Flooded forests of the Mekong, Cambodia

The Mekong river used to have extreme seasonal variations, with water levels rising enormously during rainy season. Trees are adapted to this special environment with the direction of the seasonal floods obvious from tree growth. Massive root systems provide support and access to nutrients at different water levels and whatever the floods deposit becomes visible during dry season and low water levels. Nowadays high floods are rare with consistent lack of water due to ever more dams built upstream, exacerbated by climate change.