Treesearch

Pools provided by beaver (Castor canadensis) contribute to critical habitat requirements of salmonids in fluvial systems of the Pacific Northwest, therefore more land managers are interested in managing watersheds that include beavers or engaging in beaver-related restoration projects. We evaluated the utility of applying an existing beaver habitat suitability model to better understand beaver dam site characteristics in coastal Oregon, identify optimum dam site locations, and guide future beaver-related restoration efforts. We used a combination of t-tests, Wilcoxon rank sum tests, and a...

Managed conifer forests in temperate regions are critical for supplying wood products, but little is known about their potential for pollinator conservation. We hosted a workshop for Pacific Northwest managers and biologists to identify perceived information gaps regarding pollinators in managed conifer forests; we also undertook a litera-ture review on this topic to assess gaps in the primary literature. The most important gaps identified by workshop participants were a need for baseline data on pollinators in managed conifer forests, and for determining how forest management influences...

Understanding why wood bonds fail is an excellent route toward understanding how to make them better. Certifying a bonded product usually requires achieving a specifc load, percent wood failure, and an ability to withstand some form of moisture exposure without excessive delamination. While these tests protect the public from catastrophic failures, they are not very helpful in understanding why bonds fail. Understanding failure often requires going beyond what meets the naked eye, conducting additional tests, probing the wood surface, the fracture surface, adhesive properties, and the...

PREMISE OF THE STUDY: Various nondestructive testing technologies have been used for detecting and visualizing internal defects in urban trees. The results obtained by using diferent nondestructive testing tools can be interpreted in diferent ways, which may result in inaccurate assessment of the true condition of the inspected trees. The main objective of this study was to evaluate the reliability of acoustic tomography and ground-penetrating radar (GPR) technology for detecting internal decay in a number of diferent tree species. METHODS: One hundred and forty-seven individual trees of...

Continuous exterior insulation is becoming more common in North American above -grade walls in both retrofit applications and new construction, as a means to improve the thermal performance of wall assemblies. Although moisture performance of wood-frame wall assemblies has been studied extensively, the drying capability of wall assemblies with exterior insulation and an interior vapor retarder in cold climates is not well characterized. This study monitored the hygrothermal performance of wall assemblies with and without exterior insulation under high and low interior humidity conditions...

Surface fuels are the critical link between structure and function in frequently burned pine ecosystems, which are found globally (Williamson and Black,1981; Rebertus et al.,1989; Glitzenstein et al.,1995) [1–3]. We bring fuels to the forefront of fire ecology through the concept of the Ecology of Fuels (Hiers et al. 2009) [4]. This concept describes a cyclic process between fuels, fire behavior, and fire effects, which ultimately affect future fuel distribution (Mitchell et al. 2009) [5]. Low-intensity surface fires are driven by the variability in fine-scale (sub-m level) fuels (Loudermil...

Near-infrared spectroscopy (NIRS) is a potential, feld-portable wood identifcation tool. NIRS has been studied as tool to identify some woods but has not been tested for Dalbergia. This study explored the efcacy of hand-held NIRS technology to discriminate, using multivariate analysis, the spectra of some high-value Dalbergia wood species: D. decipularis, D. sissoo, D. stevensonii, D. latifolia, D. retusa, all of which are listed in CITES Appendix II, and D. nigra, which is listed in CITES Appendix I. Identifcation models developed using partial least squares discriminant analysis (PLS-DA)...

Starting from the cobweb theorem, a model of demand, supply, multilateral trade, and prices was formulated for the softwood lumber and newsprint markets in Canada, the United States (US), and the rest of the world. Parameters were estimated with panel data from multiple years and countries. The model was used to project the effects of US tariffs on softwood lumber and newsprint imports from Canada. To assess the uncertainty of the projections, multiple replications were performed by repeated sampling from the parameters’ statistical distributions. The results suggested that the initial...

Prescribed fire is an active management tool used to address wildfire hazard and ecological concerns associated with fire exclusion and suppression over the past century. Despite widespread application in the United States, there is considerable inconsistency and lack of information regarding the extent to which specific outcomes are achieved and under what prescribed fire regimes, particularly in regard to ecological goals related to plant community structure. We quantify differences and patterns in plant functional group abundance, species richness and diversity, and other key forest...