Brown leaves before fall could signal lasting heat damage, researchers warn

Due to increasing heat and drought, forests are turning brown more often before autumn, when leaf senescence normally occurs. It is often unclear whether the trees are actively shedding foliage to avoid a breakdown in water transport or whether browning leaves are a consequence of irreversible damage caused by both heat and drought. As a result, the resilience of forests to climate extremes could be overestimated, WSL researchers warn in a recent commentary.