Exotic a go-go
Die-hard volunteers put a damaged ecosystem back together again
On a recent Saturday morning, the “Hardcore” met at an old barn in a rural area about 20 miles south of Sacramento. They loaded shovels, chain saws and herbicides into trucks and then drove off to fields, forests and wetlands around the 45,000-acre Cosumnes River Preserve. One of their number, Joe Watson, had advised the group earlier: “All we have to worry about is sunburn, ticks, mosquitoes, hay fever, poison oak, wasps, dehydration, chain-saw accidents, hazardous chemicals and fatigue.”
The dozen or so unofficial members of the Hardcore are the heart of the preserve’s largely volunteer habitat-restoration team (HRT), whose primary mission is to restore the preserve’s natural habitat. These volunteers meet twice a month to do battle with the “exotics”—the non-native weeds, trees and aquatic plants that threaten to overwhelm the preserve’s native plant species.
The Cosumnes River is unique because it is the one and only river that flows out of the Sierra Nevada and meanders to the sea without a single dam in its way. And in some spots, the Cosumnes is allowed to do what rivers do best: to flood and replenish the land.
The Nature Conservancy created the Cosumnes River Preserve in 1987 with a mission to protect and restore wetlands and riparian forests along the river. More than 90 percent of California’s original wetlands and riparian forests have been destroyed. The preserve has become a haven for birds and other wildlife, and an escape from the modern world for its human visitors. The preserve also serves as a sort of living laboratory, a place to puzzle out the techniques of restoring damaged land back to health.
In 1988, the call went out for volunteers to help plant oak trees at the new nature preserve, and it was answered by an unexpected horde of 200 people from across Northern California. Watson showed up with his friend Lou Gouveia of Sebastopol and says that because of the enormous crowd, “I think we managed to plant two trees that day.” From that beginning, the HRT was born. The team has continued to meet on Saturdays on a monthly, and now bimonthly, basis ever since. The small corps of individuals who regularly showed up for HRT workdays month after month and year after year came to be known as the Hardcore.
Becky Waegell joined the preserve’s staff back in 1995. Although educated as a zoologist at UC Davis, she works on grassland and riparian restoration projects at the preserve and directs the volunteers on projects like planting trees, conducting plant surveys and repairing the barn. But the work mostly consists of removing a whole suite of non-native plants: perennial pepper weed, several types of thistles, Himalaya berry and water hyacinth among others.
Non-native trees can be eliminated by stripping a narrow band of bark from around the tree’s trunk. The standing dead tree serves as a home for wildlife for several years before it finally falls. The fallen tree then becomes habitat for other animals before it gradually decomposes, nourishing the forest soils.
Water hyacinths are not a problem in the Cosumnes River itself because the current and annual flooding prevent them from getting established. But the calm waters of the preserve’s sloughs and canals are in danger of becoming solid green mats of floating vegetation if the hyacinths are left unchecked. The soggy work of removing the plants usually happens during the hottest days of summer, when the aquatic plants are loaded into canoes and then dumped on the shore.
Most terrestrial plants are eliminated by simply uprooting them and returning periodically to see that the offending plants do not grow back. Waegell sees perennial pepper weed as the biggest threat. It grows in high-density populations, it spreads by roots, and “it’s just super-duper aggressive,” Waegell explained. The plant uses salt as a form of chemical warfare to eliminate competition. “It brings salt from deep down; the roots are something like 9 meters deep,” and then it concentrates salt in the topsoil to prevent other plants from germinating. Waegell has experimented with different techniques to control the super-weed—flooding the plants with water, spraying herbicide and persistently yanking them out.
Mike Savino of Sacramento compared constant weed pulling to crop harvesting: “It seems like a form of agriculture; every year we’re dealing with the crops, but the crop is an invasive non-native weed.” But Savino and the others don’t see their war against weeds as un-winnable. On the contrary, they like to point out the victories, like a large field without a thistle in sight or a plot of young, knee-high oaks planted as acorns just last year.
Hardcore members continue to return to the forests and fields of the preserve year after year. Steve McClellan from Elk Grove said, “The main reason I come here is to give back. I’d never done volunteer work before I came here. It’s better to give than receive, right?” He sees his labor as helping basic research: “We did four different techniques for getting rid of perennial pepper weed, and we’re measuring the success of different techniques.” And, he added, “it’s a good way to have a workout.”
Greg Williams of Sacramento said the workdays are a “peaceful counterpart to what I do the rest of the week; I’m a therapist and mental-health coordinator—abused children and such.”
Tara Hansen from Sacramento usually brings homemade cookies for the team and explained her reason for volunteering: “I grew up in a rural area, and now I like coming out here because I miss open space.”
Gouveia said, “I come for Tara’s cookies.” But he added, “You come out here, and you meet some really nice people, people who have sort of the same general views as you do. There’s so many of us who have come for so long, it’s like coming and hanging out with your friends instead of actually working.”
Not that habitat restoration isn’t hard work. The intense summer heat is often accompanied by mosquitoes and ticks. In the winter, heavy, sticky mud clings to boots, making them almost too heavy to walk in. In the forests, poison oak seems to hide in ambush, waiting for a passerby.
Despite these minor hardships, everyone who comes to pull weeds looks up from his or her work once in a while to see a landscape overflowing with life. They see oaks out in the fields of tall grass, the forests and the river, and they hear the birds. Savino thinks of the HRT workdays as an investment in the future: “The time is going to come when you’re going to want to get away from the city and have a chance to breathe fresh air and relax and not have cement and traffic lights. Just look at the wide-open spaces—we’re saving those spaces, not just for people, but for wildlife and the native plants.”