Invasion

The Invasion of the Eel River Watershed
By John Griffith
You’ll hear no bomb blasts or sirens, nor will you see throngs of fleeing refugees. But I assure you that the Eel River watershed is under invasion. The invaders are ruthless and deceptively beautiful. They destroy and displace the native inhabitants in battlefields strewn with thorns and flowers. The massacre is happening now! It is the invasion of nonnative plants!
Okay, so I’m sure that none of you just gasped or shouted a shocked “Lord have mercy!” upon reading that revelation. But you may after going deeper into this article. Nonnative invasive species are the second leading cause of native species decline and extinctions after direct habitat destruction. One invader called yellow star thistle already dominates 12 million acres in California and has little to no livestock or wildlife value. And (get your “Lord have mercies” ready), according to the USDA, invasive species infest millions of acres of U.S. soil, impact half the species federally listed as Threatened or Endangered, and cost more than $100 billion in economic losses per year. Even more serious is the estimated rate at which the invasive plants are spreading just in public natural areas—5,000 acres every day.
Over the next few alarming minutes, you will read how these cold-chlorophyll’d killers destroy pollination corridors, massacre salmon, and wage a multi-fronted blitzkrieg on native habitats and the species that depend on them. We will even profile two of the most villainous soldiers in this highly evolved force. We need to know our enemies. Better yet, we must understand what these plants talk about. Talk about? Yes, I know this is going to be an exercise in gross anthropomorphism for some of you. But the view most people have of plants is already skewed. I’m simply going to replace your old misconceptions with a more accurate interpretation of our green friends and enemies.
Let’s start by understanding plants. When most people pull off the highway to stand at some high “vista” point and gaze over the rolling hills covered in a tapestry of vibrantly green, wind-swept grasses interspersed with colorful eruptions of wildflowers, they imagine a particular song accompanying this visual harmony—something like: “The hills are alive with the sound of music.”
After reading that last sentence, you may be picturing a blond woman standing at the vista point next to her ’50s-era Suburban, wearing an ankle-length dress, an elegant wide-brimmed hat, and singing with her arms raised in revelry. If so, look into your mind and tell her to “shut up and get back in the car!” She’s full of crap! Music? Puhleeze! The perception of a landscape covered with happy plants is cliché-riddled nonsense. That Hollywood-seeded image is distracting us from hearing what all those “musical” plants are really saying.
So let’s start over. Imagine pulling over to that vista point again. Get out of your car, look out over the hills, and listen to what the plants are really saying. (I removed all curse words from the following translation for our younger readers.)
Plant 1. “My roots will grow deeper than yours and suck up all the water. I’ll be watching you wither away any day now!”
Plant 2. “Oh, yeah? I’ll grow faster than you and shade you out before spring equinox!”
Plant 3. “Would you guys stop hogging all the bees?!”
Plant 4. “Hey, look! Here come some cows! Too bad you idiots don’t have any lip-piercing thorns like I do. Guess you’ll be getting munched! Ha-ha! See ya!”
Okay, get back in your car. We’ve heard enough. The fact is, plants are locked in a nasty competition for survival. Long before Noah’s ark or writings about Galapagos finches, native plants in the Eel River watershed evolved with some checks and balances in this brutal game. But enter plants from other parts of the world brought here by yours and mine truly. Yes, our immigrant ancestors, and their animals, transported the invaders here, but they failed to bring those exotic plants’ competitors and predators from the homeland. The result was an unchecked botanical invasion that has destroyed many native Californian habitats and is threatening the fragile balance of almost all the others—including habitats in the Eel River watershed.
Migratory Nectar Collapse: Where have all the red and orange flowers gone?
Take pollination corridors as an example. The invaders are fragmenting habitat vital for migrating pollinators. Hummingbirds and other pollinators, such as monarchs, have evolved to migrate seasonally based on the blooming times of specific native plants. All but one species of Northern Cal’s hummingbirds migrate here from the south to nest. They follow a wave of blooms up along the coast in the spring and return south with a wave of blooms along the mountain ranges in mid to late summer. In recent times, those tiny, feathered pollinators are discovering that the coast is no longer the sequentially blooming buffet it was a hundred or even ten years ago. Hummers must now pass over miles of un-satiating, monotypic stands of European beachgrass, rattlesnake grass, jubata grass, and scotch broom to get to their preferred nesting habitat. Those four invasives are among numerous nonnatives that have conquered the coastline and contributed to what is called a migratory nectar collapse.
How Can You Help?
Turn your yard, porch, or balcony into a pollinator pit stop. Plant a few of the hummingbirds’ favorites like red-flowering currant, sticky monkey flower, and California fuschia. (See our local California Native Plant Society website for more hummingbird plant options.) Then sit back and enjoy watching the tiny birds that are exclusive to North and South America.
Invasive Plants Kill Salmon: Smother Them While They’re Young
Even without nets, dams, chainsaws, or water diversions, invasive plants kill lots of salmon. They strike out at our fish just by being. Historically local grasslands were inhabited by a huge percentage of deep-rooted perennial grasses. The introduction of European livestock, and the purposeful and inadvertent seeding of nonnative grasses, disrupted that stable matrix. Today most of the grasses you see in our watershed are shallow-rooted European annuals. These plants have far less soil-holding capability than the perennial natives. After logging, these grasses, along with a plethora of other invasives, colonize those hillside clearcuts. After the cut trees’ roots decompose, the soil is held solely by the shallow roots of those invasive species. It doesn’t work. Landslides become more frequent, and spawning gravels in the creeks below are inundated with silt. The salmon eggs in those gravels are smothered.
What can you do? Plant native grasses, insist that soil stabilization controls follow all practices that disrupt the integrity of our streamside soils, and collaborate with agencies like our local Cooperative Extension or nonprofits such as the California Native Grass Association to see if they have helpful (and free) advice on how to best manage your own streamside property.
Purple Loosestrife: A Mile a Minute!
Recently invasives have been getting a lot of local print and air time, especially the beautiful invader purple loosestrife (Lythrum salicaria). After the USDA determined that it spreads to an additional one million acres of wetlands each year, it was dubbed the “mile-a-minute” loosestrife. Sadly, this aggressive weed has begun invading the Eel River watershed. State Parks decided that the weed needed to be judiciously sprayed back before it took over the Eel River’s wetlands and estuary, where it would then require large-scale and very expensive control measures (if it even could be controlled at that point). Some accused State Parks of making their spraying decision in a box without considering other control methods like a nonnative beetle that has been proven to reduce loosestrife in some areas.
One must hope that all the differences in opinion on control methodologies will not delay eradication efforts of this highly invasive weed. Loosestrife must not be allowed to proliferate. Left on the sidelines of ethical and legal battles, it will form massive monotypic stands and dramatically reduce biodiversity in our watershed, including in our already compromised estuary! I applaud State Parks’ timely response to this scourge but encourage them to be team players and to continue to investigate a multi-tactical defense against this invader.
What can you do about loosestrife? This plant should be removed by hand only if it is very young. Attempts to dig it out usually backfire because purple loosestrife resprouts from root fragments; disturbing the soil just provides more room for it to spread. You can cut off the flowers to keep it from seeding. One loosestrife plant is capable of producing 2.7 million seeds. If you discover some loosestrife in our watershed, please call Jeff Dolf of the Humboldt Department of Agriculture at 441-5260. He would certainly be glad to help.
Arundo: To Kill a Postcard
Imagine going to the Peg House to buy your grandmother (or granddaughter) a scenic postcard of our region, only to find that the most recent postcards depict redwoods surrounded by tropical-looking, leafy bamboo thickets. This fictional scenario is not far from our potential reality. The plant that might one day be on those postcards is not really bamboo. It just looks like it. It’s an invader called Arundo donax—yet another highly invasive water-loving plant with the ability to drastically diminish the native species diversity along the Eel River.
Arundo started out as elephant food in India. Then, about three hundred years before the world was round, people transported arundo to Europe to use it as roofing material and to make flutes. It was brought to California in the 19th century (for the same reasons) and now claims more than 70% of the prime riparian real estate along the Santa Ana River and dominates the vegetation of many other southern and central Californian watercourses. It forms stands so large and dense it can become a barrier that prevents some wildlife from even reaching the water to drink. In fact, it has very little wildlife value. Arundo spreads quickly by rhizomes, roots, or clipped-off aerial plant parts and grows Wal-Mart fast to shade out natives and slurp up all their water. Water transports it to colonize new areas. As the river flows so the arundo goes.
Now arundo is gaining a foothold along the Eel. This summer the California Conservation Corps, armed with digging tools and sharp implements of arundo killing, will attack this invader before it has the chance to ruin all our postcards—and reduce our biodiversity, of course.
Every friend of the Eel River has a lot of work to do to manage and/or eradicate these heinous invaders. Before some arrogant weed wearing a pilot suit lands on the deck of a fishing boat and declares “mission accomplished,” we need to educate ourselves about our enemy and be armed and vigilant. Below are helpful resources where you can learn about battle strategies and weapons of mass weed destruction.
California Invasive Plant Council. Their statement: Across California, invasive plants damage wildlands. Invasive plants displace native plants and wildlife, increase wildfire and flood danger, consume valuable water, degrade recreational opportunities, and destroy productive range and timber lands. Cal-IPC works with land managers, researchers, concerned citizens, and policy makers to protect the state from invasive plants. http://www.cal-ipc.org/
Other resources:
California Native Plant Society. http://www.northcoastcnps.org
The Nature Conservancy, The Global Invasive Species Team. http://tncweeds.ucdavis.edu
California Department of Food and Agriculture. http://www.cdfa.ca.gov/ (Search for Loosestrife)