A solar panel sits near the top of a Douglas Fir tree about 70 feet off the ground somewhere on a steep ridge near Gibson Jack Creek, miles from the nearest trailhead.
“You know those things you enjoy as a child sometimes have applications afterwards,” said John Whiting, an Idaho State University geosciences master’s student, who has accompanied a group of ISU researchers to a study site where he climbed the tree and installed the solar panel about a year ago.
“I usually do the tree climbing, because I am most comfortable with it,” Whiting continued, “I am relatively safe and I usually use a harness, but Sarah doesn’t even like watching me install them.”
He was referring to Sarah Godsey, an ISU geosciences assistant professor who is leading the study at U.S. Forest Service’s Gibson Jack Research Natural Area. In part, the study is one of the many facets of the National Science Foundations Managing Idaho’s Landscapes for Ecosystems Services (MILES) project that encompasses large regions of Idaho, focusing on the Portneuf, Boise and Coeur d’Alene River watersheds. Gibson Jack Creek is a tributary of the Portneuf River.
The solar panel, along with some batteries that work when the panel isn’t producing energy, help power a variety of sensors that are set up in surrounding trees. These trees each feature ISU-crafted sap-flow sensors (made in part by hypodermic needles that are inserted into the sides of the trees) and the site also includes sensors that measure soil moisture, temperature, relative humidity and photosynthetically-activate radiation, or how much sunlight is available for trees to use.
There are a network of data cables from all of these sensors that lead into a protected plastic box hanging on the tree, where data is collected in a data logger, which is small device researchers can connect laptop computer to and download data.
“The MILES grant covers ecosystems services, which is such a broad term, for all the benefits we get from the environment around us that we don’t pay for,” Godsey said. “In this particular part of the MILES project, we are looking at Gibson Jack and plant water use. We want to know how that can relate to stream flow and water quality.”
The researchers here are checking the water transpiration rates of the Douglas Fir trees, measuring the amount of water released by the trees into the air.