Genetic and environmental contributions to the impact of a range‐expanding predator on aquatic ecosystems

Abstract

Global change is altering biodiversity locally and globally and subsequently affecting the dynamics of communities and ecosystems. Biodiversity can be impacted both at the interspecific (i.e., species composition of communities) and at the intraspecific (evolutionary modification of phenotypic traits through selection or plasticity) levels. Changes in intraspecific diversity have been demonstrated to generate evolutionary feedbacks acting on ecological dynamics. Quantifying the role of intraspecific trait variation, global change and their interactions on ecological dynamics is of utmost importance. Here, we used the range‐expanding dragonfly Crocothemis erythraea as a model species to test the relative effects of intraspecific trait variation in larvae and thermal conditions on the dynamics of freshwater community and ecosystem functioning. Using experimental mesocosms, we manipulated intraspecific trait variation arising from genetic (G), early developmental environment (EE) and late developmental environment (EL) contributions in a full factorial design. We showed that intraspecific trait variation arising from genetic effects has the strongest consequences on community and ecosystem dynamics relative to trait variation driven by the thermal environment (EE and EL). Importantly, the ecological effects of trait variation due to genetic effects were partly modulated by thermal conditions (G × EL, and to a lesser extent G × EE interactions) and varied among ecological response variables. For instance, the strongest G × EL effects were observed on primary productivity and zooplankton dynamics. Trait variation driven by plasticity related to early or late developmental environments has an overall weak effect on ecological dynamics. Intraspecific trait variation induced by genetic effects can affect ecological dynamics (evo‐to‐eco dynamics) more strongly than variation induced by the developmental environment. However, they likely interact to modulate the structure of communities and the functioning of ecosystems, highlighting the strong context (environmental) dependency of evo‐to‐eco dynamics.

The diversity of eco‐evolutionary dynamics: Comparing the feedbacks between ecology and evolution across scales

“…Depending on the strength of the abiotic pressure, shifts in trade‐offs between defence and competition traits governing evolutionary responses can slow down, speed up or completely disrupt eco‐evolutionary feedback loops. This diversity of outcomes predicted for the evo‐to‐eco pathway confirms that effects of the abiotic environment can differ over time and space (De Meester et al, ; Therry et al, ; Ware et al, ). It also shows that impacts of environmental variation on eco‐evolutionary dynamics can be predictable, as long as a system is well enough studied in its evolutionary and population dynamics.…”

“…It also shows that impacts of environmental variation on eco‐evolutionary dynamics can be predictable, as long as a system is well enough studied in its evolutionary and population dynamics. Abiotic factors can vary over space and time, such as with seasons (e.g., temperature, Therry et al, ) or ongoing geochemical processes (e.g., nutrients via processing by other species), independently of other evolutionary pressures. However, abiotic factors can also sometimes be influenced by evolutionary processes, creating feedbacks, for example via abiotic ecosystem properties (e.g., Brunner et al, ).…”

“…Abiotic factors can vary over space and time, such as with seasons (e.g., temperature, Therry et al, 2019) or ongoing geochemical processes (e.g., nutrients via processing by other species), independently of other evolutionary pressures. However, abiotic factors can also sometimes be influenced by evolutionary processes, creating feedbacks, for example via abiotic ecosystem properties (e.g., Brunner et al, 2017).…”

“…One of the difficulties in elucidating the evo‐to‐eco pathway is separating the relative contribution of ecological and evolutionary response to changes in ecological properties. Focusing on the evo‐to‐eco pathway, Therry et al () show that intraspecific trait variation arising from genetic effects in the range‐expanding dragonfly Crocothemis erythraea has stronger consequences for community and ecosystem dynamics than trait variation driven by the thermal environment. Teasing these contributions apart is challenging within a single population but is further complicated when considering them over ecological and spatial scales.…”

“…Abiotic factors underlying these local biotic interactions are seen as the drivers of spatiotemporal differentiation of eco‐evolutionary feedbacks at the landscape level. This is reflected in empirical examples (Van Nuland et al, ; Therry et al, ), although it is unclear whether those feedbacks are generally more common. Such abiotic large‐scale feedbacks may simply be more tractable at larger scales that go beyond a single population.…”