Abstract
Shifts in flowering phenology have cascade effects across entire ecosystems and are indicative of more severe effects of climate change. Studies investigating flowering phenology at large geographic and taxonomic scales have been limited to temperate and boreal latitudes. Here, we employ a global-scale dataset to analyze changes in flowering times across tropical latitudes using museum specimens. Between 1850 to 2021, flowering times shifted significantly at all 14 locations investigated, on average 98 days across sites. These shifts ranged from a low of 56 days at Las Cruces Research Station in Costa Rica to 110 days at Korup National Park in Cameroon. Parsed by region, the Neotropics witnessed an average of 81 days shifted compared to 92 in the Afrotropics and 103 in Southeast Asia. The severity of shifts is indicative of greater ecosystem-wide changes occurring amongst the most biodiverse regions of Earth.