From Cloudbridge to Nature: The Science of Seasonal Asynchrony
At Cloudbridge, we believe that meaningful science often begins with quiet observation: a flower opening in the mist, a bird calling from a young forest, a researcher pausing to wonder about the rhythm of life. This month, we are honored to celebrate one such story—Drew Terasaki Hart, former resident biologist and longtime friend of Cloudbridge, has published a groundbreaking study in Nature titled “Global phenology maps reveal the drivers and effects of seasonal asynchrony.” His work transforms a simple question—how do seasons unfold in tropical mountains?—into a global understanding of how timing shapes biodiversity.
In 2011, Drew arrived at Cloudbridge searching for direction. “I spent a few months living at Cloudbridge—truly formative months,” he recalls. “I was preparing visitor materials, giving tours, placing camera traps. And birdwatching and stargazing constantly. (And clearing trails like a wayward pirate with a vengeant hatred for bracken ferns). And all that while, I was falling deeply in love with the complex biology of tropical mountains.” During this time, he began to notice that seasonal patterns here were not uniform; flowering and fruiting varied across elevation and cloud cover in ways that defied simple climatic explanations. When he returned in 2017 as part of his PhD research, he focused on how cloud immersion influences plant and animal life cycles. Though the original field data proved unusable, the idea persisted: small-scale environmental variation could have large-scale evolutionary consequences.
Drew Terasaki Hart during his time at Cloudbridge, enjoying the sunrise from the research dorms with a cup of Costa Rican coffee.
That insight grew into a planetary-scale investigation. Using over 7.25 million flowering observations from iNaturalist and satellite-derived land surface phenology (LSP) data from MODIS, Drew and his team created the first high-resolution global maps of plant phenology. They found that more than 20% of species flower twice annually, particularly in tropical and Mediterranean climates. Crucially, they showed that topography and microclimate—not just temperature or rainfall—are dominant drivers of phenological timing. In mountainous regions like the Talamanca range, slight changes in elevation can shift flowering by months, creating “phenological asynchrony” across short distances. This mismatch isn’t merely ecological; it can lead to genetic divergence and speciation, as populations flowering at different times become reproductively isolated.
The study introduces a biome-agnostic method for mapping phenology, correcting a long-standing temperate bias in ecological models. For Cloudbridge, the findings are deeply relevant. Our mission is not only to restore trees but to restore the timing of life—the moments when plants bloom, pollinators appear, and seeds disperse. Drew’s work shows that microclimatic diversity, such as daily cloud cover, is essential to this process. It also affirms the value of local observation: the patterns he first noticed here contributed to a framework now used to understand biodiversity dynamics across continents. As he writes, “After I returned to Berkeley, my field samples turned out to be unusable, but that notion unexpectedly blew up into a global study of the spatial patterns of seasonal timing and their effects on evolutionary biogeography. Fast forward to today: The results of that work are finally out in Nature. This is my love letter to Cloudbridge—one of my favorite places on Earth. And to tropical mountains everywhere, and to the world at large. I am overjoyed—and indeed, proud—to finally be able to share this work. I can only hope that it stirs up ideas and disagreements and deep thoughts and inspiration for others.”
We are profoundly moved. Drew’s journey—from trail-clearing biologist to Nature author—is a testament to the power of place, curiosity, and mentorship. Cloudbridge may be small, but it nurtures big ideas. We extend our deepest congratulations to Drew, co-authors Thào-Nguyên Bùi, Lauren Di Maggio and Ian J. Wang, and to all the citizen scientists and field staff whose contributions made this research possible.
Much has changed at Cloudbridge since Drew first walked these trails—our reforestation efforts have expanded, our monitoring programs have grown more sophisticated, and the reserve itself has matured into a thriving corridor of regenerating forest. But one thing will never change: our unwavering support for researchers who follow their ideas, ask bold questions, and remain deeply curious about the natural world. We will always welcome scientists like Drew, who begin with a simple observation in the mist and end with a discovery that reshapes our understanding of life on Earth.
The full article is available at https://www.nature.com/articles/s41586-025-09410-3 .