Seed Production and 22 Years of Climatic Changes in an Everwet Neotropical Forest

BACKGROUND:

Yasuní National Park in western Amazonia hosts one of the world’s most biodiverse and everwet tropical forests, with minimal seasonal variation in rainfall and temperature. Its stable climate and relative insulation from large-scale disturbances such as ENSO make it an ideal site to investigate long-term ecological responses to climate change. The forest’s biological richness and global conservation importance underscore the need to understand how shifting climatic conditions influence seed production and, by extension, forest regeneration and community dynamics.

GOALS AND METHODS:

The study aims to examine how long-term climate variation influences seed production in an everwet tropical forest in Yasuní National Park, Ecuador. The authors analyze 22 years of seed and flower production data from 203 plant species, alongside five key climate variables: solar irradiance, rainfall, minimum and maximum temperatures, and vapor pressure deficit. The analysis uses ordinary least squares regression models to separate the direct effects of climate on seed production from indirect effects mediated through flower production.

CONCLUSIONS AND TAKEAWAYS:

The study finds that community-level seed production declines over time, primarily due to rising nighttime temperatures and decreasing vapor pressure deficit. Daytime temperatures positively influence seed production, mainly through increased flower production, while rainfall has both positive and negative effects depending on its seasonal timing. These results suggest that ongoing climatic changes in everwet tropical forests may disrupt reproductive cycles and alter forest dynamics, with potential consequences for biodiversity and ecosystem function.