Percorrer por autor "Frade, Duarte"
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- A fine-tuned global distribution dataset of marine forestsPublication . Assis, J.; Fragkopoulou, Eliza; Frade, Duarte; Neiva, J.; Oliveira, André; Abecasis, David; Faugeron, Sylvain; Serrao, EsterSpecies distribution records are a prerequisite to follow climate-induced range shifts across space and time. However, synthesizing information from various sources such as peer-reviewed literature, herbaria, digital repositories and citizen science initiatives is not only costly and time consuming, but also challenging, as data may contain thematic and taxonomic errors and generally lack standardized formats. We address this gap for important marine ecosystem-structuring species of large brown algae and seagrasses. We gathered distribution records from various sources and provide a fine-tuned dataset with ~2.8 million dereplicated records, taxonomically standardized for 682 species, and considering important physiological and biogeographical traits. Specifically, a flagging system was implemented to signal potentially incorrect records reported on land, in regions with limiting light conditions for photosynthesis, and outside the known distribution of species, as inferred from the most recent published literature. We document the procedure and provide a dataset in tabular format based on Darwin Core Standard (DwC), alongside with a set of functions in R language for data management and visualization.
- Predicted regime shift in the seagrass ecosystem of the Gulf of Arguin driven by climate changePublication . Chefaoui, Rosa M.; Duarte, Carlos M.; Tavares, Ana I; Frade, Duarte; Sidi Cheikh, M.A.; Abdoull Ba, M.; Serrao, EsterThe Banc d′Arguin is a marine ecosystem of global conservation significance, the largest bird sanctuary of western Africa, supported by one of the most extensive seagrass beds in the world composed by three seagrass species, two temperate near their southern limit (Zostera noltei and Cymodocea nodosa) and one tropical at its northern limit (Halodule wrightii). Here we predict the fate of this seagrass ecosystem under climate change scenarios during the 21st century, using species distribution models and sea level rise estimates. We forecast a probable decline in total seagrass area of 3340 Km2 (78%) by 2100, involving the loss of both temperate seagrasses (Z. noltei, C. nodosa), the foundational ecosystem components. By 2050, only the tropical species (H. wrightii) would remain, which forms thin and sparse shallow stands functionally distinct from the previous tall dense meadows that span wider vertical ranges. Intertidal flats, the essential bird foraging habitats, would become unvegetated and also suffer a major reduction in area (114 km2 by 2050, 587 km2 by 2100). The large projected loss of foundational seagrass species portends a collapse of major ecosystem functions with profound impacts on biodiversity, fishery resources and ecosystem services.
- Updated extinction risk of seagrass species in the tropical atlantic bioregionPublication . Samper-Villarreal, Jimena; Creed, Joel C.; Frade, Duarte; Furman, Bradley T.; Bandeira, Salomão; El-Hacen, Hacen M.; Peralta, A. Carolina; Serrao, Ester A.; Vegas, Beatriz E. Vera; Tussenbroek, Brigitta I. van; Frade, Duarte GonçalvesSeagrasses can form vast meadows in coastal areas and provide valuable ecosystem services. Despite their importance, seagrasses are threatened, and their spatial extent and ecological condition have declined worldwide. Globally, there are six seagrass bioregions based on ocean basin and species distribution. The Tropical Atlantic Bioregion encompasses seagrasses in the warm waters off the Atlantic American continent, the eastern Pacific and the west coast of Africa. Here, the extinction risk of the species was determined through the Categories and Criteria of the IUCN Red List of Threatened Species. The extinction risk for the 15 native seagrass species in the bioregion was assessed and summarized as an update to the previous IUCN effort, conducted 15 years ago. The updated regional assessments were based on expert opinion and compilation of revised data on species´ distribution, population status and trend. Of the 15 native species, nine were endemic to the bioregion; thus, the regional assessment was also a global one. Two other species were typical for the region but also occurred beyond bioregional boundaries (Halodule beaudettei and H. wrightii). The remaining species were either distributed circumglobally (2 species), or consisted of peripheral populations of species characteristic of neighboring bioregions (2 species). The detailed information of 15 assessments have been made freely accessible in an open repository. Nine species maintained their previous risk of extinction status, while one species (Thalassia testudinum) changed from the Least Concern to the Near Threatened category. Downgrading of the status of T. testudinum is worrying, as this is the dominant climax species in the wider Caribbean. Its replacement by less resistant and smaller but faster growing species, such as Syringodium filiforme and H. wrightii (both classified as Least Concern), could compromise the ecosystem services of seagrasses in this bioregion. An additional two species had been recently introduced, and are also briefly covered. The assessments included past and present taxonomical uncertainties of various assessed species. Issues concerning the current boundaries of the bioregions themselves were also encountered. To address this and better capture future and ongoing range expansion or reduction associated with climate change, we propose overlapping transitional boundaries with neighboring seagrass bioregions.