Treesearch

A ductile lateral force resisting system (LFRS) for mass timber frames is proposed utilizing Mass Timber Buckling- Restrained Braces (MT-BRBs), with mass timber as the primary casing material. Compressive tests were conducted on Mass Plywood Panels (MPP) with and without horizontal self-tapping screws inserted perpendicular to laminations to assess differences in stiffness, peak load, and maximum displacement. Screws perpendicular to lamination enhanced performance, increasing the peak load by nearly four times and peak displacement by more than three times. Withdrawal tests were also...

An historic 1934 building on the campus of the U.S. Department of Agriculture, Forest Service, Forest Products Laboratory was deconstructed in 2010. The glued-laminated (glulam) beams from the building were preserved, creating a unique opportunity to test the casein adhesive bonding in the beams that had been in service for more than 75 years. The goal of the testing reported in this study was to extend the understanding of protein adhesives in wood products. In this study, we tested wet and dry strength of the bonds using compressive block shear tests. We also tested for delamination and...

This indicator provides information on the number and distribution of forest-associated species and infraspecies (e.g., subspecies, varieties) at risk of losing genetic variation across their geographic range. Comparing current geographic distributions with historical distributions is the basis for identifying the species and infraspecies whose range has contracted significantly (based on per-State presence and absence). Human activities, like land use conversions, climate change, the alteration of native habitats, the introduction of exotic species, and direct exploitation, are acceleratin...

This indicator reports the area and percentage of U.S. forests that are used for subsistence activities. In the United States, subsistence rights are codified through Federal laws, State constitutions, and Federal treaties with Tribal Nations and Canada. These bodies of legislation protect subsistence rights in Alaska, the Pacific Northwest (States of Washington and Oregon), Hawaii, and the Great Lakes region (States of Minnesota, Wisconsin, and Michigan), which are the focus of this analysis. More specifically, Alaska and Hawaii are the only States to codify in their constitutions the...

This summary report provides an overview of the current conditions, changing trends, issues, and threats to statewide forest resources based on findings from the 2018 inventory of New Jersey’s forests. New Jersey’s forests report an estimated 1.9 million acres of forest land and 89 tree species. Forest land is dominated by maples in the north and pitch pine in the south. The volume of growing stock on timberland currently totals 3.3 billion cubic feet. Average annual mortality of sound volume of live trees on forest land has remained relatively stable since 2013 and currently totals 54.7...

This chapter provides an overview and comparisons of the precipitation intensity–duration–frequency (PIDF) and flood (FFRQ) and low-flow (LFRQ) frequencies for return intervals of 25 years or more at ten relatively undisturbed reference watersheds in the US Forest Service Experimental Forest (EF) network. We demonstrate potential effects of recent climate change on the PIDFs, FFRQ and LFRQ developed with high-resolution temporal data at these ten sites with widely contrasting hydrogeological, topographical, climatic and ecological characteristics. Similarly, we evaluate the on-site-based...

Biological nitrogen fixation (BNF) is the largest natural source of new nitrogen (N) that supports terrestrial productivity1,2, yet estimates of global terrestrial BNF remain highly uncertain3,4. Here we show that this uncertainty is partly because of sampling bias, as field BNF measurements in natural terrestrial ecosystems occur where N fixers are 17 times more prevalent than their mean abundances worldwide. To correct this bias, we develop new estimates of global terrestrial BNF by upscaling field BNF measurements using spatially explicit abundances of all major biogeochemical N-fixing...

The US Forest Services (USFS) under the Forest Inventory and Analysis (FIA) program estimates resource characteristics and statistics regarding forest attributes and ecosystem processes at various strategic scales with different levels of precision and refinement. A vital forest resource attribute is tree size-density, which informs regional and national policies and project-scale management. To enhance the development and distribution of key forest tree-size density metrics, a 30 × 30 m wall to wall spatial dataset for stand density index (SDI), maximum SDI (SDIMAX) and relative density...

Aim: To map the probability of landscape use of invading barred owls (Strix varia) across the range of the threatened northern spotted owl (S. Occidentallis Caurina) in the Pacific Northwest, USA, identifying environmental drivers of barred owl landscape use to inform targeted management interventions.Location: Forests of the Pacific Northwest, USA.Taxon: Barred Owl (Strix varia).Methods: We deployed 4081 autonomous recording units (ARUs) within 1027 randomly selected long-term monitoring sites consisting of 5-km2 hexagons in 2023. We processed audio recordings using convolutional neural...

In the moist, coniferous forests of Oregon and Washington, a dense network of headwater streams supports high levels of amphibian species endemism and diversity, including the torrent salamanders (Rhyacotriton spp.). The Columbia and Cascade torrent salamanders (R. kezeri and R. cascadae, respectively) are species of greatest conservation need, but current information is insufficient for an adequate status assessment. We aimed to determine the current distributional extent, occurrence, and abundance of both species across their respective ranges, and to characterize watershed-scale habitat...