Treesearch

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...

In the course of routine examinations of powdery mildews collected in Idaho and Oregon, USA, some of the identified species proved to be new to North America, in some cases on new host plants. Leveillula papilionacearum and L. picridis are first records from the USA. Astragalus filipes, Dalea ornata and D. searlsiae are new hosts for Leveillula papilionacearum. Enceliopsis, Heliomeris and Machaeranthera are new host genera for L. picridis. Additional records refer to powdery mildew species which have been rarely reported from North America or first records on certain hosts.

Most spatially explicit hydrologic models require estimates of air temperature patterns. For these models, empirical relationships between elevation and air temperature are frequently used to upscale point measurements or downscale regional and global climate model estimates of air temperature. Mountainous environments are particularly sensitive to air temperature estimates as spatial gradients are substantial, and air temperature plays a critical role in snow-related processes. We use a distributed, coupled ecohydrologic model to compare estimates of streamflow, snowmelt, transpiration,...

Bark beetle outbreaks have killed large numbers of trees across North America in recent years. Lidar remote sensing can be used to effectively estimate forest biomass, but prediction of both live and dead standing biomass in beetle-affected forests using lidar alone has not been demonstrated. We developed Random Forest (RF) models predicting total, live, dead, and percent dead basal area (BA) from lidar metrics in five different beetle-affected coniferous forests across western North America. Study areas included the Kenai Peninsula of Alaska, southeastern Arizona, north-central Colorado,...

The science associated with the use of airborne and satellite Light Detection and Ranging (LiDAR) to remotely sense forest structure has rapidly progressed over the past decade. LiDAR has evolved from being a poorly understood, potentially useful tool to an operational technology in a little over a decade, and these instruments have become a major success story in terms of their application to the measurement, mapping, or monitoring of forests worldwide. Invented in 1960, the laser and, a short time later, LiDAR, were found in research and military laboratories. Since the early 2000s,...