Assessing canopy fuel stratum characteristics in crown fire prone fuel types of western North America

Application of crown fire behavior models in fire management decision-making have been limited by the difficulty of quantitatively describing fuel complexes, specifically characteristics of the canopy fuel stratum. To estimate canopy fuel stratum characteristics of four broad fuel types found in the western United States and adjacent areas of Canada, namely Douglas-fir, ponderosa pine, mixed conifer, and lodgepole pine forest stands, data from the USDA Forest Service's Forest Inventory and Analysis (FIA) database were analysed and linked with tree-level foliage dry weight equations. Models to predict canopy base height (CBH), canopy fuel load (CFL) and canopy bulk density (CBD) were developed through linear regression analysis and using common stand descriptors (e.g. stand density, basal area, stand height) as explanatory variables. The models developed were fuel type specific and coefficients of determination ranged from 0.90 to 0.95 for CFL, between 0.84 and 0.92 for CBD and from 0.64 to 0.88 for CBH. Although not formally evaluated, the models seem to give a reasonable characterization of the canopy fuel stratum for use in fire management applications.

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Evaluating a model for predicting active crown fire rate of spread using wildfire observations

Canadian Journal of Forest Research ◽

10.1139/x06-174 ◽

2006 ◽

Vol 36 (11) ◽

pp. 3015-3028 ◽

Cited By ~ 61

Author(s):

Martin E Alexander ◽

Miguel G Cruz

Keyword(s):

Fire Management ◽

Model Performance ◽

The United States ◽

Fire Research ◽

Management Decision ◽

Crown Fire ◽

Predictive Capacity ◽

Data Set ◽

Rate Of Spread ◽

Spread Model

We evaluated the predictive capacity of a rate of spread model for active crown fires (M.G. Cruz, M.E. Alexander, and R.H. Wakimoto. 2005. Can. J. For. Res. 35: 1626–1639) using a relatively large (n = 57) independent data set originating from wildfire observations undertaken in Canada and the United States. The assembled wildfire data were characterized by more severe burning conditions and fire behavior in terms of rate of spread and the degree of crowning activity than the data set used to parameterize the crown fire rate of spread model. The statistics used to evaluate model adequacy showed good fit and a level of uncertainty considered acceptable for a wide variety of fire management and fire research applications. The crown fire rate of spread model predicted 42% of the data with an error lower then ±25%. Mean absolute percent errors of 51% and 60% were obtained for Canadian and American wildfires, respectively. The characteristics of the data set did not allow us to determine where model performance was weaker and consequently identify its shortcomings and areas of future improvement. The level of uncertainty observed suggests that the model can be readily utilized in support of operational fire management decision making and for simulations in fire research studies.

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Thinning ponderosa pine (Pinus ponderosa) stands reduces mortality while maintaining stand productivity

Canadian Journal of Forest Research ◽

10.1139/cjfr-2012-0411 ◽

2013 ◽

Vol 43 (4) ◽

pp. 311-320 ◽

Cited By ~ 21

Author(s):

Jianwei Zhang ◽

Martin W. Ritchie ◽

Douglas A. Maguire ◽

William W. Oliver

Keyword(s):

Pinus Ponderosa ◽

Ponderosa Pine ◽

Bark Beetles ◽

Basal Area ◽

Stand Density ◽

Growth Efficiency ◽

Stand Age ◽

Annual Increment ◽

Stand Productivity ◽

Residual Variation

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) of diameter, basal area (BA), volume, and aboveground dry mass were significantly related to stand density index (SDI) and stand age at start of the period; the quadratic trends varied among sites. Precipitation departure from the normal for each period explained a significant amount of residual variation in all PAI variables except diameter. BA production did not change significantly as SDI exceeded 270 trees·ha−1 at the OR sites and 320 trees·ha−1 at the CA site. Stand productivity was the highest at Elliot Ranch (CA) and the least at Blue Mountains (OR). A similar trend held in growth efficiency under lower stand densities (SDI < 600). Most of the mortality was caused by Dendroctonus bark beetles in stands that exceeded SDI of 500 trees·ha−1. Limiting SDI was about 900 trees·ha−1, although plots at Elliot Ranch reached much higher than that. The results demonstrate that silvicultural control of stand density can be a powerful tool for reducing bark beetle caused mortality without sacrificing stand productivity.

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Improving estimates of savanna burning emissions for greenhouse accounting in northern Australia: limitations, challenges, applications

International Journal of Wildland Fire ◽

10.1071/wf08009 ◽

2009 ◽

Vol 18 (1) ◽

pp. 1 ◽

Cited By ~ 116

Author(s):

Jeremy Russell-Smith ◽

Brett P. Murphy ◽

C. P. (Mick) Meyer ◽

Garry D. Cook ◽

Stefan Maier ◽

...

Keyword(s):

Greenhouse Gas ◽

Fire History ◽

Fire Management ◽

Combustion Efficiency ◽

Management Program ◽

Anthropogenic Sources ◽

Fuel Load ◽

Northern Australia ◽

Savanna Burning ◽

In Fire

Although biomass burning of savannas is recognised as a major global source of greenhouse gas emissions, quantification remains problematic with resulting regional emissions estimates often differing markedly. Here we undertake a critical assessment of Australia’s National Greenhouse Gas Inventory (NGGI) savanna burning emissions methodology. We describe the methodology developed for, and results and associated uncertainties derived from, a landscape-scale emissions abatement project in fire-prone western Arnhem Land, northern Australia. The methodology incorporates (i) detailed fire history and vegetation structure and fuels type mapping derived from satellite imagery; (ii) field-based assessments of fuel load accumulation, burning efficiencies (patchiness, combustion efficiency, ash retention) and N : C composition; and (iii) application of standard, regionally derived emission factors. Importantly, this refined methodology differs from the NGGI by incorporation of fire seasonality and severity components, and substantial improvements in baseline data. We consider how the application of a fire management program aimed at shifting the seasonality of burning (from one currently dominated by extensive late dry season wildfires to one where strategic fire management is undertaken earlier in the year) can provide significant project-based emissions abatement. The approach has wider application to fire-prone savanna systems dominated by anthropogenic sources of ignition.

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Lowering Stand Density Enhances Resiliency of Ponderosa Pine Forests to Disturbances and Climate Change

Forest Science ◽

10.1093/forsci/fxz006 ◽

2019 ◽

Vol 65 (4) ◽

pp. 496-507 ◽

Cited By ~ 3

Author(s):

Jianwei Zhang ◽

Kaelyn A Finley ◽

Nels G Johnson ◽

Martin W Ritchie

Keyword(s):

Climate Change ◽

Tree Growth ◽

Ponderosa Pine ◽

Tree Mortality ◽

Ring Width ◽

Basal Area ◽

Stand Density ◽

Site Quality ◽

Climate Trends ◽

Ponderosa Pine Forests

AbstractStand density affects not only structure and growth, but also the health of forests and, subsequently, the functions of forest ecosystems. Here, we integrated dendrochronology and repeated inventories for ponderosa pine research plots to determine whether long-term growth and mortality responded to climate trends and how varying stand density influenced the responses. The plots were established prior to 1975 on existing stands throughout northern California. Although annual temperature increased consistently for the last 65 years, ring-width indices produced by eliminating age and thinning effects failed to detect radial trend regardless of site quality. However, interannual variation for the indices was substantial, reflecting a strong influence of climate on tree growth. Plot-level basal area increments were significantly affected by tree mortality. Stand density index explained most variation of mortality. Lowering stand density enhanced remaining tree growth, reduced mortality, and increased stand resiliency to disturbances and climate change. Besides higher climate moisture indices or lower vapor pressure deficits, any treatments that improve tree vigor and reduce stress will have a similar effect to reducing stand density. Although neither biotic disturbances nor abiotic conditions can be controlled, forest managers can manage stand density appropriately to enhance resilience to climate change and disturbances.

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Short-Term Impacts of Thinning Ponderosa Pine on Pandora Moth Densities, Pupal Weights, and Phenology

Western Journal of Applied Forestry ◽

10.1093/wjaf/10.3.91 ◽

1995 ◽

Vol 10 (3) ◽

pp. 91-94

Author(s):

Darrell W. Ross

Keyword(s):

Pinus Ponderosa ◽

Ponderosa Pine ◽

Basal Area ◽

Stand Density ◽

Adult Emergence ◽

Adult Density ◽

Egg Hatch ◽

Second Growth ◽

Insect Phenology ◽

Foliage Weight

Abstract Second-growth ponderosa pine (Pinus ponderosa) stands with outbreak populations of the pandora moth (Coloradia pandora) were thinned from below removing about half of the basal area. Thinning had no effect on pandora moth pupal density or weight, or emerging adult density in the following generation. However, adult emergence and egg hatch occurred 7-10 days earlier in thinned plots compared with unthinned plots. Egg and larval densities on a foliage weight basis were not significantly different between thinned and unthinned plots. Thinning stands infested with pandora moth will not significantly affect the course of an outbreak for at least one generation. Timing of direct controls for the pandora moth should consider the effect of stand density on insect phenology. West. J. Appl. For. 10(3):91-94.

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Double Sampling Increases the Efficiency of Forest Floor Inventories for Arizona Ponderosa Pine Forests

International Journal of Wildland Fire ◽

10.1071/wf9940003 ◽

1994 ◽

Vol 4 (1) ◽

pp. 3 ◽

Cited By ~ 6

Author(s):

PZ Fule ◽

WW Covington

Keyword(s):

Ponderosa Pine ◽

Basal Area ◽

Stand Density ◽

Cost Effective ◽

Pine Forests ◽

Double Sampling ◽

Fuel Loading ◽

Size Classes ◽

Ponderosa Pine Forests ◽

Stand Density Index

Stand and natural fuel conditions were sampled in ponderosa pine forests in northern and central Arizona to develop predictive fuel depth and loading equations. Litter and duff depths can be estimated from measurements of stand density (basal area, stand density index). Although woody fuel loading did not correlate well with stand variables, correlations were found among loadings of different woody fuel size classes, so that results from a planar intersect tally of certain single woody fuel size classes may be used to predict the loadings in certain other size classes. The relatively low precision of estimates from these predictive equations can be substantially increased by applying them in a double sampling scheme. Making use of these predictive relationships, managers can devise simple, rapid, arid cost-effective fuel inventories that focus on the fuel category of interest. Fuel loads can be estimated at a desired precision with reduced investment of time and funds compared to a more comprehensive direct fuel inventory.

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Calibrating jack pine allometric relationships with simultaneous regressions

Canadian Journal of Forest Research ◽

10.1139/x08-090 ◽

2008 ◽

Vol 38 (10) ◽

pp. 2566-2578 ◽

Cited By ~ 10

Author(s):

Robert Schneider ◽

Frank Berninger ◽

Chhun-Huor Ung ◽

Pierre Y. Bernier ◽

D. Edwin Swift ◽

...

Keyword(s):

Pinus Banksiana ◽

Basal Area ◽

Stand Density ◽

Jack Pine ◽

Seemingly Unrelated Regression ◽

Tree Level ◽

Model Parameters ◽

Eastern Canada ◽

Sapwood Area ◽

Pipe Model

Allometric equations for estimating foliage biomass, sapwood area, and branch basal area from tree diameters and crown lengths for jack pine ( Pinus banksiana Lamb.) in eastern Canada were calibrated using mixed models. A first model is presented that relates branch foliage biomass to branch diameter and relative position within the crown. These results show that a branch’s foliage biomass is inversely proportional to its depth within the crown. At the tree level, foliage biomass was found to be proportional to crown length and to vary with stem age and slenderness. Pipe model parameters (sapwood area and branch basal area to foliage biomass) were also calculated. The sapwood area to foliage biomass parameter is proportional to stand density, whereas branch basal area to foliage biomass is constant. The tree-level allometeric models were calibrated using a mixed-effects seemingly unrelated regression to account for between-model correlations.

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Precommercial Thinning in a Ponderosa Pine Stand Affected by Armillaria Root Disease in Central Oregon: 30 Years of Growth and Mortality

Western Journal of Applied Forestry ◽

10.1093/wjaf/14.3.144 ◽

1999 ◽

Vol 14 (3) ◽

pp. 144-148 ◽

Cited By ~ 4

Author(s):

Gregory M. Filip ◽

Stephen A. Fitzgerald ◽

Lisa M. Ganio

Keyword(s):

Ponderosa Pine ◽

Tree Mortality ◽

Basal Area ◽

Stand Density ◽

Root Disease ◽

Diameter Growth ◽

Individual Tree ◽

Precommercial Thinning ◽

Tree Diameter ◽

Armillaria Root Disease

Abstract A 30-yr-old stand of ponderosa pine was precommercially thinned in 1966 to determine the effects of thinning on tree growth and mortality caused by Armillaria root disease in central Oregon. After 30 yr, crop tree mortality was significantly (P = 0.02) less in thinned plots than in unthinned plots. Tree diameter growth was not significantly (P = 0.17) increased by thinning. Crop-tree basal area/ac growth was significantly (P = 0.03) greater in thinned plots. Apparently, from a root disease perspective, precommercial thinning of pure ponderosa stands significantly decreases the incidence of crop-tree mortality after 30 yr and significantly increases basal area/ac growth but not individual tree diameter growth. Recommendations for thinning based on stand density index (SDI) are given. West. J. Appl. For. 14(3):144-148.

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Evaluating regression model estimates of canopy fuel stratum characteristics in four crown fire-prone fuel types in western North America

International Journal of Wildland Fire ◽

10.1071/wf10066 ◽

2012 ◽

Vol 21 (2) ◽

pp. 168 ◽

Cited By ~ 7

Author(s):

Miguel G. Cruz ◽

Martin E. Alexander

Keyword(s):

North America ◽

Bulk Density ◽

Ponderosa Pine ◽

Stand Structure ◽

Coniferous Forest ◽

Fuel Load ◽

Regression Equations ◽

Western North America ◽

Crown Fire ◽

Canopy Bulk Density

Two evaluations were undertaken of the regression equations developed by M. Cruz, M. Alexander and R. Wakimoto (2003, International Journal of Wildland Fire 12, 39–50) for estimating canopy fuel stratum characteristics from stand structure variables for four broad coniferous forest fuel types found in western North America. The first evaluation involved a random selection of 10 stands each from the four datasets used in the original study. These were in turn subjected to two simulated thinning regimes (i.e. 25 and 50% basal area removal). The second evaluation involved a completely independent dataset for ponderosa pine consisting of 16 stands sampled by T. Keyser and F. Smith (2010, Forest Science 56, 156–165). Evaluation statistics were comparable for the thinning scenarios and independent evaluations. Mean absolute percentage errors varied between 13.8 and 41.3% for canopy base height, 5.3 and 67.9% for canopy fuel load, and 20.7 and 71% for canopy bulk density. Bias errors were negligible. The results of both evaluations clearly show that the stand-level models of Cruz et al. (2003) used for estimating canopy base height, canopy fuel load and canopy bulk density in the assessment of crown fire potential are, considering their simplicity, quite robust.

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