Parks Work to Root Out Exotic Pests

As legend has it, the first foreign invader was brought to Orange County by the area’s future governor, Spanish adventurer Gaspar de Portola.

As he wandered through the wilderness of early 18th century Southern California, de Portola was said to have dropped mustard seed along the way. On his journey back, the plant’s bright yellow flowers bloomed, blazing a trail to DePortola’s ship.

But yesterday’s beacon is today’s weed.

In 1996, the mustard plant is one of several foreign species threatening local flora. For the last three years, it and other nonnative vegetation have been the targets of a massive eradication program in the 33,000-acre county regional park system.

From the Russian roots of the common tumbleweed to the rapidly growing South American reed known as Arundo donax, these exotic visitors take firm grip in Orange County soil and often move hometown plant out life completely.

“It’s apparent to us that the nonnative species have taken over portions of our parks,” said county parks manager Tim Miller. “Whether we use volunteers, jail crews or staff, our goal is to go out there, attack these weeds and get rid of them.”

One battlefront is in the state and county parks in Newport Bay. Here, the enemy is the mild-sounding pampas grass.

But this grass comes with sharp, silica-edged blades that rise about six feet above the ground, topped by a beautiful white plume that was the cosmetic reason for the plant being imported from Argentina earlier this century.

In the swirling winds blowing off the ocean, the plumes erupt with seeds that are spread through the area. The plant covers about 35 acres of the combined 800 acres of the county’s Upper Newport Bay Regional Park and the state’s Upper Newport Bay Ecological Reserve.

“It’s pretty nasty stuff to deal with,” said Erik Katzmaier, a landscape architect who helps run a volunteer group that goes out monthly to cut down pampas grass in both parks. “It’ll cut you pretty easily.”

*

About 10 people generally show up on a weekend morning to hack at the giant weed. Breaking into two-person teams, the volunteers attack the dense, fibrous roots using shovels and pickaxes.

“In a way, it’s just like weeding your garden,” said Katzmaier. “You locate the parent plant, destroy it, then pull out the little ones as they come up.”

Many of the exotic species were brought into Orange County for ornamental purposes.

“But people just didn’t realize how easily they can invade a new area,” said Celia Kutcher, a spokeswoman for the California Native Plant Society’s Orange County chapter. “In their own native habitats, they tend to have controls like insects or herbivores that feed on them.

“In a new place, these weeds grow really wild,” she said. “That’s why we call them invasive exotics.”

The effect of pampas grass or other foreign invaders, such as the purple-flowered artichoke thistle, on local ecosystems can be far-reaching and devastating.

Local plants are literally starved out of the ground, removing food sources for birds and rendering huge areas impassable by larger animals.

“They come into a habitat and crowd out everything,” said county ranger Nancy Bruland, who runs Upper Newport Bay Regional Park. “They offer absolutely nothing of value for the rest of the habitat.”

*

Different parks face different challenges. In Aliso and Wood Canyons Regional Park, rangers deal with Russian thistle, otherwise known as tumbleweed. At Peters Canyon Regional Park, eradication efforts focus on mustard, castor bean plants and the artichoke thistle.

Rangers generally are in charge of organizing volunteers. Many school and community groups put in time helping to weed the parks, but the long, hard hours are usually served by nearby residents who use the park.

“I’m always amazed at the sincerity and hard work that volunteers put in,” said Katzmaier. “We go out about 8 a.m. and finish about noon and it’s pretty amazing what 10 people working for four hours can accomplish.”

The county also uses inmate labor as part of the effort. Developers whose building projects encroach on county land occasionally remove foreign weeds as mitigation.

In all, 10 regional parks are involved in the eradication program.

“The way I look at it is we’re stewards of the land and our job is to protect these resources,” Miller said. “These weeds can’t go unchecked and we’ll do everything we can to stop them.”

(BEGIN TEXT OF INFOBOX / INFOGRAPHIC)

Marked for Eradication

Orange County has begun a program aimed at removing exotic plants that are threatening native vegetation in the park system. Here’s what’s targeted and where:

Park: Featherly

Species: Arundo (giant cane)

Acres removed: 23

*

Park: Laguna Coast Wilderness

Species: Artichoke thistle

Acres removed: 1,000

*

Park: Laguna Coast Wilderness

Species: Tree tobacco

Acres removed: 8

*

Park: Mason

Species: Pampas grass

Acres removed: 5

*

Park: Upper Newport Bay

Species: Pampas grass

Acres removed: 32

*

Park: Aliso and Wood Canyons

Species: Russian thistle

Acres removed: 30

*

Park: Riley Wilderness

Species: Artichoke thistle

Acres removed: 20

*

Park: Whiting Ranch Wilderness

Species: Artichoke thistle

Acres removed: 20

*

Park: Whiting Ranch Wilderness

Species: Castor Bean, Pampas grass

Acres removed: 8

*

Park: Carbon Canyon

Species: Arundo, castor bean

Acres removed: 5

*

Park: Peters Canyon

Species: Artichoke thistle, mustard, castor bean

Acres removed: 50

*

Park: Santiago Oaks

Species: Mustard, artichoke thistle

Acres removed: 10

* Source: Orange County Harbors, Beaches and Parks Department