Fruit and Seed Chemistry, Biomass and Dispersal Amazonian Floodplain Forests

Fruits and seeds are released into the water and may be submerged or floating for several days to months – a situation which normally makes most seeds unviable. Trees are adapted and seeds remain visually sound for >2 months when continuously submerged. This stands in contrast to the majority of land plants, whose seeds quickly lose viability if submerged for prolonged periods. On the contrary, seeds of floodplain species kept in air dry or decompose within few days or weeks. Many species have high nutrient contents as a function of the relation to fish dispersal, just as in upland forests diaspores of species dispersed by mammals are rich in fat and proteins. However, in Amazonian floodplain trees dispersal syndromes are closely linked to water, with all necessary adaptations enhancing floatation and attractiveness for fish. High nutrient contents are also advantageous for the seedling, because a high investment of the parent tree into seed reserves guarantees fast initial growth. This can be crucial in an environment with a flood amplitude exceeding 10m. Time for seedling establishment in the non flooded terrestrial period is reduced to few months or weeks. For a fast and well timed establishment, seeds must germinate fast and they need adequate nutrient reserves.