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Climate change is affecting freshwater habitats worldwide through multiple, interacting pressures that influence the survival, distribution, and persistence of freshwater organisms. Temporary freshwater habitats, or those that dry seasonally, can exhibit wide‐ranging variability in temperature and drying regimes. Aquatic organisms with complex life cycles (e.g., aquatic and terrestrial life stages) often rely on temporary freshwaters to complete their life cycles and have specific adaptations to cope with these dynamic environments. However, climate change is altering the temperature and drying regime of many temporary freshwater habitats worldwide, often resulting in warmer habitats available for shorter durations of time. The ways in which climate‐mediated changes to temporary freshwaters affect development and life history of aquatic organisms, particularly those with complex life cycles, remains poorly understood.We investigated larval development, growth, survival, and relationships among them for two amphibian species, wood frogs (Lithobates sylvaticus) and spring peepers (Pseudacris crucifer), in response to warming and drying in a mesocosm experiment. Over 13 weeks in the spring and summer of 2019, we manipulated temperature and water levels in 48 outdoor pond mesocosms to produce four treatments: control (ambient conditions), drying alone, warming alone, and drying + warming. We predicted reduced survival, body size, and time to metamorphosis for both species in response to warming and drying, with the effect being stronger on wood frogs due to their more specialised habitat use and shorter breeding period.Warming treatments were on average 2°C higher than controls, and drying treatments decreased water depth by 2.5 cm each week. We found that warming temperature shortened larval time to metamorphosis, and drying decreased body size at metamorphosis. Surprisingly, we also found that, across all treatment groups, individuals with early metamorphosis tended to be larger in size and from mesocosms with generally higher survival.Our study indicates that warming and drying may act independently on different developmental responses for amphibians. Our results echo recent calls for a better understanding of the nuanced, often unpredictable, relationships among climate‐mediated environmental pressures and the developmental traits they influence, particularly for organisms with complex life cycles that depend upon dynamic habitat for growth and survival. Understanding these relationships and the mechanisms that drive them will be key to predicting the response of freshwater organisms to climate change. [ABSTRACT FROM AUTHOR]

The study of the environmental features affecting amphibian communities is a priority task for addressing effective conservation initiatives. In the southern edge of the Apennines (Sila Massif, Calabria Region, Italy), we surveyed the distribution of amphibians in lotic freshwater habitats (eight rivers, 17 sampling stations, 87 transects) and recorded nine environmental variables, including the occurrence of potential predators (fish and Eurasian otter Lutra lutra), potentially affecting the distribution and breeding success of amphibian species. A total of seven amphibian species was recorded (75.9% of transects). Fish occurred in all rivers while the otter was found in four rivers (Amato, Lese, Neto, and Savuto). Illuminance and bank heterogeneity were the main factors affecting amphibian reproduction, while neither otter nor fish presence showed significant effects on the amphibian community. Overall, habitat complexity and coevolution history seemed to shape the distribution of amphibians and their breeding sites, while the ongoing recolonization of the study area by the otter is expected to have a negligible impact on the richness of the amphibian community. [ABSTRACT FROM AUTHOR]

Metacommunity ecology provides a basis for understanding how ecological communities are assembled. Metacommunity theory can be applied to assess the effects of anthropogenic disturbance on freshwater communities. However, few studies have examined how species-specific responses to environmental covariates can generate broader patterns in freshwater metacommunities. I determined occupancy patterns in an amphibian metacommunity to identify important predictors of reproduction at wetland sites. I conducted surveys at 49 wetlands for tadpoles with fish traps and dip netting in an urbanising region in southeastern Australia. The larvae of seven frog species were detected. There were negative relationships between the probabilities of reproduction at a site and the relative abundance of the eastern mosquitofish (Gambusia holbrooki) and wetland electrical conductivity. There was a positive relationship between tadpole occupancy and the proportion of accessible habitat within 1000 m of a site, a measure of the combined effects of roads and habitat amount. These results highlight the negative effect of predatory Gambusia on frog communities and illustrate the importance of the species-sorting and mass-effect perspectives of metacommunity theory at multiple spatial scales. Habitat restoration projects for amphibians should remove exotic fish or prevent their establishment in managed wetlands and maintain habitat connectivity to facilitate dispersal. [ABSTRACT FROM AUTHOR]