Short-term impact of post-fire salvage logging on regeneration, hazardous fuel accumulation, and understorey development in ponderosa pine forests of the Black Hills, SD, USA

2009 ◽  
Vol 18 (4) ◽  
pp. 451 ◽  
Author(s):  
Tara L. Keyser ◽  
Frederick W. Smith ◽  
Wayne D. Shepperd
Keyword(s):  
Ponderosa Pine ◽  
Tree Mortality ◽  
Woody Debris ◽  
Fire Severity ◽  
Plant Cover ◽  
Black Hills ◽  
Understorey Vegetation ◽  
Salvage Logging ◽  
Ponderosa Pine Forests ◽  
Fuel Accumulation

We examined the impacts of post-fire salvage logging on regeneration, fuel accumulation, and understorey vegetation and assessed whether the effects of salvage logging differed between stands burned under moderate and high fire severity following the 2000 Jasper Fire in the Black Hills. In unsalvaged sites, fire-related tree mortality created a large standing pool of available fuel, resulting in a rapid increase in surface fuel loads. After 5 years, fine woody debris (FWD) and coarse woody debris (CWD) increased ~1380% and 980% in unsalvaged sites, resulting in FWD and CWD loads of 13 and 25 Mg ha–1, respectively. In contrast, salvage logging limited the rate of accumulation of FWD to ~110% over the same time period and total accumulation of CWD to 16 Mg ha–1. In moderate-severity sites, regeneration was 75% lower in salvaged sites owing to low seed-tree retention, suggesting a re-evaluation of salvage guidelines during future operations in the Black Hills. The likelihood of timely regeneration in high-severity sites, regardless of salvage treatment, is low. We found no discernible effect of salvage logging on understorey development 5 years after fire. Logging caused neither a reduction in total plant cover nor an increase in the abundance of exotic species.

Pre-wildfire fuel reduction treatments result in more resilient forest structure a decade after wildfire

2013 ◽  
Vol 22 (8) ◽  
pp. 1108 ◽  
Author(s):  
Camille Stevens-Rumann ◽  
Kristen Shive ◽  
Peter Fulé ◽  
Carolyn H. Sieg
Keyword(s):  
Ponderosa Pine ◽  
Coarse Woody Debris ◽  
Stand Structure ◽  
Woody Debris ◽  
Fire Severity ◽  
Stand Density ◽  
Wildlife Habitat ◽  
Minimum Size ◽  
Forest Fuels ◽  
Ponderosa Pine Forests

Increasing size and severity of wildfires have led to an interest in the effectiveness of forest fuels treatments on reducing fire severity and post-wildfire fuels. Our objective was to contrast stand structure and surface fuel loadings on treated and untreated sites within the 2002 Rodeo–Chediski Fire area. Data from 140 plots on seven paired treated–untreated sites indicated that pre-wildfire treatments reduced fire severity compared with untreated sites. In 2011, coarse woody debris loading (woody material>7.62cm in diameter) was 257% higher and fine woody debris (woody material<7.62cm) was 152% higher on untreated sites than on treated sites. Yet, in spite of higher levels of coarse woody debris on untreated sites, loadings did not exceed recommended ranges based on published literature and many treated sites fell below recommendations. By 2011, basal area and stand density on treated sites and stand density on untreated sites met management guidelines for ponderosa pine forests, but untreated sites had basal areas well below recommendations. Snags declined over this period and only three plots had snags that met minimum size and density requirements for wildlife habitat by 2011. The effects of pre-wildfire treatments are long-lasting and contribute to changes in both overstorey and understorey fuel complexes.

scholarly journals Allometric Equation Development, Biomass, and Aboveground Productivity in Ponderosa Pine Forests, Black Hills, Wyoming

2010 ◽  
Vol 25 (3) ◽  
pp. 112-119 ◽  
Author(s):  
Daniel Tinker ◽  
Gail K. Stakes ◽  
Richard M. Arcano
Keyword(s):  
Carbon Storage ◽  
Ponderosa Pine ◽  
Aboveground Biomass ◽  
Carbon Allocation ◽  
Black Hills ◽  
Allometric Equations ◽  
Pine Forests ◽  
Mature Trees ◽  
Ponderosa Pine Forests ◽  
Aboveground Productivity

Abstract Temperate forest ecosystems continue to play an important role in the global carbon cycle, and the ability to accurately quantify carbon storage and allocation remains a critical tool for managers and researchers. This study was aimed at developing new allometric equations for predicting above- and belowground biomass of both mature trees and saplings of ponderosa pine trees in the Black Hills region of the western United States and at evaluating thinning effects on biomass pools and aboveground productivity. Study sites included three stands that had been commercially thinned and one unmanaged stand. Nine allometric equations were developed for mature trees, and six equations were developed for saplings; all models exhibited strong predictive power. The unmanaged stand contained more than twice as much total aboveground biomass as any of the thinned stands. Aboveground biomass allocation among tree compartments was similar among the three older stands but quite different from the young, even-aged stand. Stand-level aboveground net primary production was higher in the unmanaged and intensively managed stands, yet tree-level annual productivity was much lower in the unmanaged stands than in any of the managed forests, suggesting that thinning of some forest stands may increase their ability to sequester and store carbon. Our data also suggest that different management approaches did not have the same effect on carbon allocation as they did on total carbon storage capacity, but rather, stand age was the most important factor in predicting carbon allocation within individual trees and stands. Identification of the relationships between stand structure and forest management practices may help identify various management strategies that maximize rates of carbon storage in ponderosa pine forests.

Effect of thinning and prescribed burning on crown fire severity in ponderosa pine forests

2002 ◽  
Vol 11 (1) ◽  
pp. 1 ◽  
Author(s):  
Jolie Pollet ◽  
Philip N. Omi
Keyword(s):  
Prescribed Fire ◽  
Ponderosa Pine ◽  
Stand Structure ◽  
Fire Severity ◽  
Fire Effects ◽  
Pine Forests ◽  
Crown Fire ◽  
Fuel Treatments ◽  
Ponderosa Pine Forests ◽  
Wildfire Hazard

Fire exclusion policies have affected stand structure and wildfire hazard in north American ponderosa pine forests. Wildfires are becoming more severe in stands where trees are densely stocked with shade-tolerant understory trees. Although forest managers have been employing fuel treatment techniques to reduce wildfire hazard for decades, little scientific evidence documents the success of treatments in reducing fire severity. Our research quantitatively examined fire effects in treated and untreated stands in western United States national forests. Four ponderosa pine sites in Montana, Washington, California and Arizona were selected for study. Fuel treatments studied include: prescribed fire only, whole-tree thinning, and thinning followed by prescribed fire. On-the-ground fire effects were measured in adjacent treated and untreated forests. We developed post facto fire severity and stand structure measurement techniques to complete field data collection. We found that crown fire severity was mitigated in stands that had some type of fuel treatment compared to stands without any treatment. At all four of the sites, the fire severity and crown scorch were significantly lower at the treated sites. Results from this research indicate that fuel treatments, which remove small diameter trees, may be beneficial for reducing crown fire hazard in ponderosa pine sites.

Post-fire soil fluxes of CO2, CH4 and N2O along the Colorado Front Range

2011 ◽  
Vol 20 (7) ◽  
pp. 838 ◽  
Author(s):  
Mark A. Gathany ◽  
Ingrid C. Burke
Keyword(s):  
Soil Moisture ◽  
Ponderosa Pine ◽  
Fire Severity ◽  
Colorado Front Range ◽  
Front Range ◽  
Soil Co2 Flux ◽  
Ponderosa Pine Forests ◽  
Time Since Fire ◽  
Wide Range ◽  
Ch4 And N2o

Wildfires affect Rocky Mountain ecosystems across a wide range of spatial and temporal scales. Many of the resulting changes are greatest for environmental factors, such as substrate and microclimate that control exchanges of greenhouse gases. We investigated this link to understand how time since fire influences the cycling of these gases through ponderosa pine forests. We measured and compared trace gas flux rates between recently burned sites and topographical aspects (north- and south-facing slopes). We calculated the ability of five factors (soil temperature, soil moisture, fire severity, aspect and time since fire) to describe the variability in the flux rates. Our study revealed that carbon dioxide (CO2) fluxes were significantly different between sites; however, methane (CH4) uptake was not different between sites or aspects. Nitrous oxide (N2O) fluxes had a significant interaction between site and aspect. Using a likelihood approach, we determined the strength of support in the data for model combinations of five variables. Of these, the single variable models soil moisture, time since fire and severity best described the CO2, CH4, and N2O flux data respectively. Our data show that following a forest fire in the Colorado Front Range, >98% of the global warming potential of the measured soil–atmosphere fluxes is contributed by the soil CO2 flux.

Prescribed-fire effects on fine-root and tree mortality in old-growth ponderosa pine

1991 ◽  
Vol 21 (5) ◽  
pp. 626-634 ◽  
Author(s):  
D. Michael Swezy ◽  
James K. Agee
Keyword(s):  
Ponderosa Pine ◽  
Tree Mortality ◽  
Prescribed Burning ◽  
Fine Root ◽  
Soil Depth ◽  
Fire Severity ◽  
Dry Weight ◽  
Prescribed Burn ◽  
Old Growth ◽  
Root Dry Weight

Old-growth Pinusponderosa Dougl. stands were surveyed at Crater Lake National Park to investigate potential accelerated mortality of large pines due to prescribed burning. Mortality of P. ponderosa greater than 22 cm diameter at breast height was higher in burned areas (19.5%) than in unburned areas (6.6%), and early-season burns had over 30% mortality. Mortality was associated with fire severity, as measured by scorch height and ground char, season of burning, and tree vigor. Pines of high, moderate, and low vigor were subjected to a prescribed burn in June; half of the trees had debris raked from tree bases as an additional treatment. Lethal heat loads (>60 °C) occurred in >75% of samples at the soil surface and at 5 cm soil depth, with duration exceeding 5 h. Burning reduced fine-root dry weight 50–75% 1 and 5 months after burning; raking and burning reduced fine-root dry weight more than burning alone after 1 month and had similar effects to burning after 5 months. A low-vigor tree that had been raked and burned died by the beginning of the fourth dry season after burning. Present fuel loads may be too high to burn during spring if old-growth P. ponderosa are to be protected.

scholarly journals Trends in Snag Populations in Drought-Stressed Mixed-Conifer and Ponderosa Pine Forests (1997–2007)

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Joseph L. Ganey ◽  
Scott C. Vojta
Keyword(s):  
Pinus Ponderosa ◽  
Ponderosa Pine ◽  
Tree Mortality ◽  
Management Practices ◽  
Pine Forests ◽  
Conifer Forest ◽  
Mixed Conifer ◽  
Ecological Processes ◽  
Ponderosa Pine Forests ◽  
Class Composition

Snags provide important biological legacies, resources for numerous species of native wildlife, and contribute to decay dynamics and ecological processes in forested ecosystems. We monitored trends in snag populations from 1997 to 2007 in drought-stressed mixed-conifer and ponderosa pine (Pinus ponderosaDougl.exLaws) forests, northern Arizona. Median snag density increased by 75 and 90% in mixed-conifer and ponderosa pine forests, respectively, over this time period. Increased snag density was driven primarily by a large pulse in drought-mediated tree mortality from 2002 to 2007, following a smaller pulse from 1997 to 2002. Decay-class composition and size-class composition of snag populations changed in both forest types, and species composition changed in mixed-conifer forest. Increases in snag abundance may benefit some species of native wildlife in the short-term by providing increased foraging and nesting resources, but these increases may be unsustainable in the long term. Observed changes in snag recruitment and fall rates during the study illustrate the difficulty involved in modeling dynamics of those populations in an era of climate change and changing land management practices.

Woody debris and tree regeneration dynamics following severe wildfires in Arizona ponderosa pine forests

2012 ◽  
Vol 42 (3) ◽  
pp. 593-604 ◽  
Author(s):  
John P. Roccaforte ◽  
Peter Z. Fulé ◽  
W. Walker Chancellor ◽  
Daniel C. Laughlin
Keyword(s):  
Pinus Ponderosa ◽  
Forest Fires ◽  
Ponderosa Pine ◽  
Woody Debris ◽  
Climatic Conditions ◽  
Pine Forest ◽  
Tree Regeneration ◽  
Forest Recovery ◽  
Regeneration Dynamics ◽  
Ponderosa Pine Forests

Severe forest fires worldwide leave behind large quantities of dead woody debris and regenerating trees that can affect future ecosystem trajectories. We studied a chronosequence of severe fires in Arizona, USA, spanning 1 to 18 years after burning to investigate postfire woody debris and regeneration dynamics. Snag densities varied over time, with predominantly recent snags in recent fires and broken or fallen snags in older fires. Coarse woody debris peaked at > 60 Mg/ha in the time period 6–12 years after fire, a value higher than previously reported in postfire fuel assessments in this region. However, debris loadings on fires older than 12 years were within the range of recommended management values (11.2–44.8 Mg/ha). Overstory and regeneration were most commonly dominated by sprouting deciduous species. Ponderosa pine ( Pinus ponderosa C. Lawson var. scopulorum Engelm.) overstory and regeneration were completely lacking in 50% and 57% of the sites, respectively, indicating that many sites were likely to experience extended periods as shrublands or grasslands rather than returning rapidly to pine forest. More time is needed to see whether these patterns will remain stable, but there are substantial obstacles to pine forest recovery: competition with sprouting species and (or) grasses, lack of seed sources, and the forecast of warmer, drier climatic conditions for coming decades.

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