Biodiversity protection against anthropogenic climate change:
conservation prioritisation of Castanea sativa in the South
Caucasus based on genetic and ecological metrics
Abstract
The climate drives species distribution and genetic diversity; the
latter defines the adaptability of populations and species. The ongoing
climate crisis induces tree decline in many regions, compromising the
mitigation potential of forests. Scientific-based strategies for
prioritising forest tree populations are critical to managing the impact
of climate change. Identifying future climate refugia, which are
locations naturally buffering the negative impact of climate change, may
facilitate local conservation. In this work, we conducted the
populations’ prioritisation for Castanea sativa (sweet chestnut), a
Neogene relict growing in the Caucasus global biodiversity hotspot. We
generated genetic and ecological metrics for 21 sites in Georgia and
Azerbaijan, which cover the natural range of sweet chestnut across the
region. We demonstrated that climate primarily drives the pattern of
genetic diversity in C. sativa, proved with a significant
Isolation-by-Environment model. In future, climate change may
significantly reorganise the species genetic diversity, inducing even
some genetic loss, especially in the very distinct eastern fringe of the
species range in Azerbaijan. Based on our combined approach, we mapped
populations suitable for ex-situ and in-situ conservation, accounting
for genetic variability and the location of future climate refugia.