SEED FEATURES OF IMPORTANT TIMBER SPECIES FROM THE FLOODPLAIN VÁRZEA FOREST: IMPLICATIONS FOR EX SITU CONSERVATION PROGRAMS IN THE AMAZON

Abstract

As an integral part of plant regeneration ecology, the ability of seeds to survive desiccation is an important functional feature. For the purpose of conservation, studies have investigated the responses of stored seeds to the desiccation process. In order to enhance the knowledge on seeds ecology of Amazonian floodplain trees, eight common tree species of the várzea floodplain forest with high economic value, were selected and their seeds classified according to their attributes. The selected species represent 80% of the number and total volume of the timber species selectively extracted from Mamirauá Sustainable Development Reserve, Central Amazon. Smaller seeds with lower water content (Calycophyllum spruceanum (Benth.) Hook. f ex K. Schum., Hura crepitans L. and Piranhea trifoliata Baill.), which remained viable and germinated after desiccation and storage, were classified as tolerant to desiccation. The species Guarea guidonia (L.) Sleumer., Laetia corymbulosa Spruce ex Benth., Ocotea cymbarum Kunth., Tabebuia barbata (E. Mey.) Sandwith, and Sterculia apetala (Jacq.) H. Karst., were classified as sensitive to desiccation because their seeds did not germinate in the same treatment and thus cannot be effectively stored. The average dry mass was ten times higher in desiccation-sensitive seeds (82.22 g) than in desiccation-tolerant (8.58 g) seeds. The study suggests that if there are mechanisms to protect floodplain seeds, these would be more efficient as a form of conferring greater tolerance to flooding. Therefore, methods of storage in moist conditions should be investigated to desiccation-sensitive seeds.