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Science Spotlights

Example of traumatic resin ducts formed during 1997, 1998, and tangentially during 1999, in response to a large spruce beetle outbreak.
The formation of traumatic resin ducts in Engelmann spruce represents an important induced defense in response to environmental perturbations. The occurrence and strength of resin ducts, in particular traumatic resin ducts, in annually resolved tree rings could be used to reconstruct a tree’s structural damage association with natural disturbances.
Winter snowpack on the Uinta-Wasatch-Cache National Forest in Utah. Photo by USDA Forest Service.
Understanding snowpack variability is an important goal of water management, in particular, in the arid west where snow represents a major water storage feature. Snowpack observations in the Intermountain West are sparse and short, making them difficult for use in depicting past variability and extremes.
Bacterial exudates covering second instar kermes scales feeding at the junction of new and one-year-old growth.
Disease complexes, the result of insects and plant pathogens interacting to compromise their plant hosts, are becoming increasingly common worldwide. These disease complexes represent an imminent threat to plant biodiversity, because the combined activity of insects and pathogens can cause more damage with a potential for increased spread than diseases caused by a single organism. To better understand and better manage emerging disease complexes...
Figure 1. A post-fire ponderosa pine seedling in a high-severity burn patch of the 2000 Pumpkin Fire, Arizona.
Over the past three decades, wildfires in southwestern United States ponderosa pine forests have increased in size and severity, leaving large patches of tree mortality. Ponderosa pine evolved under fire regimes dominated by low- to moderate-severity wildfires, and they are poorly adapted to regenerating in large patches of high-severity fire. There is concern about these high-severity burn patches because the lack of seed-producing trees can...
Verde River above Horseshoe Dam in Arizona. Photo by D.M. Smith
A frequently discussed function of aridland riparian ecosystems is the contribution of woody riparian plants to breeding bird habitat. The structurally diverse, species-rich vegetation along many southwestern streams supports high densities of territories and nest sites for a variety of birds including several species of high conservation priority.A frequently discussed function of aridland riparian ecosystems is the contribution of woody...
Crossdating and digitizing an increment core using a microscope and sliding stage. Photo by Lawrence Lam.
The spruce beetle is the most significant mortality agent of spruce in western North America. Management options are limited but an effective semiochemical repellent could be economically and environmentally advantageous, compared to insecticide applications, for protection single trees and small stands.
Rocky Mountain bristlecone pines are long-lived, exhibit delayed maturation, have low genetic diversity, and inhabit cold, high-elevation environments. They are threatened by the non-native disease white pine blister rust, warming temperatures, changing precipitation patterns, and altered disturbance regimes. Sustaining bristlecone pine populations is essential to (1) maintain healthy mountain-top ecosystems and (2) ensure that the young...
Restoring abandoned mine sites with no environmental hazard or chemical contamination can be expensive because of the inhospitable (hot, dry) environment.  However, the large number of abandoned mine sites located across the west make it imperative to begin restoration activities to help shade streams, reduce erosion, provide habitat, and generally improve soil properties. 
Research Ecologist Justin DeRose measuring ring widths to crossdate and digitize tree-ring features. Photo by Lawrence Lam.
Forest fungi in the Armillaria genus comprise destructive root-disease pathogens and beneficial decomposers. It is critical to understand worldwide distributions of Armillaria species to assess invasive threats posed by Armillaria species. This collaborative work with scientists from 15 countries focused on DNA-based analyses of Armillaria species from the Northern Hemisphere.
A handful of biochar-amendment nursery substrate being tested for its potential to grow high-quality native plants for restoration.
Forest and range soils in the western United States are in need of restoration for a variety of reasons (e.g., overgrazing, fire, health). Disposing of the woody slash after restoration cuttings has been problematic for many years, and open burning has often been the easiest method for reducing wildfire risk. However, this damages the soil, limits successful regeneration on the burn sites, and encourages invasive weeds. Creating biochar is one...

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