• Energy Research

Species interactions are central in predicting the impairment of biodiversity with climate change. Trophic interactions may be altered through climate-dependent changes in either predator food preferences or prey communities. Yet, climate change impacts on predator diet remain surprisingly poorly understood. We experimentally studied the consequences of 2°C warmer climatic conditions on the trophic niche of a generalist lizard predator. We used a system of semi-natural mesocosms housing a variety of invertebrate species and in which climatic conditions were manipulated. Lizards in warmer climatic conditions ate at a greater predatory to phytophagous invertebrate ratio and had smaller individual dietary breadths. These shifts mainly arose from direct impacts of climate on lizard diets rather than from changes in prey communities. Dietary changes were associated with negative changes in fitness-related traits (body condition, gut microbiota) and survival. We demonstrate that climate change alters trophic interactions through top-predator dietary shifts, which might disrupt eco-evolutionary dynamics.

Climate warming and landscape fragmentation are both factors well known to threaten biodiversity and to generate species responses and adaptation. However, the impact of warming and fragmentation interplay on organismal responses remains largely under-explored, especially when it comes to gut symbionts, which may play a key role in essential host functions and traits by extending its functional and genetic repertoire. Here, we experimentally examined the combined effects of climate warming and habitat connectivity on the gut bacterial communities of the common lizard ( Zootoca vivipara ) over three years. While the strength of effects varied over the years, we found that a 2°C warmer climate decreases lizard gut microbiome diversity in isolated habitats. However, enabling connectivity among habitats with warmer and cooler climates offset or even reversed warming effects. The warming effects and the association between host dispersal behaviour and microbiome diversity appear to be a potential driver of this interplay. This study suggests that preserving habitat connectivity will play a key role in mitigating climate change impacts, including the diversity of the gut microbiome, and calls for more studies combining multiple anthropogenic stressors when predicting the persistence of species and communities through global changes.

Climate change is now considered to be the greatest threat to biodiversity and ecological networks, but its impacts on the bacterial communities associated with plants and animals remain largely unknown. Here, we studied the consequences of climate warming on the gut bacterial communities of an ectotherm, the common lizard (Zootoca vivipara), using a semi-natural experimental approach. We found that 2-3 °C warmer climates cause a 34% loss of populations' microbiota diversity, with possible negative consequences for host survival.

Raw data for the article: Bestion, E, Soriano-Redondo, A, Cucherousset, J, Jacob, S, White, J, Zinger, L, Fourtune, L, Di Gesu, L, Teyssier, A, Cote, J. Altered trophic interactions in warming climates: consequences for predator diet breadth and fitness. Proceedings of the Royal Society: B. 2019. 286:20192227. https://doi.org/10.1098/rspb.2019.2227 This data should be cited as: Bestion, E, Soriano-Redondo, A, Cucherousset, J, Jacob, S, White, J, Zinger, L, Fourtune, L, Di Gesu, L, Teyssier, A, Cote, J (2019). Raw data for: "Altered trophic interactions in warming climates: consequences for predator diet breadth and fitness", Bestion et al 2019 Proceedings B. (Version 1). Zenodo. https://doi.org/10.5281/zenodo.3475402 This data is composed of one dataset with 21 columns and a README file Composition of the Bestion_2019_isotopy_dataset_for_zenodo.csv dataset - Individual: numerical index corresponding to each of the 327 individuals in the dataset - Age: age class, J = juvenile (<1 year old), A = adult (1 and 2+ year old) - Sex: F (female) or M (male) - Climate: Present-day climate or Warm climate - Enclosure: enclosure number (10 enclosures, 5 per climatic treatment) - delta13C_september: stable isotope values for delta13C in september - delta15N_september: stable isotope values for delta15N in september - delta13C_september_corrected: stable isotope values for delta13C in september corrected for the stable isotope value of the three invertebrate prey categories - delta15N_september_corrected: stable isotope values for delta15N in september corrected for the stable isotope value of the three invertebrate prey categories - Prop_predator_eaten: proportion of predatory invertebrates eaten by each individual derived from the corrected stable isotope values - Prop_phytophagous_eaten: proportion of phytophagous invertebrates eaten by each individual derived from the corrected stable isotope values - Prop_detritivorous_eaten: proportion of detritivorous invertebrates eaten by each individual derived from the corrected stable isotope values - Levins_diet_index: levins' dietary index corresponding to lizard diet specialization (with 3 = completely generalist and 1 = completely specialist lizard) - Body_Size_september: lizard body size (snout-vent length in mm) - Body_Mass_september: lizard body mass (in g) - Body_Condition_september: lizard body condition (residuals of body mass by body size) - Microbiota_shannon_index: shannon index representing gut microbial bacteria community diversity - Survival_winter: survival during the winter (1 = survived, 0 = died) - Abundance_predator_enclosure: abundance of predatory invertebrates within the enclosure - Abundance_phytophagous_enclosure: abundance of phytophagous invertebrates within the enclosure - Abundance_detitivorous_enclosure: abundance of detritivorous invertebrates within the enclosure