To paint a clearer picture of how global climate change will affect Earth's ecosystems, a team of 80 international research scientists set out to complete an unparalleled experiment: forcing the world's only enclosed rainforest – housed in the University of Arizona's Biosphere 2 – through a four-month-long controlled drought and recovery.
Their findings, published this week in the journal Science, revealed a roughly 70% drop in the rainforest's carbon storage – speaking to concerns surrounding forests' ability to capture and store carbon dioxide from the atmosphere as climate change progresses. However, an intricate web of water-use strategies and soil interactions were found to support the forest's stability in the face of extreme drought.
"The forest was, in some ways, surprisingly resilient to the drought," said Laura Meredith, one of three leads on the project and an assistant professor in the School of Natural Resources and the Environment in the College of Agriculture and Life Sciences.
The glass-enclosed rainforest at Biosphere 2, which houses 90 plant species across an area the size of seven tennis courts, allowed the researchers to simulate a full ecosystem drought.
The experiment, called Water, Atmosphere and Life Dynamics – or WALD, which is German for "forest" – set out to capture every bit of data possible throughout the drought and rewet process. Nearly 2 miles of Teflon tubing and more than 133 sensors were placed throughout the roughly 3-acre rainforest to simultaneously collect measurements on everything from carbon pools in the atmosphere and vegetation, to microbiome and deep-water soil processes.
Read more at: University of Arizona
The "rainforest under-glass" at Biosphere 2 receives rain after a 2 month drought as part of the B2 WALD experiment. (Photo Credit: Rosemary Brandt)