Browsing by Author "Dawson, Terence P."

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    A continental-scale validation of ecosystem service models
    (Springer, 2019-04-22) Willcock, Simon; Hooftman, Danny A. P.; Balbi, Stefano; Blanchard, Ryan; Dawson, Terence P.; O’Farrell, Patrick J.; Hickler, Thomas; Hudson, Malcolm D.; Lindeskog, Mats; Martinez-Lopez, Javier; Mulligan, Mark; Reyers, Belinda; Shackleton, Charlie; Sitas, Nadia; Villa, Ferdinando; Watts, Sophie M.; Eigenbrod, Felix; Bullock, James M.
    Faced with environmental degradation, governments worldwide are developing policies to safeguard ecosystem services (ES). Many ES models exist to support these policies, but they are generally poorly validated, especially at large scales, which undermines their credibility. To address this gap, we describe a study of multiple models of five ES, which we validate at an unprecedented scale against 1675 data points across sub-Saharan Africa. We find that potential ES (biophysical supply of carbon and water) are reasonably well predicted by the existing models. These potential ES models can also be used as inputs to new models for realised ES (use of charcoal, firewood, grazing resources and water), by adding information on human population density. We find that increasing model complexity can improve estimates of both potential and realised ES, suggesting that developing more detailed models of ES will be beneficial. Furthermore, in 85% of cases, human population density alone was as good or a better predictor of realised ES than ES models, suggesting that it is demand, rather than supply that is predominantly determining current patterns of ES use. Our study demonstrates the feasibility of ES model validation, even in data-deficient locations such as sub-Saharan Africa. Our work also shows the clear need for more work on the demand side of ES models, and the importance of model validation in providing a stronger base to support policies which seek to achieve sustainable development in support of human well-being.
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    Framing the concept of satellite remote sensing essential biodiversity variables : challenges and future directions
    (John Wiley & Sons Ltd., 2016-03) Pettorelli, Nathalie; Wegmann, Martin; Skidmore, Andrew; Mucher, Sander; Dawson, Terence P.; Fernandez, Miguel; Lucas, Richard; Schaepman, Michael E.; Wang, Tiejun; O’Connor, Brian; Jongman, Robert H. G.; Kempeneers, Pieter; Sonnenschein, Ruth; Leidner, Allison K.; Bohm, Monika; He, Kate S.; Nagendra, Harini; Dubois, Gregoire; Fatoyinbo, Temilola; Hansen, Matthew C.; Paganini, Marc; De Klerk, Helen Margaret; Asner, Gregory P.; Kerr, Jeremy T.; Estes, Anna B.; Schmeller, Dirk S.; Heiden, Uta; Rocchini, Duccio; Pereira, Henrique M.; Turak, Eren; Fernandez, Nestor; Lausch, Angela; Cho, Moses A.; Alcaraz-Segura, Domingo; McGeoch, Melodie A.; Turner, Woody; Mueller, Andreas; St-Louis, Veronique; Penner, Johannes; Vihervaara, Petteri; Belward, Alan; Reyers, Belinda; Geller, Gary N.
    Although satellite-based variables have for long been expected to be key components to a unified and global biodiversity monitoring strategy, a definitive and agreed list of these variables still remains elusive. The growth of interest in biodiversity variables observable from space has been partly underpinned by the development of the essential biodiversity variable (EBV) framework by the Group on Earth Observations – Biodiversity Observation Network, which itself was guided by the process of identifying essential climate variables. This contribution aims to advance the development of a global biodiversity monitoring strategy by updating the previously published definition of EBV, providing a definition of satellite remote sensing (SRS) EBVs and introducing a set of principles that are believed to be necessary if ecologists and space agencies are to agree on a list of EBVs that can be routinely monitored from space. Progress toward the identification of SRS-EBVs will require a clear understanding of what makes a biodiversity variable essential, as well as agreement on who the users of the SRS-EBVs are. Technological and algorithmic developments are rapidly expanding the set of opportunities for SRS in monitoring biodiversity, and so the list of SRS-EBVs is likely to evolve over time. This means that a clear and common platform for data providers, ecologists, environmental managers, policy makers and remote sensing experts to interact and share ideas needs to be identified to support long-term coordinated actions.