Like most ecological communities, aspen (Populus tremuloides) forests are influenced by a synergy of bottom-up (resources-driven) and top-down (predator-driven) processes. Since the 1920s, ecologists have observed the decline of many aspen communities throughout the Intermountain West. The extent and possible drivers of this decline are topics of much recent scientific...
Herein, we posit a link between the ecological extinction of wolves in the American West
and the expansion in distribution, increased abundance, and inflated ecological influence
of coyotes. We investigate the hypothesis that the release of this mesopredator from wolf
suppression across much of the American West is affecting, via...
To guide the future development of CO₂-atmospheric inversion modeling systems, we analyzed the errors arising from prior information about terrestrial ecosystem fluxes. We compared the surface fluxes calculated by a process-based terrestrial ecosystem model with daily averages of CO₂ flux measurements at 156 sites across the world in the FLUXNET...
This article examines visitor perceptions of voluntary environmental programs (VEPs) at the Mt. Bachelor ski area in Oregon, USA by examining what they know about VEPs, how these programs influence motivations to visit this area currently and in the future, and how place attachment, value orientations, and specialization influence these...
The emergence of a new generation of remote sensing and geopositioning technologies, as well as increased capabilities in image processing, computing, and inferential techniques, have enabled the development and implementation of increasingly efficient and cost-effective multilevel sampling designs for forest inventory. In this paper, we (i) describe the conceptual basis...
Lidar is currently the most accurate method for remote estimation of forest structure, but it has limited spatial and temporal coverage. Conversely, Landsat data are more widely available, but exhibit a weaker relationship with structure under medium to high leaf area conditions. One potentially valuable means of enhancing the relationship...
Airborne laser scanning, collected in a sampling mode, has the potential to be a valuable tool for estimating the biomass resources available to support bioenergy production in rural communities of interior Alaska. In this study, we present a methodology for estimating forest biomass over a 201,226-ha area (of which 163,913...
Retreating glaciers and the periglacial areas they vacate for organismal colonization produce a harsh environment of extreme radiation, nutrient limitations, and temperature oscillations. They provide a model system for studying mechanisms that drive establishment and early assembly of communities. Here, we synthesize more than twenty years of research at the...
When large carnivores are extirpated from ecosystems that evolved with apex predators, these systems can change at the herbivore and plant trophic levels. Such changes across trophic levels are called cascading effects and they are very important to conservation. Studies on the effects of reintroduced wolves in Yellowstone National Park...
To examine whether stream nitrogen concentrations in forested reference catchments have
changed over time and if patterns were consistent across the USA, we synthesized up to 44 yr
of data collected from 22 catchments at seven USDA Forest Service Experimental Forests.
Trends in stream nitrogen presented high spatial variability both...
Both the structure and composition of naturally generated early-seral forests in the Pacific Northwest (PNW) can be profoundly different than that of more developed forest seres, especially in the period after a major disturbance but before conifers re-develop a closed canopy. While it is reasonable to suggest that the unique...
We sought to improve net ecosystem exchange (NEE) estimates for a tall, dense, mature Douglas-Fir forest in the Oregon Coast range characterized by weak flows, systematic wind directional shear, and limited turbulent mixing throughout the diurnal period. We used eddy covariance (EC) observations at two levels and concurrent biological measurements...
We analyzed 45 years of data collected from three ponderosa pine (Pinus ponderosa Douglas ex P. Lawson & C. Lawson) levels-of-growing-stock installations in Oregon (OR) and northern California (CA), USA, to determine the effect of stand density regimes on stand productivity and mortality. We found that periodic annual increment (PAI)...
Large-scale commercial thinning of young forests in the Pacific Northwest is currently promoted on public lands to accelerate the development of late-seral forest structure for the benefit of wildlife species such as northern spotted owls (Strix occidentalis caurina) and their prey, including the northern flying squirrel (Glaucomys sabrinus). Attempts to...
Background: Management strategies have been proposed to minimise the effects of climate
change on forest resilience.
Aims: We investigated the Pacific Northwest US region forest carbon balance under current
practices, and changes that may result from management practices proposed for the region’s
34 million ha of forests to mitigate climate...
Many protected areas or parks in developing countries have buffer zones at their
boundaries to achieve the dual goals of protecting park resources and providing
resource benefits to neighbouring people. Despite the prevalence of these zoning
policies, few behavioural models of people’s buffer zone use inform the sizing and
management...
Hydrological processes in the humid tropics differ from other regions in having greater energy inputs and faster rates of change, including human-induced change. Human influences on population growth, land use and climate change will profoundly influence tropical hydrology, yet understanding of key hydrological interactions is limited. We propose that efforts...
Fracture toughness of wood and wood composites has traditionally been characterized by a stress intensity factor, an initiation strain energy release rate (G[subscript init]) or a total energy to fracture (G[subscript f]). These parameters provide incomplete fracture characterization for these materials because the toughness changes as the crack propagates. Thus...
The metabolic theory of ecology (MTE) predicts the effects of body size and temperature on metabolism through considerations of vascular distribution networks and biochemical kinetics. MTE has also been extended to characterise processes from cellular to global levels. MTE has generated both enthusiasm and controversy across a broad range of...
Swiss needle cast, a foliar disease caused by the Ascomycete Phaeocryptopus gaeumannii (T. Rohde) Petr., continues to afflict Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) in north coastal Oregon. Permanent plots were installed in 1998 to assess growth impacts and monitor disease severity. Gross periodic annual increment was measured for three 2-year...
The hyporheic zone is of great interest for stream ecologists because of its role in stream biogeochemical processing. Our study addresses the effects of leaf-litter inputs and varying discharge on surface–hyporheic water exchange and their possible consequences for the hyporheic zone biogeochemistry. Our study was conducted during autumn in Riera...
Foresters face new and evolving challenges as society reconsiders the balance of its interests between wood production and the provision of ecosystem services in the management of forests. Whatever paths this process may take, sound and broad-based decisions will continue to require accurate and relevant measurements of current forest conditions...
Gomphus sensu lato (Gomphales) was described to include species of cantharelloid-gomphoid fungi that had 'merulioid' (wrinkled) hymenia and verrucose spores. Gomphus sensu stricto is currently characterized by unipileate to merismatoid (composed of several pilei) basidiomata, depressed funnel- to fan-shaped pilei, presence of clamp connections, and verrucose spores; it has three...
Global sustainability goals have led to the development of the green building movement. The Green
Building Program, stemming from the movement, has had unprecedented success as it provides a quantifi able
metric to people’s efforts towards sustainable development. Sustainable development and green buildings are often
used interchangeably. Although, sustainable development...
The U.S, Forest Service regularly removes tons of dead biomass from federal forestlands to control and prevent devastating wildfires. Every year thinning young trees and brush, as well as removing dead biomass from the forest floor generates large quantities of low-grade woody material for which there is little use. Currently...
Stream temperatures were monitored on seven low-elevation western Oregon streams immediately after clearcut harvesting and 14-17 years later in two studies that examined buffer designs. One study on four streams used no-tree buffers with all trees next to the stream harvested within the clearcut units. The second study on three...
Understanding fine-grain patterns of forest disturbance and regrowth at the landscape scale is critical for effective management, particularly in forests in western Washington, Oregon, and California, U.S., where the policy known as the Northwest Forest Plan (NWFP) was imposed in 1994 over > 8 million ha of forest in an...
Small-scale urban natural parks have the potential to contribute to the health and well-being of urban communities. Although recreation researchers have seldom focused on such areas, recreation research theory can be successfully applied to urban natural parks, especially if augmented by the application of social capital and social networks theory....
The ultimate properties of a fibrous composite system depend highly on the transverse mechanical properties of the fibers. Here, we report the size dependency of transverse elastic modulus in cellulose nanocrystals (CNCs). In addition, the mechanical properties of CNCs prepared from wood and cotton resources were investigated. Nanoindentation in an...
In the Pacific Northwest, previous studies have found a negative effect of timber management on the abundance of stream amphibians, but results have been variable and region specific. These studies have generally used survey methods that did not account for differences in capture probability and focused on stands that were...
Four species of the sequestrate fungal genus Elaphomyces are reported from New Zealand: Elaphomyces bollardii sp. nov. associated with Leptospermum spp. and Kunzea ericoides, E. luteicrustus sp. nov. associated with Nothofagus menziesii, E. putridus sp. nov. associated with Nothofagus spp., and an unnamed species associated with Nothofagus spp.
Global vegetation models require the photosynthetic parameters, maximum carboxylation capacity (V[subscript cm]), and quantum yield (alpha) to parameterize their plant functional types (PFTs). The purpose of this work is to determine how much the scaling of the parameters from leaf to ecosystem level through a seasonally varying leaf area index...
The Mongolian Steppe is one of the largest remaining grassland ecosystems. Recent studies have reported widespread
decline of vegetation across the steppe and about 70% of this ecosystem is now considered degraded. Among
the scientific community there has been an active debate about whether the observed degradation is related to...
Conifer crowns can be highly variable both within and between trees, particularly with respect to foliage biomass and leaf area. A variety of sampling schemes have been used to estimate biomass and leaf area at the individual tree and stand scales. Rarely has the effectiveness of these sampling schemes been...
For wood beams, it is often assumed that the neutral axis (NA) is located at the centroid of the beam. This would be the case for isotropic and homogeneous materials but these prerequisites are not valid for wood. The varying grain patterns and knots located throughout wood make wood anisotropic...
The resistance of three naturally durable heartwood species and a stranded giant bamboo product to fungal and termite (Coptotermes formosanus) attack was evaluated at a test site located near Hilo, Hawaii. Merbau (Intsia bijuga or I. palembanica) and ipe (Tabebuia spp.) were both exceptionally resistant to fungal and termite attack,...
Quaking aspen (Populus tremuloides) sustainability is a topic of intense interest in forest ecology.
Reports range from declines to persisting or increasing coverage in some areas. Moreover, there is little
agreement on ultimate factors driving changes. Low aspen recruitment has been attributed to climate
patterns, past management, herbivore increases, competitive...
Tropical rainforests are significant contributors to the global cycles of energy, water and carbon. As a result, monitoring of the vegetation status over regions such as Amazônia has been a long standing interest of Earth scientists trying to determine the effect of climate change and anthropogenic disturbance on the tropical...
Surface energy balance is a major determinant of land surface temperature and the Earth's climate. To date, there is no approach that can produce effective, physically consistent, global and multi-decadal energy–water flux data over land. Net radiation (R[subscript n]) can be quantified regionally using satellite retrievals of surface reflectance and...
Three sets of linear models were developed to predict several forest attributes, using stand-level and single-tree remote sensing (STRS) light detection and ranging (LiDAR) metrics as predictor variables. The first used only area-level metrics (ALM) associated with first-return height distribution, percentage of cover, and canopy transparency. The second alternative included...
Mitigation strategies for reducing CO2 emissions include substitution of fossil fuel with bioenergy from forests, where carbon emitted is expected to be re-captured in the growth of new biomass to achieve zero net emissions, and forest thinning to reduce wildfire emissions. Here we use forest inventory data to show that...
Fossil fuel emissions aside, temperate North America is a net sink of carbon dioxide at present¹⁻³. Year-to-year variations in this carbon sink are linked to variations in hydroclimate that affect net ecosystem productivity³,⁴. The severity and incidence of climatic extremes, including drought, have increased as a result of climate warming⁵⁻⁸....
More than 40 years have passed since Shafer (1969) challenged the existence of the “average
camper.” Recognizing that participants in recreation activities are heterogeneous in their
commitments and interests, researchers have emphasized the importance of differentiating
users into meaningful homogeneous subgroups. In his seminal article, Bryan (1977) coined
the concept...
We develop an approach for estimating net ecosystem exchange (NEE) using inventory-based information over North America (NA) for a recent 7-year period (ca. 2000–2006). The approach notably retains information on the spatial distribution of NEE, or the vertical exchange between land and atmosphere of all non-fossil fuel sources and sinks...
Using qualitative research methods we examined how group ranch privatization and settlement of individual Maasai households across the landscape have affected traditional livestock herding and social capital mechanisms of Maasai livestock herders. This process has altered decision-making processes, social networks, and cooperation of Maasai herders and limited access to water...
The occurrence of wildfires within municipal watersheds can result in significant impacts to water quality and ultimately human health and safety. In this paper, we illustrate the application of geospatial analysis and burn probability modeling to assess the exposure of municipal watersheds to wildfire. Our assessment of wildfire exposure consists...
We investigated the potential use of airborne light detection and ranging (LiDAR) data to predict key wood fiber properties from extrinsic indicators in lodgepole pine leading forest stands located in the foothills of central Alberta, Canada. Six wood fiber attributes (wood density, cell perimeter, cell coarseness, mature fiber length, microfibril...
Forest understory communities are important components in forest ecosystems providing wildlife habitat and influencing nutrient cycling, fuel loadings, fire behavior and tree species composition over time. One of the most widely utilized understory component metrics is understory vegetation cover, often used as a measure of vegetation abundance. To date, understory...
The potential for using pretreatment with cinnamon leaf oil or juniper foliage oil to improve the durability of viscoelastic thermal compression (VTC)–treated hybrid poplar was explored in a field termite test and a laboratory mold test. The addition of oils prior to VTC processing had variable effects on resistance to...
The forest products industry has faced numerous challenges in remaining innovative: outside forces such as industry culture and policy provide few incentives while poor communication among industry actors impedes creative growth from within. This article outlines results gathered from personal interviews with industry professionals and an industry survey on key...
The amounts of treated wood present at a wood recycling center in western Oregon were surveyed over a 10-year period. Treated wood was found at 106 of 112 inspections, but the levels never exceeded 2 percent of the volume present. The amount of treated wood averaged 0.15 percent of the...
Disturbance processes of various types substantially modify ecosystem carbon dynamics both temporally and spatially, and constitute a fundamental part of larger landscape-level dynamics. Forests typically lose carbon for several years to several decades following severe disturbance, but our understanding of the duration and dynamics of post-disturbance forest carbon fluxes remains...
Small hydropower plants divert part of the water from wide and physically complex
stream channels with active hyporheic areas to narrow and hydraulically simple concrete canals,
and thus, might affect nutrient dynamics. We compared nutrient uptake in diversion canals and
in stream channels in the Leitzaran Stream (Basque Country, northern...
Symbiotic N₂-fixing tree species can accelerate ecosystem N dynamics through decomposition feedbacks via both direct and indirect pathways. Direct pathways include the production of readily decomposed leaf litter and increased N supply to decomposers, whereas indirect pathways include increased tissue N and altered detrital dynamics of non-fixing vegetation. To evaluate...
Forest ecosystems are the most important terrestrial carbon (C) storage globally, and presently mitigate anthropogenic climate change by acting as a large and persistent sink for atmospheric CO₂. Yet, forest C density varies greatly in space, both globally and at stand and landscape levels. Understanding the multi-scale drivers of this...
This paper describes the atmospheric correction (AC) component of the Multi-Angle Implementation of Atmospheric Correction algorithm (MAIAC) which introduces a new way to compute parameters of the Ross-Thick Li-Sparse (RTLS) Bi-directional reflectance distribution function (BRDF), spectral surface albedo and bidirectional reflectance factors (BRF) from satellite measurements obtained by the Moderate...
Models relating species distribution records to environmental variables are increasingly applied to biodiversity conservation. Such techniques could be valuable to predict the distribution, abundance or habitat requirements of species that are rare or otherwise difficult to survey. However, despite widely-documented positive intraspecific relationships between occupancy and abundance, few studies have...
Models relating species distribution records to environmental variables are increasingly
applied to biodiversity conservation. Such techniques could be valuable to predict the
distribution, abundance or habitat requirements of species that are rare or otherwise difficult
to survey. However, despite widely-documented positive intraspecific relationships between
occupancy and abundance, few studies have...
Previous studies have demonstrated that light detection and ranging (LiDAR)-derived variables can be used to model forest yield variables, such as biomass, volume, and number of stems. However, the next step is underrepresented in the literature: estimation of forest yield with appropriate confidence intervals. It is of great importance that...
The paper describes for the first time the analysis of the structure of compressed wood using computed tomography. The anatomical structures of Douglas-fir and hybrid poplar before and after densification with the Viscoelastic Thermal Compression (VTC) process were described by pore size distributions and mean pore sizes and compared. The...
The 2004 Indian Ocean tsunami and the 2011 Great Tohoku Japan earthquake and tsunami focused a great deal of the world’s attention on the effect of tsunamis on buildings and infrastructure. When a tsunami impacts structures in a coastal community, the structures are often not strong enough to withstand the...
Factors influencing soil organic matter (SOM) stabilization and dissolved organic carbon (DOC) content in complex terrain, where vegetation, climate, and topography vary over the scale of a few meters, are not well understood. We examined the spatial correlations of lidar and geographic information system-derived landscape topography, empirically measured soil characteristics,...
Distribution of fishes, both occupancy and abundance, is often correlated with landscape-scale characteristics (e.g., geology, climate, and human disturbance). Understanding these relationships is essential for effective conservation of depressed populations. We used landscape characteristics to explain the distribution of coho salmon (Oncorhynchus kisutch) in the Oregon Plan data set, one...
KEYWORDS: Cindy Glick, Eric White, Institude for Working Forest Landscapes, Emily Jane Davis, Thomas Maness, Forest service, Sweet Home Ranger District
Kalapuya is described as a new, monotypic truffle genus in the Morchellaceae known only from the Pacific northwestern United States. Its relationship to other hypogeous genera within Morchellaceae is explored by phylogenetic analysis of the ribosomal LSU and EF1α protein coding region. The type species, K. brunnea, occurs in Douglas-fir...
We report on user conflicts at six Hawaiian beaches, and compare the extent to which evaluations of coastal recreation conflicts differ among groups. This information can be used to help understand current recreation users at coastal sites in Hawaii. Exploratory factor analyses supported a multidimensional interpersonal conflict factor based on...
Surface albedo is a key parameter in the Earth's energy balance since it affects the amount of solar radiation directly absorbed at the planet surface. Its variability in time and space can be globally retrieved through the use of remote sensing products. To evaluate and improve the quality of satellite...
Components of biodiversity in intensively managed forest stands may be reduced in comparison to naturally regenerated stands. Use of herbicides to suppress herbaceous and woody plant species that compete with planted seedlings has been implicated in negative impacts. We designed a large-scale experimental study to test the influence of intensive...
Quantification of the transient storage zone (A[subscript s]) has become critical in stream biogeochemical studies addressed to examine factors controlling nutrient uptake. It is expected that higher A[subscript s] may enhance the interaction between nutrients and biota and thus, increase nutrient uptake. However, results from the literature are controversial. We...
Hybrid poplar (Populus deltoides × Populus trichocarpa) and Douglas-fir (Pseudotsuga menziesii) wood specimens were densified with three variations of Thermo-Hydro-Mechanical (THM) treatment. The THM treatments differed in the steam environment, including transient steam (TS), saturated steam (SS), and saturated steam with 1 minute post-heat-treatment at 200°C (SS+PHT). The bending properties,...
The effects of precommercial thinning on the understory vegetative cover of 16- to 18-year-old spruce–hemlock (Picea sitchensis (Bong.) Carrière – Tsuga heterophylla (Raf.) Sarg.) stands were studied in seven replicate areas over seven growing seasons postthinning. Vegetative cover was analyzed at the class level, but species-specific effects were examined in...
In many regions of the world, forest management has shifted from practices emphasizing timber production to more sustainable harvesting that integrates ecological values, including maintenance of biodiversity, wildlife habitat, and ecological goods and services. To this end, management strategies emphasize retention of stand structures that meet the needs of forest-obligate...
A plan irregularity rapid visual screening method for seismic performance assessment of
wood-frame, single-family dwellings is presented. Results from 124 samples were compared
with (i) building-specific, non-linear time-history analysis, and (ii) FEMA 154 and ASCE 31
Tier 1. Verification using two houses damaged in the 1994 Northridge Earthquake is
presented....
Postfire logging recoups the economic value of timber killed by wildfire, but whether such forest management activity supports or impedes forest recovery in stands differing in structure from historic conditions remains unclear. The aim of this study was to determine the impact of mechanical logging after wildfire on soil bacterial...
Angiosperm and coniferous tree species utilize a continuum of hydraulic strategies. Hydraulic safety margins (defined as differences between naturally occurring xylem pressures and pressures that would cause hydraulic dysfunction, or differences between pressures resulting in loss of hydraulic function in adjacent organs (e.g., stems vs. leaves) tend to be much...
Dwarf mistletoes (Arceuthobium species) influence many processes within forested ecosystems, but few studies have examined their distribution in relation to climate. An analysis of 1549 forested plots within a 14.5 million ha region of southeast Alaska provided strong indications that climate currently limits hemlock dwarf mistletoe (Arceuthobium tsugense (Rosendahl) G.N....
Multiple parasitism of host nests by generalist brood parasites reflects the decisions of laying females and may influence the development and behavior of parasitic young. We used microsatellite and mtDNA control-region haplotype data to examine the relatedness of Brown-headed Cowbird (Molothrus ater) offspring in multiply parasitized nests sampled from a...
Fungal mitospores may function as dispersal units and/ or spermatia, and thus play a role in
distribution and/or mating of species that produce them. Mitospore production in
ectomycorrhizal (EcM) Pezizales is rarely reported, but here we document mitospore production
by a high diversity of EcM Pezizales on three continents, in...
Semidwarfism has been used extensively in row crops and horticulture to promote yield, reduce lodging, and improve harvest index, and it might have similar benefits for trees for short-rotation forestry or energy plantations, reclamation, phytoremediation, or other applications. We studied the effects of the dominant semidwarfism transgenes GA Insensitive (GAI)...
Herbicides are the primary method used to control exotic, invasive plants. This study evaluated restoration efforts applied to grasslands dominated by an invasive plant, sulfur cinquefoil, 6 yr after treatments. Of the five herbicides we evaluated, picloram continued to provide the best control of sulfur cinquefoil over 6 yr. We...
Les modèles de prédiction du microclimat pour différentes conditions de station dans les zones riveraines boisées
des cours d’eau de tête de bassin sont peu développés et les procédures d’échantillonnage pour caractériser les gradients
sous-jacents du microclimat riverain sont rares. Nous avons utilisé des données de microclimat riverain collectées le...
•Plant population genomics informs evolutionary biology, breeding, conservation and bioenergy feedstock development. For example, the detection of reliable phenotype–genotype associations and molecular signatures of selection requires a detailed knowledge about genome-wide patterns of allele frequency variation, linkage disequilibrium and recombination.
•We resequenced 16 genomes of the model tree Populus trichocarpa...
A new approach was developed for the evaluation of energy release rate by the virtual crack closure technique in quadratic and linear elements. The generalized method allows arbitrary placement of the side nodes for quadratic elements and thus includes both standard elements, with mid-side nodes, and singularity elements, with quarter-point...
Douglas-fir (Pseudotsuga menziesii) forest residues were physically fractionated through sieving. The bark and wood were separated for large-sized fractions (>12.7 mm), and their contents were determined. The chemical compositions of the large fractions were calculated based on the contents and chemical compositions of the bark and wood. The chemical compositions...
Euro-American settlement and organized fire suppression have been associated with structural and compositional changes in many upland forests of the western United States, but little is known about the impacts on riparian forests, portions of the landscape protected for habitat and water quality. In this study, we used dendro-ecological methods...
The influence of fertilization on disease severity is unknown in most forest pathosystems. Fertilization treatments were randomly applied to 0.01 ha plots centered on individual dominant or co-dominant Douglas-fir trees in ten Douglas-fir stands from coastal Oregon to the foothills of the Oregon Cascade Range, USA. This region is affected...
Many forest products companies in the southeastern United States store large volumes of round-wood under wet storage. Log quality depends on maintaining a high and constant wood moisture content; however, limited knowledge exists regarding moisture variation within individual logs, and within wet decks as a whole, making it impossible to...
Hydraulic conductance of leaves (K[subscript leaf]) typically decreases with increasing water stress and recent studies have proposed different mechanisms responsible for decreasing K[subscript leaf]. We measured K[subscript leaf] concurrently with ultrasonic acoustic emissions (UAEs) in dehydrating leaves of several species to determine whether declining K[subscript leaf] was associated with xylem...
Discerning the intricacies of mating systems in butterflies can be difficult,
particularly when multiple mating strategies are employed and are cryptic and not
exclusive. We observed the behavior and habitat use of 113 male Taylor’s
checkerspot butterflies (Euphydryas editha taylori). We confirmed that two distinct
mating strategies were exhibited; patrolling...