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Dr. Jonathan Lenoir: The stay-or-go paradox of plants in a warming world

BIOCHANGE Seminar Series

Info about event

Time

Monday 8 November 2021,  at 14:00 - 15:00

Location

Via Zoom

Speaker: Dr. Jonathan Lenoir, Jules Verne University of Picardy (UPJV), France

Abstract: As climate change (exposure) exceeds species’ intrinsic ability to tolerate it (safety margin), species can stay (persist), to adapt to the new conditions (niche shifts), or go (move), to track the shifting isotherms (distribution shifts) to avoid local extinction (risk). For terrestrial plants moving usually means reproducing, which costs a lot of energy and time. I will provide empirical evidence showing that the magnitude of recent range shifts for terrestrial plants is usually lower than the magnitude of expected range shifts predicted by the velocity of isotherm shifts. Similarly, I will provide evidence showing that community thermophilization is happening at a slower pace than the pace at which temperature is warming, generating the so-called climatic debt. All this suggests time-lag dynamics in the biotic responses of plants to contemporary climate change. Several drivers could explain these time-lag dynamics. Beyond the obvious inertia of plants that require reproduction to disperse the next generation, plant species could also persist locally and stay in a warming world without necessary changing their niche requirements. Indeed, the fractal nature of climate may provide, locally, both (i) steep microclimatic gradients across short spatial distances as well as (ii) buffered microclimatic conditions over long time periods: the physical basis of climatic microrefugia. I will show that such microclimatic processes are very common in forest ecosystems and contribute to explain the climatic debt in understory plant communities.

Host: Prof. Jens-Christian Svenning, Department of Biology, Aarhus University. Sign up to receive zoom link by contacting Anne Blach Overgaard: anne.overgaard[@]bio.au.dk