Summary1. Freshwater ecosystems are especially vulnerable to climate change and pollution. One key challenge for aquatic toxicology is to determine and manage the combined effects of temperature increase and contaminants across species' ranges. 2. We tested how thermal adaptation and life-history evolution along a natural temperature gradient influence the vulnerability of an aquatic insect to a pesticide under global warming. We applied a space-for-time substitution approach to study the effect of warming on the vulnerability of Ischnura elegans damselfly larvae to the pesticide chlorpyrifos in a common garden warming experiment (20 and 24°C) with replicated populations from three latitudes spanning >1500 km in Europe. 3. Chlorpyrifos was more toxic to damselfly larvae at the higher temperature: mortality only occurred at 24°C and the reductions in growth rate were stronger at 24°C. This could partly be explained by parallel reductions in food intake but not by the activities of two widespread enzymatic biomarkers, glutathione S-transferase (GST) and acetylcholinesterase (AChE). 4. There was some evidence that the increased toxicity of the high chlorpyrifos concentration at 24°C was stronger in terms of growth reduction in the faster-growing larvae from the low-latitude populations. This is consistent with energy allocation trade-offs between growth rate and pesticide tolerance, but suggests that local thermal adaptation does not play a role in coping with pesticide stress. 5. Synthesis and applications. Damselfly larvae from populations in lower latitudes were more vulnerable to a common pesticide at higher temperatures and pesticide concentrations, whereas evidence for the influence of local thermal adaptation on the vulnerability of larvae was weak. These results emphasize the need for spatially explicit bioassessment and conservation tools. Management practices aimed at mitigating pesticide run-off into aquatic ecosystems are particularly important in agricultural areas at low latitudes.

The increase in temperature as consequence of the recent global warming has been reported to generate new ice-free areas in the Antarctic continent, propitiating the colonization and spread of plant populations. Consequently, antarctic vascular plants have been observed extending their southern distribution. But as the environmental conditions toward southern localities are progressively far apart from these species' physiological optimum, the colonization of new sites and ecophysiological responses could be decreased. However, if processes of local adaptation are the main cause of the observed southern expansion, those populations could appear constrained to respond positively to the expected global warming. Using individuals from the southern tip of South America, the South Shetland Islands and the Antarctic Peninsula, we assess with a long term experiment (3 years) under controlled conditions if the responsiveness of Colobanthus quitensis populations to the expected global warming, is related with their different foliar traits and photoprotective mechanisms along their latitudinal gradient. In addition, we tested if the release of the stress condition by the global warming in theses cold environments increase the ecophysiological performance. For this, we describe the latitudinal pattern of net photosynthetic capacity, biomass accumulation, and number of flowers under current and future temperatures-by warming-respective to each site of origin after three growing seasons. Overall, was showed a clinal trend was found in the foliar traits and photoprotective mechanisms in the evaluated C. quitensis populations. On the other hand, an asymmetric response to warming was observed for southern populations in all ecophysiological traits evaluated, suggesting that low temperature is limiting the performance of C. quitensis populations, mainly in those from southern. Our results suggest that under a global warming scenario those plant populations that inhabiting cold zones at high latitudes could be improved in their ecophysiological PeerJ Preprints | https://doi.org/10.7287/peerj.preprints.3069v1 | CC BY 4.0 Open Access | rec performance, enhancing the size of populations or their spread. PeerJ Preprints | https://doi.org/10.7287/peerj.preprints.3069v1 | CC BY 4.0 Open Access | rec ABSTRACT 22 The increase in temperature as consequence of the recent global warming has been reported to generate 23 new ice-free areas in the Antarctic continent, propitiating the colonization and spread of plant 24 populations. Consequently, Antarctic vascular plants have been observed extending their southern 25 distribution. But, as the environmental conditions toward southern localities become progressively more 26 departed from the species' physiological optimum, the ecophysiological responses and survival to the 27 expected global warming could be reduced. However, if processes of local adaptation are the main cause 28 of the observed southern expansion, those populations could appear constrained to respond positively to 29 the expec...

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The ability to deal with temperature-induced changes in interactions with contaminants and predators under global warming is one of the outstanding, applied evolutionary questions. For this, it is crucial to understand how contaminants will affect activity levels, predator avoidance and antipredator responses under global warming and to what extent gradual thermal evolution may mitigate these effects. Using a space-for-time substitution approach, we assessed the potential for gradual thermal evolution shaping activity (mobility and foraging), predator avoidance and antipredator responses when Ischnura elegans damselfly larvae were exposed to zinc in a common-garden warming experiment at the mean summer water temperatures of shallow water bodies at southern and northern latitudes (24 and 20°C, respectively). Zinc reduced mobility and foraging, predator avoidance and escape swimming speed. Importantly, high-latitude populations showed stronger zinc-induced reductions in escape swimming speed at both temperatures, and in activity levels at the high temperature. The latter indicates that local thermal adaptation may strongly change the ecological impact of contaminants under global warming. Our study underscores the critical importance of considering local adaptation along natural gradients when integrating biotic interactions in ecological risk assessment, and the potential of gradual thermal evolution mitigating the effects of warming on the vulnerability to contaminants.