Tree Regeneration Following Large Wildfires in Southwestern Ponderosa Pine Forests

Tree Regeneration Following Large Wildfires in Southwestern Ponderosa Pine Forests PDF Author: Suzanne M. Owen
Publisher:
ISBN:
Category : Trees
Languages : en
Pages : 177

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Book Description
Wildfires in southwestern US ponderosa pine (Pinus ponderosa Lawson & C. Lawson) forests have recently increased in size and severity, leaving large, contiguous patches of tree mortality, and raising concerns about post-fire recovery. Ponderosa pines are a dominant species in the Southwest and they evolved with low- to moderate-severity fire regimes. They are poorly adapted to regenerate after large, high-severity fires because they do not have serotinous cones, re-sprouting capabilities, or long-lived seed banks. Additionally, high-severity fires can favor competing understory plants or induce long-term changes to soil nutrient dynamics and surface fuel loads, potentially altering ponderosa pine regeneration niches. Furthermore, high-severity wildfires and the loss of ponderosa pines may alter fungal community composition, including pine-symbiotic ectomycorrhizal (EM) fungi and saprotrophic fungi, which are important for forest recovery and productivity. My research objectives were to understand the effects of fire severity > 10 years post-fire on: (1) the spatial patterns, and interactions of regenerating ponderosa pine and sprouting tree species, (2) ponderosa pine regeneration niches and seedling growth, and (3) fungal sporocarp and root tip EM community composition and colonization. My study sites for the first objective included large, 4-ha plots located in two types of high-severity (100% tree mortality) burn, either adjacent to residual live forest edges (edge plots) or > 200 m from any residual live trees (interior plots) in two Arizona wildfires, the 2000 Pumpkin and 2002 Rodeo-Chediski Fires.

Tree Regeneration Following Large Wildfires in Southwestern Ponderosa Pine Forests

Tree Regeneration Following Large Wildfires in Southwestern Ponderosa Pine Forests PDF Author: Suzanne M. Owen
Publisher:
ISBN:
Category : Trees
Languages : en
Pages : 177

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Book Description
Wildfires in southwestern US ponderosa pine (Pinus ponderosa Lawson & C. Lawson) forests have recently increased in size and severity, leaving large, contiguous patches of tree mortality, and raising concerns about post-fire recovery. Ponderosa pines are a dominant species in the Southwest and they evolved with low- to moderate-severity fire regimes. They are poorly adapted to regenerate after large, high-severity fires because they do not have serotinous cones, re-sprouting capabilities, or long-lived seed banks. Additionally, high-severity fires can favor competing understory plants or induce long-term changes to soil nutrient dynamics and surface fuel loads, potentially altering ponderosa pine regeneration niches. Furthermore, high-severity wildfires and the loss of ponderosa pines may alter fungal community composition, including pine-symbiotic ectomycorrhizal (EM) fungi and saprotrophic fungi, which are important for forest recovery and productivity. My research objectives were to understand the effects of fire severity > 10 years post-fire on: (1) the spatial patterns, and interactions of regenerating ponderosa pine and sprouting tree species, (2) ponderosa pine regeneration niches and seedling growth, and (3) fungal sporocarp and root tip EM community composition and colonization. My study sites for the first objective included large, 4-ha plots located in two types of high-severity (100% tree mortality) burn, either adjacent to residual live forest edges (edge plots) or > 200 m from any residual live trees (interior plots) in two Arizona wildfires, the 2000 Pumpkin and 2002 Rodeo-Chediski Fires.

Observations on Natural Regeneration in Ponderosa Pine Following a Prescribed Fire in Arizona

Observations on Natural Regeneration in Ponderosa Pine Following a Prescribed Fire in Arizona PDF Author: Stephen S. Sackett
Publisher:
ISBN:
Category : Forest regeneration
Languages : en
Pages : 8

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Book Description


Historical Wildfire Impacts on Ponderosa Pine Tree Overstories

Historical Wildfire Impacts on Ponderosa Pine Tree Overstories PDF Author: Peter F. Ffolliott
Publisher:
ISBN:
Category : Forest fires
Languages : en
Pages : 28

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Book Description
The Rodeo-Chediski Wildfire--the largest in Arizona's history--damaged or destroyed ecosystem resources and disrupted ecosystem functioning in a largely mosaic pattern throughout the ponderosa pine (Pinus ponderosa) forests exposed to the burn. Impacts of this wildfire on tree overstories were studied for 5 years (2002 to 2007) on two watersheds in the area burned. One watershed was burned by a high severity (stand-replacing) fire, while the other watershed was burned by a low severity (stand-modifying) fire. In this paper, we focus on the effects of the wildfire on stand structures, post-fire mortality of fire-damaged trees, and stocking of tree reproduction. We also present a fire severity classification system based on the fire-damaged tree crowns and a retrospective description of fire behavior on the two burned watersheds.

Mitigating Old Tree Mortality in Long-Unburned, Fire-Dependent Forests

Mitigating Old Tree Mortality in Long-Unburned, Fire-Dependent Forests PDF Author: Sharon M. Hood
Publisher: DIANE Publishing
ISBN: 1437939031
Category : Nature
Languages : en
Pages : 80

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Book Description
This is a print on demand edition of a hard to find publication. This report synthesizes the literature and current state of knowledge pertaining to re-introducing fire in stands where it has been excluded for long periods and the impact of these introductory fires on overstory tree injury and mortality. Only forested ecosystems in the United States that are adapted to survive frequent fire are included. Treatment options that minimize large-diameter and old tree injury and mortality in areas with deep duff and methods to manage and reduce duff accumulations are discussed. Pertinent background information on tree physiology, properties of duff, and historical versus current disturbance regimes are also discussed. Charts and tables.

Effects of Timber Harvest Following Wildfire in Western North America

Effects of Timber Harvest Following Wildfire in Western North America PDF Author:
Publisher:
ISBN:
Category : Post-fire forest management
Languages : en
Pages : 60

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Book Description
This synthesis provides an ecological foundation for management of the diverse ecosystems and fire regimes of North America, based on scientific principles of fire interactions with vegetation, fuels, and biophysical processes. Although a large amount of scientific data on fire exists, most of those data have been collected at small spatial and temporal scales. Thus, it is challenging to develop consistent science-based plans for large spatial and temporal scales where most fire management and planning occur. Understanding the regional geographic context of fire regimes is critical for developing appropriate and sustainable management strategies and policy. The degree to which human intervention has modified fire frequency, intensity, and severity varies greatly among different ecosystems, and must be considered when planning to alter fuel loads or implement restorative treatments. Detailed discussion of six ecosystems--ponderosa pine forest (western North America), chaparral (California), boreal forest (Alaska and Canada), Great Basin sagebrush (intermountain West), pine and pine-hardwood forests (Southern Appalachian Mountains), and longleaf pine (Southeastern United States)--illustrates the complexity of fire regimes and that fire management requires a clear regional focus that recognizes where conflicts might exist between fire hazard reduction and resource needs. In some systems, such as ponderosa pine, treatments are usually compatible with both fuel reduction and resource needs, whereas in others, such as chaparral, the potential exists for conflicts that need to be closely evaluated. Managing fire regimes in a changing climate and social environment requires a strong scientific basis for developing fire management and policy. --

Fire Effects Following the Egley Fire Complex (OR, USA) in a Dry Ponderosa Pine Forest

Fire Effects Following the Egley Fire Complex (OR, USA) in a Dry Ponderosa Pine Forest PDF Author: Jessie M. Dodge
Publisher:
ISBN: 9781085577861
Category : Forest management
Languages : en
Pages : 152

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Book Description
Land managers have been using mechanical treatments to reduce fuels in ponderosa pine (Pinus ponderosa) forests to mitigate high severity fire effects. Before the 2007 Egley Fire Complex, mechanical thinning, slash and pile burns, and understory burns were implemented as fuel reduction treatments in the dry ponderosa pine-dominated Malheur National Forest in eastern Oregon. To compare post-fire vegetation recovery between mechanical treatments and untreated control areas, 35 treated and untreated paired plots were sampled in 2016. Sites were stratified by elevation, aspect, and the remotely sensed burn severity gradient represented by the delta Normalized Burn Ratio (dNBR). Post-fire vegetation recovery was assessed at the 35 paired field sites by measuring tree density, seedling regeneration, understory plant response, and fuel loads. The intent of this study was to document to what extent tree density, seedling regeneration, understory plant community composition, and fuels change across the burn severity gradient and to quantify to what extent pre-fire fuel treatments affect burn severity and long term (9 years) vegetation recovery. Estimated site recovery time and other implications for management of dry coniferous forests are discussed.

Effects of Timber Harvest Following Wildfire in Western North America

Effects of Timber Harvest Following Wildfire in Western North America PDF Author: David L. Peterson
Publisher: DIANE Publishing
ISBN: 1437926665
Category : Technology & Engineering
Languages : en
Pages : 60

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Book Description
Timber harvest following wildfire leads to different outcomes depending on the biophysical setting of the forest, pattern of burn severity, operational aspects of tree removal, and other activities. Postfire logging adds to these effects by removing standing dead trees (snags) and disturbing the soil. The influence of postfire logging depends on the intensity of the fire, intensity of the logging operation, and mgmt. activities such as fuel treatments. Removal of snags reduces long-term fuel loads but generally results in increased amounts of fine fuels for the first few years after logging. Cavity-nesting birds, small mammals, and amphibians may be affected by harvest of standing dead and live trees, with negative effects on most species. Illustrations.

Mitigating Old Tree Mortality in Long-Unburned, Fire-Dependent Forests

Mitigating Old Tree Mortality in Long-Unburned, Fire-Dependent Forests PDF Author: Sharon M. Hood
Publisher: CreateSpace
ISBN: 9781480173965
Category : Nature
Languages : en
Pages : 78

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Book Description
Historically, many forested ecosystems in the United States burned frequently, both from lightning ignited fires and from Native American burning. Frequent fire maintained low fuel loadings and shaped forests composed of tree species adapted to survive low-intensity frequent fire. In the early 1900s, the United States government initiated a program to suppress all fires, both natural and anthropogenic. Many unintended consequences have resulted from over a century of fire suppression, such as increased tree densities and fuel, increased stress on older trees from competition, and greater risk of bark beetle attacks. These consequences are especially apparent in forests that historically burned frequently and have thus missed many fire cycles. Maintaining old trees and perpetuating large-diameter trees is an increasing concern. Stands of old trees that were historically common across vast landscapes in the United States are now relatively rare on the landscape because of harvesting (Noss and others 1995). Though logging is no longer the principal threat to most old-growth forests, they now face other risks (Vosick and others 2007). Prescribed fire has become a major tool for restoring fire-dependent ecosystem health and sustainability throughout the United States and use will likely increase in the future. However, increased mortality of large-diameter and old trees following fire has been reported in many areas around the country, and there is increased concern about maintaining these on the landscape (Kolb and others 2007; Varner and others 2005). As early as 1960, Ferguson and others (1960) reported high longleaf pine mortality after a low-intensity prescribed burn consumed the majority of heavy duff accumulations around the base of the trees. Mortality of pre-settlement ponderosa pines in prescribed burn areas in Grand Canyon National Park was higher than in control plots (Kaufmann and Covington 2001). After beginning a forest restoration program that reintroduced fire by prescribed burning at Crater Lake National Park, excessive post-fire mortality of larger ponderosa pine was observed in the burn areas, and early season burns had an even higher mortality than late season burns (Swezy and Agee 1991). Both Swezy and Agee (1991) and McHugh and Kolb (2003) reported a U-shaped mortality distribution for ponderosa pine following wildfires, with smaller- and larger-diameter trees having higher mortality than mid-diameter trees. Forest managers around the country have expressed concerns about large-diameter and old tree mortality when prescribed burning in long-unburned forests. The synthesis herein suggests recommendations for maintaining and perpetuating old trees in fire-dependent ecosystems. It expands on efforts funded by the Joint Fire Science Program (JFSP) to define the issues surrounding burning in fire excluded forests of the United States that are adapted to survive frequent fire. When the JFSP initially funded this synthesis, two JFSP projects were examining the effect of raking on reducing old ponderosa and Jeffrey pine (subsequently published in Fowler and others 2010; Hood and others 2007a). Another JFSP project examined the effect of prescribed burning under different duff moisture conditions on long-unburned old longleaf pine mortality (Varner and others 2007). Two other syntheses were also recently published on this subject: Perpetuating old ponderosa pine (Kolb and others 2007) and The conservation and restoration of old growth in frequent-fire forests of the American West (Egan 2007). The scope of the synthesis herein focuses only on limiting over story tree mortality in species adapted to survive frequent fire; therefore, the implications of fire suppression and fuel treatments on other ecosystem components are not discussed.

Old Growth Ponderosa Pine and Western Larch Stand Structures

Old Growth Ponderosa Pine and Western Larch Stand Structures PDF Author: Stephen F. Arno
Publisher:
ISBN:
Category : Forest fires
Languages : en
Pages : 24

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Book Description


Restoring Spatial Pattern to Southwestern Ponderosa Pine Forests

Restoring Spatial Pattern to Southwestern Ponderosa Pine Forests PDF Author: Dave Egan
Publisher:
ISBN:
Category : Forest restoration
Languages : en
Pages : 12

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Book Description
Until recently, forest managers have largely ignored the value of maintaining dynamic spatial patterns in forested ecosystems. In the America Southwest, where the norm in overstocked forests that are extremely susceptible to catastrophic fires and/or insect infestations and disease, restoring a spatial pattern of openings and tree groups would help alleviate these threats and move the forests within their historic range of variability. This ERI working paper focuses on restoring a dynamic spatial pattern to ponderosa pine forests in the American Southwest. It also addresses basic questions that land managers and others have about how to restore active spatial patterns across the forested Southwest.