Weeding out the wildlife
Green and lean — that’s one way to describe the spread of empty calories on the region’s wild lands this month. Vegetation is thriving in yards, meadows, river valleys and hills in the wake of two consecutive wet spring seasons.
Unfortunately, noxious weeds are an increasing portion of that lush growth, edging out native plants and grasses and leaving some wildlife rangelands with less nutrition than a sugary breakfast cereal.
Indeed, maybe even less palatability and nutrition than a cereal box.
“I hate to see the word ‘threat’ used to describe the problem with weeds and their impact on wildlife,” said Jerry Asher, a Bureau of Lands Management natural resources specialist who coordinated a weed awareness program with several federal agencies until he retired a few years ago. “The word ‘threat’ refers to something that might happen. Noxious weeds have already happened in a big way and they’re spreading at a rate of 300,000 acres a year in Washington alone.”
Nationally, the problem seems overwhelming.
Non-native invasive weeds spread at an estimated rate of 14 million acres per year in the United States, making them the No. 1 threat to the 100-million-acre National Wildlife Refuge System, according to Evan Hirsche, president of the National Wildlife Refuge Association.
The cost of fighting weeds on refuges alone is more than $150 million, he said.
“When it comes to environmental threats, everyone knows the usual suspects — dirty air, polluted water and suburban sprawl — but invasive plants are strangling the life out of our precious wild lands right in our own backyards,” he said.
About 420,000 acres of national forests and grasslands in the Pacific Northwest are infested to some degree by some of the 95 weed species that have invaded the region’s forests, according to the agency’s regional officials in Portland.
“Invasive plant species can cause loss of wildlife habitat, loss of rare or endangered plants, decreased biodiversity, degradation of water quality and loss of recreation opportunities,” said Doug Daoust, Forest Service regional forest health protection team leader. “They are spreading rapidly (on the forests) — around 8 to 12 percent a year.”
Most invasive plant species are introduced to North America from Europe or Asia. They may come accidentally, or they may have been brought in on purpose for erosion control, ornamental plants, forage, medicine and dyes, to name a few. But in their new home, they can out-compete plants that are not adapted to coexisting with them.
“Noxious weeds are taking over Western federal lands at the rate of about 4,600 acres a day,” said Asher, a weed-issue consultant who lives in Oregon. “That’s the equivalent of infesting all of Turnbull National Wildlife refuge in just four days.”
Over the years, in fact, reed canary grass has invaded virtually all of Turnbull’s seasonal wetlands, according to a report Asher helped prepare with state and federal agencies.
“More than 100 species of native plants should occur in such habitats,” he said. “However, surveys on the refuge show that species diversity has been reduced to an average of 11 species, and in some cases as few as three species,” he said. “This greatly reduces the habitat for lesser yellowlegs and other shorebirds, and it’s crowding out the more nutritious vegetation for ducks.”
Other examples are popping up like, well, weeds:
“Spotted knapweed, rampant at lower elevations, has been making headway into wilderness areas where it takes over important range for species such as deer, elk and bears. Knapweed and other noxious weeds have taken hold in a quarter of the 652,488-acre Hells Canyon National Recreation Area that’s in Oregon’s Wallowa County.
“Yellow star thistle is spreading like a wave across the breaks of the Snake and Grande Ronde rivers as well as 45 miles of Idaho’s Salmon River corridor, in some spots from river to rim tops. Lynn Danly, BLM rangeland specialist in Cottonwood, Idaho, said she watched the Salmon River’s Rattlesnake Ridge area go from native plants to “a sea of yellow star thistle” in nine years.
The weed robs the land of 30-90 percent of its forage value for stock as well as habitat for wildlife ranging from chukar partridge to bighorn sheep.
“Eurasian milfoil is choking out fish habitat in many rivers and lakes throughout the region. McDowell Lake, formerly a prime trout fly-fishing water on the Little Pend Oreille Wildlife Refuge, is undergoing an extensive drawdown and treatment this summer to contend with a 100 percent milfoil infestation.
Infestations can start from a mere fragment of milfoil vegetation that hitches a ride on felt-soled wading boots, the side of a boat or hidden in a trailer wheel from another infested lake.
“Thousands of public land watersheds in the West are rapidly undergoing the greatest permanent degradation in their recorded history,” Asher said.
That’s not to say there haven’t been success stories.
Spotted knapweed has all but disappeared in the Dishman Hills of Spokane Valley a few years after beetles were released, said Mike Hamilton, president of the Dishman Hills Natural Area Association. But Tim Gallagher, Washington Department of Natural Resources weed control manager, said knapweed can disappear, but it’s never really “gone.”
“When the beetles do their job, they lose their food source and die out,” he said. “Knapweed seed is viable in the soil for years and sooner or later it will come back and then you start all over.”
North Dakota made great gains on eradicating leafy spurge a few years ago using biological controls. Two bug species introduced in Oregon virtually wiped out the tansy ragwort infestation. The weed, toxic to cattle and horses, once poisoned $5 million worth of livestock a year in Oregon.
The problems didn’t end there, of course.
Oregon still lists 105 noxious weeds, but a mere 21 of those varieties cost taxpayers $83 million a year — largely in grazing and timberland losses, said Tim Butler, manager of the Oregon Department of Agriculture’s noxious weed program.
But unlike agriculture officials, wildlife managers don’t have dollar figures to put on losses of wildlife, except to say they are priceless. The impacts range from endangered species already on life support from spendy recovery programs to common game species important to local economies.
The spread of weeds is accelerated as more ground is broken in rural areas for roads and development.
“Most farmers are on top of their weeds because it’s important to their production,” said David Mundt of the Spokane County Weed Board. “But people who buy a house on 10 acres to enjoy the open space may have no idea of how to control their weeds.”
Weeds don’t pay attention to property boundaries, said Pat Munts, weed education program manager for the Spokane County Extension. If one landowner has an issue, his neighbors have an issue, and they all need to work together, she said.
“Our goal is to get people the information they need to restore open country to good native or sustainable plant cover, which will enhance property values as well as wildlife capabilities,” she said.
Spokane County, for areas outside the city of Spokane, allocates about $320,000 a year mostly for landowner notifications and education in the effort to combat weeds, Mundt said.
On the positive side, Spokane County has been infested with only 26 of the 126 noxious weeds found in Washington, he added.
Wildlife managers would love to draw the line there, Asher said.
“We have to keep fighting weeds on all fronts, but I’d prefer to dwell less on what’s infested and more on what remains to be protected,” he said. “About 15 million acres of wildlife land in Washington remains relatively uninfested with weeds. If we don’t stop the trend, half of that acreage could be infested in the next 30 years.”
After weeks of rainy weather, many land managers finally kicked their spraying programs into gear last week. Weed control on the Coeur d’Alene National Forest Forest targets leafy spurge, knapweed, meadow hawkweed, orange hawkweed, St. Johnswort, thistle, rush skeletonweed, dalmatian toadflax and common tansy.
The program includes hand-pulling, chemical treatment, seeding of competitive grasses and biological controls.
And nobody says that’s enough.
“As weed managers get well-deserved credit for that work, it creates the illusion that the weed situation is being managed fairly well,” Asher said. “Meanwhile, other infestations grow out of control.
“If 5 to 10 percent of what we spend on public lands fire management were spent on weeds, we could make some real headway.”
But the clock is ticking.
“Three years ago I was saying that 95 percent of our federal lands were not yet seriously infested with weeds,” Asher said. “Now I’m reducing that to 90 percent. Weeds are even starting to show up in Alaska.”