Landscape prerequisites for the survival of a modelled metapopulation and its neutral genetic diversity are affected by climate change

Abstract

In response to climate change a species may move, adapt, or go extinct. For the adaptability of a population its genetic diversity is essential, but climate change-induced range shifts can cause a loss of genetic diversity. We investigated how landscape structure affects the level and distribution of genetic diversity in metapopulations subject to climate change-induced range shifts. For this we used the spatially explicit, individual-based model METAPHOR which simulates metapopulation demography and genetics under different temperature increase scenarios. The results indicated that increasing total habitat area may enhance the maintenance of the genetic diversity in metapopulations while they are shifting their range under climate change. However, the results also showed that a high level of total habitat area did not prevent the populations in the newly colonised habitat area of being depleted of much of the original genetic diversity. We therefore conclude that enhancing landscape connectivity may lead to a delayed loss of genetic diversity in metapopulations under climate change, but that additional measures would be necessary to ensure its long-term conservation. Importantly, our simulations also show that a landscape which could be regarded as well-structured under stable climatic conditions, may be inferior for the conservation of genetic diversity during a range shift. This is important information for landscape management when developing strategies for the in situ conservation of genetic variation in natural populations under climate change.