Pre-adaptation to climate change through topography-driven evolution of traits and their plasticity

Abstract

Climate change is expected to increase the level of drought stress experienced by many plant populations, yet the spatial distribution of changes in dryness remains highly uncertain. Species can, to some extent, adapt to climate uncertainty through evolving increased trait plasticity. Biodiversity conservation could capitalize on such natural variation in the ability of populations to cope with climate variability. Yet, disentangling evolution of trait means vs. trait plasticity is challenging, as it requires a sampling design with genetic replicates grown under distinct environmental conditions. Here, we applied different soil moisture treatments to clones of Fragaria vesca plants that were raised from seeds that were sampled in distinct mountainous topographical settings, to study adaptive trait and plasticity divergence in response to drought. We demonstrate that various fitness traits evolved along topographical gradients, including increased specific leaf area (SLA) with increasing slope, and increased growth plasticity with increasing altitude. Our results indicate that traits and their plasticity can evolve independently in response to distinct topographical stressors. We further show that trait heritability varies considerably among traits and topographical settings. Heritability of phenotypic plasticity tended to increase with altitude for all traits, with populations from high altitudes harboring more than twice the heritability for growth and SLA plasticity compared to populations from low altitudes. We conclude that (i) low altitudinal populations, which are expected to be least vulnerable to climate change, may only withstand limited increases in drought stress, while (ii) populations that evolved to thrive under more heterogeneous mountain conditions are pre-adapted to climate change through high plasticity and heritability. Highly heterogeneous landscapes may thus represent invaluable sources of quantitative genetic variation that could support conservation under climate change across the globe.

Ecological divergence of wild strawberry DNA methylation patterns at distinct spatial scales

“…Here, we explore genome-wide epigenetic profiles of second-generation common garden plants originating from three natural woodland strawberry (Fragaria vesca L.) populations that were found to harbour strong natural differentiation in terms of traits related to fitness, probably driven by local topography impacting local soil moisture levels (De Kort et al, 2020). One of the most notable patterns observed in a controlled common garden environment was that plants adapted to the stressful conditions at high-altitude, south-oriented locations were smaller and produced fewer flowers than plants originating from low-altitude, north-oriented locations (De Kort et al, 2020). These data illustrate strong fine-scale adaptive divergence along the altitudinal gradient studied here.…”

Ecological divergence of DNA methylation patterns at distinct spatial scales

“…Here, we explore genome-wide epigenetic profiles of F1 plants originating from three natural Fragaria vesca populations that were found to harbor strong natural differentiation in terms of traits related to fitness, most likely driven by local topography impacting local soil moisture levels ( De Kort et al . 2019).…”

“…2019). Among the most notable patterns observed in a controlled common garden environment were that plants adapted to the stressful conditions at high altitudinal, south-oriented locations were small and produced less flowers than plants originating from low altitudinal, north-oriented locations ( De Kort et al . 2019).…”

Pre‐adaptation to climate change through topography‐driven phenotypic plasticity

“…All data required for the data analysis are archived on Dryad Digital Repository: https://doi.org/10.5061/dryad.5tb2r bp17 (De Kort et al, 2020).…”