Eye in the sky

Cedar Creek embarks on plans to use remote sensing for large-scale monitoring of biodiversity.

Healthy ecosystems are essential to the survival of life on Earth. But how do you tell if an ecosystem is ailing so you can do something about it? Conventional monitoring relies on either on-the-ground studies of relatively small samples of habitat or large-scale but superficial observations—the equivalent of a doctor trying to do a checkup by looking at a toe or a photo of the patient. Under rapidly changing conditions like those we face today, that’s not good enough.

Now, a $2 million, five-year study funded by the National Science Foundation and NASA aims to take a big leap forward in our ability to monitor ecosystem health on a megascale. The biodiversity project includes seven investigators from the U.S. and Canada and is led by Jeannine Cavender-Bares in the Department of Ecology, Evolution and Behavior (EEB) at the University of Minnesota. A team of researchers from the University of Minnesota, including Sarah Hobbie (also from EEB) and Rebecca Montgomery and Peter Reich from the College of Food, Agricultural and Natural Resource Sciences, as well as scientists from four other institutions, will make and compare observations of plants and soil ecosystems from the ground and the air. Their goal: to identify the extent to which it’s possible to use remote sensing from trams, airplanes, or even satellites to get a finger on the pulse of four key measures of ecosystem well-being.

“In the face of global change, monitoring biodiversity and changes in biodiversity is important,” Cavender-Bares says. “We are using novel methods to monitor different kinds of biodiversity, including variation in plant genotypes and in functional attributes that influence how plants interact with their environment. Our goal is to understand the mechanisms that allow us to detect biodiversity from the sky and to develop methods that can be applied globally.” 

Anyone who’s flown in a plane knows we can already get some indication from the air of the variety of vegetation found in a place. Because of the way genetics affects plants’ appearance, and because of the tight link between plants and the condition of the soil in which they are rooted, the researchers suspect there is a whole lot more we can learn about ecosystems via remote sensing. They aim to see whether it’s possible to detect not only the different plant species, but also diversity within species; the rate at which plants accumulate leaves, roots, and flowers; and even soil properties, including the genetic diversity of soil microbes—in Hobbie’s words, “to be able to remotely sense information about various levels of diversity and how variation in diversity alters ecosystem processes, including those that are invisible from space, like decomposition and nutrient cycling that occur in soils.”

The testing grounds for the study will be three experimental sites at the College of Biological Sciences’ Cedar Creek Ecosystem Science Reserve: a set of research plots harboring various combinations of grasses and forbs that was established in 1994; a second study site being established now with a dozen tree species; and a third containing willows and poplars.

Cedar Creek is a perfect place for a study like this, Hobbie says, because it is home to a number of ongoing experiments involving a variety of plant species mixes. Ultimately, the researchers hope the results will make it possible to monitor biodiversity and predict the health of ecosystems on a global scale.

In addition to University of Minnesota researchers, the team also includes collaborators from the University of Alberta in Canada, the University of Nebraska–Lincoln, the University of Wisconsin, and Appalachian State University. The study will also involve citizen scientists through the Cedar Creek Schoolyard Ecology program, the Minnesota Phenology Network, and other outreach opportunities.

— Mary Hoff