Abies Amabilis Research Articles

A 20-Year Ecotone Study of Pacific Northwest Mountain Forest Vulnerability to Changing Snow Conditions

(1) Background: Global climate change is expected to significantly alter growing conditions along mountain gradients. Landscape ecological patterns are likely to shift significantly as species attempt to adapt to these changes. We evaluated the extent to which spatial (elevation and canopy cover) and temporal (decadal trend and El Niño–Southern Oscillation/Pacific Decadal Oscillation) factors impact seasonal snowmelt and forest community dynamics in the Western Hemlock–True Fir ecotone region of the Oregon Western Cascades, USA. (2) Methods: Tsuga heterophylla and Abies amabilis seedling locations were mapped three times over 20 years (2002–2022) on five sample transects strategically placed to cross the ecotone. Additionally, daily ground temperature readings were collected over 10 years for the five transects using 123 data loggers to estimate below-canopy snow metrics. (3) Results: Based on validation using time-lapse cameras, the data loggers proved highly reliable for estimating snow cover. The method reported fewer days of snow cover as compared to meteorological station-based snow products for the region, emphasizing the importance of direct under-canopy field observations of snow. Snow season variability was most significantly impacted temporally by cyclical ENSO/PDO climate patterns and spatially by differences in canopy cover within the ecotone. The associated seedling analysis identified clear sorting of species by elevation within the ecotone but reflected a lack of a long-term trend, as species dominance in the seedling strata did not significantly shift along the elevation gradient over the 20-year study. (4) Conclusions: The data logger-based approach provided estimates of snow cover at ecologically significant locations and fine enough spatial resolutions to allow for the study of forest regeneration dynamics. The results highlight the importance of long-term, understory snow measurements and the influence of climatic oscillations in understanding the vulnerability of mountain areas to the changing climate.

Pacific Northwest conifer forest stand carrying capacity under future climate scenarios

AbstractMaximum stand density index (SDIMAX) represents the carrying capacity of a forest stand based on the relationship between the number of trees and their size. Plot‐level inventory data provided through a collaborative network of federal, state, and private forest management groups were utilized to develop SDIMAX models for important Pacific Northwest conifers of western Washington and Oregon, USA. The influence of site‐specific climatic and environmental variables was explored within an ensemble learning model. Future climate projections based on global circulation models under different representative CO2 concentration pathways (RCP 4.5 and RCP 8.5) and timeframes (2050s and 2080s) were utilized in a space‐for‐time substitution to understand potential shifts in modeled SDIMAX. A majority of the region showed decreases in carrying capacity under future climate conditions. Modeled mean SDIMAX decreased 5.4% and 11.4% for Douglas‐fir (Pseudotsuga menziesii (Mirb.) Franco) dominated forests and decreased 6.6% and 8.9% for western hemlock (Tsuga heterophylla (Raf.) Sarg.) and Pacific silver fir (Abies amabilis), dominated forests under the RCP 4.5 in the 2050s and RCP 8.5 in the 2080s, respectively. Projected future conditions often fall outside the range of any contemporary climate profile, resulting in what may be referred to as extramural conditions. Within the study region, 45% and 46% of climate variables included in the final model were extramural for the Douglas‐fir and hemlock models, respectively, under RCP 8.5 in the 2080s. Although extrapolating beyond the range of input data is not appropriate and many unknowns remain regarding future climate projections, these results allow for general interpretations of the direction and magnitude of potential shifts in forest carrying capacity.

Cold-season freeze frequency is a pervasive driver of subcontinental forest growth

As northern latitudes experience rapid winter warming, there is an urgent need to assess the effect of varying winter conditions on tree growth and forest carbon sequestration potential. We examined tree growth responses to variability in cold-season (November–April) frequency of freeze days (FFD) over 1951 to 2018 using tree-ring data from 35,217 trees and 57 species at 4,375 sites distributed across Canada. We found that annual radial growth responses to FFD varied by species, with some commonalities across genera and clades. The growth of gymnosperms with late spring leaf-out strategies was negatively related to FFD; years with high FFD were most detrimental to the annual growth of Pinus banksiana, Pinus contorta, Larix lyalli, Abies amabilis, and Abies lasiocarpa. In contrast, the growth of angiosperms with early leaf-out strategies, namely, Populus tremuloides and Betula papyrifera, was better in the coldest years, and gymnosperms with intermediate leaf-out timing, such as widespread Picea mariana and Picea glauca, had no consistent relationship to FFD. Tree growth responses to FFD were further modulated by tree size, tree age, regional climate (i.e., mean cold-season temperature), and local site conditions. Overall, our results suggest that moderately warming winters may temporarily improve the growth of widespread pines and some high-elevation conifers in western Canada, whereas warming winters may be detrimental to the growth of widespread boreal angiosperms. Our findings also highlight the value of using species-specific climate-growth relationships to refine predictions of forest carbon dynamics.

Abies amabilis (Pacific silver fir)

Abies amabilis (Pacific silver fir)

Highlighting Complex Long-Term Succession Pathways in Mixed Forests of the Pacific Northwest: A Markov Chain Modelling Approach

Forest succession is an ecological phenomenon that can span centuries. Although the concept of succession was originally formulated as a deterministic sequence of different plant communities by F. Clements more than a century ago, nowadays it is recognized that stochastic events and disturbances play a pivotal role in forest succession. In spite of that, forest maps and management plans around the world are developed and focused on a unique “climax” community, likely due to the difficulty of quantifying alternative succession pathways. In this research, we explored the possibility of developing a Markov Chain model to study multiple pathway succession scenarios in mixed forests of western red cedar, hemlock and Pacific silver fir on northern Vancouver Island (western Canada). We created a transition matrix using the probabilities of change between alternative ecological stages as well as red cedar regeneration. Each ecological state was defined by the dominant tree species and ages. Our results indicate that, compared to the traditional Clementsian, deterministic one-pathway succession model, which is unable to replicate current stand distribution of these forests in the region, a three-pathway stochastic succession model, calibrated by a panel of experts, can mimic the observed landscape distribution among different stand types before commercial logging started in the region. We conclude that, while knowing the difficulty of parameterizing this type of models, their use is needed to recognize that for a given site, there may be multiple “climax” communities and hence forest management should account for them.

Investigating factors that set the lower elevational limit of Canada Jays (Perisoreus canadensis) on Vancouver Island, British Columbia, Canada

The biotic and abiotic factors responsible for determining ranges of most species are poorly understood. The Canada Jay (Perisoreus canadensis (Linnaeus, 1766)) relies on perishable cached food for over-winter survival and late-winter breeding and the persistence of cached food could be a driver of range limits. We confirmed that the Canada Jay’s lower elevational limit on Vancouver Island, British Columbia, Canada, matches that of the subalpine zone (900 m) and then conducted simulated caching experiments to examine the influence of antimicrobial properties of subalpine tree species (biotic) and of temperature (abiotic) on the preservation of cached food. We found that two high-elevation species, yellow cedar (Callitropsis nootkatensis (D. Don) D.P. Little) and Amabilis fir (Abies amabilis Douglas ex J. Forbes), preserved cached blueberries and chicken flesh better than other trees, but they also occurred well below the lower limit of Canada Jays. The effect of temperature was similarly unclear; while food cached at 1150 m retained 17% more mass than food cached at 550 m, there was no difference in percent mass remaining of food placed 70 m above versus 120 m below the Canada Jay’s lower elevational limit. Thus, we were unable to provide definitive evidence that either of the proposed abiotic or biotic factors was responsible for setting thelower elevational limit of resident Canada Jays.

Using X-ray CT Scanned Reconstructed Logs to Predict Knot Characteristics and Tree Value

Research Highlights: Stand density was connected with wood quality and lumber production to develop a predictive model to better estimate tree value. Background and Objectives: The available standing wood volume in British Columbia (BC), Canada has consistently decreased since 1990. Better understanding the link between stand growth conditions, knot characteristics, the sawmilling process and product quality is essential in making informed forest management decisions and efficiently utilizing wood. The overall objective was to investigate and predict the impact of tree growth as affected by stand density on knot characteristics, lumber volume and value recoveries for two conifer species, two types of sawmills and three economic scenarios. Materials and Methods: Seventy-two amabilis fir and western hemlock trees were harvested from three stands located on Vancouver Island, BC. Sawlogs were scanned using an X-ray computed tomography (CT) scanner and images were processed to extract knot characteristics and reconstruct three-dimensional (3D) log models. The effects of three diameter at breast height (DBH) classes (30, 40 and 50 cm) and three stand densities on knot characteristics, including knot volume, number of knots, average knot area and knot/tree volume ratio, as well as the simulated lumber volume and value recoveries from two types of sawmills (i.e., Coastal and Interior) under three economic scenarios (i.e., baseline, optimistic, and pessimistic) were investigated. Results: As expected, the knot characteristics of both species increased with the DBH. The difference of knot distribution between amabilis fir and western hemlock suggests that the latter is more sensitive to growth site conditions. The sawmilling simulations revealed that the Coastal mill produced a lower lumber volume due to the type of products manufactured and the primary breakdown patterns being used. Conclusions: The developed linear mixed effects models based on the knot characteristics and tree features could predict the value of a standing tree and can be used for estimating preharvest stand value of similar Coastal Hem-Fir forests.

A multi-century July-August streamflow reconstruction of Metro Vancouver's water supply contribution from the Capilano and Seymour watersheds in southwestern British Columbia, Canada

Recent summer water shortages in Metro Vancouver are the result of unanticipated changes in the timing of regional snowmelt and rising summer temperatures. Continuing shortfalls over the next century would pose a significant challenge for water supply management decisions. To understand the magnitude of recent drought events in the context of those that happened in the past, we developed a tree-ring reconstruction of regionalised July–August streamflow to 1711 for Metro Vancouver’s Capilano and Seymour watersheds. We used the annual tree-ring widths of mountain hemlock (Tsuga mertensiana (Bong.) Carr.) and Pacific silver fir (Abies amabilis Douglas ex J. Forbes) trees exhibiting a relationship to the seasonal snowpack as proxies for the nival component of streamflow in a regression model. The model indicates that more multi-year, below-average, streamflow departures occurred during the instrumental record than over the 1711–1992 reconstruction period. The El Niño-Southern Oscillation was significantly (p < 0.05) associated with both reconstructed and measured streamflow for the study region. Similarly, seasonal Pacific Decadal Oscillation demonstrated strong statistical relationships (p < 0.05) with measured streamflow. Over the duration of the reconstruction, significant decadal and multi-decadal periodicities were also observed. The research places the Metro Vancouver water supply in a longer-term context than was previously possible and offers a basis for advancing water supply planning decisions in the context of a rapidly changing climate.

Secondary disturbance following a deposit of volcanic tephra: a 30-year record from old-growth forest understory

Forest disturbance is usually described by effects on trees, and small disturbances to forest understory are seldom studied. Nevertheless, effective analyses of succession need to consider both stand-replacing and subsequent “secondary” disturbances in both the canopy and understory. We estimated the characteristics of 13 types of secondary disturbances in old-growth forest understory, as well as change in the canopy cover, after the deposition of tephra (aerially transported volcanic ejecta) in 1980 from Mount St. Helens, Washington. We sampled 100 plots (1 m2) at each of four sites for vegetation change and types of disturbance at 10 different times from 1980 to 2010; we sampled the tree canopy above each plot in 1980 and 2016. The number of canopy gaps increased by 23% and mean gap dimension increased by 68% over 36 years, mostly from the loss of Abies amabilis (Douglas ex Loudon) Douglas ex Forbes. Secondary disturbance in understory affected 1.4% of stand area per year. The areas affected by soil disturbance and effects of woody litter were similar. Erosion, greater in deep than in shallow tephra, peaked in 1981, whereas most litter-caused disturbances increased after 2000. Less frequent litter-based disturbances covered greater area. Our results differ from conclusions about nonvolcanic understory disturbances. Secondary disturbances are variable, need more study, and are likely to affect many other systems.

Growth rates and crown morphology of Abies amabilis in the seedling bank of an ancient subalpine conifer forest

The population dynamics of shade-tolerant tree species often includes a seedling bank — small trees persisting in the understory until canopy opening allows increased height growth. We studied the growth and morphology of 0.1–1.3 m tall Abies amabilis Douglas ex J. Forbes trees in the seedling bank of an ancient (&gt;1300 years old) subalpine conifer forest on Vancouver Island, western Canada. We determined rates of height growth by counting growth rings at 10 cm intervals along the main stem and assessed crown morphology by measuring the length and location of each branch along the main stem. These small trees were very old (mean basal ring count, 112 years) and grew very slowly, taking on average 170 years to reach a height of 1 m. Instead of the typical conical form of open-grown Abies Mill., seedling bank individuals had flat crowns. Most branches were near the top of the main stem. The maximum distance along the main stem plus a branch was 1.6 times the main stem length, indicating that resource allocation is focused on lateral growth. The ability to grow slowly and adjust crown morphology allows seedling bank trees to persist for decades to centuries and to retain the possibility of release and growth into the canopy.

On-line species identification of green hem-fir timber mix based on near infrared spectroscopy and chemometrics

In this study, a method suitable for on-line rapid species classification of western hemlock and amabilis fir (hem-fir) green mix of timber was developed and tested with the use of near infrared spectroscopy (NIRS) and chemometrics. The spectra of 600 wood specimens obtained from each species were collected over the wavelength range of 350–2500 nm. They were thereafter pretreated by smoothing; first derivative, second derivative and standard normal variate and calibration models were developed using the wavelength range of 800–1800 nm by partial least squares-linear discriminant analysis (PLS-LDA) and least squares-support vector machines (LS-SVM). The effects of wood surface (transverse, tangential and radial), wood zone (heartwood and sapwood) and sample moving speed (0, 0.5 and 1 m/s) were also explored. LS-SVM is superior to PLS-LDA in terms of classification performance at moving conditions. The best results were obtained using the LS-SVM method when spectra were collected on the transverse surface at a speed of 1 m/s and pretreated by smoothing. The sensitivity, specificity, and accuracy for both calibration and validation sets were all 100%. Collectively, NIR spectroscopy combined with LS-SVM is capable of on-line species separation of green hem-fir mix prior to wood drying.

Species- and moisture-based sorting of green timber mix with near infrared spectroscopy

Methods suitable for the determination and classification of green timber mix (western hemlock and amabilis fir), with respect to species and moisture content, were developed and tested using near infrared spectroscopy and chemometrics. One thousand two hundred samples were distributed into a calibration set (720 samples) and a prediction set (480 samples). Partial least squares (PLS) and least squares-support vector machines (LS-SVM) for both regression (PLSR and LS-SVR) and classification (PLS-DA and LS-SVC) with different spectral preprocessing methods were implemented. LS-SVM outperformed PLS models for both regression and classification. The coefficient of determination (R2p) and root mean square error (RMSEP) of prediction for the best LS-SVR model with spectra pretreated by smooth and first derivative were 0.9824 and 8.7%, respectively, for wood moisture content prediction in the range of 30% to 253%. The best classification model was LS-SVC with spectra pretreated by smooth and second derivative, with overall accuracies of 99.8% in the prediction set, when the samples were divided into four classes. NIRS combined with LS-SVM can be used as a rapid alternative method for qualitative and quantitative analysis of green hem-fir mix before kiln drying. The results could be helpful for sorting green hem-fir mixes with an on-line application.

An exploratory study of composite cross-laminated timber (CCLT) made from bamboo and hemlock-fir mix

This work investigated the feasibility of manufacturing composite cross-laminated timber (CCLT) from bamboo and a western hemlock and amabilis fir mix (hem-fir). Bamboo parallel strand lumber (bamboo PSL) was first fabricated as the surface laminae of CCLT. No. 2 and Btr 2×6 western hem-fir dimension lumber was imported from British Columbia (BC), Canada. The lumber was then sorted and further dried to form the inner laminae of CCLT. Multiple 800 × 800-mm CLT billets were fabricated using a commercial single-component polyurethane (PUR) adhesive. Block shear and delamination tests were conducted to examine the bond quality and durability of bamboo-wood CCLT. The results demonstrated that it is technically feasible to manufacture bamboo-wood CCLT with acceptable bond quality (shear strength, wood failure percentage, etc.) and delamination. Further studies should focus on the optimization of process parameters for manufacturing and surface treatment to improve the bond quality and durability and quantify the mechanical performance of bamboo-wood CCLT with a full-size production trial.

Characterization of pacific silver fir impregnated with extractives from western redcedar

Alternative and higher value uses are needed for residual materials generated from wood products processing. Western redcedar sawdust contains an array of unique chemicals and has the potential to be used to alter the appearance, stability and durability of non-durable timbers. Here it was hypothesized that impregnation of Western redcedar heartwood extractives into Pacific silver fir would decrease shrinkage, hygroscopicity, and susceptibility to decay. Western redcedar hot water extracts were obtained from sawdust and used to pressure-treat Pacific silver fir blocks. Extractive impregnation enhanced the wood’s appearance and gave it a more cedar-like brown colour. Impregnated samples had reduced shrinkage, but were not as dimensionally stable as Western redcedar heartwood. Pacific silver fir blocks impregnated with water-soluble extractives were also highly susceptible to leaching, and leached samples had similar shrinkage values to untreated controls. In contrast, leaching had little effect on the hygroscopicity of the Western redcedar heartwood. Extractive-impregnated Pacific silver fir blocks had increased resistance to decay by two brown-rot fungi, and showed resistance similar to that of Western redcedar heartwood. However, leached blocks did not have the same decay resistance.

Histology of resin vesicles and oleoresin terpene composition of conifer seeds

The seed coats of several conifers contain terpene-filled resin vesicles, which may be involved in the protection of the dormant embryo and the seed storage tissue against herbivores or pathogens. We analyzed the terpenoid composition of seeds from four Abies species (Abies amabilis Douglas ex J. Forbes, Abies balsamea (L.) Mill., Abies grandis (Douglas ex D. Don) Lindl., and Abies lasiocarpa (Hook.) Nutt.), two Thuja species (Thuja plicata Donn ex D. Don and Thuja occidentalis L.), and three Tsuga species (Tsuga canadensis (L.) Carrière, Tsuga mertensiana (Bong.) Carrière, and Tsuga heterophylla (Raf.) Sarg.) and examined histological features of resin vesicles in seeds from one species from each genus. Resin vesicle morphology was generally similar among the species analyzed. The composition of the seed terpenes varied largely between species. The described seed terpene profiles of the nine species will serve as a foundation for future studies into the function of seed terpenes and resin vesicles in the seed coat.

Alternative Carrier Solvents for Pigments Extracted from Spalting Fungi.

The use of both naturally occurring and synthetic pigmented wood has been prevalent in woodcraft for centuries. Modern manifestations generally involve either woodworkers’ aniline dyes, or pigments derived from a special class of fungi known as spalting fungi. While fungal pigments are more renewable than anilines and pose less of an environmental risk, the carrier required for these pigments—dichloromethane (DCM)—is both problematic for humans and tends to only deposit the pigments on the surface of wood instead of evenly within the material. Internal coloration of wood is key to adoption of a pigmenting system by woodworkers. To address this issue, five solvents that had moderate solubility with the pigments extracted from Chlorociboria aeruginosa and Scytalidium cuboideum were identified, in the hopes that a reduction in solubility would result in a greater amount of the pigment deposited inside the wood. Of the tested solvents, acetonitrile was found to produce the highest internal color in ash, Douglas-fir, madrone, mountain hemlock, Port-Orford cedar, Pacific silver fir, red alder and sugar maple. While these carrier solvents are not ideal for extracting the pigments from the fungi, acetonitrile in particular does appear to allow for more pigment to be deposited within wood. The use of acetonitrile over DCM offers new opportunities for possible industrial spalting applications, in which larger pieces of wood could be uniformly pigmented and sold to the end user in larger quantities than are currently available with spalted wood.

Leaf-level physiology in four subalpine plants in tephra-impacted forests during drought

Ecological impacts of climate change in the Pacific Northwest may hinge on acclimation to drier summers, highlighting the importance of plant physiological studies in forests. Evaluating dominant forest plant species under old-growth and managed forest conditions is similarly important as timber harvest might change microclimates and alter drought effects on plants. We examined water potential and gas exchange rates of four dominant plant species in understories of subalpine forests of the Pacific Northwest region of the United States during 2015 — a year with drought conditions representative of future climate projections. We examined two conifer species (Abies amabilis Douglas ex J. Forbes and Tsuga heterophylla (Raf.) Sarg.) and two huckleberry species (Vaccinium membranaceum Douglas ex Torr. and Vaccinium ovalifolium Sm.) in old-growth and formerly clear-cut forests at two elevations. Contrary to expectations, we found no evidence of hydraulic stress, and there were no significant differences between old-growth and clear-cut stands, consistent with an edaphic buffering effect in this volcanic landscape. Variation in stem elongation rates among years also indicated the lack of a strong drought response in 2015. Water potential, photosynthesis, and stomatal conductance varied among species and among elevations. In combination, our results help constrain expected physiological activity of understory species in subalpine forests and emphasize the importance of the edaphic context (e.g., tephra deposits) in framing expectations for the responses to drought.

Manufacture of Profiled Amabilis Fir Deckboards with Reduced Susceptibility to Surface Checking

Machining grooves and ridges (peaks) into the surface of wooden deckboards reduces undesirable checking that develops when “profiled” boards are exposed to the weather. We aim to develop improved profiles for amabilis fir decking to reduce its susceptibility to checking, and also to examine whether profiling influences distortion (cupping) of deckboards. We systematically varied radii of grooves and peaks, and the heights and widths of peaks in profiled deckboards, exposed them to the weather, and measured checking and cupping of boards. Profiling significantly reduced the numbers and sizes of checks in amabilis fir deckboards, but increased cupping. Profiles with narrow grooves and tall peaks were generally better at restricting checking than profiles with wide grooves and shorter peaks. Our results suggest that one of the profiles we tested would be better at restricting checking than profiles used previously to manufacture profiled decking from amabilis fir. We conclude that the surface checking of profiled amabilis fir decking can be significantly reduced by altering the geometry of surface profiles. In principal, the same approach could be used with other softwood species that have potential to capture a share of the large and important market for wood decking.

The evaluation of panel bond quality and durability of hem-fir cross-laminated timber (CLT)

To better use the second-growth wood resources in value-added applications, this work addressed the manufacturing aspects of cross-laminated timber (CLT) products from western hemlock (Tsuga heterophylla (Raf.) Sarg) and amabilis fir (Abies amabilis (Dougl.) Forbes) (or hem-fir) harvested from coastal British Columbia, Canada. Small CLT billets (nominal 610 mm × 610 mm) were made to examine CLT bond quality and durability through block shear and delamination tests. Two types of adhesives, single-component polyurethane (PUR) and emulsion polymer isocyanate (EPI) and two critical applied pressure parameters (0.28 and 0.83 MPa) were adopted to manufacture hem-fir CLT. It was found that the adhesive type and applied pressure significantly affected wood failure percentage (WFP) and delamination of hem-fir CLT. When PUR adhesive was used, CLT made at 0.83 MPa pressure yielded significantly higher WFP and lower delamination than that made at 0.28 MPa pressure. The results demonstrated that despite the fact that hem-fir lumber is not particularly specified in the current North American CLT standard, it could be used for manufacturing CLT with the required panel bond quality.

Predicting post-fire tree mortality for 14 conifers in the Pacific Northwest, USA: Model evaluation, development, and thresholds

Fire is a driving force in the North American landscape and predicting post-fire tree mortality is vital to land management. Post-fire tree mortality can have substantial economic and social impacts, and natural resource managers need reliable predictive methods to anticipate potential mortality following fire events. Current fire mortality models are limited to a few species and regions, notably Pinus ponderosa and Pseudotsuga menziesii in the western United States. The efficacy of existing mortality models to predict fire-induced tree mortality is central to effective forest management. This study validated 54 logistic regression mortality models from seven published articles and two sets of mortality guidelines from two sources. Survival and a suite of fire injury metrics were monitored for 3654 trees representing 14 species that burned in fires between 2002 and 2009 in the Pacific Northwest, USA. Tree species included Abies amabilis, A. concolor, A. grandis, A. lasiocarpa, Calocedrus decurrens, Chamaecyparis lawsoniana, C. nootkatensis, Thuja plicata, Pinus contorta, P. lambertiana, P. monticola, Picea engelmannii, Larix occidentalis, and Tsuga heterophylla. Existing logistic models adequately described post-fire mortality of A. concolor, A. lasiocarpa, C. decurrens, C. lawsoniana, L. occidentalis, P. engelmannii, P. contorta, and P. lambertiana. We also evaluated predictive accuracy of two published mortality guidelines that apply to species in the Pacific Northwest. In addition to validating existing models, we also developed new logistic regression models and simplified mortality guidelines, or thresholds. We created new logistic regression models for species with adequate sample size and which had no existing species-specific model (A. amabilis, A. grandis, P. monticola, and T. heterophylla). Most recommended models contained a crown scorch term and either a cambium injury term or a bark beetle infestation term. New post-fire mortality thresholds were developed for A. amabilis, A. concolor, A. grandis, P. contorta, P. lambertiana, P. monticola, P. engelmannii, L. occidentalis, and T. heterophylla. We were not able to validate or develop acceptable logistic mortality models or thresholds for C. nootkatensis or T. plicata. Injury to cambium and crown were both significant predictors in all but one set of new thresholds. The validation of existing models and guidelines allows managers to determine which models will likely perform best and identifies knowledge gaps where no adequate models exist to predict post-fire tree mortality. The new logistic regression models and threshold guidelines provide improved accuracy, with simpler application for fire and forest management.