Treesearch

Relatively little is known about the ecology and distribution of Armillaria altimontana compared with some other Armillaria species in North America. After first being recognized as an unnamed North American Biological Species X based on mating tests (Anderson and Ullrich 1979), A. altimontana was subsequently formally described by Brazee et al. (2012). While A. altimontana is occasionally found as a pathogen causing Armillaria root disease, it is often only found in a saprophytic state as rhizomorphs on diverse coniferous and broad-leaved trees and shrubs. A previous study suggests that...

Black stain root disease (BSRD), a vascular wilt disease of conifers caused by a native insect-vectored fungus, is among the top five most damaging root diseases in forests of the western United States (Hadfield et al., 1986). Previously, the fungi that cause BSRD were described as three varieties of Leptographium wageneri - L. wageneri var. wageneri, L. wageneri var. ponderosum, and L. wageneri var. pseudotsugae (Kendrick) Wingfield (Kendrick, 1962; Wingfield, 1985). These L. wageneri varieties were differentiated based on morphology, physiology (Harrington and Cobb, 1987), and ecology...

Cronartium ribicola is an invasive forest pathogen that causes white pine blister rust, which threatens the health and productivity of five-needled white pines including iconic species, such as western white pine (WWP; Pinus monticola) and whitebark pine (WBP; P. albicaulis) in western North America. The pathogen has invaded most of the natural ranges of WWP and WBP and has dramatically altered forest composition and structure across the landscape (Neuenschwander et al. 1999). In recent decades, efforts to increase resilience of forest landscapes have led to a renewed interest in restoring...

The virulent root disease pathogen Armillaria solidipes causes a white rot of conifers in the western USA, leading to tree mortality and altering forest structure. Few effective methods are available for managing Armillaria root disease on the landscape scale. While previous studies have indicated the potential for the soil microbial community, including biological control agents, to influence the disease activity of A. solidipes, these communities will likely be impacted by increasingly common wildfires in these forest ecosystems. This research aims to determine the potential influence of...

To achieve reliable detection of environmental DNA from multiple species, a method which combines the specificity of single-taxon assays with the broad taxonomic coverage of metabarcoding is needed. High-throughput quantitative PCR (HT-qPCR) has emerged as one such method that holds particular promise for ecological applications. Here, we present the development and validation of a HT-qPCR biochip (i.e., biochip) protocol for a suite of western North American fishes with high cultural, economic, and ecological significance. Coupling this biochip with systematically distributed eDNA samples...

A few iconic examples have proven the value of facilitated gene flow for counteracting inbreeding depression and staving off extinction, yet the practice is often not implemented for fear of causing outbreeding depression. Using genomic sequencing, climatic niche modeling, and demographic reconstruction, we sought to assess the risks and benefits of using translocations as a tool for recovery of endangered montane red fox (Vulpes vulpes) populations in the western United States. We demonstrated elevated inbreeding and homozygosity of deleterious alleles across all populations, but especiall...

Nitrogen stable isotope ratios (δ15N) are widely used to quantify trophic position in aquatic ecosystems. Comparing trophic position across space requires identifying baselines to account for variation in δ15N values of basal energy resources, but few standardized methods exist for identifying suitable baselines. We evaluated a standardized method for identifying optimal isotopic baselines in streams spanning the Rocky Mountains–Great Plains ecotone. We assessed candidate taxonomic groups and feeding groups following four criteria: (1) Organisms should be easy to collect and widely...

As wildfire risks increase, more homes are being damaged and communities impacted. Fortunately, decades of research and post-fire analysis have provided useful lessons for a new path forward. That path starts by redefining how we look at the wildfire threat to our homes and neighborhoods.

High rates of atmospheric N deposition can increase ecosystem N availability and stimulate N losses from soils via nitric oxide (NO; an air pollutant at high concentrations) and nitrous oxide (N2O; a strong greenhouse gas) emissions as predicted by N saturation theory. However, it remains unclear whether theories developed in mesic ecosystems apply to drylands, where plant N uptake and N availability are often decoupled. NO and N2O are produced during the oxidation of ammonia (i.e., nitrification) by ammonia-oxidizing archaea (AOA) or ammonia-oxidizing bacteria (AOB). Because AOB may be...

Context: Species-agnostic connectivity models are often used to inform management over broad spatial scales. The four main approaches to species-agnostic models parameterize resistance to movement based on naturalness, structural features, climate, or geodiversity variables. Though all four of these factors simultaneously affect species movement and flow of ecological processes, they are rarely combined.Objectives: We built upon an approach that uses all four of these factors to model current and future ecological connectivity for the Crown of the Continent Ecoregion, in Canada and the...