Treesearch

Recent studies have highlighted the need for im- proved characterizations of aerodynamic conductance and temperature ( g A and T 0 ) in thermal remote-sensing-based surface energy balance (SEB) models to reduce uncertain- ties in regional-scale evapotranspiration (ET) mapping. By integrating radiometric surface temperature ( T R ) into the Penman–Monteith (PM) equation and finding analytical so- lutions of g A and T 0 , this need was recently addressed by the Surface Temperature Initiated Closure (STIC) model. However, previous implementations of STIC were confined to the ecosystem-scale...

We studied blue-stain fungi (Ophiostomataceae: Ophiostomatales) of mountain pine beetle in declining epidemic populations affecting three pine species in Colorado. Using morphological and molecular characterizations, we determined the presence of the mutualist L. longiclavatum in the southern Rocky Mountains of Colorado, where it was as common as the warm temperature adapted O. montium within the insect’s specialized maxillary mycangium. The species was more prevalent than its “sibling species” G. clavigera which is the the common mycangial mutualist documented in USA populations. Findings...

The mite and fungal biota associated with the mountain pine beetle (MPB) (Dendroctonus ponderosae Hopk.) may not be stable throughout an irruptive event. In congeneric beetles, variations in the frequency of their associated organisms affect population trends and similar effects may occur in MPB.We studied fungi and mite trends in a declining irruptive MPB population as it attacked three different pine hosts in the Colorado Front Range. During the study, we found two new associates including one biologically relevant mite and one beneficial blue-stain fungus. Fungi hyperphoretic on mites...

The La Sal daisy, Erigeron mancus, is endemic to treeline ecotone and alpine meadow habitats of the La Sal Mountains in Utah, an insular, laccolithic mountain range on the Colorado Plateau in southeastern Utah. From 2009 to 2011 we established elevational transects through upper spruce-fir forest, treeline ecotone, and alpine meadow habitats on Laurel Ridge in the Middle Mountain group of the La Sal Mountains to measure (1) periodic changes in E. mancus population density, (2) changes in the elevation of the E. mancus population centroid, (3) changes in patch size occupied by E. mancus,...

Environmental DNA (eDNA) sampling - the detection of genetic material in the environment to infer species presence - has rapidly grown as a tool for sampling aquatic animal communities. A potentially powerful feature of environmental sampling is that all taxa within the habitat shed DNA and so may be detectable, creating opportunity for whole‐community assessments. However, animal DNA in the environment tends to be comparatively rare, making it necessary to enrich for genetic targets from focal taxa prior to sequencing. Current metabarcoding approaches for enrichment rely on bulk amplificat...

An integrated approach to understanding ecosystem service values in Wyoming and Montana, USA is presented. The assessment encompasses a major river basin, and includes a synthesis of existing data and research related to the natural system and separate data collection efforts regarding the social and economic importance of ecosystem services. A holistic look at the social-ecological system provides nuanced information about ecosystem service values and tradeoffs for the purpose of public land decision-making.The initial ecological assessment concluded that water resources were particularly...

Locations within forest fires that remain unburned or burn at low severity—known as fire refugia - are important components of contemporary burn mosaics, but their composition and structure at regional scales are poorly understood. Focusing on recent, large wildfires across the US Pacific Northwest (Oregon and Washington), our research objectives are to (1) classify fire refugia and burn severity based on relativized spectral change in Landsat time series; (2) quantify the pre-fire composition and structure of mapped fire refugia; (3) in forested areas, assess the relative abundance of...

Southern California chaparral environments, with steep mountain slopes, semi-arid climate, and non-cohesive soils, are very erosive landscapes. Wildfire is the dominant ecological disturbance event in chaparral and it greatly accelerates flooding and erosion, which are directly and/or indirectly related to the loss of the protective vegetation. Since the 1920s, dams and debris basins have been constructed by public works agencies to protect the growing population and infrastructure of southern California by intercepting and impounding flows of water and debris. Dams also capture stream...

Dormant seeds in the soil are an important contribution to the regenerative potential of an area. Understanding factors that affect seed bank dynamics in arid regions provides insight into how communities respond to disturbance and environmental change. We characterized seed banks in a Great Basin sagebrush steppe system, using field surveys and seed bank studies to compare 17 sites that differed in above-ground vegetation, fire history, and grazing use. We asked whether shrub cover, ground cover, climate, or disturbance history were predictive of seed densities, diversity, the presence of...

1. Climate change vulnerability assessments are commonly used to identify species or populations at risk from global climate change, but few translate impact assessments to climate change adaptation actions. Furthermore, most climate change adaptation efforts emphasize where to implement management actions, whereas timing remains largely overlooked. The rate of modern climate change introduces urgency in evaluating whether delaying conservation actions compromises theirefficacy for reaching important conservation targets.2. We evaluated the importance of multiple climate change adaptation...