Validation of Festuca idahoensis subsp. roemeri comb.nov.

1998 ◽  
Vol 76 (1) ◽  
pp. 179
Author(s):  
S G Aiken
Keyword(s):  
Festuca Idahoensis

Carbon allocation in Euphorbia esula and neighbours after defoliation

2000 ◽  
Vol 77 (11) ◽  
pp. 1641-1647 ◽  
Author(s):  
Bret E Olson ◽  
Roseann T Wallander
Keyword(s):  
Root System ◽  
Carbon Allocation ◽  
Poa Pratensis ◽  
Kentucky Bluegrass ◽  
Euphorbia Esula ◽  
Sink Strength ◽  
Relative Distribution ◽  
Grazing Tolerance ◽  
Allocation Patterns ◽  
Festuca Idahoensis

Weeds increase their dominance in a grazed plant community by avoiding herbivory and (or) by tolerating herbivory more than neighbouring plants. After defoliation, allocating carbon to shoots at the expense of roots may confer tolerance. We determined carbon allocation patterns of undefoliated and recently defoliated (75% clipping level) plants of the invasive leafy spurge (Euphorbia esula L.) growing with alfalfa (Medicago sativa L.), Kentucky bluegrass (Poa pratensis L.), or Idaho fescue (Festuca idahoensis Elmer). Plants were labeled with 13CO2 24 h after clipping to determine allocation patterns; all plants had equal access to the 13CO2. Based on relative distribution of 13C, defoliation did not affect the amount of carbon allocated to roots of E. esula. The amount of carbon allocated to shoots of E. esula was higher when growing with P. pratensis than when growing with the other species. Based on relative enrichment of 13C, defoliation increased sink strength of remaining shoots on defoliated E. esula plants. Conversely, roots of unclipped E. esula plants were stronger sinks for carbon than roots of clipped plants. Even though defoliation increased "sink strength" of remaining shoots of E. esula, the amount of carbon allocated to the root system was unaffected by defoliation, suggesting that uninterrupted allocation of carbon to its extensive root system, not increased allocation to its shoot system, confers grazing tolerance.

Mycorrhizal fungi associated with Festuca in the western United States and Canada

1978 ◽  
Vol 56 (14) ◽  
pp. 1691-1695 ◽  
Author(s):  
Randolph J. Molina ◽  
James M. Trappe ◽  
Gerald S. Strickler
Keyword(s):  
United States ◽  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizal ◽  
Western United States ◽  
Individual Plant ◽  
Mycorrhizal Infection ◽  
Acaulospora Laevis ◽  
Fine Root Length ◽  
Vesicular Arbuscular ◽  
Festuca Idahoensis

Vesicular–arbuscular mycorrhizal infection and associated mycorrhizal fungi were examined for Festuca viridula, Festuca idahoensis, Festuca scabrella, Festuca thurberi, Festuca ovina, and Festuca arizonica occurring in Festuca-dominated grasslands in the western United States and Canada. All plants were mycorrhizal. Nearly all had mycorrhizal infection in 75% or more of their fine root length. Although levels of infection were consistently high, spore numbers were generally low. No differences in the degree of infection between Festuca species or habitats were observed.Eleven mycorrhizal fungi were identified and ranked by decreasing frequency as follows: Glomus fasciculatus, Glomus tenuis, Gigaspora calospora, Acaulospora laevis, Glomus macrocarpus var. macrocarpus, Glomus microcarpus, Acaulospora scrobiculata, Glomus mosseae, Glomus macrocarpus var. geosporus, Sclerocystis rubiformis, and an unidentified Acaulospora species. It was common to find two or more species infecting an individual plant. The mean number of fungal associates per community site ranged from 2.7 species for F. idahoensis to 5.0 species for F. arizonica. We found no evidence for specificity of any of the mycorrhizal fungi for any particular Festuca host.

After-Ripening in Festuca idahoensis Seeds: Adaptive Dormancy and Implications for Restoration

1995 ◽  
Vol 3 (2) ◽  
pp. 137-142 ◽  
Author(s):  
Jay R. Goodwin ◽  
Paul S. Doescher ◽  
Lee E. Eddleman
Keyword(s):  
Festuca Idahoensis

Genetic differentiation and admixture among Festuca idahoensis, F. roemeri, and F. ovina detected in AFLP, ITS, and chloroplast DNA

Botany ◽  
2008 ◽  
Vol 86 (4) ◽  
pp. 422-434 ◽  
Author(s):  
Thomas A. Jones ◽  
Steven R. Larson ◽  
Barbara L. Wilson
Keyword(s):  
Chloroplast Dna ◽  
Genetic Relatedness ◽  
Sequence Divergence ◽  
Natural Source ◽  
Nuclear Ribosomal Dna ◽  
Genetic Admixture ◽  
Festuca Rubra ◽  
Model Based Clustering ◽  
Intergenic Sequences ◽  
Festuca Idahoensis

North American forms of the Festuca ovina L. complex, Festuca idahoensis Elmer and Festuca roemeri (Pavlick) E.B. Alexeev, are distributed broadly east and narrowly west of the Cascade Mountains, respectively. The psbA-trnH and rps16-trnK chloroplast DNA intergenic sequences, 18S-5.8S-26S nuclear ribosomal DNA internal transcribed spacer (ITS) sequences, and six AFLP primer combinations were used to investigate genetic relatedness and differences among 327 plant samples from 24 F. idahoensis and 33 F. roemeri natural-source germplasm accessions, two multiple-origin F. idahoensis × F. roemeri cultivars, one apparently admixed F. ovina × F. idahoensis accession, four naturalized populations or cultivars of Eurasian-source F. ovina s. l., and several Festuca arizonica Vasey, Festuca occidentalis Hooker, and Festuca rubra L. reference accessions. The AFLP profiles of individual plants were unique, but distance-based and Bayesian model-based clustering separated AFLP genotypes into groups corresponding to taxa. Approximately 15.9% of the AFLP variation was apportioned between F. idahoensis and F. roemeri, with the remaining 61.2% and 22.9% variation maintained within and among natural-source accessions, respectively. Genetic admixture between F. idahoensis, F. roemeri, and F. ovina was detectable and DNA sequence divergence was very low in the chloroplast and ITS regions. These three taxa are genetically differentiated, but capable of hybridization.

scholarly journals Responses of Nematodes to Ungulate Herbivory on Bluebunch Wheatgrass and Idaho Fescue in Yellowstone National Park

1994 ◽  
Vol 18 ◽  
pp. 126-130
Author(s):  
Evelyn Merrill ◽  
Jon Hak ◽  
Nancy Stanton
Keyword(s):  
Root Growth ◽  
Yellowstone National Park ◽  
Root Biomass ◽  
National Park ◽  
Growing Season ◽  
Belowground Biomass ◽  
Winter Range ◽  
Bluebunch Wheatgrass ◽  
Festuca Idahoensis ◽  
Agropyron Spicatum

Above- and belowground biomass of Idaho fescue Festuca idahoensis and bluebunch wheatgrass Agropyron spicatum and nematode densities under these plant species were sampled during the growing season inside and outside a 2-year old exclosure on Crystal Bench in Yellowstone National Park. Early in the growing season, grazed plants of both species had lower shoot and root biomass than ungrazed plants. Standing biomass of grazed plants was equal to ungrazed plants at the end of the growing season. Densities/g root biomass of phytophagous and bacterial feeding nematodes were higher under grazed than ungrazed plants of both plant species only early in the growing season. Foliar concentrations of nitrogen in grazed plants were higher than ungrazed plants but there was no difference in root nitrogen between grazed and ungrazed plants. The effects of ungulate grazing on the Northern winter range of Yellowstone National Park has recently received considerable attention (Frank 1990, Coughenour 1991, Singer 1992, Wallace submitted). Early interest in this topic centered around the question to cull or not to cull elk in the Park. However, as the concepts of "maintaining ecological processes" (Houston 1982) and "ecosystem management" (Keiter 1991) have gained acceptance in Park management, understanding the dynamics and interactions of a broader array of herbivores inhabiting the Park have become increasingly important. In this paper, we describe the results of a study which focused on the effects of aboveground herbivory on nematode density and trophic structure. Root-feeding nematodes are major herbivores in other grassland systems and may consume twice as much biomass as aboveground consumers (Ingham and Detling 1984, Stanton 1988). Houston (1982) reported that nothing is known about the effects of nematodes on the native grasses of the northern range especially in combination with aboveground grazers. We hypothesized that if spring grazing is intense, grazed plants would initially show a decline in root growth and phytophagous nematodes. Cessation of root growth is a common response of plants to grazing and may occur within the first 2-24 hours (Hodgkinson and Baas Becking 1977). Evidence to date supports the idea that phytophagous nematode densities are highest under moderate levels of grazing and low under heavily grazed and ungrazed plants (Stanton 1983, Stanton et al. 1984, Seastedt 1985, Seastedt et al. 1988). Because senescing roots, subsequent to grazing, provide increased substrates for decomposers, we also hypothesized that microbial activity and nitrogen mineralization should increase (Stanton et al. 1984). As a result, we expected to detect an increase in microbial feeding nematodes. As root regrowth occurred, we expected phytophagous nematodes to increase. However, we predicted that populations would not reach levels found under ungrazed plants because plants in grazed areas experience higher levels of nitrogen mineralization (Holland and Detling 1990) than ungrazed plants and may produce proportionally fewer numbers of root hairs (nutrient absorption organs) which serve as feeding sites for nematodes. Because of reduced densities of phytophagous nematodes and increased mineralization rates under grazed plants, we expected grazed plants to recoup their losses rapidly. The net result we predicted would be no detectable differences in aboveground or belowground biomass during years of normal rainfall. Thus, our study addressed 3 null hypotheses. First, root and shoot biomass of grazed and ungrazed plants will be similar at the end of the growing season. Second, density of phytophagous and microbial feeding nematodes will not differ between grazed and ungrazed plants. Finally, nitrogen concentration of roots and aboveground foliage will not be higher in grazed than in ungrazed plants. We focused our attention on bluebunch wheatgrass Agropyron spicatum and Idaho fescue Festuca idahoensis because of their importance as winter range forages and because Mueggler (1975) reported that bluebunch wheatgrass was more sensitive and recovered more slowly to heavy clipping than Idaho fescue.

scholarly journals Responses of Nematodes to Ungulate Herbivory on Bluebunch Wheatgrass and Idaho Fescue in Yellowstone National Park

1991 ◽  
Vol 15 ◽  
pp. 231-234
Author(s):  
Evelyn Merrill ◽  
Nancy Stanton
Keyword(s):  
Yellowstone National Park ◽  
National Park ◽  
Ecological Processes ◽  
Winter Range ◽  
Ungulate Herbivory ◽  
Bluebunch Wheatgrass ◽  
Ungulate Grazing ◽  
Northern Winter ◽  
Festuca Idahoensis ◽  
Agropyron Spicatum

The effects of ungulate grazing on the Northern winter range of Yellowstone National Park has recently received considerable attention. Early interest in this topic centered around the question to cull or not to cull elk in the Park. However, as the concepts of "maintaining ecological processes" (Houston 1982) and "ecosystem management" (Keiter 1991) have gained acceptance in Park management, understanding the dynamics and interactions of a broader array of herbivores inhabiting the Park will become increasingly important. In 1990, we studied the responses of Idaho fescue (Festuca idahoensis) and bluebunch wheatgrass (Agropyron spicatum) and their associated nematode communities to ungulate herbivory.

The taxonomy and distribution of Festuca idahoensis in British Columbia and northwestern Washington

1983 ◽  
Vol 61 (1) ◽  
pp. 345-353 ◽  
Author(s):  
Leon E. Pavlick
Keyword(s):  
British Columbia ◽  
Leaf Morphology ◽  
Ecological Distribution ◽  
Cascade Mountains ◽  
Festuca Idahoensis

Plants of Festuca idahoensis from west of the Cascade Mountains in British Columbia and northwestern Washington differ in their leaf morphology and panicle size from those east of the Cascade Mountains. The western plants are recognized as F. idahoensis var. roemeri. The geographic and ecological distribution of the species and a key for distinguishing the two varieties are given.

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