Treesearch

The emerald ash borer (EAB) has caused extensive damage and high mortality to native ash trees (Fraxinus; sp.) in North America. As European countries battle with the deadly pathogen Hymenoscyphus fraxineus (ash dieback) affecting European ash (Fraxinus excelsior), there is concern that the arrival of EAB will signal the demise of this much-loved tree. While Europe prepares for EAB it is vital that we understand the social dimensions that will likely influence the social acceptability of potential management measures, and experiences from the USA can potentially guide this. We draw on...

In many ways, biodiversity is a foundational component of healthy, productive forests and maintenance of the many ecosystem services that they provide (e.g., carbon sequestration, nutrient cycling, water filtration and provisioning, wildlife habitat). Forested landscapes are often characterized by a mosaic of species, age classes, and structural characteristics that results from natural patterns of disturbance. This diversity within stands and across forested landscapes increases resilience of larger forested ecosystems, enabling them to recover and maintain ecological function following...

Land managers face a mounting variety of challenges, including how to efficiently dispose of excessive woody residues on forest sites (especially in the Western United States), maintain and improve soil productivity, improve forest resilience to changes in climate (especially as it pertains to drought and fire), and increase the effectiveness of reforestation activities. The use of biochar, a charcoal that is not readily degraded and is made specifically for land application, may have a role in meeting these challenges. Moreover, biochar may provide nursery managers with opportunities to...

In northern California, United States, a cut-to-length (CTL) system was recently used for the first time to harvest young redwood (Sequoia sempervirens (Lamb. ex D. Don) Endl.) forests. Landowners and public agencies in this region have been concerned about the potential negative impacts of CTL on soils during wet-season harvest operations. To determine soil impacts, we measured changes in soil bulk density (BD) and hydraulic conductivity (HC) after CTL operations in May and August. Soil samples were collected at two locations (track and center) along forwarder trails and at a reference...

Forest soil disturbances are unavoidable in ground-based skidding operations and it is well-known that the extent, duration, and severity of disturbances increase with increasing trafficking from harvest equipment and slope gradient. It is unclear, however, how different types of harvest equipment affect the extent of disturbance along the margins of skid trails. The aim of this study was to investigate changes in topsoil (0–10 cm depth) physical properties beyond the margins of skid trails in mountainous terrain in response to skidding with three different skidder types with varying tire...

Nettleleaf giant hyssop (Agastache urticifolia [Benth.] Kuntze) belongs to the Lamiaceae or mint family, Mentheae tribe, and Nepetinae subtribe (Drew and Sytsma 2012). The Agastache genus is comprised of two sections, Agastache (syn: Chiastandra) and Brittonastrum, which are geographically distinct. Nettleleaf giant hyssop is part of the more northerly distributed Agastache section (Lint and Epling 1945; Vogelmann 1985). Taxonomy for this review follows Cronquist et al. (1984).

Nakedstem sunray occurs in Idaho, Utah, Nevada, Arizona, and California (Curtis 2006). It is widespread throughout the Great Basin (Clark 1998) and occurs as restricted populations in southwestern and central Idaho, northern Arizona’s Mohave and Coconino counties, and southeastern California’s Inyo and San Bernardino counties (Cronquist et al. 1994).

1. Non-native insects pose threats to forest health and often spread via stratified dispersal in which long-distance jumps cause elevated rates of range expansion. Quantifying patterns and developing models of spread are central to understanding drivers of invasion and forecasting future invasions. 2. We investigated the utility of models for characterizing and predicting spread of emerald ash borer (EAB), quantified temporal dynamics of spread and identified correlates of county-level invasion risk. 3. We estimated rates and frequency of EAB spread and length of long-distance jumps...

Surface fires are often prescribed to favor oak (Quercus) regeneration in eastern forests, but there is potential for fire to damage residual overstory timber. This study evaluated the potential economic effects of prescribed fire on sawtimber volume and value across 139 stands, each with a known history of one to six prescribed fires, on the Hoosier, Mark Twain, Wayne, and Daniel Boone National Forests. Sawtimber volume and value losses were highly variable, ranging from 0 to 2,269 bd ft ac–1 and from US$0 to US$272.95 ac–1, respectively, for stands that had received at least one prescribe...

Springsnails (genus Pyrgulopsis, hereafter pyrgs) are small freshwater aquatic gastropods that occur in isolated springs in western North America. Pyrgs are species of conservation concern, but patterns of occupancy and speciation are complex. We investigated patterns of occurrence for pyrgs in the Spring Mountains, Clark County, Nevada. We were primarily concerned with identifying springs containing the species P. deaconi, the Spring Mountains pyrg, and P. turbatrix, the southeast Nevada pyrg. We identified species through genetic analysis of the COI-1 mitochondrial region and examined...