A new study analyzing 8,000 tropical plant specimens spanning about two centuries finds that flowering times in tropical regions are shifting earlier or later due to climate breakdown, with potential cascading effects on ecosystems.

Published in PLOS One, the research examined 33 tropical species using museum specimens collected between 1794 and 2024 to track flowering times, revealing an average shift of roughly two days per decade.

The findings indicate a general disruption to tropical phenology, highlighting that tropical ecosystems are experiencing climate-driven timing changes just as temperate regions are.

Skylar Graves, a University of Colorado PhD student and co-author, notes that tropical regions are highly biodiverse yet understudied and calls for more funding and digitisation of herbaria to support climate impact research.

Co-author Dr. Erin Manzitto-Tripp emphasizes the value of herbarium data in documenting temporal changes and urges conservation planning informed by long-term records.

Researchers warn of cascading impacts across ecosystems, pointing out that tropical ecosystems are a critical, yet understudied, component of global planetary health and biodiversity.

Dr. Emma Bush of the Royal Botanic Garden Edinburgh stresses that tropical seasonality is complex and understudied, reinforcing the need for more documentation and conservation efforts in tropical regions.

The study, published in PLOS ONE, underscores that the tropical biome is as vulnerable as temperate regions to climate-induced disruptions, highlighting urgent conservation considerations.

Led by Skylar Graves of the University of Colorado Boulder, the team challenges the assumption that tropical regions are less affected by climate change in flowering timing, asserting that no region is untouched by climate change.

While ecological impacts are not yet fully understood, shifts in flowering timing could cascade through ecosystems, affecting pollination, seed dispersal, and food webs.

Changes in flowering timing may disrupt synchronization with fruit-eating animals, pollinators, and other plants, potentially impacting ecosystem services.

Specimens from Brazil, Ecuador, Ghana, and Thailand reveal notable changes, such as the Brazilian amaranth tree flowering about 80 days later since the 1950s and the Ghanaian rattlepod shrub flowering about 17 days earlier between the 1950s and 1990s.