Have you ever watched a plant bloom, unfold its leaves in the spring, or drop them as the seasons changed? These are all examples of “phenology”, the study of recurring lifecycle events, like fruiting, flowering, and leafing. How do plants know when to start and end their growth? Obviously, they don’t have smartphone calendars or watches to tell them when. Instead, plants rely on changes in the weather and how long the days are to tell them what season it is.
We can study the lifecycles of plants by watching how they change day after day. This is exactly what the PhenoCam Network does using 700+ cameras across North America and the greater world. Through pictures that are recorded every 30 minutes, from sunrise to sunset, 365 days a year, “phenocams” (short for phenology camera) let us keep our eyes on the plants all the time.
Over the last few decades, scientists have become increasingly interested in how climate change is impacting phenology. For example, there are many regions of the world where spring is arriving earlier for plants due to warmer temperatures. Scientists care about these changes because it affects not only the plants, but also the insects and animals that rely on their leaves or fruit for food, and it can also affect how elements like carbon cycle through entire ecosystems.
The impacts of climate change on phenology will probably be different for each ecosystem. For example, in grasslands of the southwestern USA, changes in summer monsoon rainfall—both how much it rains and when it falls—will probably be most impactful. To study how the grasslands might respond, we have installed a total of 72 phenocams at the Sevilleta National Wildlife Refuge in central New Mexico. Each camera there is photographing an individual experiment where the rainfall pattern is being changed using a mix of shelters that block the rain, and sprinklers that add water.
Left: A phenocam at the Sevilleta National Wildlife Refuge in New Mexico keeps an eye on a climate change experiment. Right: Phenocam pictures capture the impact of experimental rainfall manipulation on grassland vegetation at this site. Both pictures on the right were taken on the same day in October, but in plots with different rainfall patterns. Photo credit: Jacob Blais (left) and the PhenoCam Network (right).
In cooler and wetter regions, it is probably not the rain that will make a difference, but rather how much warmer it gets. Hidden among the forests and wetlands of northern Minnesota is the SPRUCE facility, where a different kind of experiment is taking place. 10 chambers, large enough to fit entire trees, are installed there with heaters to simulate climate warming (by up to 16 degrees Fahrenheit). At this site, phenocams in each of the chambers have been useful for tracking not only the impacts of warming on vegetation, but also how much snow is on the ground.
Phenocam pictures capture the impact of experimental warming on forest and wetland vegetation, as well as snow cover, at the SPRUCE facility in Minnesota. Both pictures were taken on the same day in January, but in chambers with different levels of warming. Photo credit: The PhenoCam Network.
These are just some examples of how PhenoCam is helping scientists study vegetation change over time. Join our workshop to learn more by virtually travelling to other camera locations across the world using the PhenoCam website (https://phenocam.nau.edu). A 500-word article is hardly enough to describe the wonders of PhenoCam; if a picture is worth a thousand words, then how many words is 70+ million PhenoCam pictures worth?
Board member, Adam Marsh, and lead paleontologist at Petrified National Forest, works with a team of scientists to uncover an approximately 300 million-year-old fossil skeleton discovered at Canyonlands National Park in Utah (June 2024)