We investigated the effects of chemical variation in thyme (Thymus vulgaris L.) on its interactions with competitors, herbivores, and herbivore predators. Four different thyme monoterpene phenotypes (chemotypes) were grown in a 4x2x2 factorial of chemotype, caging (sham half-cages vs. full cages), and competition (control vs. the grass Bromus madritensis L.). Cages reduced numbers of arthropod ...

nomic relationships among species (Vosa, 1975; Cai and Chinnappa, 1987; Fominaya et al., 1988; Gill and Sears, Previous cytogenetic studies of the genus Bromus L. were limited 1988; Tayyar et al., 1994; Falistocco et al., 1995). The to chromosome counts and construction of karyotypes on the basis of Feulgen staining. Since the chromosomes of Bromus are similar in C-banding procedure has not bee...

The expansion of piñon-juniper woodlands the past 100 years in the western United States has resulted in large scale efforts to kill trees and recover sagebrush steppe rangelands. It is important to evaluate vegetation recovery following woodland control to develop best management practices. In this study, we compared two fuel reduction treatments and a cut-and-leave (CUT) treatment used to con...

negatively affected by disturbance. meadow barley (Hordeum brachyantherum Nevski) (Hickman 1993). Purple needlegrass, blue wildrye, bluegrass and California melic are droughttolerant species that typically occupy well-drained upland sites. In contrast, creeping wildrye and meadow barley are less drought-tolerant and typically grow in the moist soils of seeps, streams and wetland margins (Walker...

Finch H., Allen P., Meyer S. (2013): Exposure to low water potentials and seed dormancy favour the fungus in the Pyrenophora semeniperda–Bromus tectorum pathosystem. Plant Protect. Sci., 49 (Special Issue): S15–S20. In semi-arid regions of the United States, Pyrenophora semeniperda kills seeds of the winter annual Bromus tectorum. We report on pathosystem outcomes under manipulated water potent...

Piñon (Pinus spp.) and juniper (Juniperus spp.) trees are reduced to restore native vegetation and avoid severe fires where they have expanded into sagebrush (Artemisia tridentata Nutt.) communities. However, what phase of tree infilling should treatments target to retain desirable understory cover and avoid weed dominance? Prescribed fire and tree felling were applied to 8–20-ha treatment plot...

Invasive weeds threaten the biodiversity and forage productivity of grasslands worldwide. However, management of these weeds is constrained by the practical difficulty of detecting small-scale infestations across large landscapes and by limits in understanding of landscape-scale invasion dynamics, including mechanisms that enable patches to expand, contract, or remain stable. While high-end hyp...

the lpsa gene, a late acting gene in the biosynthetic pathway of ergovaline, a suspected causative agent for fescue toxicosis in cattle, has been cloned from neotyphodium lolii, an endophytic fungus of lolium perenne. in this study, a similar gene was detected in several strains of endophytic neotyphodium spp. isolated from grass hosts endogenous to iran using direct and nested-pcr assays. exce...

silvicultural operation need to notice the plant species diversity in forest. to this study gomarlang district in marivan region, northern zagros forest was selected. selected 100 ha area because have similar physiography condition (north aspect and 1650 to 1800 m s.a.l. in study area 100 micro plots of 5m by 5 m (25 m2) including the species and the numbers of this species randomized-systemati...