Treesearch

This article presents the design optimization of an un-notched Iosipescu test specimen whose goal is the characterization of the material elastic stiffnesses of a Loblolly (Pinus taeda) or Lodgepole pine (Pinus contorta) sample in one single test. A series of finite element (FE) and grid simulations were conducted to determine displacement and strain fields for various ring angles, ring spaces, and proportions of latewood per ring. These displacement and strain fields were utilized to determine the constitutive parameters for the woody material using VFM. Using an error function based on a...

Manchurian walnut (Juglans mandshurica Maxim.) is a vulnerable, temperate deciduous tree valued for its wood and nut, but transcriptomic and genomic data for the species are very limited. Next generation sequencing (NGS) has made it possible to develop molecular markers for this species rapidly and efficiently. Our goal is to use transcriptome information from RNA-Seq to understand development in J. mandshurica and develop polymorphic simple sequence repeats (SSRs, microsatellites) to understand the species' population genetics. In this study, more than 47.7 million clean reads were...

We describe the historical and current distribution of tree voles (Arborimus longicaudus; A. pomo) and compare the minimum density of trees with tree vole nests in different forest age-classes based on museum records, field notes of previous collectors, tree vole nest surveys conducted by federal agencies, and our field studies in Oregon and California. We conclude that tree voles are still fairly common in old forests within much of their historical range, but have become uncommon or rare in some areas as a result of fire and logging. Our analysis of food stored at red tree vole (A....

High-intensity wildfires are one of the leading causes of severe soil erosion in western U.S. watersheds. This erosion can lead to disruptive deposits of sediment in reservoirs and water supply systems. Fuel treatments such as controlled burns and forest thinning can reduce wildfire intensity and help preserve topsoil. But while these treatments are generally much less expensive than firefighting, property loss, and sediment removal, there are limited funds available for controlled burns and forest thinning. For this reason, land managers can benefit from estimating the erosion potential...

Maps of the number, size, and species of trees in forests across the western United States are desirable for many applications such as estimating terrestrial carbon resources, predicting tree mortality following wildfires, and for forest inventory. However, detailed mapping of trees for large areas is not feasible with current technologies, but statistical methods for matching the forest plot data with biophysical characteristics of the landscape offer a practical means to populate landscapes with a limited set of forest plot inventory data. We used a modified random forests approach with...

Increasing the frequency of resistance to the non-native fungus Cronartium ribicola (causative agent of white pine blister rust, WPBR) in limber pine populations is a primary management objective to sustain high-elevation forest communities. However, it is not known to what extent genetic disease resistance is costly to plant growth or carbon economy. In this study, we measured growth and leaf-level physiology in (1) seedling families from seed trees that have previously been inferred to carry or not carry Cr4, the dominant R gene allele conferring complete, gene-for-gene resistance to...

Following wildfire, forest managers are challenged with meeting both socioeconomic demands (e.g., salvage logging) and mandates requiring habitat conservation for disturbance-associated wildlife (e.g., woodpeckers). Habitat suitability models for nesting woodpeckers can be informative, but tests of model transferability are needed to understand how broadly models developed at one location can be applied to inform post-fire forest management at other locations. We developed habitat suitability models and tested their transferability for 2 disturbance-associated woodpecker species, Black-back...

Recovery of ecological communities following disturbance is a central theme of ecology and may be mediated by priority effects, in which the species or individuals that first arrive at a site alter the biotic or abiotic environment in ways that affect the establishment and growth of species or individuals that arrive at a later time. Priority effects are common, influencing species distributions and how ecosystems function (Connell and Slatyer 1977; Werner et al. 2016). Ubiquitous in arid and semi-arid regions worldwide, biological soil crusts (Figure 1) contribute to a large number of...

The use of remote sensing in ecosystem management has transformed how land managers, practitioners, and policymakers evaluate ecosystem loss, gain, and change at multiple spatial and temporal scales. Less developed is the use of these spatial tools for planning, implementing, and evaluating ecosystem restoration projects and especially so in multifunctional landscapes. We use a case study approach in a multistakeholder tropical dryland restoration project to highlight the potential of remotely sensed products to quantitatively and economically guide often conflicting restoration priorities...

We measured pH, cations, nutrients, and total organic carbon (TOC) over 3 years to examine weekly to monthly variability in porewater chemistry depth profiles (0–3.0 m) in an ombrotrophic bog in Minnesota, USA. We also compared temporal variation at one location to spatial variation in depth profiles at 16 locations across the bog. Most solutes exhibited large gradients with depth. pH increased by two units and calcium concentrations increased over 20 fold with depth, and may reflect peatland development from minerotrophic to ombrotrophic conditions. Ammonium concentrations increased...