Responses of three Central Amazonian tree species to drought and flooding under controlled conditions.

The forest species in Central Amazonia are able to overcome the extreme stress of flooding and drought in the floodplains. We investigated the survival strategies of three tree species representative of the Amazonian floodplain forest, under controlled conditions in climatic chambers in the University of Kiel. We measured a) the anatomical and morphological characteristics such as adventitious roots, roots with a pneumatophore-like structure, lenticels, and stem dimorphism; and b) the growth and photosynthetic activity under different stress conditions. Two different patterns of adaptive responses to stress in the floodplain forests were observed: high-light-demanding plants grow quickly in height and shed their leaves during inundation, and the shade-tolearnt plants grow at a much slower rate and maintain their leaves during inundation. These leaves seem to perform photosynthesis underwater