Woody plants phenology of the coastal dunes in eastern Amazon, Brazil

Abstract

Phenological studies are fundamental for understanding the structure and dynamics of the plant community and assist in understanding the influence of climate on vegetation and for the analysis of plant-animal interactions. In this work, we present the phenology of 19 woody species of coastal dunes located in the eastern end of the Amazon coast. We evaluate the phenological aspects of the community and their relationship with climatic factors (photoperiod, precipitation, and temperature). For this evaluation, 19 woody species with a diameter at soil height (DBH) > 3 cm and whole crown visible were selected. Information on leaf abscission, new leaves, flowering, and fruiting was collected fortnightly. The activity and intensity of each phenophase were estimated according to the Fournier index. Circular statistic was employed to determine the mean dates for the start and peak of the phenophases, and the percentage of activity and intensity for each phenophase. Multiple linear regression analysis was applied to investigate the relationships between phenophases and climatic variables. Additionally, leaf habits and pollination and dispersion syndromes were defined for each species. The results reveal that the species evaluated did not show seasonally defined behavior, nor were they related to the climatic factors evaluated. Most species showed evergreen leaf habit (83.4%), melittophilly as the primary pollination syndrome (78.9%), and zoochoric dispersal (84.22%). Although it does not present a seasonally defined behavior, nor is it related to the climatic factors evaluated, the dry season presented the highest percentages for all phenophases, which may indicate that other factors associated with the dry period may influence the trigger off the phenophases. The information collected expands the knowledge about the functioning of this ecosystem and reinforces the need for more ecological studies and reduced impact management measures, aiming at coastal vegetation conservation.