A framework to quantify the vulnerability of insular biota to global changes

The majority of vulnerability assessments of biodiversity to global changes have so far been applied to, and designed for, mainland systems, overlooking islands. However, islands harbour unique biodiversity and are epicentres of ongoing extinctions. We thus introduce a specific framework for quantifying the vulnerability of terrestrial insular biota to multiple threats. This framework uses markers of exposure, sensitivity, and adaptive capacity to account for the unique characteristics of island biodiversity. Our assessment framework involves five steps: (1) defining the scope of the vulnerability assessment, (2) selecting the most appropriate markers, (3) computing the vulnerability metric, (4) evaluating uncertainties, and (5) providing recommendations for conservation. The development of this vulnerability framework tailored for island systems is part of a larger initiative to meet international policy targets that better integrate biodiversity threats and dimensions. We thus discuss the need and urgency for applying this framework to guide evidence-based decisions for the conservation of insular biodiversity, and for increased attention to insular biota at the science-policy interface.