NSF's Weather or Not!
Harvard biologist Andrew Richardson explains how the PhenoCam Network provides continuous monitoring of vegetation across the U.S.
National Science Foundation
What’s phenology and how does it help scientist explain a changing climate?
Interviewer: Charlie Heck
Interviewee: Andrew Richardson
Phen—no—lo—gy. Phenology, can you say it with me? One more time, phenology…the study of cyclic and seasonal natural phenomena, especially in relation to climate and plant and animal life.
But personally…I’m a fan of Andrew Richardson’s description a touch better…the study of reoccurring biological events. Things like leaf-out in trees, autumn colors, migration patterns, spring flowers, things that may not affect our day-to-day life but have huge implications for our future planet.
Andrew: As one reason that, you know, scientists are interested is just because of the biological impact thing, but also it's really a great way to explain climate change to a non-scientist. It's much more tangible to say the growing season is now 10 days longer than it was for your grandparents.
Charlie: That’s Andrew Richardson, he’s an associate biology professor at Harvard University and he’s the head researcher at the Phenocam Network, an automated, near-surface remote sensing of canopy phenology. But, before we virtually hop tree tops, Richardson explains the history of phenology:
Andrew: For a long time phenological observations were kept by sort of amateur naturalists and gentleman farmer types. So on some estates in England there's records going back several hundred years of when the first birds of the species arrived or when a certain wild flower started to bloom in spring. And all of these phenological events are very sensitive to recent weather patterns. So in earlier spring you generally see flowers coming-- sorry, in warmer spring you generally see flowers coming out earlier in-- If it's warmer in the fall, you often see trees holding onto their leaves longer. So short-term variability and weather affects phenology. And what has also been shown is that over the longer term as the climate has gradually warmed over the last 100 years that that's also affecting phenology. So compared to, say, in the 1970s, depending on where you are flowers are coming out maybe a week earlier than they used to. Some migrations are happening later and so forth. So it's a really key example of the biological impacts of climate change. And one reason that, you know, scientists are interested is just because of the biological impact thing, but also it's really a great way to explain climate change to a non-scientist. It's much more tangible to say the growing season is now 10 days longer than it was for your grandparents.
Charlie: Now that we’ve covered the pheno in phenocam, Richardson talks about the cam part:
Andrew: Phenocam is a network that started about 7 or 8 years ago. And what we're doing is using digital cameras, just conventional visual cameras mounted on research towers to take pictures of the vegetation every day. And originally we put an inexpensive webcam on one of our towers in New Hampshire. And then analyzing the pictures we got from that, we realized, oh, there's actually a quantitative signal that we can get out of these images. Basically, we treat them like a remote sensing picture from a satellite. We can do the same kind of image analysis with our digital camera pictures. And that made me think if we want to monitor phenology across a large number of sites it would be much easier just to put cameras up than to try to coordinate a massive on the ground effort. So the cameras take pictures automatically every 30 minutes. They are all plugged into a network, and they send images to our network server. And the images get analyzed every night. And if you look on our project webpage you can see how the greenness of the canopy at Harvard Forest or a site in Alaska or a grassland in Hawaii, how that's changed over the seasons. It's all done sort of automatically providing us very high frequency data on how weather and vegetation-- how weather affects the seasonal activity of vegetation across the country.
Charlie: Richardson and his team aren’t doing it all alone either. Collaborating with local researchers all over the country, Phenocam is all about team work.
Andrew: We send them a camera, they put it up on their tower. They plug it into their local network. And then if there's ever any problems, whether it's lighting damage or a loose mount on the camera or whatever, the collaborators go out and fix it. So they benefit because they can-- from the comfort of their own home, they can see what it looks like at their research site day or night, any day of the year. And we benefit because we get-- over the years we end up with long-term data on the vegetation phenology at that site.
Charlie: And we, the general public, benefit too! Phenocam’s images are available to the public at phenocam.sr.unh.edu. You can browse 250 cameras, across the US and a few in Canada and Europe, drill down on a specific date, time, or even take a trip down the study of cyclic and seasonal natural phenomena memory lane.
Andrew: It is being widely used both in K to 12 and university classrooms for science education. Through a collaboration with the Harvard Forest LTER and their schoolyard program. They've got a 15 year program where local school kids go out and make phenological observations. But we put cameras at some of those schools as well. And for the kids it's really a neat way to say, "Hey, what's it look like in Hawaii right now?" Or "Is there snow on the ground in Alaska?" And they can do that kind of armchair tourism through our project webpage. But then even at the college level for studying biosphere atmosphere interactions and more in-depth processes related to phenology, I know that there's a number of university instructors who are also using data from our web page. So it's a really great way to reach out to the general public and, as I said, highlight the biological impacts of climate change.
Charlie: So what’s next in Richardson’s research? Looking to the future, 100 years or so and the potential impacts phenology plays on ecosystems.
Andrew: We're using models that we've developed for deciduous forest phenology to look at how spring leaf-out is going to be affected by climate change over the next 100 years and what that means for carbon and water cycling in those ecosystems. One thing that we'd like to do in the future is start to think about not just what it means for how ecosystems work but how phenology affects some of the feedbacks of those ecosystems to the climate system. So not just that weather affects forests, for example, but also that forests can affect weather.
Charlie: That was Andrew Richardson, an associate professor at Harvard University. He runs the Phenocam Network. Tomorrow, he’s going to tell us why some leaves turn yellow and some turn purple and how climate change may impact the fall foliage season.
I’m Charlie Heck, co-editor of Science360’s News Service and co-host of the Super Science News Show, at the National Science Foundation.