Treesearch

Differences in species performance (i.e. how a species captures and utilizes resources to maintain and increase population size), influences the rate and direction of plant community change (Sheley et al., 2006). Species performance is determined by a number of interacting factors. This includes resource supply rates, physiological traits that determine how a species affects and responds to the environment, life history traits that determine patterns of birth, mortality and growth of individuals in a population, as well as abiotic and biotic stressors such as herbivory or drought. Researche...

Nineleaf biscuit is native to western North America, occurring from northeastern California to British Columbia and east to Alberta and Colorado. Seed matures in July or August. Wildland seed is easily hand collected. The seed disarticulates readily from the stems, and very clean, small collections can be made by shaking ripened inflorescences over a bag or tarp.

Gray's biscuitroot occurs in Northwest North America, primarily from the Cascade and Sierra Nevada to the Rocky Mountains in Washington, Idaho, Oregon, Wyoming, Nevada, Utah, Colorado and New Mexico. There are two populations in British Columbia, Canada where it is considered a threatened species. Seed matures in July into August. Wildland seed disarticulates readily and is easily hand collected. Very clean collections can be made by shaking ripened inflorescences over a bag or tarp.

One of the most important steps in planning a restoration project is careful selection of ecologically adapted native plant material. As species-specific seed zone maps are not available for most species in the Artemisia tridentata ssp. wyomingensis (Wyoming big sagebrush) ecoregion in the Great Basin, USA, we are employing a provisional seed zone map based on annual precipitation and mean maximum daily growing season (April through September) temperatures. We plotted known populations of three potential restoration species over this map to demonstrate its value as a decision support tool...

Barestem biscuitroot is palatable primarily to sheep but grows in such limited quantities that it is hardly an important forage species (Hermann 1966). It serves as a host plant for the larvae of anise swallowtail butterfly (Papilio zelicaon) (Pelini et al 2009).

Everglades freshwater marshes were once carbon sinks, but human-driven hydrologic changes have led to uncertainty about the current state of their carbon dynamics. To investigate the effect of hydrology on CO2 exchange, we used eddy covariance measurements for 2 years (2008-2009) in marl (short-hydroperiod) and peat (long-hydroperiod) wetlands in Everglades National Park. The importance of site, season, and environmental drivers was evaluated using linear and nonlinear modeling, and a novel method was used to test for temporally lagged patterns in the data. Unexpectedly, the long-hydroperio...

White pine blister rust (WPBR) is caused by the fungal pathogen Cronartium ribicola. The pathogen is native to Eurasia and was introduced to North America early in the 20th century and is still spreading destructively throughout the range of native western white pines (Douglas ex D. Don) (McDonald and Hoff 2001). All of the North American five-needle (white) pines are susceptible to the pathogen and the disease is currently present in native populations of each species, except Pinus longaeva D.K. Bailey (Schwandt et al. 2010, Sniezko et al. 2011).

The core distribution of Rocky Mountain bristlecone pine, Pinus aristata Engelm., extends from central Colorado into northern New Mexico, with a disjunct population on the San Francisco Peaks in northern Arizona. Populations are primarily at high elevations and often define the alpine treeline; however, the species can also be found in open mixed conifer stands with ponderosa (Pinus ponderosa Lawson & C. Lawson) and/or pinyon (Pinus edulis Engelm.) pines in some locations. On dry, exposed sites the stands are open and sparse and Rocky Mountain bristlecone (hereafter referred to as bristleco...

Happy 100 years to the Priest River Experimental Forest (PREF)! PREF, which is managed by the Research and Development Branch of the USDA Forest Service, celebrated its centennial in September 2011. It was established in northern Idaho to provide useful information that would improve forest management in the western part of District One at a time when US forestry was in its infancy. In 1911, there were only a handful of university studies on forest development in the United States and little was known about tree establishment and growth, the impact of fire, or how to sufficiently supply...

Turbulent eddies in the planetary boundary layer of the terrestrial planet atmospheres are the primary mechanism by which energy, momentum, gasses, and aerosols are exchanged between the surface and the atmosphere [1]. The importance of eddies has long been recognized by the Earth atmospheric science community, and turbulent theory for Earth has a long history with a massive amount of literature backed by over half a century of detailed field campaigns. Every climate and weather forecasting model in existence relies extensively on turbulent eddy theory supported through observational...