Microplastics (<5 mm) are now reaching forest soils at levels comparable to cities and farmland, with deposition rates up to 300 particles per m² per day and accumulation of thousands of particles per kg of soil. They disrupt fungal systems by increasing oxidative stress, altering growth, and shifting communities toward stress-tolerant and pathogenic species while reducing key decomposers. This can slow decomposition and nutrient cycling, weakening forest health and carbon storage over time.