Microplastics in forest soils arrive almost entirely from the air. Particles settle on tree canopies, wash or fall to the ground with rain and autumn leaves, and are then buried deeper in the soil as litter decomposes — making remote forests reservoirs of airborne plastic pollution.
Geoscientists at TU Darmstadt sampled soil, leaf litter and atmospheric fallout at four forest sites in Germany and modelled microplastic input since the 1950s. Published in Communications Earth and Environment (Nature Portfolio), it is the first study to trace how forests, far from any direct plastic source, become contaminated.
