Treesearch

Projections for the future health and abundance of whitebark pine (Pinus albicaulis Engelm.) populations in western North America are dire. Not only has the species been declining due to the combined effects of fire exclusion policies, mountain pine beetle (Dendroctonus ponderosae Hopkins 1902) outbreaks, and white pine blister rust (Cronartium ribicola J.C. Fisch), many are predicting that climate change will amplify these effects and whitebark pine habitat may be lost in many areas. One method to evaluate the validity of future predictions is to examine current migration patterns of...

By killing trees, wildland fires influence ecosystems in many ways, including limiting ecosystem productivity, altering resource availability, and changing the structure and composition of vegetation (Bond and Keeley 2005). These changes can have both positive and negative impacts on carbon storage, biodiversity conservation, hydrologic processes, and economic and social services (Bowman et al. 2009). In fire-adapted and fire-dependent ecosystems, fire controls tree density and species dominance, creating habitat that supports diverse plant and animal species that cannot persist in the...

Wildland fire is perhaps the most influential disturbance over vast areas in the modern world (Bowman et al. 2009). Fire is both a natural and anthropogenic disturbance influencing the distribution, structure, and functioning of terrestrial ecosystems around the world (Bond et al. 2005; Scott et al. 2014). Many plants and animals depend on fire for their continued existence, and those that don’t, such as rainforest and tundra plants, are extremely intolerant of burning (DeBano et al. 1998). A sound understanding of the interactions of biotic and abiotic ecosystem elements on fire dynamics...

Many ecosystems and landscapes are experiencing rapid and potentially persistent changes as the result of complex and potentially novel interactions of anthropogenic climate changes; shifting fire regimes; exotic plant, insect, and pathogen invasions; and industrial, agricultural, and urban development (Moritz and Agudo 2013; Joyce et al. 2014; Bone et al. 2016; Kolb et al. 2016; Smith et al. 2016; Stephens et al. 2016; Schoennagel et al. 2017). In fire-prone, fire-adapted landscapes - those where fire is an integral part of ecosystem maintenance and functioning - anthropogenic actions can...

Wildland fuelbeds are diverse collections of biomass categorized specifically to compute fire behavior and effects. When wildland fuelbeds are created by solely “natural” processes, fire scientists, and managers often refer to these as natural fuels (Fig. 1). NWCG (2018) defines natural fuels as fuels resulting from natural processes and not directly generated or altered by land management practices. However, when humans have a direct impact of fuelbed conditions, such as after timber harvest activities, forest thinnings, and fuel treatments, these are called activity fuels (Fig. 2) -...

Whitebark pine is difficult to distinguish from limber pine when seed cones are not present. This is often the case because of young stand age, growth at environmental extremes, or harvesting by vertebrate species. Developing an economical genetic identification tool that distinguishes non-cone-bearing limber from whitebark pine, therefore, could aid many kinds of research on these species. Phylogenetic studies involving limber and whitebark pine suggest that chloroplast DNA sequences differ between these species. We therefore wanted to identify chloroplast loci that could differentiate...

Agroforestry can provide ecosystem services and benefits such as soil erosion control, microclimate modification for yield enhancement, economic diversification, livestock production and well-being, and water quality protection. Through increased structural and functional diversity in agricultural landscapes, agroforestry practices can also affect ecosystem services provided by insect pollinators. A literature review was conducted to synthesize information on how temperate agroforestry systems influence insect pollinators and their pollination services with particular focus on the role of...

This study is part of a research project examining fire risk in cross aminated timber (CLT) bui dings. “De amination”, a major concern for CLT fire safety, can occur when the adhesive bondline fails in the pane before it chars which can lead to additional fuel for fire regrowth. Understanding the mechanical strength and stiffness of the adhesive bond under elevated temperature is one of the fundamenta steps towards better understanding delamination. In this study, the materia properties of wood and wood adhesive bonds are studied at various temperatures levels below the char temperature of...

As glaciers thaw in response to warming, they release dissolved organic matter (DOM) to alpine lakes and streams. The United States contains an abundance of both alpine glaciers and rock glaciers. Differences in DOM composition and bioavailability between glacier types, like rock and ice glaciers, remain undefined. To assess differences in glacier and rock glacier DOM we evaluated bioavailability and molecular composition of DOM from four alpine catchments each with a glacier and a rock glacier at their headwaters. We assessed bioavailability of DOM by incubating each DOM source with a...

Biogeochemical processing of dissolved organic matter (DOM) in headwater rivers regulates aquatic food web dynamics, water quality, and carbon storage. Although headwater rivers are critical sources of energy to downstream ecosystems, underlying mechanisms structuring DOM composition and reactivity are not well quantified. By pairing mass spectrometry and fluorescence spectroscopy, here we show that hydrology and river geomorphology interactively shape molecular patterns in DOM composition. River segments with a single channel flowing across the valley bottom export DOM with a similar...