Prospecting the presence of aluminum-accumulating species inhabiting temperate rainforests from southern Chile

Background and aimsAluminum (Al) is toxic to most agricultural plants in acidic soils. However, many native species growing on acidic soils are Al tolerant. Indeed, Al-accumulating species maintain high Al concentrations in their leaves without harm. We surveyed native plants across different temperate rainforests of Chile to determine whether Al accumulator species occur in these regions and assessed how soil chemistry correlates with their ability to accumulate Al.MethodsMature leaves or fronds were collected from 107 native trees, shrubs, climbers, herbs, mosses, epiphytes and ferns growing in four sites of south-central Chile. Chemical analyses were performed on these organs and adjacent soils and were compared among the different sites.ResultsSoils from the four collection sites ranged from slightly acidic (pH 6.2, Al saturation of 1.3%) to very acidic (pH 4.7, Al saturation of 70%). Only 7% of the plants sampled were designated as Al-accumulators, including species from the Proteaceae, Dryopteridaceae, Lycopodiaceae, Gleicheniaceae and Polytrichaceae families. Most Al-accumulators were found in the soil with the lowest pH and highest soil Al saturation. However, some of the Al-accumulating plants accumulated similar concentrations of Al in their leaves despite large differences in pH and soil Al saturation.ConclusionsAl-accumulating species were found in the temperate forests of southern South America and soil chemistry can only partly explain the differences in Al accumulation in different sites. These new Al-accumulator species can be investigated further to reveal the mechanisms and genes controlling this trait.