Effects of wildfire ash on the growth and biochemical profiles of the aquatic macrophyte Lemna minor.

Wildfires are a social and environmental concern to the world due to their many adverse effects, including risk to the public health and security, economic damages in prevention and fight, ecosystems pollution, land usage sustainability, and biodiversity. In the Mediterranean region, these events have increased in the last years. Although several studies evaluated the impacts of the wildfires on the structure and function of the ecosystems and their communities, there is a lack of information at the biochemical level beyond the toxicological effects to the organisms. So, aiming to evaluate the potential toxic and biochemical effects of pine and eucalypt ash from high and low severity burned areas in the aquatic environments, L. minor growth, fatty acid and carbohydrate profiles were studied. Data showed that the wildfires ash from high severity burned areas are more toxic, with a higher growth inhibition than when exposed to ash from low severity burned areas. Considering the ash from low severity burned areas, eucalypt ash revealed to be more noxious to the macrophyte than pine ash. Furthermore, it was observed a decrease in the diversity and abundance of fatty acids content, comparing with the control. An opposite trend was observed in carbohydrates which increased with the organisms' exposure to almost all ash types, except in case of the organisms exposed to eucalypt ash from high severity burned areas, where carbohydrate content decreased.