CALABASAS, Calif. — The rustling and snap of dry brush and brittle twigs is constant when walking through the Cold Creek Preserve, but it is an emergency siren for Kevin Gaston — the deputy director of TreePeople Land Trust.

“I’ve been working in the Santa Monica Mountains for over 10 years now, and I’ve just never seen anything like this,” he said.  

He is referring to the lack of growth at a site that TreePeople has been rehabilitating for years. Each year they come out to do vegetation monitoring and chart the growth of both native and nonnative species.

The red flag went off when he saw a spring, he said.

“We’re actually getting to the point now where we’re not really seeing much growth from existing shrubs and trees,” he explained. “But also this year, which is a first, with grasses, forbs, other more annual species,” he said.

The way they measure growth is simple. 

Mark Fiege, a staff biologist, ran a tape measurer between two pieces of rebar set 50 feet apart. He then dropped a pole every foot and recorded any vegetation that touched it — or in this case, did not.

“Eleven. That’s a dead stalk, so nothing,” he said as Gaston jotted down the observations. “Twelve. Pretty dead. Nothing.”

The change has not been gradual. It is sudden and severe. In 2018, TreePeople recorded 130% of what they call absolute cover.

“That means at least every single point we marked got one species, some got multiple,” Gaston explained.

This spring, that number plummeted to 48%.

“We’re finding just blank spaces because the drought has been so severe,” Gaston said. “The soil is so dry. It’s difficult for even species that we consider to be invasive, weedy species — even they aren’t growing.”

Normally around this time of year, vegetation in the area would be drying out, but what is troubling, Fiege said, is that this year, it happened much sooner, if things even blossomed at all.

“It just didn’t have a chance this year,” he said, observing one isolated stalk of dry leaves barely a few inches off the ground. “Usually, this species does well in dry, exposed areas, so seeing this dead seedling is not good.”

Further down the path is the creek itself — at least where it should be. By late summer, it would be dry.

“This year, it was dry by late March,” Gaston pointed out.

He worries this could spell disaster for the vital canopy of native trees, and that could set off even more troubling changes.

“When you remove the canopy, you have this influx of nonnatives which lead to erosional issues, reduced habitat quality,” he explained.

It is a bit of a cycle.

The water irrigates the trees, which in turn helps keep the water temperature down. Without that shade, “that water will come at a higher temperature, you’re going to get algae and other things polluting the waterways and making it more difficult for wildlife to utilize it.” 

What is happening in the area, he said, is a huge concern — and not just in the Santa Monica Mountains.

“I think this is a kind of a canary in the coalmine,” Gaston said. “This is occurring in Arizona, in Nevada, the whole Western United States. So in terms of water supply, fire risk, longevity of our natural resources, this is shocking.”

He is surprised there have not been mandatory cutbacks since he said folks in the environmental world have sounded the alarm for a while.

He hopes people will come out to the preserve to see — and hear — the conditions for themselves.

Maybe that will finally be the wake-up call.