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PAGE UNDER RE-CONSTRUCTION 11/09/2011

Current Projects    Click project title to view abstract.
Completed Projects    Click project title to view abstract.
Research Abstracts from the Stephens Lab:

Sierra Nevada Adaptive Management Plan
Scott Stephens, Associate Professor of Fire Science, University of California Berkeley   stephens@nature.berkeley.edu 
and other University of California Faculty

 The goals of the research proposed here is to learn how to use an adaptive management and monitoring system to understand ecosystem behavior, incorporate stakeholder participation, and inform the implementation of adaptive management for Forest Service lands in the Sierra Nevada of California. The preferred alternative is to apply strategic fuel management at the landscape level. The approach is based on the theory (Finney 2001) that disconnected fuel treatment patches that overlap in the direction of the head fire spread reduce the overall rate and intensity of the fire. Despite the sound conceptual underpinning of strategic fuel treatments, there is uncertainty regarding their efficacy in modifying fire behavior and concern regarding potential impacts on wildlife and water resources. Scott Stephens and John Battles are leading the Fire and Forest Health module of this project.

 The three main questions will investigate address include modification of fire behavior across a fireshed, tree morbidity and mortality patterns associated with treatment design, and secondary effects of SPLATs on forest health through insect interactions. We expect that the strategic fuel manipulations will modify fire behavior in the treated fireshed as predicted by Finney’s (2001) model. In terms of tree morbidity and mortality across the fireshed, we expect that the management regime will improve tree growth and survival within the treated areas and the immediate edge environments. The removal of some fraction of the vegetation will reduce competitive stress on the remaining trees. However, the extent of improvements of tree health across the landscape will depend on the specific spatial arrangements of the treatments. At the local level, there may be instances where insect interactions in the residual forest left after the creation of SPLATs have a negative effect on tree health. For example, if mechanical methods are used alone to reduce small tree density and the resultant activity fuels (i.e., slash) is left on site, it could provide habitat for Ips beetles to multiply. Ips beetles can seriously injure and kill trees under outbreak conditions. Alternatively, if prescribed fire is used to consume natural and activity fuels, we expect red turpentine beetles to attack residual pine trees (ponderosa, sugar, and Jeffrey pines). Such attacks may predispose these trees to the often lethal predation of mountain and western pine beetles. Our tree measurement and monitoring program is designed to capture both landscape and local impacts on tree health. This complexity related to issues of scale and ecological interactions further reinforces the need for a strong adaptive management program to reduce the uncertainty associated with the implementation of SPLATs. More information can be found at http://snamp.cnr.berkeley.edu/

 

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 Mechanisms and probability of fire scar formation in Monterey pine trees.
Scott Stephens, Associate Professor of Fire Science, University of California Berkeley   stephens@nature.berkeley.edu 
Rick Everett, Postdoctoral Researcher, Wildland Fire Lab, University of California Berkeley  everett@nature.berkeley.edu

This research addresses a number of fundamental questions about how and when forest trees are scarred by wildfire: what is the mechanism of fire-scar formation, what is the probability of scarring occurring on a tree which has never been previously subjected to fire, and what is the probability of recording another fire  compared to neighboring unscarred trees?   Radiant transfer of sufficient heat to damage or kill the cambial tissues beneath bark as the mechanism of scarring is well known, and is employed here to test the research hypothesis that significantly increased levels of scarring will occur when 1000 hour fuels are emplaced adjacent to trees during prescription fire treatments in otherwise uniform fuel loads.  Our null hypothesis is that fire scar formation will not differ between trees subject to prescription fire, irregardless of species, slope, or fuels manipulations.  As an initial test of both protocol & hypothesis, pilot studies have been placed within research-completed portions of Western Gall Rust study plantations, at the UC’s Center for Forestry Russell Research Station (RRS), Lafayette, California.  These studies co-ordinate with prescription fire plans for inactive research plots.  The species to be investigated is Monterey Pine.  The subject trees are a mix of subspecies, all 20-22 years of age, greater than 20cm dbh, and all within similar topographical constraints. 

 

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A Study of the Consequences of Fire and Fire Surrogates (Fire and Fire Surrogates for Forest Restoration)
Scott Stephens, Associate Professor of Fire Science, University of California Berkeley (P.I. Blodgett Forest Study Site)  stephens@nature.berkeley.edu 
Jason Moghaddas
, Staff Researcher, University of California Berkeley (Site Manager Blodgett Forest Study Site)  moghad@nature.berkeley.edu
and other UC Faculty

Compared to historic conditions, many forests in the U.S. are now more dense and have more down fuels. For years, managers have recognized this problem and have acted to reduce stem density and fuels by thinning, burning, and/or fuel treatments Yet although silvicultural treatments can mimic the effects of fire on structural patterns of woody vegetation, virtually no comparative data exist on how these treatments mimic ecological functions of fire. For many, the long term goal of these treatments is to restore historic ecosystem structure and function. Thus while silvicultural treatments can create patterns of woody vegetation that appear similar to those that fire would create, the consequences for nutrient cycling, seed scarification, plant diversity, disease and insect abundance, and wildlife are mostly unknown. Similarly, although combining managed fire with silvicultural treatments adds the critical effects of combustion, we know little about ecological effects, economics, and fire hazard reduction of these methods.  

The Fire-Fire Surrogate (FFS) study responds to this void in our knowledge. The USDI-USDA Joint Fire Science Program has provided funding for a long-term study to assess how ecological components or processes may be changed or lost, if fire "surrogates" such as cuttings and mechanical fuel treatments are used instead of fire, or in combination with fire.  

For more information, visit::
FFS – Blodgett Study Site 

FFS – National Home

Photo gallery

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Fire History, Climate, and Forest Structure of the Sierra San Pedro de Martir Mountains, Mexico
Scott Stephens, Associate Professor of Fire Science, University of California Berkeley  stephens@nature.berkeley.edu
Samantha Gill, Asst. Professor, Natural Resources Management Dept., Cal Poly State University  sgill@calpoly.edu
Carl Skinner, Research Geographer, US Forest Service PSW Research Station  cskinner@fs.fed.us

Past logging practices and the policy of fire suppression during the last century has drastically changed the composition and structure of California’s east-side coniferous forests. One mixed conifer ecosystem exists in North America where logging has never occurred and a policy of wide-scale fire suppression was never initiated, this area is in the Sierra San Pedro Martir (SSPM), Mexico. The SSPM is unique within the California floristic province in that its open forests are still influenced by a lightning ignited fires that are very similar to those that once occurred in the Transverse Ranges and possibly the eastern Sierra Nevada. The objective of this project are to spatially analyze fire history, past climate, and corresponding forest structure information (fuel loads, snag densities, live tree and seedling densities, size of regeneration patches) in the coniferous forests of the SSPM. Wildfires continue to destroy millions of acres annually in the western United States but there is currently great debate on desired future conditions. The mixed conifer forests of the SSPM can provide information on one type of desired future condition, forests that have not been modified by active management. This information could be used to help describe desired future conditions of California’s mixed conifer forests.

Photo Gallery

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The Eastern Sierra Nevada and the Sierra San Pedro de Martir:  A comparison of fire history, climate and forest structure
Scott Stephens, Associate Professor of Fire Science, University of California Berkeley  stephens@nature.berkeley.edu
Domenico Caramagno, Staff Researcher, University of California Berkeley  dcaramagno@nature.berkeley.edu 

High severity wildfires are common in pine forests of the western United States. Many have suggested this is primarily due to changes in stand structures and composition from past logging and systematic fire suppression of the last century. There is currently debate on appropriate target conditions for fire hazard reduction and forest restoration. This is due to the lack of unmanaged forests that could serve as references in the western US. The pine-dominated, mixed conifer forests of the Sierra San Pedro Martir (SSPM), Mexico, have not experienced logging and systematic fire suppression. The SSPM is unique within the California floristic province in that its forests are still regularly influenced by fires similar to those that once occurred throughout the western United States. The mixed conifer forests of the SSPM may provide information on reference conditions for forests that prehistorically experienced frequent, low to moderate intensity fires. This information could be used to help develop target stand conditions for reducing the fire hazard in large portions of California and Nevada mixed conifer forests. The objectives of this project are to compare climate, fire history, and stand structures of coniferous forests of the Sierra San Pedro Martir with similar forests of the eastern Sierra Nevada. This project will spatially analyze fire history, past climate, and corresponding forest structure information (fuel loads, snag densities, live tree and seedling densities, size of regeneration patches) and compare them to forests in the Sierra San Pedro Martir.

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Fire History of Blodgett Forest Research Station Using Fire Scars in Calocedrus Decurrens
Scott Stephens, Associate Professor of Fire Science, University of California Berkeley  stephens@nature.berkeley.edu
Brandon M. Collins, University of California Berkeley Doctoral Candidate bcollins@nature.berkeley.edu

The objective of this research is to create a fire history for the University of California Berkeley research forest, Blodgett Forest.  This involves assigning dates to individual fires recorded within the growth rings, called fire scars.  The method for assigning dates is called cross dating. Cross dating involves comparing ring width sequences of unknown dates, to a set of ring width sequences of known dates.  The set of ring width sequences of known dates is called a master tree ring chronology.  In many areas, master tree ring chronologies have already been developed.  In our case, at Blodgett Forest, we found it necessary to create our own master tree ring chronology.  We chose to do this because most of the established master tree ring chronologies in areas near Blodgett Forest were for pines.  Most of our samples with fire scars are from Calocedrus decurrens, and we haven’t found good correlation in ring width sequences between the pines and Calocedrus decurrens. Once we feel we have sampled a large enough area, and collected enough fire scar samples, we will be able to say, with some certainty, when the major fire events occurred in the last 350 years.  And, we will be able to describe the fire return interval in the last 350 years.  We will hopefully be able to see if the fire return interval changed with a number of variables, such as: topography, distance to riparian areas, and time.

Detailed project description and photos

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Stand Structure and Fire History in a Native Monterey Pine Forest
Scott Stephens, Associate Professor of Fire Science, UC Berkeley  stephens@nature.berkeley.edu
Doug Piirto, Professor of Silviculture and Forest Mangement, Cal Poly State University  dpiirto@calpoly.edu 

Monterey pine is an interesting species that has a crown stored seed back (closed cone) but lives on the coast of California where crown fires may be rare. This study has investigated the age structure and fire history of the Ano Nuevo Monterey pine forest near Santa Cruz. The goal is to determine if tree ages are clumped around one or more fire events or if the stands exhibit multiple age characteristics. The history of fire will also be determined over the last 100 years using dendrochronlogy. Sampling has been relatively extensive in Cal Poly's Swanton Pacific Ranch Research Station. Age structure of coast live oak and Douglas-fir will also be investigated in this Monterey pine forest.

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Fire History of Mixed Conifer Forests of the Transverse and Peninsular Ranges of Southern California 


Rick Everett, Postdoctoral Researcher, Wildland Fire Lab, University of California Berkeley  everett@nature.berkeley.edu
Scott Stephens, Associate Professor of Fire Science, University of California Berkeley stephens@nature.berkeley.edu
Carl Skinner, Research Geographer, Forest Service Pacific Southwest Experimental Station (Redding) cskinner@fs.fed.us

The USFS recently released the Southern California Mountains and Foothill Assessment for the Cleveland, San Bernardino, Angeles, and Los Padres National Forests. This assessment identified fire management as one of its important goals but only one published fire history study is available to assist in plan development. The single fire history study did not use cross-dating and had a very limited spatial extent. Information on past fire season was not obtained. Lack of comprehensive information makes it extremely difficult to understand past fire dynamics in this large, diverse area. The science of dendrochronology has been used in many areas of the United States to quantify past fire regimes. When cross-dating techniques are used an accurate and precise reconstruction of fire frequency, fire season, and fire extent can be created. Some have hypothesized that forest fires in the southern California mountains were of relatively high severity and more infrequent than other pine dominated ecosystems. A dendrochronology based fire history study in this region will provide strong evidence to support or refute this hypothesis. Should managers design fire management plans to incorporate relatively infrequent (25-40 years), moderate-high severity fires or should they include frequent (5-15 years), low-moderate intensity fires? What season of fire should be prescribed? At present it is not possible to answer these questions. The objective of this project is to collect, cross-date, and analyze fire history information from the Cleveland, San Bernardino, Angeles, and Los Padres National Forests in southern California. The interaction of climate and past fires will also be examined. Information from this study can assist in development of fire management and forest plans that will be revised in response to the Southern California Mountains and Foothills Assessment.

For more information about this project, please visit the website:

JFSP Fire History Southern California

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Landscape Fuel Treatment Effectiveness in the Plumas and Lassen National Forests
Kurt Menning, Postdoctoral Fellow, University of California  Berkeley  kmenning@nature.berkeley.edu
Scott Stephens, Associate Professor of Fire Science, University of California  Berkeley  stephens@nature.berkeley.edu

The goal of this project is to determine how landscape level fuels and silvicultural treatments affect potential fire behavior and effects. Past management activities including fire suppression, harvesting, and livestock grazing have changed the structure of many coniferous forest in the western United States, particularly those that once experienced frequent, low to moderate intensity fires. Changes in climate over the 20th century also have influenced present ecosystem structure. Restoration of these ecosystems is a common goal but there currently is limited information of the effects of such treatments, particularly at the landscape scale. This project will link remotely sensed data to ground based data at the watershed scale (17,800-32,000 ha). Spatially explicit fire effects models will be developed to evaluate the effectiveness of the different treatments.

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Fire History of the Plumas National Forest 
Tadashi Moody, University of California  Staff Research Associate tmoody@nature.berkeley.edu
Scott Stephens, Associate Professor of Fire Science, University of California  Berkeley  stephens@nature.berkeley.edu

Dendrochronological techniques are employed to develop a record of historical and pre-historical fire events in the Plumas National Forest, by dating fire scar formation in tree ring sequences. A collection of stump and remnant wood cross-sections werecollected from 1997 to 2000 by US Forest Service staff. These samples represent a variety of Sierra Nevada mixed-coniferous species, elevations and microsites. Using fire history developed from these stumps and forest inventory data, differences and changes in fire regimes over time and space are analyzed.

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Landscape Scale Effects of Prescribed Natural Fire Programs in Three Wilderness Areas 
Brandon Collins, Doctoral Candidate, Wildland Fire Sciences bcollins@nature.berkeley.edu
Scott Stephens, Associate Professor of Fire Science, University of California Berkeley  stephens@nature.berkeley.edu

In the early 1970's, the National Park Service and the Forest Service introduced the Prescribed Natural Fire (PNF) program [now called the Wildland Fire Use (WFU) Program] in several wilderness areas, in efforts to restore fire as a natural ecosystem process. The Sugarloaf-Roaring River region of the Sequoia-Kings Canyon National Park, the Illouette Creek Basin in Yosemite, and the Gila Wilderness in New Mexico were among the first areas in which naturally ignited fires have been allowed to burn under prescribed conditions, as long as they do not threaten life or property. This project proposes to evaluate the effectiveness of this program on a landscape scale using, ground based sampling of forest characteristics and Geographic Information Systems (GIS) analyses. The primary research questions are: 1) Are fires in these wilderness areas becoming limited in size and effects? and 2) How have forest characteristics such as ground, surface, and ladder fuels, forest structure, composition, biodiversity been affected at different scales by short interval fires? Ground based measurements are aimed at sampling these characteristics in burned and unburned portions of the study areas. GIS analyses will examine changes in fire shapes and aerial extents over time. Synthesis of ground and GIS analyses will help determine how WFU policies have affected forest processes and resiliency, as indicated by forest and fire characteristics. This may lend information to today's debates about roadless area management and ecosystem restoration.

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Does Dirt Burn? Soil Response To Forest Harvest And Prescribed Fire
Emily Moghaddas, University of California Berkeley Doctoral Candidate   emoghaddas@nature.berkeley.edu

As part of the Fire and Fire Surrogate Study, I am assessing soil responses to fuel manipulations at University of California Berkeley's Blodgett Forest Research Station in the northern Sierra Nevada. To experimentally reduce fuel loads, we are using prescribed fire, mechanical thinning, and a combination of thinning and fire. How will soil properties and processes respond to fire? How will this compare to mechanical harvests with chainsaws and skidders? How are these related to vegetation responses? What are the implications for forest management? I am investigating physical, chemical, and biological soil characteristics to shed light on these questions. The forest harvest component will be complete by fall, 2001. Prescribed burning is scheduled for fall, 2002. But the fun has already begun!

For more information, visit::
FFS – Blodgett Study Site 

FFS – National Home

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Ecological Effects of Fire and Silviculture Treatments in the Stanislaus National Forest 
Leda Kobziar, Assistant Professor, Fire Science and Forest Conservation, University of Florida 

The forests of the Granite Project Area, in the Groveland District of the Stanislaus National Forest, suffered high mortality from a wildfire in 1973. Following the burn, an area of approximately 4500 acres of mixed-conifer second growth forest was replanted predominately with ponderosa and Jeffrey pine. Potential fire danger in these stands is increasing yearly. My dissertation project involves measuring some key ecological responses to combinations of silvicultural and prescribed burning treatments designed to reduce fuel loads and promote sustainability. I will model fire behavior both before and after treatments, and compare measures of seedbank composition, soil chemistry, understory plant community dynamics, tree vigor, incidence of disease or insect pathogens, and fuels characteristics. I will also work to approximate the effect of the treatments on carbon relations, flux, and the net capacity of the stands to sequester carbon.

For more information, visit:
http://www.r5.fs.fed.us/stanislaus/groveland/granite/index.htm

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Ecological Diversity in Chaparral Following Prescribed Fire and Mastication in Varying Seasons
Jennifer Potts, University of California Berkeley Doctoral Candidate  jpotts@nature.berkeley.edu  

High severity wildfires are common in chaparral and present serious risks to human life and property, particularly in urban-wildland intermix areas. The objective of this study is to contrast prescribed burning with mastication in reducing fire hazard. This study will examine the effect of season of treatment --fall, winter and spring-- on 1) fire hazard reduction, 2) recovery of vegetation, 3) resurgence of fuels and 4) costs of treatments. Study sites are located in Mendocino County at the University of California Hopland Research & Extension Center and BLM Cow Mountain Recreation Area. This project is funded by the Joint Fire Science Program.

Project Website

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The Fire and Fire Surrogate Study: Effects of Fire and Mechanical Treatments on Wildlife
Andrew J. Amacher, University of California Berkeley Doctoral Candidate aamacher@nature.berkeley.edu



 

Fire is a natural component of California coniferous forests. A legacy of fire suppression has created current forest conditions that do not reflect historical conditions. In the absence of fire, current forests are much denser, have higher fuel loads, and have been invaded by fire-intolerant species. Restoration of forests by fuel reduction can be achieved through both prescribed fire and/or mechanical treatments (fire "surrogates"). Although fire surrogate treatments can mimic the effects of fire on structural patterns of woody vegetation, virtually no data exist on the ability of fire surrogates to mimic ecological functions of fires. The Fire and Fire Surrogate study (FFS) is a national program, funded by the Joint Fire Sciences Program, to quantify the ecological and economic consequences of prescribed fire and mechanical fuel-reduction treatments. Thirteen ecosystems have been selected across the United States that were once maintained by frequent fire. At each site, a strict set of measurement protocols is being used to study ecosystem structure, vegetation, fuels, small mammals, herpetofauna, avifauna, soils, entomology, pathology, economics, and utilization. I am conducting my research on wildlife at Blodgett Forest Research Station, located near Georgetown, California. Twelve mixed-conifer stands (15-25 hectares) with similar stand structure, composition and management histories were selected randomly from a set of available stands. Each selected stand was randomly assigned to 4 treatment groups: control (no manipulation), prescribed fire only, mechanical only (both thinning and mastication combined), and mechanical/fire combined. For local avifauna and mammalian species, community diversity and structural changes will be monitored and species-specific abundance tracked through time. Avian nest productivity, nest site selection and foraging behavior will be documented. Coupled with collaborative research on soils, insects, fire, vegetation, and forest pathology, this research will provide quantitative information on not only wildlife responses, but ecosystem responses as well.

For more information, visit::
FFS – Blodgett Study Site 

FFS – National Home

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Fire-Fire Surrogate Study: an Entomological and Pathological Analysis
Dan Stark, University of California Berkeley Doctoral Candidate danstark@nature.berkeley.edu  

At Blodgett Forest Research Station located in El Dorado County, CA, entomological and pathological pre-treatment data were obtained for each plot in each of four treatment areas (control, mechanical only, fire only, and mechanical plus fire) each replicated three times in June and July 2001. In addition, 360-degree scans were taken from each plot center to identify symptomatic trees (discolored foliage) outside of the plot areas. The incidence and severity of various bark beetle killed trees, trees exhibiting defoliation, scale insects, as well as root diseases, mistletoes, rusts, and other diseases are being compiled and analyzed. These data will be collected again in all plots on an annual basis for up to five years post-treatment

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Fire History of the Whiskeytown National Recreation Area
Scott Stephens, Associate Professor of Fire Science, University of California Berkeley  stephens@nature.berkeley.edu
Danny Fry, Staff Researcher, University of California Berkeley  dfry@nature.berkeley.edu

The forests in the Klamath mountains are very diverse in both species composition and topography and it is unknown how past fires affected this diverse ecosystem. Some have hypothesized that forest fires in this region were of relatively high severity and more infrequent than other pine dominated ecosystems. A dendrochronology-based fire history study in this region will provide strong evidence to support or refute this hypothesis. Should managers design fire management plans to incorporate relatively infrequent (25-40 years), moderate-high severity fires, or should they include frequent (5-15 years), low-moderate intensity fires as well? The overall goal of this work is to quantify the past fire regimes through collection, cross-dating, and analyzing samples of fire-scarred trees from the Whiskeytown National Recreation Area. Fire scar samples have already obtained by park staff, which will be supplemented by University of California Berkeley researchers. The interaction of climate and past fires will also be explored. Information from this study can assist in development of plans fire management and restoration plans.

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The Effects of Seasonal Prescribed Fire and Fire Surrogates on Crown-Fire Adapted Knobcone Pine Forests
Danny Fry, Staff Researcher, University of California Berkeley  dfry@nature.berkeley.edu

Knobcone pine (Pinus attenuata) forests are challenging to manage because high intensity crown fires are thought to be necessary for successful regeneration. The use of prescribed crown fires produces high amounts of emissions and air quality regulators are becoming less supportive of such fires, especially if alternatives treatments are available. Many knobcone pine forests are surrounded by urban-wildland intermix areas and some (BLM Cow Mountain) are used for recreational purposes such as off-road vehicle use and camping which further restricts management options. The use of high severity crown fires is rare in these ecosystems, particularly in the historic fall season when adjacent vegetation is at high fire risk. The effects of the season of prescribed fire and fire surrogates is not understood in knobcone pine forests. Burning in the spring reduces the chance for fire escapes but may be inappropriate for regeneration because this coincides with the beginning of the dry season. There is no published information on the effects of fire surrogates treatments (tree falling and lop and scatter of activity fuels with and without prescribed fire) in these ecosystems. The objective of this study is to contrast the efficacy of prescribed burning in different seasons, mechanical methods and fire, and mechanical methods alone in regenerating knobcone pine forests. This work will assist in the development of land management plans for the BLM Cow Mountain National Recreational Area. In achieving the primary objective several secondary objectives will be addressed including the effect of the season of fire and fire surrogates on (1) fire hazard reduction, (2) recovery of competing vegetation, (3) resurgence of fuels, and (4) costs of the different treatments, and (5) identification of the most effective treatment for regeneration of knobcone pine that is least intrusive to air quality. An experiment is proposed at the Bureau of Land Management Cow Mountain Recreation Area using a complete randomize design with replication (3 replicates for prescribed fire treatments including spring and fall burns, 3 replicates of mechanical and fire treatments including felling and lop and scatter followed by prescribed fire in spring and fall, and 3 replicates of mechanical only in spring and fall).  Pre-treatment vegetation and fuels data will be collected in all units and post-treatment tree, shrub, and fuel variables will be measured. Technology transfer will occur with a combination of written materials, a world wide web site, and short courses for manages. The University of California Extension services will be used to disseminate results. This is a five-year project funded by The Joint Fire Sciences Program, Bureau of Land Management-Ukiah Field Office, California Department of Forestry and Fire Protection, and UC Berkeley.

Project Webpage

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Reconstructing Late Holocene Changes in Climate, Vegetation, and Fire Regimes in the Sierra San Pedro Martir Mountains, Mexico, through Microfossil Analysis
Rand Evett, Assistant Researcher, University of California Berkeley   revett@sonic.net

In association with Scott Stephens' fire history study in the Sierra San Pedro Martir Mountains in north central Baja California, I am reconstructing large scale changes in vegetation and fire regime that have occurred in the coniferous forest from a couple of thousand years to the present. I have sampled sediment from several promising chronologically stratified sites. From each layer of sediment, I am chemically extracting a variety of microfossils that are identified and counted microscopically to provide insight into the paleoenvironment at the time of deposition. Fossil pollen, when preserved, provides valuable evidence of the presence and extent of a wide range of vegetation, particularly trees. Opal phytoliths, microscopic bodies of silica that are deposited in plants and released into the soil as they decay, are very useful for determining the nature of understory vegetation, particularly grasses. Diatoms record changes in the hydrologic regime of the sediment. Changes in the concentration of macro and microscopic charcoal indicate long term changes in the fire regime.

Detailed project description and photos

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Fire Hazard and Silvicultural Systems: 25 Years of Experience from the Sierra Nevada
Jason Moghaddas, Staff Researcher, University of California Berkeley moghad@nature.berkeley.edu
Scott Stephens, Associate Professor of Fire Science, University of California Berkeley stephens@nature.berkeley.edu 

Silviculture systems influence fire hazard by changing the arrangement and quantities of live and dead biomass. Each system regulates forest growth and development but their long-term influence on fire hazard is largely unknown. Using archived data from the Blodgett Forest Research Station (BFRS) Interactive Web Database, this paper determines if significant differences (p < 0.05) exist in fuel characteristics (1, 10, 100, 1000 hour, duff, and litter loads), surface fuel depth, crown cover, and height to live crown base between several treatment types at BFRS. We used Fuels Management Analyst™ to compare fire performance in these treatment types in terms of a) rate of spread, b) flame length, c) fire line intensity, d) crowning index , and e) torching index. Treatment types include a) single-tree selection, b) commercial thinning from below, c) over story removal, d) regeneration units less than 5 years old, e) regeneration units xx-xx years old with no treatments after planting, f) regeneration units that have been pre-commercially thinned using a rotary masticator, g) regeneration units that have been pre-commercially thinned using chainsaw crews, h) reserve units with an old growth component, i) young growth reserve units greater than 60 years old. All areas have experienced a policy of fire suppression over the last century. Activity fuels were lopped and scattered with the exception of regeneration units which were tractor piled and burned. With the exception of fuel depth, surface fuel characteristics were generally not significantly different between reserve and non-plantation treatment units. Fuel depth in old growth reserve units was deeper than that in over story removal units. Preliminary analysis indicate that activity fuel treatments must be an integral component of silvicultural systems to produce forests with low surface fuel hazard. We will report our findings on fire performance at the Blodgett Symposium.

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Translating SPLATs from a theoretical to a real world landscape: The implications of fuel management strategies for Sagehen Creek Basin, Tahoe National Forest

Nicole Vaillant, University of California Berkeley Graduate Student, vaillant@nature.berkeley.edu

Nearly a century of fire suppression in the Sierra Nevada has had the unintended consequence of placing millions of hectares of forest at risk of catastrophic fire. Modifying wildland fire behavior across landscapes in the Sierran National Forests has been identified as a management priority. The preferred response is to apply strategic fuel treatments at the landscape level, yet there is little guidance for the implementation of this strategy. Sagehen Creek Basin in the Tahoe National Forest provides a representative landscape, where the accumulation of forest fuels has created a severe risk of catastrophic wildfire. The primary goal of the proposed administrative study is: To evaluate the effectiveness of strategically placed area treatments (SPLAT) in reducing fire hazard at Sagehen Creek Basin. Our approach is first to build a field-parameterized version of the fire behavior model, FARSITE, and simulate alternative fuel management designs. The performances of these designs would be evaluated in terms of slowing fire spread and reducing fire intensity. The data needed to develop the map layers for FARSITE would be obtained from a network of geo-referenced field plots where we would measure the fire-relevant attributes of the vegetation and the surface fuels. Since these attributes are not only heterogeneous but also resistant to measurement via remote sensing, we will explore innovative, efficient field methods for assessing fuel loads. We will capitalize on the long-term monitoring record at Sagehen to quantify the recent trends in forest change and use the results to inform fuel management strategies. Our hope is that the specific lessons learned during this intensive study of one landscape will help guide planning for other management units in the Tahoe National Forest and other forest in the Sierra Nevada. The presence of Sagehen Creek Field Station provides vital infrastructure support to extend these results to both professional managers and the interested public.

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Evaluating Changes in Fire Hazard in Coastal Oak Woodlands Due to Sudden Oak Death Syndrome

Travis Freed, University of California Berkeley Graduate Student , tfreed@nature.berkeley.edu

 
A widespread forest disease, Sudden Oak Death  (SOD) caused by the pathogen Phytophthora ramorum,  is altering forest structure and composition along the California coast.   We are studying the effects of SOD on the fire hazard and fire risk in Marin County's coastal woodlands.   This refers to the probability that a specific area will burn at a high intensity, which not only creates conditions that put lives and property at risk but causes ecological changes that are beyond an ecosystems ability to recover.   The change in fire hazard is likely expressed in a pulse of ground fuel that follows the death of a tree and the changes to microclimatic variables.   Changes in the microclimate will likely cause changes in understory composition in the longer term.   In the short term, the increase in incident solar radiation will lower relative humidity, quicken the drying of fuels and increase average wind speed throughout affected areas.   All of these factors influence fire behavior.
      Many studies have documented the accumulation of fuel due to the exclusion of fire in Western pine forests.  Accumulation of fuel in coastal mountains is less well understood.   One thing is certain, fuel levels and fuel structure is being fundamentally altered due to the effects of SOD.   The focus of this study is to determine to what degree this changing fuel structure may be changing potentially destructive fire behavior in Marin county.     

http://www.suddenoakdeath.org/

 

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Effectiveness of prescribed fire as a fuel treatment in Californian coniferous forests.

Nicole Vaillant, University of California Berkeley Graduate Student, vaillant@nature.berkeley.edu

 

 

 

 Effective fire suppression for the past century has altered forest structure and increased fuel loads in many forests. Prescribed fire as a fuels treatment can reduce wildfire size and severity. This study investigates how prescribed fire affects fuel loads, forest structure, potential fire behavior, and modeled tree mortality at 80th, 90th, and 97.5th percentile fire weather conditions on eight National Forests in California. Potential fire behavior and effects were modeled using Fuel Management Analyst.  Prescription burning did not significantly change forest structure at most sites. Total fuel loads (litter, duff, 1, 10, 100, and 1000-hour) were reduced by 23 to 78 percent across the sites. This reduction in fuels altered potential fire behavior by reducing rate of spread, flame length, and fireline intensity. Increased torching index values coupled with decreased fuel loads reduced crown fire potential post-treatment in some stands. Predicted tree mortality decreased post-treatment as an effect of reduced potential fire behavior and fuel loads. With the vast forested areas classified at high risk for catastrophic wildland fire in California, it is most efficient to target stands that benefit the most from treatment.

          

 

 

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Sierra Nevada Forests: Quantification of Forest Change since 1911

Rick Everett, Postdoctoral Researcher, Wildland Fire Lab, University of California Berkeley  everett@nature.berkeley.edu
Scott Stephens, Associate Professor of Fire Science, University of California Berkeley stephens@nature.berkeley.edu

 

 

 

The Sierra Nevada 1911 project is assessing change in mixed-conifer forests since 1911 in portions of the Yosemite National Park and the adjoining Stanislaus National Forest.  This project compares mixed-conifer forests in in relatively unmanaged Yosemite National Park lands, with adjoining off-park lands, subject to the effects of fire suppression, logging, and diverse forms of management.  These assements are possible using a forest inventory survey performed in both areas in 1911, prior to the Park aquisition of these lands.  Changes in vegetation, and some of the factors affecting these plant communities will be described using detectable alterations in variables such as species size, composition, and stand structure.  The role of fire within this vegetation is reconstructed using fire scar dendrochronological samples tied directly to the reconstructed 1911 transects.  As such, these methodologies form a basis for a large scale landscape level description of changes within a Sierran mixed conifer plant community during the last 95 years, as well as providing insight into the fire regime of the last 5 centuries.  This will ultimately mesh fire regime history and vegetation change into a suite of information crucial to the management of forests within both Park lands and adjoining National Forest lands.

           

 

 

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