Institute of the Environment 2017

Water, Soil, and Air: Understanding Life in a Life-sized Landscape

Monday, February 23, 2015

It’s the world’s largest artificial watershed, and after a few good douses of rainfall here and a bit of drought there, Biosphere 2’s Landscape Observation Laboratory (LEO) is helping us understand how ecosystems will respond to climate change.

Built side by side, three manmade hillslopes, each 100 feet long and 40 feet wide, form LEO. Each hillslope is packed with 600 tons of crushed volcanic rock and lava fragments known as tephra. The slopes also have their own rainwater systems, which simulate everything from steady to spotty rainfall, allowing researchers to study how water, energy, and carbon move through the landscape. Nearly 2,000 sensors placed in the tephra transmit data to researchers to help them better understand how Earth systems evolve and affect each other.

“No, this is not a real hillside, but that’s the point,” says Peter Troch, science director at Biosphere 2. “We can understand how landscapes adapt not by theorizing about it but by doing experiments at a very large scale. That’s never been done anywhere in the world.”

LEO will allow scientists to observe how climate will affect soil, hydrology, and the atmosphere and to create experiments that are not possible out in the elements, such as limiting water supply for a period of time to simulate the effects of drought or observing how water is not only absorbed by the soil but also how it evaporates or moves laterally through the landscape.

IE helped fund key instrumentation for LEO, including the sensors and samplers critical to tracking the flow of water and measuring moisture in the atmosphere, Troch says.

LEO draws faculty and student researchers from various UA colleges and departments, including the School of Natural Resources and the Environment, the Departments of Soil, Water and Environmental sciences, Geosciences, Atmospheric Sciences, and Hydrology and Water Resources, and the School of Geography and Development. Additional funding from the National Science Foundation will support research by scientists from B2 and Johns Hopkins University to better understand how solutes and pollutants move through the landscape.


A school in Tucson’s Barrio Hollywood neighborhood now houses “Little LEO,” a small-scale version of Biosphere 2’s LEO. A research site for fourth graders and a compliment to the school’s successful learning garden, the mini LEO recreates the hillslopes of the B2 LEO, using the same slope and aspect degrees, volcanic tephra, and seed samples.

“This kind of experiential learning allows schoolchildren to collect data on the impacts of hydrological change, soil nutrients, sunlight, and temperature on seed germination,” says Michelle Coe, a master’s student in the UA College of Geography and Development who developed the diminutive replica in collaboration with Manzo Elementary School. “Manzo students are not only learning scientific techniques, but will actually be presenting and providing useable data to B2 scientists at the end of the year.”

The project aims to boost elementary school students’ interest and awareness in science, technology, engineering, and math (STEM) while also providing a tested curriculum unit that can be easily integrated into the classroom and used by school district staff, faculty, and volunteers.