VULnerability of Populations under Extreme Scenarios (2016 - 2020)
​The overall key question in this project is "are microrefugia the key to ecosystem sustainability and species persistence in montane ecosystems under projected climate change?"
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We define a microrefugium as a mountainous habitat that may harbor small or reduced populations of several species during a period where the global climate is unfavorable for a wider geographical range. A microrefugium offers suitable local conditions, including microclimate, for the long-term survival of species until a more favorable climate allows their expansion. Microrefugia may occur either during cold (glacial) or warm periods (interglacials). The restricted range and the time span over which species remain isolated in a microrefugium could lead to a local adaptation of the harbored species compared with their original wider-ranging population. Furthermore, at the infra-specific level, due to relatively low population size, genetic drift is expected, leading to reduced genetic polymorphism in each microrefugium; consequently, different organelle DNA haplotypes and nuclear DNA genotypes could be found in the different microrefugia. While local adaptation may be difficult to quantify, different haplotypes and genotypes originating from the different microrefugia should be readily detectable.
Our research plan consists of a set of scientific questions that will lead us to identify the locations of microrefugia, their role in the persistence of tree species and their potential use for preserving biodiversity.
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Approach
Microrefugia will be identified from fossil record, genetic data, and models simulations, based on warmer-than-modern periods of our recent past. Bioclimatic modeling will test the sensitivity of these areas to projected climate change, and socio-ecological modeling will inform the willingness of local communities to take steps to conserve the microrefugia.
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We will focus on five species: Cedrus atlantica (Morocco), Podocarpus latifolius (Cameroon), Podocarpus glomeratus (Ecuador/Peru/Bolivia), Podocarpus lambertii (Brazil), and Fagus longipetiolata (China).
These species are (1) located in mountainous areas with different topographies which may have local climates that deviate from the regional or global climate, (2) have persisted in situ over several thousands of years, (3) have a fragmented range today, (4) and are considered either as vulnerable or as threatened of extinction according to the IUCN Red List (http://www.iucnredlist.org/).