Treesearch

Background: Fire danger indexes (FDIs) are used as proxies for fire potential and are often developed for specific locations. For practical purposes, the extrapolation of the underlying calculations into novel locations is common, but it is generally uncertain if the relationships between FDIs and fire potential observed in the environment in which the index was developed are equally relevant in others. For example, although a topographically, ecologically, and climatologically complex country, f ire danger forecasts in Peru use a standard set of nationwide thresholds applied to the Fire...

Firecracker penstemon is native to northern Arizona, northwestern New Mexico, southern California, east central and southern Nevada, central and southern Utah, and southwestern Colorado (Munz and Keck 1973; Hitchcock and Cronquist 2018). It occurs in all North American deserts except the Chihuahuan and in the Colorado Plateau, Wasatch Mountains, Utah Canyonlands, San Bernardino Mountains, and Arizona mountains and sky islands (Cronquist et al. 1984; Taylor 1992; Taylor 1998; Xerces Society & USDA NRCS 2012). It has become naturalized in some areas outside its natural range through its use...

Lemon scurfpea is widely distributed, occurring in the western half of the US and in Alberta and Saskatchewan, Canada (Hermann 1966; Toft and Welsh 1972; Hickman 1993; USDA NRCS 2021). It is most widespread in the western Great Plains and the Intermountain West (Barneby 1989; Grimm 2001; Egan and Reveal 2009; Welsh et al. 2016).

Scabland penstemon is a widespread species occurring as scattered populations from central Washington to western Montana and northwestern Wyoming to Nevada and California (Lindgren and Wilde 2003; St. John et al. 2009; LBJWC 2014). Populations are limited to Box Elder County in northwestern Utah (Cronquist et al. 1984; Welsh et al. 2016), the northern two-thirds of Nevada (Cronquist et al. 1984; Hitchcock and Cronquist 2018), and the Klamath, North Coast, Cascade, Sierra Nevada Ranges and Modoc Plateau regions of California (Hickman 1993).

Sharpleaf penstemon occupies a limited range in central Washington, eastern Oregon, southern and east-central Idaho, northwestern Nevada, and northern Utah (Hitchcock et al. 1959; St. John et al. 2009; Hitchcock and Cronquist 2018). It is most common in low-elevation habitats of the Columbia River Basin in Washington and Oregon and the Snake River Plains of southern Idaho (Hitchcock et al. 1959; Holmgren 1979).

Thickleaf beardtongue has a limited distribution, occurring in Utah, east-central Nevada, and northern Arizona. Reports of the species in Wyoming and Colorado are likely referring to mucronate penstemon (Penstemon mucronatus), which was considered a thickleaf beardtongue variety by some taxonomists. Variety pachyphyllus occurs in Carbon, Daggett, Duchesne, Uinta, and Wasatch Counties of Utah. Variety congestus occurs from the calcareous region of east-central Nevada to the Unita Basin in northeastern Utah, and through the Grand Canyon Plateau of northern Arizona (Freeman 2019). Holmgren...

American vetch grows throughout North America. In the United States, it grows in all but the southeastern states, and it is widely distributed west of the Mississippi River (Hickman 1993; Allen and Tilley 2014). It is widespread in the Intermountain Region but becomes less common toward the arid southwestern edge (Barneby 1989). Variety americana occupies the range described for the species (Allen and Tilley 2014; Hitchcock and Cronquist 2018). Variety minor is most common in short-grass prairies and dry woodlands east of the Rocky Mountains, but also occurs in western Montana and eastern...

Wildfire burned area, fire size, fire severity and the ecological and socio-economic impacts of fire have been increasing rapidly in California in recent decades. We summarize the record-breaking 2020 wildfire season in California statistically, evaluate the drivers of high-severity burning in the 2020 fires and consider implications for fire and resource management.

Changes in atmospheric pressure continuously ventilate soils and snowpacks. This physical process, known as pressure pumping, is a major factor in the exchange fluxes of H2O, CO2, and other trace gases between the soil and atmosphere. Thus models of pressure pumping are relevant to many areas of critical importance. This study compares the three principal models used to describe pressure pumping. Beginning with the fundamental physical principles and whether the flow field is compressible or incompressible, these models are categorized as linear parabolic (one model - compressible) or...

Background: Advances in fire modeling help quantify and map various components and characterizations of wildfire risk and furthermore help evaluate the ability of fuel treatments to mitigate risk. However, a need remains for guidance in designing landscape-scale fuel treatments with protection objectives, resource management objectives, and wildfire response in mind. It is also important to consider how human factors related to risk tolerance may affect opportunities to manage fire. We build on these themes to illustrate an approach for examining whether, and how, fuel management can...