BLM'S WAR AGAINST WEEDS IN NEVADA

Introduction

Maintaining or restoring ecosystem health on our public lands is clearly a Bureau of Land Management (BLM) goal of the highest order. One of the greatest obstacles to maintaining healthy ecosystems and restoring impaired ecosystems is the rapid expansion of noxious weeds because these invasive plants dominate many sites and often cause permanent damage to plant communities.¹

 
Musk thistle invades a healthy meadow in central Nevada.

BLM is truly engaged in a "War Against Weeds." Noxious weeds are increasing on BLM-administered land at approximately 2,300 acres per day and on all western public lands at approximately 4,600 acres per day. This is occurring in both disturbed and relatively undisturbed areas.² Even though these weeds are degrading Nevada’s wildland ecosystems at a rapid and ever-increasing rate, a vast proportion of our public lands are still weed free. Therefore, it is imperative that we apply effective and economical strategies that are available to immediately protect these lands from infestation.

The BLM defines a noxious weed as: "A plant that interferes with management objectives for a given area of land at a given point in time."³ The State of Nevada Revised Statutes (555.005) legally defines a noxious weed as: "means any species of plant which is, or is likely to be, detrimental or destructive and difficult to control or eradicate." Approximately 45 weed species are currently listed as noxious by the State of Nevada in the Nevada Administrative Code (NAC 555.010). Many of these are found on public lands administered by BLM.
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¹USDI Bureau of Land Management, 1996. Partners Against Weeds, page1.
²Ibid.
³Ibid.

Noxious weeds normally are introduced through human activity to a location(s) outside its native or natural range. In many cases these plants have been moved into North America from another continent. They have been accidentally introduced through contaminated grain or hay, sometimes intentionally introduced for erosion control or as an ornamental. In addition, seed may be carried by birds or livestock, spread by vehicles, or brought in with contaminated fill dirt. Regardless of how they were introduced, they possess the ability to survive, propagate and aggressively invade native plant communities. For example, Yellow Starthistle (Centaurea solstitialis), a native to Eurasia, was introduced to California around 1850 via South America in contaminated alfalfa seed. It is now common in open areas on roadsides, rangelands, wildlands, hay fields, pastures, and waste areas. Recent reports indicate that Yellow Starthistle infests between 10 and 15 million acres in California. Yellow Starthistle has been found around Reno and appears to be on the move into northeastern Nevada.

Tall Whitetop (Lepidium latifolium), a native of Europe and southwestern Asia, may have come into the United States as a contaminant in sugar beet seed in about 1900. It has rapidly spread across the US, first appearing along the Truckee River in 1971. By 1992, this weed occupied about 12,000 acres along the lower portion of the River. Today, tens of thousands of riverfront acres have been invaded, and it is found in most Nevada counties. It infests the Carson River, Walker River, Humboldt River basin east of Elko, and several locations in Ely, Caliente and Las Vegas.⁴

Tall Whitetop invades portions of the Humboldt River.

How bad are noxious weeds?

Noxious weeds typically possess characteristics which allow them to compete aggressively with native vegetation. These characteristics include prolific seed production, ability to reproduce vegetatively from plant parts, rapid growth from seedling to seed production, and ease in adapting to new environments.

Noxious weeds impact native plants, animals, and natural ecosystems by:

Reducing biodiversity
Altering hydrologic conditions
Altering soil characteristics
Altering fire intensity and frequency
Interfering with natural succession
Competing for pollinators
Displacing rare plant species
Serving as reservoirs of plant pathogens
Replacing complex communities with single species monocultures

Invasive weeds affect all of our lives daily. According to Dr. George Beck, Professor of Weed Science, Colorado State University, impacts occur in many forms ranging from economic losses to unemployment, food and water shortages, and increased severity of natural disasters. David Pimentel, Cornell University, estimates that invasive species as a whole cause about $137 billion in damages and losses to the U.S. economy annually. About $5 billion are spent annually by US ranchers to control weeds in private pastures and rangelands.⁵

Dr. Beck further states that a 1988 survey in the State of Washington indicated that 130 million pounds of forage are lost each year in knapweed infested rangeland. This equates to $951,000 lost annually as pasture or rangeland feed for cattle forage or $2.9 million in hay replacement. The total annual loses in North Dakota from leafy spurge (Euphorbia esula) are $87.3 million. About $28.7 million of these losses occur in the household sector and over 1000 jobs are lost each year because of leafy spurge.⁶

Real estate value and transactions are dramatically influenced by invasive weeds. The Brooks Area cattle ranch in North Dakota was badly infested with leafy spurge and a decision was made to sell it in 1975. It finally sold in 1991 for about $40 per acre, but should have sold for $100 to $125 per acre – a 60 percent decrease in land value. In Klamath County, Oregon, a 1,360-acre ranch should have been worth from $125 to $150 per acre ($170,000 to $204,000) but sold for $27,000 because of leafy spurge – an 83 percent decrease in land value.⁷

Eiswerth, et al. 2001, found that the costs of control of 75 acres of Tall Whitetop in Douglas County, Nevada, rose from $12,647 in the first year after detection to $174,350 ten years later assuming a 30 percent annual rate of increase in spread.⁸

As the previous examples show, noxious weeds affect all Americans directly or indirectly and cost billions of dollars in damages and losses annually. As a society, we can ill-afford to wait any longer to become engaged in the battle against invasive weeds.
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⁴Donaldson, et al, 1995. The War Against Tall Whitetop. University of Nevada Cooperative Extension, 
Fact Sheet 99-95.
⁵Beck, G. 2003. Invasive Weeds Are Stealing Our Money. Unpublished paper presented at Nevada Weed Management Association Conference, Elko, NV.
⁶Ibid.
⁷Ibid.
⁸Eiswerth, et al, 2001. Economic Costs of Delaying Invasive Weed Control: An Illustration based on Nevada's Tall Whitetop Initiative. University of Nevada Cooperative Extension Special Publication SP-01-08.

Over the past 10 years, funding to the BLM (all states) has steadily increased for the management of noxious weeds. In fiscal year 1994, BLM received $850,000. This has increased to $8.2 million in fiscal year 2004. In Nevada, the allocation in fiscal years 2002, 2003 and 2004 has been about $1.5 million annually.

Nevada has a state office (located in Reno), six Field Offices (located in Elko, Winnemucca, Carson City, Ely, Las Vegas, Battle Mountain), and two field station offices (Tonopah, Caliente). Full-time weed specialists are located in Reno, Elko, Winnemucca and Battle Mountain. Half-time or part-time personnel support most of the other offices. These employees plan and implement weed control activities, inventory public lands for weed occurrences, follow up on weed control activities to evaluate success, promote awareness of BLM staff and the public on the weed problem, and participate in cooperative efforts with land owners and other agencies to address weed management opportunities.

Almost 14 million acres of public lands in Nevada were inventoried for the presence of noxious weeds in fiscal years 2000 through 2003. During that same period 25,000 acres of noxious weeds have been treated either with herbicides or hand grubbing. Close to 5 million acres were inventoried in 2004. Over 13,000 acres were treated in 2004, as well.

BLM crew at a Scotch thistle control project in  Elko County.

In addition to inventory and treatment activities, weed specialists are actively engaged in 25 different Coordinated Weed Management Area (CWMA) groups scattered throughout the State. The groups are composed of interested private land owners; agency employees at the County, State and Federal levels; special interest groups and other interested public. Funding is also provided to several Weed Districts and Conservation Districts for weed control activities.

In order to be effective in the "War Against Weeds," citizens need to prepare themselves in four different areas.

1. Awareness – Be aware of the problem and be able to identify noxious weeds in the field. Know your weeds! An excellent guide to weed identification is available from the University of Nevada Cooperative Extension. Also the Nevada Weed Action Committee maintains a website with some excellent information on noxious weeds.

2. Prevention – Be sure that weed seed and reproductive plant parts are not introduced into a new area. Here are some ways to prevent the spread of weeds:

Drive only on established roads and trails away from weed-infested areas.

When using pack animals, carry only feed that is certified weed free.

Within 96 hours before entering back country areas, feed pack animals only food that is certified weed free.

Remove weed seeds from pack animals by brushing them thoroughly and cleansing their hooves before transporting.

If you find a few weeds without flowers or seeds, pull them and leave them where found. If flowers or seeds are present, place the weeds in a plastic bag and deposit in a refuse container.

If you find a weed-infested area, let the landowner or land managing agency know so that they can take steps to control the weeds.

3. Detection - Be able to identify weed locations and the extent of the infestations. If you observe weed infestations on public lands, you can assist BLM by reporting locations of weeds to the Noxious Weed Program Coordinator at the nearest BLM Nevada Field Office.

4. Treatment –Learn about the different methods of treating or controlling weeds. Utilize the proper type of herbicide that is known to control the weed you are targeting. Apply herbicides strictly according to label directions. Employ other methods, such as, hand-pulling, if the method has been proven to be effective.

For further information or questions concerning BLM’s weed program in Nevada, please contact the State Weed Program Coordinator, at (775) 861-6400.

Click here for more information on noxious weeds.

Click here for more information from the BLM Environmental Education homepage.

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