[1] The extent of Arctic perennial sea ice, the year-round ice cover, was significantly reduced between March 2005 and March 2007 by 1.08 10 km, a 23% loss from 4.69 10 km to 3.61 10 km, as observed by the QuikSCAT/SeaWinds satellite scatterometer (QSCAT). Moreover, the buoy-based Drift-Age Model (DM) provided long-term trends in Arctic sea-ice age since the 1950s. Perennial-ice extent loss in ...

Throughout the western United States, the invasive annual grass, medusahead (Taeniatherum caputmedusae L. Nevski), is rapidly invading grasslands once dominated by native perennial grasses, such as bluebunch wheatgrass (Pseudoroegneria spicata (Pursh) A). It is also invading grasslands dominated by less undesirable invasive annual grasses, especially cheatgrass (Bromus tectorum L.). Understandi...

Sheep were fed once daily with 300 or 600 g dried perennial ryegrass (Lolium perenne) or white clover (Trifolium repens). Total rumen contents were sampled once daily at various intervals up to 24 h after feeding for 6 d. Total weight of fresh rumen contents and dry matter (DM), organic matter and particulate matter concentrations were measured and the particle size distribution of rumen conten...

The Palouse Prairie of eastern Washington was identified in the 1997 USDA National Resources Inventory as one of the most highly erodible areas in the United States. It is estimated that 10% of the original topsoil in eastern Washington has been lost since cultivation began in the region in the late 1800s (32). Furthermore, runoff from agricultural land reduces water quality in streams and rive...

Contamination of annual ryegrass with perennial ryegrassby physical seed mixing or gene flow can result in a significant reduction in forage production.Therefore, this study aimed to develop a suitable technique using near-infrared spectroscopy (NIRS) for discriminating and quantifying adulteration of annual ryegrass seeds with perennial ryegrass. A partial least squares regression for discrimi...

Biomass crops grown on marginal soils are expected to fuel an emerging bioenergy industry in the United States. Bioenergy crop choice and position in the landscape could have important impacts on a range of ecosystem services, including natural pest-suppression (biocontrol services) provided by predatory arthropods. In this study we use predation rates of three sentinel crop pests to develop a ...

Medusahead (Taeniatherum caput-medusae [L.] Nevski) is an exotic annual grass invading western rangelands. Invasion by medusahead is problematic because it decreases livestock forage production, degrades wildlife habitat, reduces biodiversity, and increases fire frequency. Revegetation of medusahead-invaded sagebrush steppe is needed to increase ecosystem and economic productivity. Most efforts...

Cinnamoyl CoA-reductase (CCR) and caffeic acid O-methyltransferase (COMT) catalyze key steps in the biosynthesis of monolignols, which serve as building blocks in the formation of plant lignin. We identified candidate genes encoding these two enzymes in perennial ryegrass (Lolium perenne) and show that the spatio-temporal expression patterns of these genes in planta correlate well with the deve...

The ecological benefits of a roadside native perennial grass stand are :ompromised when invasive species become estab· lished. We evaluated the potential to regenerate existing native perennial grass stand5 populat~d with yellow starthistle (Centaurea solstitialis) on a roadside planting in the lowland hills of t1e interior Coast Range of northern California. The experiment was designed to dete...