on average. However, only slight relationships were found between genome size, morphological traits, and environmental variables. These results underscore the importance of characterizing the cytogenomic diversity and conservation status of endemic plants found in Macaronesian Islands, providing, therefore, new data to establish conservation priorities.
- Disease-Causing Agents in Cashew: A Review in a Tropical Cash CropPublication . Monteiro, Filipa; Romeiras, Maria M.; Barnabé, João; Catarino, Silvia; Batista, Dora; Sebastiana, MónicaDue to the high market value of cashew nut, cashew became a significantly important cash crop in many countries. Originating from Brazil, the plant was introduced into Africa, India, and Southeast Asia and is nowadays found across most of the tropical regions. However, the diseases that threaten and compromise crop production have not yet been comprehensively documented. The aim of this study was to examine the published scientific data on cashew diseases, to identify current knowledge gaps, and to present a review of the most important diseases and pathogens affecting cashew productivity. The most described diseases are caused by fungi genera—mainly Colletotrichum, Lasiodiplodia, and Erysiphe (worldwide); Cryptosporiopsis (East Africa); and recently Fusarium in Tanzania. Other fungal genera (e.g., Septoria, Pilgeriella, and Pestalotia) may correspond to emerging local cashew diseases that have not yet expanded to other geographic regions or for which records are lacking. Gummosis (Lasiodiplodia spp.), which is considered the most prevalent and damaging disease of cashew, has a pantropical distribution. There is large discrepancy concerning the causal agents of cashew diseases that might be explained by the lack of proper species identification through morpho-cultural and molecular approaches. This, in turn, can easily lead to misdiagnoses that have serious negative consequences for the implementation of specific control actions. It is important to establish a standardized identification workflow that will allow a reliable identification of the disease-causing agent and to determine the occurrence and/or expansion of a given pathogen across cashew-producing regions.