Seasonal patterns of Vouacapoua americana in the Amazon: influence of climatic variables on phenological cycles

Key message

Phenological studies are essential for understanding the structure and dynamics of forests, as well as the influence of climate on plants. The phenology of Vouacapoua americana revealed a clear distinction between reproductive and vegetative phases.

Abstract

Understanding the phenological patterns of endangered species is essential for managing and conserving tropical forests, particularly in the biodiversity-rich Amazon. This study examined the phenological behavior of Vouacapoua americana Aubl. (Acapu), an endangered hardwood species with economic potential, over a period of 7 years (2016–2022). We used canopy observation to monitor 35 individuals for reproductive phenophases (floral bud, anthesis, immature and mature fruits, and dispersal) and vegetative phenophases (leaf abscission and sprouting). Analyses were conducted using Principal Component Analysis (PCA), circular analysis, and the Rayleigh test in R software. Results indicated that reproductive phenophases correlated positively with rainfall and relative humidity, peaking from January to April, the period with the highest precipitation. In contrast, leaf phenophases were most intense in the dry season and showed a positive correlation with solar radiation and temperature. Vouacapoua americana displayed clear seasonal and annual behavior, reflecting its adaptation to local climatic variations. These findings are critical for developing conservation strategies, both ex situ and in situ, and for supporting the sustainable use of this species.