Birmensdorf ZH – Trees can store nanoparticles from the environment in their annual rings and thus provide information about environmental pollution. This is what researchers at the Research Institute for Forests, Snow and Landscape have found out in an experiment.
Trees absorb tiny metal particles from the air and soil and deposit them in their tissues. According to a media release, this is proven by an experiment conducted by the Swiss Federal Institute for Forest, Snow and Landscape Research(WSL). Trees could thus serve as silent witnesses to the pollution caused by an industrial plant, for example.
Arable plants are already known to absorb such particles from the environment. In this study, Paula Ballikaya, a doctoral student at WSL, wanted to find out whether this is also the case with trees. In a greenhouse experiment, she was able to show for the first time that intact nanoparticles pass through the leaves into other parts of the tree. The results of the study were published in the University of Oxford journal Tree Physiology.
For their experiment, Ballikaya and her team sprayed nanoparticles of gold onto young copper beeches and Scots pines in the lab. They do not harm trees and are readily detectable in plant tissue. After twenty days, the particles were present not only in the leaves, but also in the stem and roots. There they can still be found years later. Tree ring chemistry uses this to determine environmental pollution to the year.
One day, it might even be possible to use trees to clean up polluted soil and air, the researchers suspect. “Fast-growing trees could store heavy metals from the soil or air in their wood, which can then be disposed of properly,” Ballikaya is quoted as saying. For this, however, more needs to be found out about interactions between nanoparticles and trees, he said. gba