Curiously near Chernobyl, decomposition microbes are suppressed, so things can hang around longer: https://www.smithsonianmag.com/science-nature/forests-around...
I love this story and have repeated it to many people because of how wonderfully it sparks the imagination. Unfortunately, this theory simply doesn't hold up to modern evidence. It turns out we've had white rot fungi as long as we've had lignin
> Rather than a consequence of a temporal decoupling of evolutionary innovations between fungi and plants, Paleozoic coal abundance was likely the result of a unique combination of everwet tropical conditions and extensive depositional systems during the assembly of Pangea.
https://www.pnas.org/doi/10.1073/pnas.1517943113
> Here, we demonstrate that lignin was of secondary importance in many floras and that shifts in lignin abundance had no obvious impact on coal formation. Evidence for lignin degradation—including fungal—was ubiquitous, and absence of lignin decay would have profoundly disrupted the carbon cycle. Instead, coal accumulation patterns implicate a unique combination of climate and tectonics during Pangea formation.