Morisette and Richardson: Phenology and Climate Change

"Phenology is the study of recurring life-cycle events, classic examples being the flowering of plants and animal migration," explain Jeffrey Morisette, Andrew Richardson and co-authors in their Frontiers in Ecology and the Environment paper, "Tracking the rhythm of the seasons in the face of global change: phenological research in the 21st century."

The two talked about their work in a Beyond the Frontiers podcast:

One thing we're doing is using networked digital cameras, or webcams, which we've deployed at about a dozen research sites across the Northeastern US. And we're using these cameras to make continuous observations of canopy phenology - basically treat the cameras sort of as multi-channel imaging sensors, so it's kind of like remote sensing, except we're close up to what we're observing. We call it near-surface remote sensing.

We send the images from camera back to the server at the University of New Hampshire, and then we quantitatively analyze the different color channels in each image --red, green and blue-- and we use those to track the seasonal changes in canopy state. And we can quantify both the timing of change and rates of change, so how fast green up occurs in the spring, how fast the canopy changes to red in the fall and how long  those peak autumn colors last in autumn.

A really nice thing about this approach is that there's literally thousands of webcams out there recording pictures of the earth's surface and posting these online. We're working on leveraging this potentially vast resource to get a very spatially dense array of ground-based observations with which we can evaluate and improve, for example, satellite remote sensing estimates of phenology.  Because one of the real limitations of satellite phenology metrics right now is that there aren't actually a lot of data that have been used to validate what we've been seeing.

Another really exciting opportunity is the recently developed US National Phenology Network, USANPN,  which is on the web at www.USANPN.org. The NPN is looking for volunteers or citizen scientists to make phenological observations in their own backyard and then to contribute these to an online database. This cooperative effort will provide us with an extremely rich data set, with which we can evaluate the effects of climate change on the plants and animals across the United States.