Treesearch

We analyzed wildfire exposure for key social and ecological features on the national forests in Oregon and Washington. The forests contain numerous urban interfaces, old growth forests, recreational sites, and habitat for rare and endangered species. Many of these resources are threatened by wildfire, especially in the east Cascade Mountains fire-prone forests. The study illustrates the application of wildfire simulation for risk assessment where the major threat is from large and rare naturally ignited fires, versus many previous studies that have focused on risk driven by frequent and...

Some Great Basin urban areas in Utah and Nevada exhibit climatic conditions that make it difficult for all but the toughest landscape plants to thrive without providing supplemental water. These areas are found at elevations from 4,000 feet to 6,000 feet in USDA cold-hardiness zones 6 and 7. Soils are often poor and gravelly, containing less than 1 percent organic matter. Soil pH ranges from 6.5 to over 7.5, and some areas have salinity levels that exceed the limits of tolerance for many plants. Precipitation is less than 10 inches per year, and drying winds are persistent much of the...

Basin wildrye (Leymus cinereus [Scribn. & Merr.] A. Love) is an important perennial, hardy, long-lived, cool season C3 native grass of rangeland plant communities throughout much of western United States and Canada. All classes of livestock and wildlife, including large and small birds and mammals, utilise the grass year round for food and protection due to its 2-3 m tall, stiff stature which pro-vides standing winter cover. Though occurring in precipitation areas of 150-500 mm and elevations of 600 to 3,000 m, it is usually found in deep, well-drained soils of high water holding capacity...

The microclimatic requirements for successful seedling establishment are much more restrictive than those required for adult plant survival. The purpose of the current study was to use hydrothermal germination models and a soil energy and water flux model to evaluate intra- and interannual variability in seedbed microclimate relative to potential germination response of six perennial grasses and cheatgrass. We used a 44-yr weather record to parameterize a seedbed microclimate model for estimation of hourly temperature and moisture at seeding depth for a sandy loam soil type at the Orchard...

Drylands support over 2 billion people and are major providers of critical ecosystem goods and services across the globe. Drylands, however, are one of the most susceptible biomes to degradation. International programmes widely recognize dryland restoration as key to combating global dryland degradation and ensuring future global sustainability. While the need to restore drylands is widely recognized and large amounts of resources are allocated to these activities, rates of restoration success remain overwhelmingly low.

The choice of germplasm is critical for sustainable restoration, yet seed transfer guidelines are lacking for all but a few herbaceous species. Seed transfer zones based on genetic variability and climate were developed using tapertip onion (Allium acuminatum Hook.) collected in the Great Basin and surrounding areas in the United States. Bulbs from 53 locations were established at two common garden sites and morphological (such as leaf and scape dimensions), phenological (such as bolting date and flowering), and production traits (such as emergence and seeds per plant) were measured....

Munro's globemallow (Sphaeralcea munroana) is an important constituent of Great Basin communities and is commonly used in restoration; however, little is known about the influence of environmental conditions on early plant establishment. The objective of this study was to evaluate the response of Munro's globemallow to a suite of temperature and moisture conditions directly following germination. In addition, this work provides a rare insight into the physiology and development of this arid land species following germination. Our results indicate that temperature influences plant growth...

Penstemons are flowering perennials much loved by the gardening public. Gardeners appreciate their diversity of flower colors that are at peak bloom in June and July, their many shapes and sizes, and their attractiveness to hummingbirds and other native pollinators. You may even have planted some in your own garden. Most people don't realize there are about 280 species of penstemon, all native to North America. Even fewer know that 51 of those grow wild right here in Nevada.

Seed-feeding beetles of the genera Acanthoscelides, Apion, and occasionally Tychius were commonly found occurring in seeds from wild populations of Astragalus filipes and Dalea ornata across rangelands of the United States Intermountain West, resulting in many new state, county, and host records. These 2 legumes, as well as other perennial herbaceous species, are being commercially farmed to produce seed supplies to rehabilitate sagebrush-steppe and adjoining juniper woodlands following wildfires. Most of the seeds examined in this study hosted one or more seedfeeding beetles; beetles that...

Extension Master Gardener (EMG) volunteers are central to expanding the outreach and engagement of extension staff. A workshop format was used at the Annual Conference of the American Society for Horticultural Science on 31 July 2012 in Miami, FL to identify successful management techniques and projects that expand EMG volunteer outreach, leading to increased extension effectiveness. One program leader described how EMGs manage a farmer's market that has been thriving for more than 30 years, generating income for the EMG program as well as the county extension office. Another program...