Can native annual forbs reduce Bromus tectorum biomass and indirectly facilitate establishment of a native perennial grass?

Downy brome (Bromus tectorumL. # BROTE) may be a troublesome weed in winter small grains, perennial legumes, perennial grasses grown for seed, and orchards. In Nebraska, winter wheat (Triticum aestivumL.) yields have been depressed 30% by downy brome populations of 11 to 22 plants/m2(8). In Oregon, downy brome densities of 108 to 160 and 538 plants/m2reduced yields by 40 and 92%, respectively (22, 23). In Idaho, wheat yields were depressed 20 to 40% with 55 to 110 plants/m2(18). Downy brome has also been shown to lower yields and quality of hay from infested fields of alfalfa (Medicago sativaL.) (29). In perennial grass seed fields, downy brome may cause a serious seed quality problem (16). Some grass seed lots have contained as much as 50 to 75% downy brome seed.

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Indirect effects of an invasive annual grass on seed fates of two native perennial grass species

Oecologia ◽

10.1007/s00442-013-2868-4 ◽

2014 ◽

Vol 174 (4) ◽

pp. 1401-1413 ◽

Cited By ~ 9

Author(s):

Susan E. Meyer ◽

Katherine T. Merrill ◽

Phil S. Allen ◽

Julie Beckstead ◽

Anna S. Norte

Keyword(s):

Indirect Effects ◽

Perennial Grass ◽

Grass Species ◽

Annual Grass ◽

Seed Fates ◽

Native Perennial Grass

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Correlations between environmental factors, the biomass of exotic annual grasses and the frequency of native perennial grasses

Australian Journal of Botany ◽

10.1071/bt05083 ◽

2006 ◽

Vol 54 (7) ◽

pp. 655 ◽

Cited By ~ 7

Author(s):

Tanja I. Lenz ◽

José M. Facelli

Keyword(s):

Species Composition ◽

Soil Fertility ◽

Perennial Grass ◽

Perennial Grasses ◽

Annual Rainfall ◽

Grass Species ◽

Soil Factors ◽

Annual Grasses ◽

Exotic Annual Grasses ◽

Native Perennial Grass

The species composition of temperate grasslands in the mid-north of South Australia has been radically altered from a system dominated by native perennial grasses to a system dominated by Mediterranean annual grasses. This study investigated the importance of chemical and physical soil characteristics, topographical features and climatic variables on the abundance of native and exotic grass species in nine ungrazed grasslands. Overall, climatic and other abiotic factors were highly variable. In addition, past management practices and original species composition are generally unknown, leading to further unexplained variation in the data. On a large spatial scale (among sites), the abundance of exotic annual grasses was positively correlated with mean annual rainfall, and on any scale, with finer soil textures and higher soil organic carbon levels. The most abundant annual grass, Avena barbata (Pott ex Link), was generally associated with soil factors denoting higher soil fertility. The abundance of native perennial grass species was not correlated with any environmental variables at any scale. The various native perennial grass species did not show clear associations with soil factors, although they tended to be associated with factors denoting lower soil fertility. However, at small spatial scales (within some sites) and among sites, the abundances of exotic annual and native perennial grasses were strongly negatively correlated. The results suggest that at the present time, rainfall and soil properties are important variables determining the abundance of annual grasses. The driving variables for the abundance of perennial grasses are less clear. They may be controlled by other factors or extreme rainfall events, which were not surveyed. In addition, they are likely to be controlled by competitive interactions with the annual grasses.

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Integrated Management of Perennial Pepperweed (Lepidium latifolium)

Invasive Plant Science and Management ◽

10.1614/ipsm-07-004.1 ◽

2008 ◽

Vol 1 (1) ◽

pp. 17-25 ◽

Cited By ~ 5

Author(s):

Rob G. Wilson ◽

Debra Boelk ◽

Guy B. Kyser ◽

Joseph M. DiTomaso

Keyword(s):

Integrated Management ◽

Perennial Grass ◽

Management Strategies ◽

Site Preparation ◽

Perennial Grasses ◽

Flower Bud ◽

No Till ◽

Wide Range ◽

Grass Establishment ◽

Native Perennial Grass

AbstractPerennial pepperweed is invasive throughout California. It thrives in a wide range of environments and is a common weed in floodplains, pastures, wetlands, and roadsides. In disturbed areas, perennial pepperweed rapidly forms monotypic stands with a thick litter layer. These infestations not only out-compete other vegetation, but prevent re-establishment of desirable species even after perennial pepperweed control. This experiment examined integrated management strategies with the goal of maximizing perennial pepperweed control and establishment of desirable native vegetation. The experiment was conducted at two sites in Lassen County, CA. Both sites were heavily infested with perennial pepperweed and lacked competing vegetation. The experimental design was a split-split-randomized block with four replications. Site preparation treatments included winter burning, summer and fall mowing, winter grazing, and fall disking. These treatments were designed to remove thatch to facilitate herbicide application and reseeding of desirable perennial grasses. Herbicide treatments included chlorsulfuron, 2,4-D, or glyphosate applied at the flower bud stage. Revegetation treatments included no seeding and no-till seeding of native perennial grasses. Most site preparation plus herbicide combinations reduced perennial pepperweed cover > 85% compared to the untreated control, although treatment efficacy was variable between sites and years. Burning, grazing, mowing, or disking in combination with herbicide treatment and no-till seeding was necessary for successful native perennial grass establishment. Burning or mowing with yearly 2,4-D applications for 3 yr gave the best combination of perennial pepperweed control and native grass establishment. Chlorsulfuron caused chlorosis and stunting to western wheatgrass, basin wildrye, and beardless wildrye at both sites when applied the spring before seeding. No treatment offered complete weed control, suggesting follow-up spot herbicide applications are needed for long-term perennial pepperweed suppression. These results provide several successful integrated strategies for control of perennial pepperweed and revegetation to a desired native perennial grass community.

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