A range of discovery: 120 years on the Santa Rita Experimental Range

The story of the Santa Rita Experimental Range is inextricable from that of the Coronado National Forest, as well as the University of Arizona and its land-grant mission.  

By Rosemary Brandt, College of Agriculture and Life Sciences
March 22, 2023

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Repeat photographer shows the SRER landds over its 120 history
The photo on the left, taken by botanist David Griffiths on September 18, 1904, shows the view from Orphan Butte. The photo on the right was taken from the same viewpoint on October 2, 2018. Santa Rita Experimental Range repeat photography archives

Make the drive 40 miles south of Tucson to visit the Coronado National Forest's Madera Canyon recreational area and you'll likely see signs along the side of the road for the Santa Rita Experimental Range, College of Agriculture and Life Sciences.

Although the signs themselves are relatively nondescript, the roughly 52,000-acres of Sonoran upland, mesquite savannah and oak woodland in the shadow of the Santa Rita Mountains have the distinction of being one of the longest continuously operating research areas in the world.

The Santa Rita Experimental Range is part of the University of Arizona's Arizona Experiment Station system, a network of research and educational areas around the state.

"Originally founded to examine ecological interactions of livestock grazing and rangeland studies, this experimental range now serves as a broad-scale, open-air laboratory," said Brett Blum, director of the university's Southern Arizona Experiment Station.

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researcher taking a photo, as part of the SRER's legacy of repeat photography colleciton
Mitch McClaran, Director of the Arizona Experiment Station and Research at the Santa Rita Experimental Range, carries on the legacy of repeat photography on the range. Santa Rita Experimental Range archive

"It's responsible for one of the richest publicly available ecological data sets in the world," said Mitchel McClaran, director of the Arizona Experiment Station and professor of rangeland management in the School of Natural Resources and the Environment.

Founded in 1902, it's also home to one of the most expansive archives of repeat photography to document ecological renewal, experimentation and sustainable management, he explained.

Born from the visionaries of the nation's conservation movement, the story of the Santa Rita Experimental Range is inextricable from that of the Coronado National Forest, as well as the University of Arizona and its land-grant mission. 

A tragedy of the commons

Arizona school children are taught the state's economic foundation was built on the 5Cs – copper, citrus, climate, cotton and cattle.

The waning decades of the 1800s saw exponential growth in Arizona's cattle population, Blum said. By 1890, cattle outnumbered the human population of the Arizona territory by a factor of 10 to one, according to census and tax assessment records.

That year, ranchers enjoyed the biggest calf crop in the history of the territory, according to professor of anthropology and Arizona historian Thomas Sheridan in his book "Arizona: A History," but trouble was on the horizon.

"When the rainy season had passed and not half the usual amount of water had fallen; when it was seen that all the old grass was gone, that the new crop was a failure … it began to dawn upon the ranchmen that there was a limit to the number of cattle that the range would feed," Colin Cameron, chairman of the Livestock Sanitary Commission wrote in the 1896 Report of the Governor of Arizona to the Secretary of the Interior.

"There was no analog for those early ranchers who moved West," McClaran said.

Many had migrated from abundant grasslands in the East, where water and feed were plenty, and drought was unfamiliar.

The Arizona Territory experienced one of the most severe periods of drought on record between 1890 and 1893. It was a disaster of "biblical proportions," according to Sheridan, resulting in the loss of an estimated 50 to 75% of cattle herds across the territory.

The "cattle crash" would become emblematic of a tragedy of the commons. Open or free-range grazing lands were, at the time, unassigned and unfenced. The science of ecology and principles of rangeland management were still emerging at the time and had not been broadly applied to desert ecosystems.

In the shadows of giants

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Robert H. Forbes stands next to a campus olive tree in 1958.
Robert H. Forbes stands next to a campus olive tree in 1958. University of Arizona Special Collections

Robert Humphrey Forbes moved to Tucson in 1894 as a young professor and chemist for the recently founded University of Arizona. He would serve as the first director of the Arizona Experiment Station, which was established through the Hatch Act of 1887 with the mission to support agricultural research through the state's land-grant institution.

Forbes was profoundly influenced by what he saw on the ground,  and as visionaries in the East sought to manage the natural resources within forests, he saw a need for a similar approach in the ranges of the West.

He sought to learn how to recover rangelands and how to support the territory's cattle industry with an understanding of range dynamics and capacity, presenting his proposal for a large experimental range reserve at the annual American Forestry Association meeting in 1901.

The idea caught the attention of Gifford Pinchot, head of the USDA's Bureau of Forestry and the "father" of the U.S. Forest Service. The two would take the idea to Theodore Roosevelt, who had recently ascended to the presidency following the assassination of William McKinley. In what would be one of his first presidential proclamations, the Santa Rita Experimental Range was born as part of the Santa Rita Forest Reserve.         

Scientists got to work constructing fencing, and research in these formative years focused on how to restore and measure range resources for management in collaboration with cattle growers.

The early years of the Santa Rita Forest Reserve were spent examining practices regarding revegetation and recovery, Blum said.

"It was also during these early years that one of the most informative long-term data series began to develop," he said.

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Pyramid Hill on the SRER with botanist David Griffiths and his buggy in the foreground
Photo by botanist David Griffiths, taken in 1902, shows his buggy in the grasslands below Pyramid Hill. Santa Rita Experimental Range archives

Across the range, numerous repeat photography stations were established by botanist David Griffiths as a means to visually assess and document change in range dynamics over time.

"This ongoing data series continues to be one of the most enduring legacies of the SRER today," Blum said. 

Over the course of its history, the range has fueled understanding and experimentation in soil health and nutrient cycling, forage capacity, ecological restoration and sustainable resource management, wildlife conservation, wildfire, drought and precipitation variability – all while directly supporting and collaborating with the region's cattle growers.

A marriage and renewal of vows

A collaboration between the U.S. Forest Service, the Arizona State Land Department and the University of Arizona, the range and its headquarters – a field station complete with cabins, a laboratory and meeting space built in the 1920s within the Coronado National Forest's Florida Canyon – continues to attract researchers and projects with global impact.

"The reason that the range and this field station are so critical is related to geography, right now where we're sitting is one of the most biologically diverse regions of North America," Blum said at a historic lease signing ceremony held Tuesday with the Coronado National Forest and UArizona. "There's more to study here than almost any other place on the continent."

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A view overlooking Florida Canyon Field Station
A general view overlooking Florida Canyon and the Santa Rita Field Station dated August 25, 1933. Santa Rita Experimental Range archives

The majority of the 52,000 acres that comprise the Santa Rita Experimental Range are state trust lands, and the terms of a historic lease agreement signed this week deal specifically with the roughly 20-acre headquarters. The facility has been officially administered by the Arizona Experiment Station since 1988, through a special-use permit that was renewed every 20 years with the U.S. Forest Service.

The new lease agreement for the field station expands the term to 60 years, something Blum hopes will spur new investment opportunities from the university, philanthropic partners and other revenue streams. 

The lease signing ceremony, in many ways, felt like a renewal of vows in a marriage between the university and the U.S. Forest Service, said Adam Milnor, who serves as the recreation, heritage and lands staff officer for the Coronado National Forest.

"I think of this place as the birthplace of the Coronado National Forest. The University of Arizona is, without a doubt, the oldest partner of the Coronado National Forest," Milnor said at the event. "This is where that relationship was born and forged; this is where it started."

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A photo dated 1934 shows the Field Station manager's house in at the Santa Rita Experimental Range headquarters
A photo dated 1934 shows the Field Station manager's house at the Santa Rita Experimental Range headquarters. Santa Rita Experimental Range archives

Beyond reflecting on the facility's legacy and significant scientific contributions, the event also provided an opportunity to discuss the future vision for the Santa Rita Experimental Range.

"We started with some of the very first fences ever applied on public lands to manage livestock grazing, back in 1902. Today, we're exploring virtual fence technology that can actually manage the movement and better understand the interactions of livestock on state and public lands," Blum said. "By better understanding how livestock interface with their environment we can work toward developing principles of adaptive management of mutual benefit for both the environment and producers. That is the mission of the entire AES (Arizona Experiment Station) network."

McClaran was instrumental in digitizing and making the Santa Rita Experimental Range's expansive ecological and repeat photography data sets publicly available online in 1995.

"What's unique about this place is you can do big data analysis in place, not in a classroom or a lab on campus that's disconnected from the place that the data describes," McClaran said. "People who are just beginning to learn about natural resources can get reconnected to the passion of being in a place, understanding it and analyzing at a depth that we could never imagine 100 years ago."

That vision and more than 100 years of meticulous ecological data collection is what drew the National Science Foundation's National Ecological Observatory Network to establish their Southwest Domain Center on the Santa Rita in 2015. The program is a continental-scale observation network designed to collect long-term, open-access ecological data to better understand how U.S. ecosystems are changing.

The Santa Rita Experimental Range is an open-air laboratory, where big data analysis in place is practiced and has the potential to be perfected, McClaran said.

"We have a brain trust in all of you," he said in his closing remarks to an audience of land managers, researchers, nonprofit volunteers and Student Conservation Association members. "That makes this place what it is, and it's going to shape the future of what it could be."

 

 

 

 

 

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Rosemary Brandt

College of Agriculture, Life and Environmental Sciences