Treesearch

Seeding is an important management tool in aridland restoration, but seeded species often fail to establish. Previous research has largely focused on the technical aspects of seeding with little effort directed at identifying demographic processes driving recruitment failures.

Leymus is a genomically defined allopolyploid of genus Triticeae with two distinct subgenomes. Chloroplast DNA sequences of Eurasian and North American species are distinct and polyphyletic. However, phylogenies derived from chloroplast and nuclear DNA sequences are confounded by polyploidy and lack of polymorphism among many taxa. The AFLP technique can resolve phylogenetic relationships between closely related species, with a curvilinear relationship expected between the proportion of shared bands and nucleotide substitution rate (D), up to about 0.100 D. The objective of this study was...

Two natural-track selected germplasms of western prairie clover (Dalea ornata (Douglas ex Hook.) Eaton & J. Wright [Fabaceae]) have been released for use in revegetation of semiarid rangelands in the western US. Western prairie clover is a perennial leguminous forb that occurs naturally in Idaho, Washington, Oregon, California, and Nevada. Majestic Germplasm western prairie clover originates from seed collected from indigenous plants near Sherar's Bridge in Sherman County, Oregon, whereas Spectrum Germplasm western prairie clover originates from seed collected from indigenous plants near...

Germination tests of Wyoming big sagebrush (Artemisia tridentata Nutt. ssp. wyomingensis Beetle & Young [Asteraceae]) seeds often exhibit fungal contamination, but the use of fungicides should be avoided because fungicides may artificially inhibit germination. We tested the effect of seed-applied fungicides on germination of Wyoming big sagebrush at 2 different water potentials (-0.033 and -0.7 MPa) and found that treating test seedlots with fungicide reduced the germination percentage by up to half in some treatments. This effect was greatest at the lower water potential. We found that...

Nineleaf biscuitroot begins growth very early in the spring, often just following snow melt, providing crucial early forage for many wildlife and domestic animals. It is considered one of the most valuable forage species of the genus due to its large stature and high production levels. It is rated as having fair to very good forage for sheep and poor to good forage for cattle (USDA-FS, 1937). Ogle and Brazee (2009) rate it as desirable spring and summer forage for cattle, sheep, horses, elk, deer and antelope.

Established plants of fernleaf biscuitroot, like other members of the Lomatium genus, begins growth very early in the spring, often just following snow melt, providing crucial early forage for many wildlife and domestic animals. It is considered a very valuable forage species due to its large stature and high biomass production levels. Ogle and Brazee (2009) rate members of the genus as desirable spring and summer forage for cattle, sheep, horses, elk, deer and antelope.

Plants of Searls' prairie clover are grazed by many animals including rabbits, deer, sheep and cattle. This legume forms a symbiotic association with soil bacteria (Rhizobium spp.) that allows fixation of atmospheric nitrogen, which can enhance forage nitrogen content for wildlife and livestock. Flowers are visited by pollinators, primarily bees, during bloom from June-July. Searls' prairie clover may have been more widely spread than its current distribution in the Great Basin, Colorado Plateau and the northern Mojave Desert prior to the arrival of European settlers. The decline may be...

Rangeland extent is an important factor for evaluating critical indicators of rangeland sustainability. Rangeland areal extent was determined for the coterminous United States in a geospatial framework by evaluating spatially explicit data from the Landscape Fire and Resource Management Planning Tools (LANDFIRE) project describing historic and current vegetative composition, average height, and average cover through the viewpoints of the Natural Resources Inventory (NRI) administered by the Natural Resources Conservation Service and the Forest Inventory and Analysis (FIA) program administer...

Resource allocation for wildland fire suppression problems, referred to here as Fire-S problems, have been studied for over a century. Not only have the many variants of the base Fire-S problem made it such a durable one to study, but advances in suppression technology and our ever-expanding knowledge of and experience with wildland fire behavior have required almost constant reformulations that introduce new techniques. Lately, there has been a strong push towards randomized or stochastic treatments because of their appeal to fire managers as planning tools. A multistage stochastic...

Introduction Wildfires often produce large increases in runoff and erosion rates (e.g., Moody and Martin, 2009), and land managers need to predict the frequency and magnitude of postfire erosion to determine the needs for hazard response and possible erosion mitigation to reduce the impacts of increased erosion on public safety and valued resources. The Water Erosion Prediction Project (WEPP) hillslope erosion model uses parameters based on field measurements to calculate the interrill and rill components of erosion (Nearing et al., 1989). Since rill erosion is the dominant hillslope...