The success of restoration practices in areas subject to seasonal flooding is associated with the selection of plant species tolerant to both flooding and post-flooding conditions. Morphophysiological changes of Ormosia arborea (Vell.) Harms (Fabaceae) seedlings were studied to evaluate the plasticity related to the water regime. O. arborea seedlings were flooded for 0, 15, 30, 45 and 60 days. At the end of each flooding period, the seedlings were removed from the pools to assess seedling survival at 75 days after completion of the flooding regime. The seedlings survived under the flooding and post-flooding regime and expressed lenticel hypertrophy. During longer periods of flooding, the seedlings exhibited a reduction in the quantum efficiency of PSII and gas exchanges (except for the internal concentration of CO2, which increased during this period). During the reestablishment, the metabolism was resumed, however, when plants was submitted to more prolonged flooding (60 days), the photosynthetic rates and carboxylation efficiency were not completely recovered. Stomatal conductance and water use efficiency was not recovered at the level of the control independent of the flooding period. These morphophysiological adjustments indicate phenotypic plasticity and potential for survival in temporarily flooded areas.

The objective of this study is to evaluate the effect of water deficit and the recovery potential following rehydration, on the metabolism of Campomanesia xanthocarpa seedlings. The seedlings were distributed in two groups: the first group was the control, in which, plants were hydrated periodically in order to maintain 70% water holding capacity and the second was the treatment group characterized by stress, in which irrigation was suspended until the photosynthetic rate showed levels close to zero, at which point the plants were once again rehydrated with subsequent daily irrigation for one week, maintaining the water holding capacity at 70%. C. xanthocarpa shows a reduction in stomatal conductance and photosystem PSII efficiency. Water deficit decreases the water potential in the leaves and all the traits of the photosynthetic metabolism in C. xanthocarpa seedlings in twenty days of suspension of irrigation. These are later recovered with the re-establishment of the water supply. However, exposure of the seedlings to a second cycle of water deficit during the evaluation period demonstrated that the metabolism traits do not re-establish equilibrium.

Knowledge of the desiccation sensitivity of Alibertia edulis seeds is essential to provide adequate conditions for maintaining viability during storage. Thus, the objective of this study was to evaluate the effect of variations in the water content, environmental conditions, and storage periods on the conservation of A. edulis seeds. After processing, the seeds were dried under ambient conditions to water contents of 20, 15, 10 and 5±2%, and then subjected to storage under laboratory (25°C), cold chamber (16°C), refrigerator (8°C), and freezer (-18°C) conditions for zero, 30, 60, 90, 120, 150 and 180 days. To assess the physiological potential of the seeds, protrusion of the primary root, percentage of normal seedlings, germination speed index, total seedling length and total dry mass of seedlings were performed. A completely randomized factorial split-plot design (4 water contents × 4 temperature × 7 storage periods) was used for the experiment. A. edulis seeds tolerated water content reduction to 5% and storage under room temperature and cold chamber storage conditions for 150 days. Seeds with water content between 10 and 5% did not tolerate more than 60 days of freezing conditions, confirming their physiological behavior as intermediate.