Rebecca Minor’s neon orange jacket isn’t the only thing that sticks out on Mt. Bigelow on a chilly Friday morning in November. Boxes of wires, spinning wind gauges and a 100-foot-tall tower also grace the slopes of this patch of forest near Mt. Lemmon, part of the Critical Zone Observatory, or CZO, where Minor collects data for research at the University of Arizona’s School of Geography.

In 2014, the National Science Foundation renewed five-year funding for the project, which brings together multiple scientific disciplines to study the soil and ecosystem on top of the Catalina Mountains. For this next round of funding, the project will focus more on human influence and how the ecosystem operates during a time of heavy human use. The new budget also accommodates more outreach and education, funding a CZO exhibit at the UA Flandrau Science Center.

Minor, research specialist for the UA School of Geography and Development, comes to the CZO weekly to maintain the research area and gather data. She is part of a team headed by Greg Barron-Gafford, research scientist and associate head of the School of Geography and Development.

The CZO allows researchers to focus on an ecosystem in the lower boundaries of the atmosphere, “about as high up as you can see and are concerned with,” said Barron-Gafford referencing the highest elevation that directly affects air we breathe, our water, soil, vegetation, trees and atmosphere.

"Where all those earth sciences come together, that's the critical zone," Barron-Gafford said. Mount Bigelow’s CZO is a complex ecosystem, a semi-arid environment with many dips and slopes, making it a challenging and invaluable source of data. Gathering the data in a complex environment takes time, said Barron-Gafford, but a lot can be learned about the global carbon cycle especially when scientists can go from desert to forest in 30 minutes.

"If you think about how climate is going to change in the future, places like Colorado might have temperatures and precipitation that look more like Arizona’s current temperatures and precipitation,” said Minor. “So, we have a lot to offer the rest of the region because of research that we're doing on this forest in our area.”

Scientists here gather data from plants, soil, wind and water and use a multitude of tools that measure rates of photosynthesis, water usage and carbon dioxide in the air. The massive scaffolding structure, known as the flux tower, rises high above the tree line and measures carbon dioxide and water in the atmosphere as invisible swirls of air run through its dizzyingly high sensors.

By doing this daily, researchers have a constant gauge of an ecosystem’s health, and measurements accumulated over years reveal fluctuations in health overtime. "You essentially take a pulse of the ecosystem,” said Barron-Gafford.


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