Effects of Creating Two Forest Structures and Using Prescribed Fire on Coarse Woody Debris in Northeastern California, USA
Author: Fabian C.C. Uzoh and Carl N. Skinner
Pages: 1-13
Little is known about the dynamics of coarse woody debris (CWD) in forests that were originally characterized by frequent, low-moderate intensity fires. We investigated effects of prescribed burning at the Blacks Mountain Experimental Forest in northeastern California following creation of two stand structure conditions: 1) high structural diversity (HiD) that included retaining large, old-growth trees while thinning smaller trees in the understory through whole-tree harvesting, and 2) low structural diversity (LoD) simulating a more traditional approach that removed overstory trees by individual tree selection while thinning the vigorous younger trees and removing the suppressed understory by whole-tree harvesting. Read More.
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Effect of Fuel Treatments on Fuels and Potential Fire Behavior in California, USA, National Forests
Author: Nicole M. Vaillant, JoAnn Fites-Kaufman, Alicia L. Reiner, Erin K. Noonan-Wright, Scott N. Dailey
Pages: 14-29
In many parts of California, past timber harvesting, livestock grazing practices, and fire exclusion have changed the fire regime from low to mixed severity to a high severity regime with an increase in active crown fire. Land managers responded by implementing hazardous fuel treatment projects to reduce the risk of such uncharacteristic stand-replacing crown fires. Various fuel treatments have been implemented using either mechanical methods or prescribed fire in forested ecosystems across 14 national forests in California, USA. Mechanical treatments significantly altered forest structure (tree density, 75th percentile quadratic mean diameter, canopy cover, canopy base height, and canopy bulk density) and generally increased surface fuel loads as compared to pre-treatment conditions. Prescribed fire significantly reduced ground and surface fuel loads and increased canopy base height, but did not appreciably alter other forest structure metrics. The changes in forest and fuel structures from prescribed fire reduced predicted fire behavior metrics (fire type, flame length, fireline intensity, and rate of spread); mechanical methods showed mixed effects on resulting fire behavior metrics. Read More.
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Interactions among Prescribed Fire, Soil Attributes, and Mycorrhizal Community Structure at Crater Lake National Park, Oregon, USA
Author: Matthew J. Trappe, Kermit Cromack, Jr., James M. Trappe, Daniel D. B. Perrakis, Efren Cazares-Gonzales, Michael A. Castellano, Steven L. Miller
Pages: 30-50
We identified relationships between prescribed burn treatments and selected soil and fuel attributes on mycorrhizal fungus fruiting patterns in an old-growth ponderosa pine (Pinus ponderosa) and white fir (Abies concolor) stand in Crater Lake National Park, Oregon, USA. Three prescribed burn treatments (early spring, late spring, and fall burns) plus non-burned controls were applied to 24 ~3 ha units in 2002. We sampled mycorrhizal fungus sporocarp production in the spring and fall in the ensuing three years, and collected data on surface fuels, soil C and N concentrations, δ13C and δ15N signatures, pH, and mineral soil bulk density. A gradient of C:N ratios and other soil attributes across the study area facilitated separation of the effect of fire from the effects of soil attributes on fungal fruiting patterns. Read More.
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Fire, Drought, and Human History near the Western Terminus of the Cross Timbers, Wichita Mountains, Oklahoma, USA
Author: Michael C. Stambaugh, Richard P. Guyette, Ralph Godfrey, E.R. McMurry, J.M. Marschall
Pages: 51-65
Dendrochronological methods were applied to reconstruct the historic occurrence of fires at a Cross Timbers forest-grassland transition site within the Wichita Mountains of southwestern Oklahoma, USA. Sixty fire events occurred within the period 1712 to 2006 (294 years). The mean fire interval (MFI) was 4.4 years for a pre-Euro-American settlement period (pre-1901) and increased to a MFI of 5.2 years after 1901. During the period between 1855 and 1880, which corresponds with the prolonged severe drought called the Civil War drought, the mean fire interval was 1.7 years. Read More.
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Long-Term Effects of High Intensity Prescribed Fire on Vegetation Dynamics in the Wine Spring Creek Watershed, Western North Carolina, USA
Author: Katherine J. Elliott, James M. Vose, Ronald L. Hendrick
Pages: 66-85
We examined the long-term effects of a prescribed fire in a southern Appalachian watershed in Nantahala National Forest, western North Carolina, USA. Fire was prescribed in 1995 on this site by forest managers to restore a degraded pine (Pinus spp.)-hardwood community, specifically to stimulate forage production, promote pine and oak (Quercus spp.) regeneration, and increase plant diversity. Before and after the prescribed fire, permanent plots were sampled across a south-facing hillslope, which corresponded to three community types: mesic, near-stream cove (riparian); dry, mixed-oak (mid-slope); and xeric, pine-hardwood (ridge). In an earlier paper, we reported the first two years of post-burn vegetation response from this prescribed burn. Read More.
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Changes in Fire Severity across Gradients of Climate, Fire Size, and Topography: A Landscape Ecological Perspective
Author: Sandra L. Haire, Kevin McGarigal
Pages: 86-103
Fire events contribute to landscape pattern at multiple spatial and temporal scales, and a landscape perspective can provide relevant information for assessing how a changing fire regime will influence pattern-process dynamics. We investigated how the amount and spatial arrangement of high-severity patches varied among 20 fires that occurred in Arizona and New Mexico, USA, across gradients in fire size and climate. The climate gradient was based on the Multivariate El Niño Southern Oscillation Index. In the southwestern US, cool dry conditions are prevalent in La Niña at one extreme, and at the other end, warm wet conditions occur in El Niño. Fires were generally larger in La Niña climates; however, several fires deviated from this trend. Read More.
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Quantifying Char in Postfire Woody Detritus Inventories
Author: Daniel C. Donato, John L. Campbell, Joseph B. Fontaine, Beverly E. Law
Pages: 104-115
Charred biomass generated by wildland fire has attracted increased interest as a functional component of terrestrial ecosystems. Black carbon (C) in the form of char is a widespread but unique material contributing to biogeochemical processes including long-term carbon storage and soil productivity. These functions have long been recognized by the biogeochemical and soil sciences, but have so far received little attention from wildland fire science. Fire scientists conducting postfire biomass (or fuel) inventories have an opportunity to quantify the formation of char on woody material, which is important to quantifying interactions between fire and global C dynamics. Read More.
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Negligible Influence of Spatial Autocorrelation in the Assessment of Fire Effects in a Mixed Conifer Forest
Author: Phillip J. van Mantgem, Dylan W. Schwilk
Pages: 116-125
Fire is an important feature of many forest ecosystems, although the quantification of its effects is compromised by the large scale at which fire occurs and its inherent unpredictability. A recurring problem is the use of subsamples collected within individual burns, potentially resulting in spatially autocorrelated data. Using subsamples from six different fires (and three unburned control areas) we show little evidence for strong spatial autocorrelation either before or after burning for eight measures of forest conditions (both fuels and vegetation). Read More.
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Comparing Locally Derived and LANDFIRE Geo-Layers in the Great Basin, USA
Author: Louis Provencher, Kori Blankenship, Jim Smith, Jeff Campbell, Mike Polly
Pages: 126-132
Locally derived maps of pre-European settlement vegetation patterns (Biophysical Setting-BpS) and Fire Regime Condition Class (FRCC) were compared to concomitant products from LANDFIRE for the Wassuk Range in western Nevada, USA. While Biophysical Settings between the two sources matched approximately half of the time, only 2.5 % of the area matched both FRCC and BpS simultaneously. The poor FRCC performance is largely due to undetected and extensive cheatgrass (Bromus tectorum L.) cover, overestimation of perennial native grass in extensive shrublands, and mapping confusion between true pinyon-juniper woodlands and areas where trees have encroached into native shrublands. Read More.
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