Perhaps nothing is a more iconic symbol of the American Southwest than the giant saguaro cactus.

“Especially during peak time of sunrise or sunset, the silhouettes cast this human-like shape across the canyons, across the deserts, into the horizon,” says Melisa Bohlman, a volunteer for Saguaro National Park in Arizona.

To protect the cacti, she’s been helping remove invasive buffelgrass from the park. This drought-resistant grass is spreading across the landscape and crowding out saguaros.

“It’s competing for resources, it’s competing for water, it’s competing for nutrients,” Bohlman says.

The dry grass also provides fuel for dangerous wildfires, which may become more common as the climate warms.

“If there’s huge swaths of buffelgrass carrying the fire, you will see large volumes of area just being absolutely destroyed by fire,” Bohlman says.

After a fire tears across the landscape, the buffelgrass will regrow quickly, but saguaros may struggle to return.

So Bohlman and her peers are dedicated to removing the buffelgrass. She says it requires difficult manual labor, but she hopes her work helps the saguaros – and other native plants – survive and thrive.

Reporting credit: ChavoBart Digital Media and Molly Matthews Multedo