Modeling Fire-induced Tree Mortality in Longleaf Pine Using Spatial Data PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Modeling Fire-induced Tree Mortality in Longleaf Pine Using Spatial Data PDF full book. Access full book title Modeling Fire-induced Tree Mortality in Longleaf Pine Using Spatial Data by Holland R. Heese. Download full books in PDF and EPUB format.
Author: Holland R. Heese
Publisher:
ISBN:
Category : Longleaf pine
Languages : en
Pages : 94
Get Book Here
Book Description
Restoration of fire-excluded pine ecosystems is a major conservation and management goal. Land managers have used prescribed fires to reduce accumulated forest floor fuels and restore pinelands. While these fires have been successful at reducing fuels, tree mortality in these restoration fires can be as high as 75 to 95 percent. In this study, I model post-fire mortality of longleaf pine (in two stands in the Mountain Longleaf National Wildlife Refuge in northeastern Alabama) using logistic models composed of only predictors that can be measured pre-fire. These methods are extended by the addition of spatial competition functions since such measures are drawn from available data for managers, and have been shown to have effects on growth and mortality. The best models, selected by AIC, predict survival as well or better than earlier models but have high false mortality predictions. The spatial dynamics of the stand are also studied pre-fire and post-fire to determine the effect of prescribed fire and inter-tree competition. Post-fire, spatial distribution of the trees did not significantly change. Earlier studies detected differences in the spatial dynamics between different classes of longleaf pine. These dynamics were confirmed in some results and in others questioned. Small trees (DBH 30 cm) clustered away from large trees (DBH 30 cm). Large trees were more dispersed than a random process (Poisson) would dictate. Juveniles (DBH
Author: Holland R. Heese
Publisher:
ISBN:
Category : Longleaf pine
Languages : en
Pages : 94
Get Book Here
Book Description
Restoration of fire-excluded pine ecosystems is a major conservation and management goal. Land managers have used prescribed fires to reduce accumulated forest floor fuels and restore pinelands. While these fires have been successful at reducing fuels, tree mortality in these restoration fires can be as high as 75 to 95 percent. In this study, I model post-fire mortality of longleaf pine (in two stands in the Mountain Longleaf National Wildlife Refuge in northeastern Alabama) using logistic models composed of only predictors that can be measured pre-fire. These methods are extended by the addition of spatial competition functions since such measures are drawn from available data for managers, and have been shown to have effects on growth and mortality. The best models, selected by AIC, predict survival as well or better than earlier models but have high false mortality predictions. The spatial dynamics of the stand are also studied pre-fire and post-fire to determine the effect of prescribed fire and inter-tree competition. Post-fire, spatial distribution of the trees did not significantly change. Earlier studies detected differences in the spatial dynamics between different classes of longleaf pine. These dynamics were confirmed in some results and in others questioned. Small trees (DBH 30 cm) clustered away from large trees (DBH 30 cm). Large trees were more dispersed than a random process (Poisson) would dictate. Juveniles (DBH
Author: Stacy Allen Drury
Publisher:
ISBN:
Category : Forest fires
Languages : en
Pages : 32
Get Book Here
Book Description
The National Tree-List Layer (NTLL) project used LANDFIRE map products to produce the first national tree-list map layer that represents tree populations at stand and regional levels. The NTLL was produced in a short time frame to address the needs of Fire and Aviation Management for a map layer that could be used as input for simulating fire-caused tree mortality across landscapes. Simulated tree mortality estimates using the NTLL as model input provided acceptable results when compared with tree mortality simulations using field-sampled tree attribute data. Our results indicate that fire managers can expect simulated tree-mortalities using the NTLL to predict fire-caused tree mortality as well as field-measured plot data, especially during extreme wildfire events. Decision makers can use tree mortality maps that are produced using the NTLL to develop and support decisions such as where to place fuels treatments or where to most effectively position fire suppression resources.
Author: Sharon M. Hood
Publisher: DIANE Publishing
ISBN: 1437939031
Category : Nature
Languages : en
Pages : 80
Get Book Here
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.
Author: Phillip John Van Mantgem
Publisher:
ISBN:
Category : Conifers
Languages : en
Pages : 222
Get Book Here
Book Description
Author: Eva Louise Loudermilk
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
A longleaf pine - hardwood simulation model was created to link population level tree dynamics with fuel characteristics and stochastic fire regimes. This is the first known modeling work to simulate interactions between longleaf pine and hardwoods. Spatial components included seed dispersal (including pine seed masting), clonal spreading (for hardwoods), fuel dispersal and distribution, and competition from neighboring trees. Evaluations with in situ data were promising for two modeled longleaf pine sites. Tree distributions and community stability were examined with varying fire frequency. The model was especially useful in identifying scientific knowledge gaps associated with plant competition and facilitation, especially in relation to hardwood demography. The model ultimately provided a foundation for studying fuel and fire heterogeneity influences on population dynamics.
Author: Elizabeth D. Reinhardt
Publisher:
ISBN:
Category : Fire ecology
Languages : en
Pages : 72
Get Book Here
Book Description
A First Order Fire Effects Model (FOFEM) was developed to predict the direct consequences of prescribed fire and wildfire. FOFEM computes duff and woody fuel consumption, smoke production, and fire-caused tree mortality for most forest and rangeland types in the United States. The model is available as a computer program for PC or Data General computer.
Author:
Publisher:
ISBN:
Category : Forest declines
Languages : en
Pages : 0
Get Book Here
Book Description
Climate change is projected to bring more frequent and prolonged droughts, causing widespread forest die-off. Identifying tree mortality over large spatial extents in response to the most recent California drought will help forest managers and conservationists understand where there may be a greater likelihood of future die-offs. In order to find more at-risk areas, this study evaluated how interacting site-specific topographic, climate, substrate, and stand characteristics mediated tree mortality in the Central Sierra Nevada during the 2012-2016 drought. The author used lidar and hyperspectral imagery provided by the National Ecological Observatory Network to identify individual dead trees using the Random Forest classification method and created a Random Forest Regression model to assess site-specific environmental variables that had a greater influence on tree mortality. The results show that the most influential variables were tree height, density, and elevation. Results also found higher mortality rates in pines and oaks, meaning further widespread die-off of these trees could reduce forest productivity, increase fire hazard risk, and drive a shift in community composition over the long-term. This study provides a finer resolution mapping of tree mortality over the research area than was reported by the USFS Aerial Detection Survey. Due to the confounding evidence regarding the relative influence of environmental factors on tree mortality during droughts, these results provide robust information to help maintain these changing forests in a climate-informed manner. Because this study is site-specific, more research is needed to assess how environmental factors mediate drought-induced mortality in other regions also projected to have more intense droughts as a result of climate change.
Author: Jason Herynk
Publisher: Createspace Independent Publishing Platform
ISBN: 9781480144408
Category :
Languages : en
Pages : 30
Get Book Here
Book Description
The National Tree-List Layer (NTLL) project used LANDFIRE map products to produce the first national tree-list map layer that represents tree populations at stand and regional levels. The NTLL was produced in a short time frame to address the needs of Fire and Aviation Management for a map layer that could be used as input for simulating fire-caused tree mortality across landscapes. Simulated tree mortality estimates using the NTLL as model input provided acceptable results when compared with tree mortality simulations using field-sampled tree attribute data. Our results indicate that fire managers can expect simulated tree-mortalities using the NTLL to predict fire-caused tree mortality as well as field-measured plot data, especially during extreme wildfire events. Decision makers can use tree mortality maps that are produced using the NTLL to develop and support decisions such as where to place fuels treatments or where to most effectively position fire suppression resources.
Author: James F. Fowler
Publisher:
ISBN:
Category : Douglas fir
Languages : en
Pages : 32
Get Book Here
Book Description
This review focused on the primary literature that described, modeled, or predicted the probability of postfire mortality in ponderosa pine (Pinus ponderosa) and Douglas-fir (Pseudotsuga menziesii). The methods and measurements that were used to predict postfire tree death tended to fall into two general categories: those focusing on measuring important aspects of fire behavior, the indirect but ultimate cause of mortality; and those focusing on tissue damage due to fire, the direct effect of fire on plant organs. Of the methods reviewed in this paper, crown scorch volume was the most effective, easiest to use, and most popular measurement in predicting postfire mortality in both conifer species. In addition to this direct measure of foliage damage, several studies showed the importance and utility of adding a measurement of stem (bole) damage. There is no clear method of choice for this, but direct assessment of cambium condition near the tree base is widely used in Douglas-fir. Only two ponderosa pine studies directly measured fine root biomass changes due to fire, but they did not use these measurements to predict postfire mortality. Indirect measures of fire behavior such as ground char classes may be the most practical choice for measuring root damage. This review did not find clear postfire survivability differences between the two species. The literature also does not show a consistent use of terminology; we propose a standard set of terms and their definitions.
Author: Sharon M. Hood
Publisher: CreateSpace
ISBN: 9781480173965
Category : Nature
Languages : en
Pages : 78
Get Book Here
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.
