Browsing by Author "Ito, Paula"
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- Mapping saltmarsh vertical distribution communities in southern Portugal using high spatiotemporal resolution satellite imageryPublication . Martins, Márcio; Parreira, Filipe; Ito, Paula; Santos, Rui; Gotha, Simon von sachsen-Coburg Und; Barrena de los Santos, CarmenSaltmarshes, transitional coastal habitats between terrestrial and marine ecosystems, offer crucial ecological benefits, including coastal protection, biodiversity enhancement, water purification and carbon sequestration. However, saltmarsh areas are shrinking, primarily due to human activities. Traditional monitoring approaches for saltmarsh coverage are often costly and restricted in spatial scope, prompting a shift towards remote sensing techniques. While remote sensing has proven effective for studies that cover large spatial areas, its application for smaller areas remains challenging. In this study, we trained classification models to identify saltmarsh vegetation communities in southern Portugal. We utilized high-resolution (3-metre) and high-frequency (near-daily) imagery to optimize image selection according to tidal conditions at the time of capture and developed an elevation proxy for the intertidal zone. Our model achieved an overall accuracy of 67%, estimating a total of 4,572 ha of saltmarsh in southern Portugal, 85% located in the Ria Formosa lagoon. The middle saltmarsh zone, dominated by Atriplex portulacoides, Salicornia perennis and Salicornia fruticosa, covered the largest area. The approach presented here holds promise for further refinement, enabling automated, high-resolution monitoring of saltmarsh communities, which is essential for conservation and management initiatives.
- Relatório Científico I: Avaliação dos ecossistemas de carbono azul em Portugal continental.Publication . Santos, Rui; Ito, Paula; de los Santos, Carmen B.Por ocasião da Conferência do Oceano das Nações Unidas, que decorreu em Lisboa em junho de 2022, a Fundação Calouste Gulbenkian lançou o projeto Gulbenkian Carbono Azul, em parceria com o Centro de Ciências do Mar (CCMAR) da Universidade do Algarve e a Associação Natureza Portugal em associação com a WWF – World Wide Fund for Nature (ANP|WWF), com o objetivo de investigar as informações disponíveis para mapear os ecossistemas marinhos e costeiros em Portugal continental que têm o potencial de sequestrar dióxido de carbono da atmosfera – os ecossistemas de carbono azul. Esta investigação científica, feita de norte a sul do país, caracteriza os ecossistemas (localização, áreas de distribuição, estado ambiental, reservas e taxas de sequestro de carbono, entre outras características) e propõe medidas adequadas de proteção e restauro.
- Seagrasses in coastal wetlands of the Algarve region (southern Portugal): past and present distribution and extentPublication . Ito, Paula; Martins, Márcio; von Sachsen-Coburg und Gotha, Simon; Santos, Rui; Barrena de los Santos, CarmenThe global biodiversity crisis urges to update the distribution maps of natural habitats, especially those that are in rapid decline and play a key role in ecosystem functioning, such as seagrasses. In Portugal, seagrass meadows have declined substantially since the 1980s and are considered one of the most endangered marine habitats. Here we aimed to 1) compile records on the distribution and area extent of seagrass meadows in the four wetlands of the Algarve region (southern Portugal) with historical occurrence of seagrasses, based on a systematic review, and 2) update the distribution maps and area extent of seagrass meadows in this region using a combination of manual and machine learning mapping techniques. The systematic review showed a general lack of data on the distribution of seagrass meadows in the Algarve, with patchy information at different times and using incomparable mapping techniques. Based on the updated mapping from 2019 to 2023, well-developed seagrass meadows were only found in the Ria Formosa lagoon and the Guadiana estuary. In the Ria de Alvor, some sparce scattered patches of seagrass were observed in the intertidal zone, while no seagrass was found in the Arade estuary. The total extent of seagrass in the Algarve region was estimated at 1231 ha, with nearly all (99 %) occurring in the Ria Formosa, where 85 % was intertidal. Although assessing temporal trends remains challenging due to methodological differences and data limitations, the estimated 20 % decline and ongoing pressures on seagrass meadows in Algarve wetlands underscore the urgent need for continuous, standardized monitoring of their distribution, extent, and condition.