Natural habitats vary in the degree to which they are invaded by exotic species, but it is unclear whether they differ in the mechanisms underlying the spatial spread of a given exotic species. To compare the dynamics of invasion in highly invaded nonserpentine oak woodlands and less-invaded serpentine habitats, we used an historical ‘‘experiment’’ consisting of the introduction of several nonn...

Three different DNA-based techniques, Random Amplified Polymorphic DNA (RAPD), Inter Simple Sequence Repeat (ISSR) and Amplified Fragment Length Polymorphism (AFLP) markers, were used for fingerprinting Dactylis glomerata genotypes and for detecting genetic variation between the three different subspecies. In this study, RAPD assays produced 97 bands, of which 40 were polymorphic (41.2%). The I...

The efficiency of wet explosion applied as modified dilute acid pretreatment at previously identified reference conditions (150°C, 0.3% H(2)SO(4), 15 min) was investigated on lucerne, ryegrass, fescue grass, cocksfoot grass, rye fescue, forage grass, and wheat straw in order to identify their potential as feedstock for cellulosic bioethanol production. After pretreatment, cellulose recovery was...

The objective of this study was to determine the specific methane yields of four grass species (cocksfoot, tall fescue, reed canary grass and timothy) cultivated under boreal conditions as well as how harvesting time and year of cultivation affects the specific methane yields per ha. The specific methane yields of all grasses and all harvests varied from 253 to 394 Nl CH4/kg volatile solids (VS...

The effects of seed source and seed size on germination and field performance were studied in five grasses. Greater seed weights were associated with better germination in Yorkshire fog, cocksfoot and timothy but not significantly so for Chewings fescue and browntop. In cocksfoot, Chewings fescue and timothy, higher seed weights were found in samples collected at altitudes above those generally...

Insect herbivores can shift the composition of a plant community, but the mechanism underlying such shifts remains largely unexplored. A possibility is that insects alter the competitive symmetry between plant species. The effect of herbivory on competition likely depends on whether the plants are subjected to aboveground or belowground herbivory or both, and also depends on soil nitrogen level...

Abstract Choke disease, which is caused by Epichloë typhina , was first reported in orchardgrass seed production fields the Willamette Valley, Oregon 1997 and has continued to persist system. The disease can cause up 30% losses yield. Unlike many species that are transmitted, it unclear how infection of E. occurs field, or spreads within plants. In this study, overall incidence choke on trap pl...