“Phenology” might not be a word you use in everyday conversation, but it’s one of the keys to tracking climate change. The term refers to the study of timing in the natural world—the dates when plants flower, leaves emerge, seeds drop, and animals migrate. The USA National Phenology Network is building a stable of citizen scientists to track events like those across the country. I joined up this spring, and the observations I’ve gathered have become part of a database used by scientists worldwide.
“Phenology is a really great indicator of climate change impacts, but we don’t have a good way to do standardized monitoring across the country,” says Erin Posthumus with USANPN. Her agency—which is based at the University of Arizona—was created in 2007 and launched the citizen scientist program, Nature’s Notebook, two years later. Since that time, 18,000 people nationwide have taken part by keeping a close eye on certain plants and animals and reporting their observations.
Among those are many groups at schools and nature centers, but also “backyard observers”—individuals, like me. When I signed up with Nature’s Notebook, I chose four plant species that grow on my property, so I could keep up with regular observations without having to get in the car. These included two trees (poplar and sassafras), one shrub (spicebush), and one wildflower (bloodroot).
As I began observing in March, everything still looked wintry, but soon things started to happen. Bloodroot leaves emerged. Poplar buds appeared. It all felt surprisingly dramatic when I had data sheets in my hand (I marked it all down on paper and entered the data manually, but another option is to use the program’s mobile app).
Posthumus says that the data collected around the country is a real resource for science. “All the data submitted are freely available,” she says. “You can filter for specific data sets, species, life cycle
events. We’re up to 82 peer-reviewed publications by scientists that have used the data.”
I found that having a reason to check on these plants every few days got me to walk in the woods more often, putting me in closer touch with the progress of the season, and acquainting me with the plants themselves. Next year, I plan to add more species to my list, and I’ll make sure some of those are part of Nature’s Notebook’s special campaigns. The Nectar Connectors campaign, for one, aims to collect data specifically on plants that monarch butterflies and other pollinators use for food. Knowing when milkweed blooms, for example, can help scientists predict whether the timing of monarch migrations will continue to align with when their food is available.
All this can help with future adaptation, Posthumus says. “National parks and national wildlife refuges are using the data to help them answer their own questions about how the onset of spring has changed in parks and refuges,” she says. “It can help them think about what’s going to happen in the future.”