Cover-based allometric estimate of aboveground biomass of a non-native, invasive annual grass (Bromus tectorum L.) in the Great Basin, USA

AbstractDowny brome (Bromus tectorumL.) is a widely distributed invasive winter annual grass across western North America.Bromus tectorumphenology can vary considerably among populations, and those differences are considered adaptively significant. A consensus hypothesis in the literature attributes the majority of observed differences inB. tectorumphenology to differing vernalization requirements among populations. A series of greenhouse experiments were conducted to identify differences inB. tectorumvernalization requirements and link vernalization to expression of annual false-brome [Brachypodium distachyon(L.) P. Beauv.]-derived vernalization gene homolog (BdVRN1). Results from this study indicate that variation in time to flowering is partially governed by differing vernalization requirements and that flowering is linked to the expression ofBdVRN1.

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Effect of Forage Kochia on Seedling Growth of Cheatgrass (Bromus tectorum) and Perennial Grasses

Invasive Plant Science and Management ◽

10.1017/inp.2018.27 ◽

2018 ◽

Vol 11 (4) ◽

pp. 201-207

Author(s):

Parmeshwor Aryal ◽

M. Anowarul Islam

Keyword(s):

Seedling Growth ◽

Aboveground Biomass ◽

Bromus Tectorum ◽

Perennial Grass ◽

Perennial Grasses ◽

Grass Species ◽

Native Grasses ◽

Native Plant ◽

Competitive Effect ◽

Forage Kochia

AbstractForage kochia [Bassia prostrata(L.) A. J. Scott] is competitive with annual weeds and has potential for use in reclamation of disturbed land. However, land managers are reluctant to use forage kochia in revegetation programs due to lack of understanding of its compatibility with or invasiveness in the native plant community. We conducted two greenhouse experiments, one to compare the competitive effect of forage kochia versus perennial grasses on growth of cheatgrass (Bromus tectorumL.) and one to study the effect of forage kochia on growth of native perennial grasses. In the first experiment, a single seedling ofB. tectorumwas grown with increasing neighbor densities (0 to 5 seedlings pot−1) of either forage kochia, crested wheatgrass [Agropyron cristatum(L.) Gaertner ×A. desertorum(Fisch. ex Link) Schultes; nonnative perennial grass], or thickspike wheatgrass [Elymus lanceolatus(Scribn. & J. G. Sm.) Gould; native perennial grass].Bromus tectorumgrowth was reduced moderately by all three perennial neighbors, butA. cristatumandE. lanceolatushad more effect onB. tectorumwhen compared with forage kochia. This experiment was repeated and similar results were observed. In the second experiment, forage kochia was grown with each of four native cool-season grass species: basin wildrye [Leymus cinereus(Scribn. & Merr.) Á. Löve], bluebunch wheatgrass [Pseudoroegneria spicata(Pursh) Á. Löve],E. lanceolatus, and western wheatgrass [Pascopyrum smithii(Rydb.) Á. Löve]. Forage kochia had no effect on height, tiller number, and aboveground biomass of native grasses. Similarly, native grasses did not show a significant effect on forage kochia seedlings. This experiment was also repeated, and forage kochia somewhat reduced the aboveground biomass ofL. cinereusandP. spicata. However, all native grasses significantly reduced change in height, branching, and aboveground biomass of forage kochia. These results suggest that forage kochia interfered withB. tectorumseedling growth, but it showed little competitive effect on native grass seedlings.

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Secondary dormancy of seeds in relation to the Bromus tectorum–Pyrenophora semeniperda pathosystem

Plant Protection Science ◽

10.17221/30/2013-pps ◽

2013 ◽

Vol 49 (Special Issue) ◽

pp. S11-S14 ◽

Cited By ~ 1

Author(s):

K.K. Hawkins ◽

P. Allen ◽

S. Meyer

Keyword(s):

Seed Germination ◽

Field Study ◽

Seed Bank ◽

Fungal Pathogen ◽

Bromus Tectorum ◽

Large Fraction ◽

Annual Grass ◽

Late Autumn ◽

Secondary Dormancy ◽

Laboratory Results

Bromus tectorum is a highly invasive annual grass. The fungal pathogen Pyrenophora semeniperda can kill a large fraction of B. tectorum seeds. Outcomes in this pathosystem are often determined by the speed of seed germination. In this paper we extend previous efforts to describe the pathosystem by characterising secondary dormancy acquisition of B. tectorum. In the laboratory approximately 80% of seeds incubated at –1.0 MPa became dormant. In the field, seeds were placed in the seed bank in late autumn, retrieved monthly and dormancy status determined. The field study confirmed the laboratory results; ungerminated seeds became increasingly dormant. Our data suggest that secondary dormancy is much more likely to occur at xeric sites.

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