Periodic Reporting for period 3 - ECOFEED (Altered eco-evolutionary feedbacks in a future climate)
Période du rapport: 2022-04-01 au 2023-09-30
Climate-driven changes at individual and population levels can therefore shape community composition and ecosystem functioning, and vice versa, altering eco-evolutionary feedbacks, namely the reciprocal interactions between ecological and evolutionary processes. Climate-driven ecological and evolutionary dynamics are yet often investigated separately. The role of eco-evolutionary feedbacks in climate change impacts on biological systems therefore hinges on little concrete empirical evidence contrasting with a profuse theoretical development.
ECOFEED investigates climate-dependent eco-evolutionary feedbacks using a realistic warming experiment reproducing natural conditions and thus allowing for both evolutionary and ecological dynamics to occur under a predicted climate change scenario. We will quantify the impacts of warmer climates on the evolution of top predator’s phenotype (Common lizards, Zootoca vivipara, WP1) and on communities structure and ecosystem functioning (WP2), and then experimentally Additional experimental studies will test for the reciprocal effects of evolutionary and ecological dynamics (WP3-4) and isolate the direct impacts of climate-induced changes of top predator phenotype on community and ecosystem functioning, and in turn the direct effects of climate-induced changes of community and ecosystem on this top predator. The reciprocity of effects between ecological and evolutionary dynamics will outline the extent of eco-evolutionary feedbacks (WP5).
Simultaneously, we kept monitoring the changes in the ecological networks of mesocosms with present-day and warm climates (WP2). We are monitoring plant and invertebrates communities as well as the microbial communities in lizards’ gut, invertebrates and in the soil to build ecological networks and estimates climate-dependent changes in their structure and in tropic interactions.
Most samples from the long-term experiment are being analyzed (i.e. stable isotopes for the diet, metabarcoding for the microbial communities) and were postponed due to the COVID-19 crisis. However, we used the databases from our short-term experiments using the exact same methods to explore and predict evolutionary and ecological dynamics.
From the repeated short-term experiments and the first three years, we found that both life history traits, thermal traits and trophic traits were influenced by climatic treatments. Common lizards, our top predator, had a faster pace-of-life, with newborns growing faster, reproducing earlier in life, and older individuals dying more. This faster pace-of-life led to population structure towards younger and bigger individuals matching predictions made in natural populations. Lizards however had a paler color and preferred lower thermal temperatures in warmer habitats 8 months after our climate manipulation and those acclimation changes mostly resulted from plastic changes to prevent overheating. Simultaneously, lizards changed their diet. They were more specialized and eat more predatory invertebrates (e.g. spiders) than herbivores ones (e.g. orthoptera). We are currently analyzing samples to have a larger database and statistically analyze diet’s heritability, plasticity and selective gradient. These changes were further related to changes in gut microbial communities, with a loss of diversity in warmer climates increasing over time, and may have knock-on effects on invertebrates’ communities (WP2). We expect further changes arising from the long-term manipulation of climatic conditions
i. We have set-up a long-term warming experiment monitoring both the evolutionary and the ecological dynamics in nearly natural conditions to estimate feedbacks between these dynamics.
ii. We revealed from our databases that the top predator may experience large modifications of life history, thermal physiology and diet.
iii. These phenotypic changes may have large consequences on species interacting with lizards including microbial and invertebrate communities.
These results allow us to expect stronger modifications of ecological and evolutionary dynamics by the end of the project.