Treesearch

Successful establishment of Pinus ponderosa seedlings in the southwestern United States is often limited by stressful and harsh site conditions related to drought severity and severe disturbances such as wildfire and mining operations. Seedling quality has an important influence on outplanting performance, but nursery practices that typically employ optimal growing environments may also be limiting seedling morphological and physiological performance on stressful outplanting sites. To address this, a study was established to test alterations in seedling characteristics subjected to...

Context In western US forests, the increasing frequency of large high-severity fires presents challenges for society. Quantifying how fuel conditions influence high-severity area is important for managing risks of large high-severity fires and understanding how they are changing with climate change. Fuel availability and heterogeneity influence high-severity fire probability, but heterogeneity is insensitive to some aspects of forest connectivity that are important to potential high-severity fire transmission and thus high-severity area. Objectives To quantify the effects of fuel availabili...

Nutria (Myocastor coypus) is a semiaquatic rodent species that is invasive across multiple regions within the United States. Here, we evaluated a qPCR assay previously described for use in Japan for application across invasive populations in the United States. We also compared two environmental DNA sampling methodologies for this assay: field filtration of large volumes of water passed through filters versus direct sampling of small volumes of water. We validated assay specificity, generality, and sensitivity, compared assay performance between two independent laboratories, and successfully...

Uncertainty and change are the hallmarks of contemporary life. Global climate change, ecological regime shifts, and urban transformations catalyze new levels of socio-spatial precarity. Exacerbated by political and economic conditions, accelerating change and uncertainty have disrupted people-place relationships and created anxiety around real and perceived place loss and threat. In this article, we outline the potential of senses of place - both pluralized and politicized - to generate new possibilities for thinking, acting, and designing in response to disruption. Three different case...

As climate change increasingly challenges the capacity of traditional decision-making modalities to contend with mounting complexities and uncertainties, natural resource management agencies have increasingly turned to nontraditional modes of planning and decision-making such as ‘futuring. Futuring methods, such as scenarios, have been increasingly utilized around the world. In the US, however, there has been a limited uptake of these tools across public land management and a preference for more traditional forecasting tools. This article explores some possibilities about why this is the...

Water vapor fluxes are a major component of the surface energy balance, hydrological cycle, and ecosystem processes. As newer sensors are developed for eddy covariance measurements, the role of different technologies and calibration uncertainties on H2O fluxes and surface energy balance closure should be assessed. Here, a field intercomparison is described testing historically significant fast-response hygrometers: Lyman-α, KH2O, LI-7000, LI-7500, LI-7200, EC155, and EC150. This study occurred in southeastern Wyoming in September 2015. Three methods of calibration are investigated:...

We present refinements for equations describing the temperature-wind covariance (v′ T′a ) reported by Massman and Lee (2002); namely, Eqs. (B.24), (B.25), and (B.28) in its Appendix B. The purpose of these equations is to express the wind covariance of air temperature (Ta) in terms of sonic temperature (Ts), as a sonic anemometer directly measures the latter rather than the former. Results of the derivations are summarized in Tables 1 and 2, and these refinements have been quantified using data from the Glacier Lakes Ecosystem Experiments Site (GLEES).

Heterobasidion annosum (Fr.) Bref. sensu lato (s.l.) is a dangerous forest pathogen causing root and butt rot disease in most conifers of the northern hemisphere. This pathogen is most widespread in the forests of Europe and North America. The economic impact on forestry related to tree mortality, reduction in timber yield, and wood rot is calculated in millions of dollars and euros. The genus Heterobasidion (Basidiomycota; Russulales) has been relatively recently separated into three genetically distinct groups (H. annosum, H. insulare and H. araucariae) comprising a total of 12 species...

In the western United States, pinyon-juniper woodlands have expanded by as much as sixfold among sagebrush landscapes since the late 19th century, with demonstrated negative impacts to the behav- ior, demography, and population dynamics of species that rely on intact sagebrush rangelands. Notably, greater sage-grouse (Centrocercus urophasianus) are unable to tolerate even low conifer cover, which can result in population declines and local extirpation, whereas removing expanding conifer cover has been demonstrated to increase sage grouse population growth rates and sagebrush obligate...

The relationship between bee community composition and habitat characteristics at local scales may inform management decisions and conservation strategies for species of conservation concern. Ecotones are transition zones between two adjacent habitats that can potentially support abundant and diverse bee communities by providing complementary habitat characteristics within the foraging distance of most bee species. In a forest-shrubland ecotone, we evaluated the relationships between multiple habitat characteristics and the taxonomic and functional diversity of bee communities. Early in...