“If San Diego lost its forest” by Walter Oechel


The forests of San Diego County that have shaded 500 generations of local people and provided pine needle bedding, oak woodland and spiritual renewal could disappear. Overly intense fires in quick succession, along with drought, borer insects and climate extremes is laying waste to trees and creating a hostile environment for regrowth.

Trees are a gift whose value is hard to measure. They absorb carbon dioxide, produce oxygen, provide shade, shelter wildlife and prevent erosion.

Beloved local places — the Laguna mountains, Cuyamaca Rancho State Park, Palomar Mountain — could convert to chaparral or even to grasses. Some scientists mention even the Torrey pines as possibly at risk.

“I can tell you the Laguna mountains look very different from when I was a kid. We are already in my opinion seeing the effect of climate change and climate extremes. I’m actually quite shocked at the change in vegetation in the Lagunas over my lifetime,” said Walt Oechel, San Diego State University distinguished professor of biology and director of the university’s global change research group.

“We are seeing the change in communities, right before our eyes and it is very strong and very palpable.”

A backcountry enthusiast, San Diego State biogeographer and physical geographer John O’Leary has noticed the changes at Palomar Mountain, among other places. “You drive up there and look around, it is remarkably apparent there is a great deal of mortality,” he said. “Some of the conifer species and even oaks are not able to endure, withstand the drought that is taking place there.”

Many trees here, and the animals that live among them, are in effect living in refuges. These are a particular concern for Oechel. “I can imagine the Torrey pines are going to have a rough time in the future,” he said, referring to San Diego’s iconic solo pines, sometimes flat across their tops, that populate the ocean bluffs in La Jolla.

Other oases, like Peñasquitos Canyon Preserve, can’t be taken for granted either. The multi-mile, partly shaded canyon offers so much variation: sage plant communities that telegraph the message, “you are in Southern California,” with their scent, chaparral plants on the north facing slopes and sycamores alongside the gently flowing creek.

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