Abstract Gymnanthes klotzschiana is a tree native to the Atlantic Forest Biome. The objective of this study was to analyze the synchronization of five phenophases and their correlation with environmental factors during two years of survey in two distinct areas (Area 1: Mixed Alluvial Ombrophilous Forest; Area 2: Montane Semi-deciduous Seasonal Forest). Ten individuals were randomly selected in each area, with the following variables being studied: leaf fall and budding, flowering, and immature and ripe fruit production. The activity index and the intensity index were determined for each phenological event. Timing and interactions with environmental factors were tested using Spearman’s correlation. The photoperiod correlated with all phenophases and precipitation did not correlate with any. There was synchronization in the foliar fall and foliage in the two areas. The species can be characterized as semi-deciduous. Flowering and fruiting were annual, with the highest intensity of fruit production occurring in Area 1.

Abstract The objective of this study was to assess hypoxia tolerance in Gymnanthes klotzschiana seeds harvested in two areas (Area 1 - subject to flooding; and Area 2 - not subject to flooding) by the imbibition curve, vigor and germination. Seeds of the two areas were submitted to: one (T-1d), three (T-3d), five (T-5d), ten (T-10d) and twenty days under hypoxia (T-20d); in addition to the control (T-0d). All treatments presented three germination stages. The highest germination was achieved in Area 1 T-1d (90%) and the lowest in Area 2 T-20d (31%). The Area 1 seeds required less time and water content to finish their germination, and they presented greater tolerance to hypoxia; a fact proven by the germination and vigor results. G. klotzschiana seeds harvested in an area subject to flooding are more tolerant to hypoxia and are recommended for restoration projects in this type of area.