Combining expert‐based and computational approaches to design protected river networks under climate change. Issue 12 (29th September 2021)

• Record Type: Journal Article
• Authors: Floury, Mathieu; Pollock, Laura J.; Buisson, Laëtitia; Thuiller, Wilfried; Chandesris, André; Souchon, Yves
• Editors: Grech, Alana
• Is Part Of: Diversity & distributions. Volume 27:Issue 12(2021)
• Page Start: 2428
• Page End: 2440
• Publication Date: 2021-09-29
• Subjects: Brown trout -- climate change uncertainty -- conservation planning -- directed longitudinal connectivity -- protected river networks -- riverine systems -- Salmo trutta -- spatial stream network model -- species distribution model -- species range shifts; Biodiversity -- Periodicals; Biodiversity conservation -- Periodicals; 577
• DOI: 10.1111/ddi.13411
• Languages: English
• ISSNs: 1366-9516

Abstract

Abstract: Aim: Estimate the current and future distribution of brown trout and identify priority areas for conservation of the species. Location: Rhône River basin and Mediterranean streams. Methods: We first developed a spatially explicit species distribution model to estimate the current and future distribution of brown trout for three time horizons (2030, 2055 and 2080) and two climate change scenarios (RCP 4.5 and RCP 8.5). We then performed a prioritization analysis to identify priority areas for brown trout conservation, accounting for: (a) spatial dependencies along the riverine system, (b) several sources of uncertainty arising from climate‐related forecasts and (c) different protected area scenarios by comparing hypothetical, optimal protected networks to an actual protected network designed by regional fish experts. Results: Future projections of brown trout densities exhibited a general trend towards a gradual range contraction, with a significant risk of extirpation across mountainous regions of low to mid‐elevation. Overall, the projected current and future distributions were well‐covered by the existing protected network. In addition, up to 70% of the river reaches included in this expert‐based protection network were also priorities in the optimal priority set (e.g. the best set of areas to maximize biodiversity protection). Finally, a large proportion of these reaches were invariably identified regardless of climate change scenarios and uncertainties or spatial dependencies. Main conclusions: Our analytical approach highlighted priority areas for brown trout conservation which were robust to a set of climate and connectivity assumptions. This core priority network could be further refined by taking into account key fine‐scale processes like thermal refugia. Therefore, we advocate for combining computational and expert‐based approaches in conservation planning of riverine ecosystems to achieve a relevant consensus between regional‐scale management and fine‐grain ecological knowledge.