Treesearch

The Great Basin region of the western United States has undergone significant disturbance and fragmentation because of overgrazing for livestock production, disruption of the natural fire regimes, and the introduction of non-native species. At present, habitat loss greatly surpasses the rate of system recovery, making restoration integral to ecosystem function and resilience. To date, restoration research and practice have focused largely on keystone plant species, however, to be effective, restoration must include myriad plant forms and guilds. Munro's globemallow (Sphaeralcea munroana...

Pollinators, even floral generalists (=polyleges), typically specialize during individual foraging bouts, infrequently switching between floral hosts. Such transient floral constancy restricts pollen flow, and thereby gene flow, to conspecific flowers in mixed plant communities. Where incipient flowering species meet, however, weak cross-fertility and often similar floral traits can yield mixed reproductive outcomes among pollinator-dependent species. In these cases, floral constancy by polyleges sometimes serves as an ethological mating barrier. More often, their foraging infidelities...

The United States Department of Agriculture, Forest Service, Rocky Mountain Research Station; United States Department of the Interior, Bureau of Land Management, Idaho State Office; Utah State University, Agricultural Experiment Station; and University of Idaho, Agricultural Experiment Station, announce the release of a selected germplasm (natural track) of western yarrow (Achillea millefolium L. var. occidentalis DC.) for use on adapted sites in the Snake River Plain and northern Great Basin. As a Selected Germplasm release this plant will be referred to as Eagle Germplasm western...

Astragalus L. (Fabaceae) is an enormous and diverse plant genus with a cosmopolitan distribution, but relatively few breeding biologies are known for its member species. Threadstalk (or basalt) milkvetch, Astragalus filipes Torrey ex. A. Gray, is common and widespread throughout the U.S. Intermountain West, including the Great Basin. It is being studied and ultimately propagated for extensive rangeland restoration projects throughout the sagebrush steppe. Understanding the breeding biology of A. filipes will be necessary for reliable and consistent commercial seed production with this...

Settlement by Anglo-Americans in the desert shrublands of North America resulted in the introduction and subsequent invasion of multiple nonnative grass species. These invasions have altered presettlement fire regimes, resulted in conversion of native perennial shrublands to nonnative annual grasslands, and placed many native desert species at risk. Effective management of these ecosystems requires an understanding of their ecological resistance to invasion and resilience to fire. Resistance and resilience differ among the cold and hot desert shrublands of the Great Basin, Mojave, Sonoran,...

Forested areas disturbed by access roads produce large amounts of sediment. One method to predict erosion and, hence, manage forest roads is the use of physically based soil erosion models. A perceived advantage of a physically based model is that it can be parameterized at one location and applied at another location with similar soil texture or geological parent material. To test this perception, a two-part study was conducted to compare soil erosion model predictions using parent material/soil texture-based parameters to predictions using site-specific parameters. The first step was to...

A combined morphological, molecular and biological study shows that the weevil species presently named Mecinus janthinus is actually composed of two different cryptic species: M. janthinus Germar, 1821 and M. janthiniformis Tosevski & Caldara sp.n. These species are morphologically distinguishable from each other by a few very subtle morphological characters. On the contrary, they are more readily distinguishable by both molecular and biological characters. A molecular assessment based on the mitochondrial DNA cytochrome oxidase subunit II gene revealed fixed differences between the two...

Mountain Home germplasm Sandberg bluegrass is a small, densely tufted short-lived perennial bunchgrass adapted to low elevation, semi-arid sites with long, hot growing seasons. Mountain Home's drought tolerance, competitive nature, and ease of establishment make it an excellent choice for post-fire restoration of cheatgrass (Bromus tectorum L.) dominated landscapes and for conversion of introduced perennial grasslands to native plant communities. The selected germplasm (natural track) release will be named Mountain Home Germplasm Sandberg bluegrass for the original collection site.

Assessing the impact of climate change on species and associated management objectives is a critical initial step for engaging in the adaptation planning process. Multiple approaches are available. While all possess limitations to their application associated with the uncertainties inherent in the data and models that inform their results, conducting and incorporating impact assessments into the adaptation planning process at least provides some basis for making resource management decisions that are becoming inevitable in the face of rapidly changing climate. Here we provide a non-exhausti...

The invasive tree, Tamarix sp., was introduced to the United States in the 1800s to stabilize stream banks. The riparian ecosystem adjacent to the middle Rio Grande River in central NewMexico consists of mature cottonwood (Populus fremontii ) gallery forests with a dense Tamarix understory. We hypothesized that Populus would compensate for reduced competition by increasing its water consumption in restored riparian plots following selective Tamarix removal, resulting in similar transpiration (T ) among stands. The northern study site included a Populus stand invaded by Tamarix (INVN) and a...