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- Spectral Unmixing of Coastal Dune Plant Species from Very High Resolution Satellite ImageryPublication . Kombiadou, Katerina; Costas, Susana; Gallego-Fernández, Juan Bautista; Yang, Zhicheng; Bon de Sousa, Luísa; Silvestri, SoniaWhile improvements in the spectral and spatial resolution of satellite imagery have opened up new prospects for large-scale environmental monitoring, this potential has remained largely unrealised in dune ecogeomorphology. This is especially true for Mediterranean coastal dunes, where the highly mixed and sparse vegetation requires high resolution satellites and spectral unmixing techniques. To achieve this aim, we employed random forest regressors to predict the fractional cover of dune plant species in two of the sandy barriers of Ria Formosa (S. Portugal) from WorldView-2 imagery (June 2024). The algorithm, tested with spatially upscaled multispectral drone data and satellite imagery, detected the fractional cover of major species (most abundant classes and bushy vegetation) with reasonable to very good accuracy (coefficient of determination, CoD: 0.4 to 0.8) for the former and reasonable to good accuracy (CoD: 0.4 to 0.6) for the latter. Additional tests showed that (a) including the distance to the shoreline can increase model accuracy (CoD by ~0.1); (b) the grouping of species resulted in an insignificant increase in model skill; and (c) testing over independent dune plots showed generalisation beyond the training set and low risk of overfitting or noise. Overall, the approach showed promising results for large-scale observations in highly mixed coastal dunes.
- Spectral unmixing of coastal dune plant species from very high resolution satellite imageryPublication . Kombiadou, Katerina; Costas, Susana; Gallego-Fernández, Juan Bautista; Yang, Zhicheng; Serrão Bon de Sousa, Maria Luísa; Silvestri, SoniaWhile improvements in the spectral and spatial resolution of satellite imagery have opened up new prospects for large-scale environmental monitoring, this potential has remained largely unrealised in dune ecogeomorphology. This is especially true for Mediterranean coastal dunes, where the highly mixed and sparse vegetation requires high resolution satellites and spectral unmixing techniques. To achieve this aim, we employed random forest regressors to predict the fractional cover of dune plant species in two of the sandy barriers of Ria Formosa (S. Portugal) from WorldView-2 imagery (June 2024). The algorithm, tested with spatially upscaled multispectral drone data and satellite imagery, detected the fractional cover of major species (most abundant classes and bushy vegetation) with reasonable to very good accuracy (coefficient of determination, CoD: 0.4 to 0.8) for the former and reasonable to good accuracy (CoD: 0.4 to 0.6) for the latter. Additional tests showed that (a) including the distance to the shoreline can increase model accuracy (CoD by ~0.1); (b) the grouping of species resulted in an insignificant increase in model skill; and (c) testing over independent dune plots showed generalisation beyond the training set and low risk of overfitting or noise. Overall, the approach showed promising results for large-scale observations in highly mixed coastal dunes.
- Five key opportunities to enhance the effectiveness of area-based marine conservationPublication . Stanley, R. R. E.; Abad-Uribarren, A.; Belackova, Adela; Belgrano, A.; Bergström, U.; Boerder, K.; Blenckner, T.; Colaço, A.; Himes-Cornell, A.; Horta e Costa, Barbara; Jacquemont, J.; Jurrius, L. H.; Langton, R.; Noble-James, T.; Ohanna, M.; Olsen, E. M.; Rubidge, E. M.; Sacre, E. C. E.; Sheehan, E. V.; Sköld, M.; Stelzenmüller, V.; Tittensor, D. P.; Vallina, T. C.; Villasante, S.; Claudet, J.Effective area-based conservation is central in global efforts to reverse marine biodiversity loss and safeguard ecosystem functioning. Here, we identify five key opportunities to maximize conservation potential as nations progress towards the Convention on Biological Diversity’s 2030 area-based management targets. These include enhancing accountability, elevating conservation in spatial planning, implementing adaptive management, coordinating conservation efforts across scales, and reconciling design with expected outcomes. Addressing these collectively will advance global marine conservation and maximize its contributions to biodiversity protection and human society.