Interactive effects of aluminium and phosphorus on microbial leaf litter processing in acidified streams: a microcosm approach.

Decline in pH, elevated aluminium (Al) concentrations, and base cations depletion often covary in acidified headwater streams. These parameters are considered as the main factors reducing microbial activities involved in detritus processing, but their individual and interactive effects are still unclear. In addition to its direct toxicity, Al can also reduce the bioavailability of phosphorus (P) in ecosystems through the formation of stable chemical complexes.

Evolution of a genetic polymorphism with climate change in a Mediterranean landscape.

Many species show changes in distribution and phenotypic trait variation in response to climatic warming. Evidence of genetically based trait responses to climate change is, however, less common. Here, we detected evolutionary variation in the landscape-scale distribution of a genetically based chemical polymorphism in Mediterranean wild thyme (Thymus vulgaris) in association with modified extreme winter freezing events.