Navigation Links
Land management options outlined to address cheatgrass invasion

CORVALLIS, Ore. A new study suggests that overgrazing and other factors increase the severity of cheatgrass invasion in sagebrush steppe, one of North America's most endangered ecosystems.

The research found that overgrazed land loses the mechanisms that can resist invasion. This includes degradation of once-abundant native bunchgrasses and trampling that disturbs biological soil crusts. The work was published today in the Journal of Applied Ecology by researchers from Oregon State University, Augustana College and the U.S. Geological Survey.

"We think there are ways to assess the risks these lands face to reduce the impact of cheatgrass invasion," said Paul Doescher, professor and head of the OSU Department of Forest Ecosystems and Society, and co-author on the study.

"In the future we should work cooperatively with ranchers and land managers to promote a diverse sagebrush and bunchgrass ecosystem," Doescher said. "That type of community will protect the native plant and wildlife species and benefit sustainable rangeland use at the same time."

Researchers suggested that one of the most effective restoration approaches would be to minimize the cumulative impact of grazing, by better managing the timing, frequency of grazing and number of animals.

The researchers also determined that, contrary to some previous suggestions, grazing does not reduce cheatgrass abundance. Cheatgrass was found by this study to be extremely tolerant of even intensive grazing, and the findings "raise serious concern" about proposals to use cattle grazing to help control its spread in areas where native bunchgrasses still persist.

The study outlines the complex ecological processes that can promote cheatgrass invasion and the indirect role overgrazing plays in that process. Increasing gaps and connection of gaps between once-abundant native bunchgrasses allow "a dramatic increase" in cheatgrass invasion, the study concluded. Such gaps could serve as a valuable "early warning indicator" and allow for management approaches that could help conserve and restore the land.

Cheatgrass threatens vast regions of the American West, especially the Great Basin in Nevada and surrounding states. These are areas which were once carpeted by millions of acres of native sagebrush, perennial bunchgrasses and associated wildlife that had evolved with little herbivore pressure. Cheatgrass displaces native grasses and wildlife, can increase fire frequency and ultimately cause an irreversible loss of these native shrub-steppe communities.

This also has grazing implications: cheatgrass is a short-lived annual grass that dries out quickly and provides lower quality forage for much of the year, compared to perennial bunchgrasses.

"Cheatgrass changes the fire regime, and as it spreads, can reach a tipping point," said Michael Reisner, now an assistant professor at Augustana College who led this study as a doctoral student at OSU.

"After you cross that threshold, a major rangeland fire will come through that takes out the sagebrush, and in most cases the native ecosystem never recovers," Reisner said. "Many of the plant and animal species that were there can disappear, mostly replaced by cheatgrass that offers poor forage for cattle."

In a more resistant system, abundant native bunchgrasses can limit the size and connectivity of gaps, which minimizes the water and nutrients available to cheatgrass. Using data from 75 study sites, researchers found that high levels of cattle grazing were associated with reduced bunchgrass cover, with wider and more connections between the gaps that provided an opportunity for cheatgrass to invade.

Cattle trampling also appeared to disturb biological soil crust that offers a second defensive barrier against cheatgrass, and further speeds the invasion. Impacts are greater on the drier and warmer sites within this region.

If the level and amount of gaps indicates that it's necessary, changes in grazing could help restore bunchgrass cover, maintain a diversity of native grass species and provide much better resistance to cheatgrass invasion, the study concluded. Continued research is needed to quantify the threshold levels of cattle grazing that would still maintain a healthy native ecosystem.


Contact: Paul Doescher
Oregon State University

Related biology news :

1. New advances in the management of patients with cirrhosis
2. Ecology, economy and management of an agro-industrial Amazon frontier
3. European Guidance for the diagnosis & management of osteoporosis in postmenopausal women
4. Risk management in fish: How cichlids prevent their young from being eaten
5. Annual Urban Pest Management Conference set for March 26
6. Launched the Saudi Aramco-KAIST CO2 Management Center in Korea
7. Report: Water and Agriculture in Canada: Towards Sustainable Management of Water Resources
8. Preventing chronic pain with stress management
9. Science synthesis to help guide land management of nations forests
10. Scientists develop improved fire management tools for Africas savannas
11. Studying bed bug actions for new management tactics
Post Your Comments:
(Date:4/13/2017)... 13, 2017 UBM,s Advanced Design and Manufacturing ... feature emerging and evolving technology through its 3D Printing ... run alongside the expo portion of the event and ... demonstrations focused on trending topics within 3D printing and ... manufacturing event will take place June 13-15, 2017 at the ...
(Date:4/11/2017)... MELBOURNE, Florida , April 11, 2017 ... "Company"), a security technology company, announces the appointment of independent ... John Bendheim to its Board of Directors, furthering the ... ... behalf of NXT-ID, we look forward to their guidance and ...
(Date:4/4/2017)... , April 4, 2017   EyeLock LLC ... announced that the United States Patent and Trademark Office ... broadly covers the linking of an iris image with ... transaction) and represents the company,s 45 th issued ... patent is very timely given the multi-modal biometric capabilities ...
Breaking Biology News(10 mins):
(Date:10/11/2017)... ... ... Personal eye wash is a basic first aid supply for any work environment, but most ... you rinse first if a dangerous substance enters both eyes? It’s one less decision, and ... unique dual eye piece. , “Whether its dirt and debris, or an acid or alkali, ...
(Date:10/11/2017)... the Netherlands and LAGUNA HILLS, Calif. ... The Institute of Cancer Research, London ... use MMprofiler™ with SKY92, SkylineDx,s prognostic tool to risk-stratify patients ... trial known as MUK nine . The University of ... trial, which is partly funded by Myeloma UK, and ICR ...
(Date:10/10/2017)... ... , ... San Diego-based team building and cooking events company, Lajollacooks4u, has unveiled ... bold new look is part of a transformation to increase awareness, appeal to new ... , It will also expand its service offering from its signature gourmet cooking classes ...
(Date:10/10/2017)... , Oct. 10, 2017 International research firm Parks Associates ... will speak at the TMA 2017 Annual Meeting , October 11 ... in the residential home security market and how smart safety and security ... Parks Associates: ... "The residential security ...
Breaking Biology Technology: