Bruno Fady is presenting a poster at CFCC15.

Many of us have seen the maps: European forest trees such as beech and fir are vanishing from large areas they currently occupy and are conquering new habitats in the 21st century. These maps have triggered worried reactions from forest managers and policy makers alike. And it�s all because of climate change.

However, in taking these maps literally, we basically assume that the area a species occupies is directly related to the climate in that area. We also assume that species will simply track their climate habitat when it changes.�

We too easily ignore the fact that species are complex systems made of populations and individuals interacting in space and time, showing different capacities to move and adapt.�

In doing so, we forget that managers can modify local demographic conditions (for example by planting, thinning and logging) and thus forest functioning and act to preserve the evolutionary potential of forests. This is what recent research conducted at the INRA Ecology of Mediterranean Forests lab shows.

Can trees move? Yes! Can they adapt? Yes! Can trees modify such traits as date of leaf unfolding in the spring or height growth? Yes!�

But not indefinitely and this has significant consequences on their ability to adjust to climate change. Using the diversity-rich mountains of southern France as models for experimental as well as simulation work, we show that sylvicultural treatments, natural selection and migration potential definitely matter for the survival of forest tree populations under climate change.

In particular, we show that seed migration along the slopes of Mediterranean mountains such as Mont Ventoux in southern France would be sufficient for fir (Abies alba) trees to track their habitat if mortality were not too high, even under a warming scenario of +6�C by 2100.�

Unfortunately, we predict tree death to be so high that the species will actually start reducing its distribution at warming levels as low as +2�C (the current goals of IPCC) and be gone if warming increases over 5.5�C.

On the other hand, adaptation potential is high in forest tree species. We have demonstrated that adjacent populations of beech (Fagus sylvatica) on the Mont Ventoux mountainside can diverge sharply for such a crucial adaptive trait as date of budburst, by as much as 5 days in 5 generations. This makes it possible for beech to expand at the lower end of its distribution range.�

In yet another species expanding in the mountains of southern France, the Atlas cedar (Cedrus atlantica), capacity to adjust (phenotypic plasticity) evolved so rapidly that the current generation of trees is able to modify its radial growth quite differently �(making a better use of favorable years) under drought conditions than it was possible 3 generations ago at plantation time.

Finally, we have also demonstrated that the sylvicultural treatments that foresters routinely apply to their managed forests (which modify density and competition) affect not only biomass production in difficult, drought stricken years (lower densities provide better biomass build up), but also affect the genetic make-up of the next generation (clumped adult trees provide higher spatial genetic diversity in seedlings than randomly or regularly distributed trees).

Taken together, the prospects for forests under climate change in regions such as the Mediterranean may not be as desperate as research usually claims.�

Specifically, beech and fir forests may not be doomed at the rear edge of their distribution area when their current habitat moves poleward and upward because of climate change.�

Processes such genetic adaptation, phenotypic plasticity, mortality, migration and competition may facilitate or hinder local survival. Their intricate interplay needs to be better understood and further integrated into species distribution models.�

Only then will they become truly realistic, particularly at the spatial scale of management and forestry practice.

Bruno Fady is a geneticist with an ecology background and a 25-year experience in Mediterranean forest ecosystems. He is a senior scientists at INRA who is interested in many fields related to forest genetics and ecology, from breeding to conservation. He is involved in activities at the crossroads between science, management and policy for the conservation of forest genetic resources and habitats.

This is part of a blog series profiling climate scientists, economists, social scientists and civil society members who are presenting and discussing innovative climate science at Our Common Future. For more follow @ClimatParis2015 and #CFCC15 on Twitter.