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Sharon M. Hood

Sharon Hood

Research Ecologist

Address: 
5775 Highway 10 West
Missoula, MT 59808-9361
Phone: 
406-329-4818
Fax: 
406-329-4877
Contact Sharon M. Hood

Current Research

The primary focus of my research is on how fire affects trees and ultimately forest dynamics. My past and current research falls into three broad categories:

  1. What are the causes and mechanisms of postfire tree mortality? Surprisingly, tree death is still not well understood and therefore hampers efforts to accurately model and predict the impact of disturbance and climate change on tree mortality. My research seeks to understand fire-related factors leading to tree death and the causes of tree mortality. Currently, my research in this area focuses on the impacts of fire and climate on tree carbon allocation patterns to defense, storage, and growth to determine how allocation relates to tree mortality. 
  2. How do changes in fire regimes affect forest succession and forest resilience to climate change and future disturbance? Local fire regimes have been altered in many ecosystems due to direct and indirect anthropogenic activities. Changes in fire frequency and seasonality can cause shifts in species composition and fuel characteristics, which can then impact fire effects through associated changes in fire intensity. Most of my research in this area has focused on the impact of reducing fire frequency in fire-dependent ecosystems. This area of research also examines the effects of silvicultural and fuel treatments to increase understanding of treatment options that foster resilient forests. 
  3. What are the effects of fire on host tree susceptibility to bark beetle attack?  Fire can directly impact tree defense and carbon acquisition, which in turn, affects susceptibility to bark beetle attack. Yet fire also can affect stand-level and landscape-level processes such as nutrient and water availability and host tree location. My research examines how fire affects tree defense and ultimately influences the susceptibility of trees to bark beetle attack. Teasing apart the contribution of host tree defenses, stand-level processes, and regional-scale synchrony due to climate on bark beetle population regulation is critical to improve our understanding of outbreaks and how both climate change and management will affect forest susceptibility to bark beetles. 

Research Interests

My research interests are: fire-induced tree mortality, fire and insect interactions, and silvicultural and fuel treatment effects.

Education

  • University of Montana, Ph.D., Organismal Biology and Ecology, 2015
  • Virginia Polytechnic Institute and State University, M.S., Forestry, 2001
  • Mississippi State University, B.S., Forestry, 1997
  • Professional Experience

    Research Ecologist, Fire, Fuel, and Smoke Science Program, Rocky Mountain Research Station, US Forest Service
    2015 to present

    Post-doctoral Researcher, University of Montana, College of Forestry and Conservation, Department of Forest Management
    2015

    Ecologist, Fire, Fuel, and Smoke Program, Fire Sciences Laboratory, Rocky Mountain Research Station, USDA Forest Service
    2009 to 2014

    Forester, Fire Ecology and Fuel Unit, Fire Sciences Laboratory, Rocky Mountain Research Station, USDA Forest Service
    2001 to 2009

    Professional Organizations

    • Association for Fire Ecology, Board Member ( 2016 to present )
      Fire Ecology Journal Committee
    • Ecological Society of America, Member ( 2013 to present )
    • Association for Fire Ecology, Member ( 2007 to present )

    Featured Publications

    Publications

    Shive, Kristen L.; Wuenschel, Amarina; Hardlund, Linnea J.; Morris, Sonia; Meyer, Marc D.; Hood, Sharon M. , 2022. Ancient trees and modern wildfires: Declining resilience to wildfire in the highly fire-adapted giant sequoia
    Keen, Rachel M.; Voelker, Steven L.; Wang, S.-Y Simon; Bentz, Barbara J.; Goulden, Michael L.; Dangerfield, Cody R.; Reed, Charlotte; Hood, Sharon M.; Csank, Adam Z.; Dawson, Todd E.; Merschel, Andrew G.; Still, Christopher J. , 2022. Changes in tree drought sensitivity provided early warning signals to the California drought and forest mortality event
    Hood, Sharon M.; Schaupp, Willis C. Jr.; Goheen, Donald J. , 2022. Radial thinning ineffective at increasing large sugar pine survival
    Bentz, Barbara J.; Soderberg, David; Runyon, Justin B.; Hood, Sharon M.; Vandygriff, James C.; Hansen, Matt; Stephens, Sky , 2021. Chapter 10 - Vulnerability of Rocky Mountain bristlecone pine to mountain pine beetle
    Hood, Sharon M.; Reed, Charlotte; Cluck, Daniel R.; Bulaon, Beverly; Hishinuma, Stacy; Hefty, Andrea; Smith, Sheri , 2021. Chapter 11 - Tree mortality and fuel changes due to extreme drought and concurrent bark beetle outbreaks in California
    Jain, Terrie B.; Abrahamson, Ilana; Anderson, Nathaniel (Nate); Hood, Sharon M.; Hanberry, Brice; Kilkenny, Francis F.; McKinney, Shawn; Ott, Jeffrey; Urza, Alexandra K.; Chambers, Jeanne C.; Battaglia, Mike A.; Varner, J. Morgan; O'Brien, Joseph J. , 2021. Effectiveness of fuel treatments at the landscape scale: State of understanding and key research gaps
    Hood, Sharon M.; Harvey, Brian J.; Fornwalt, Paula J.; Naficy, Cameron E.; Hansen, Winslow D.; Davis, Kimberley T.; Battaglia, Mike A.; Stevens-Rumann, Camille S.; Saab, Victoria A. , 2021. Fire ecology of Rocky Mountain forests [Chapter 8]
    Jang, Woongsoon; Crotteau, Justin S.; Ortega, Yvette K.; Hood, Sharon M.; Keyes, Christopher R.; Pearson, Dean E.; Lutes, Duncan C.; Sala, Anna , 2021. Native and non-native understory vegetation responses to restoration treatments in a dry conifer forest over 23 years
    Keane II, Robert E.; Bower, Andrew; Hood, Sharon M. , 2020. A burning paradox: Whitebark is easy to kill but also dependent on fire
    Hood, Sharon M.; Reed, Charlotte; Kane, Jeffrey M. , 2020. Axial resin duct quantification in tree rings: A functional defense trait
    Bowen, Katelynn J.; Keyes, Christopher R.; Hood, Sharon M.; Seielstad, Carl; Lutes, Duncan C. , 2020. Comparison of three methods for quantifying coarse surface fuel loading
    Cansler, C. Alina; Hood, Sharon M.; Varner, J. Morgan; van Mantgem, Phillip , 2020. Evaluating and optimizing the use of logistic regression for tree mortality models in the First Order Fire Effects Model (FOFEM)
    Hood, Sharon M. , 2020. Fire and bark beetle interactions
    Hiers, J. Kevin; O’Brien, Joseph J.; Varner, J. Morgan; Butler, Bret W.; Dickinson, Matthew; Furman, James; Gallagher, Michael; Godwin, David; Goodrick, Scott L.; Hood, Sharon M.; Hudak, Andrew T.; Kobziar, Leda N.; Linn, Rodman; Loudermilk, E. Louise; McCaffrey, Sarah M.; Robertson, Kevin; Rowell, Eric M.; Skowronski, Nicholas; Watts, Adam C.; Yedinak, Kara M. , 2020. Prescribed fire science: the case for a refined research agenda
    Hood, Sharon M.; Drury, Stacy; Steelman, Toddi; Steffens, Ron , 2020. Proceedings of the Fire Continuum-Preparing for the future of wildland fire; 2018 May 21-24; Missoula, MT
    Keane II, Robert E.; Hood, Sharon M.; Loehman, Rachel A.; Holsinger, Lisa M.; Higuera, Philip; Falk, Donald A. , 2020. Using landscape simulation modeling to develop an operational resilience metric
    Crotteau, Justin S.; Keyes, Christopher R.; Hood, Sharon M.; Larson, Andrew J. , 2020. Vegetation dynamics following compound disturbance in a dry pine forest: fuel treatment then bark beetle outbreak
    Kichas, Nickolas E.; Hood, Sharon M.; Pederson, Gregory T.; Everett, Richard G.; McWethy, David B. , 2020. Whitebark pine (Pinus albicaulis) growth and defense in response to mountain pine beetle outbreaks
    Roskilly, Beth; Keeling, Eric; Hood, Sharon M.; Giuggiola, Arnaud; Sala, Anna , 2019. Conflicting functional effects of xylem pit structure relate to the growth-longevity trade-off in a conifer species
    Higuera, Philip E.; Metcalf, Alexander L.; Miller, Carol L.; Buma, Brian; McWethy, David B.; Metcalf, Elizabeth C.; Ratajczak, Zak; Nelson, Cara R.; Chaffin, Brian C.; Stedman, Richard C.; McCaffrey, Sarah; Schoennagel, Tania; Harvey, Brian J.; Hood, Sharon M.; Schultz, Courtney A.; Black, Anne E.; Campbell, David; Haggerty, Julia H.; Keane II, Robert E.; Krawchuk, Meg A.; Kulig, Judith C.; Rafferty, Rebekah; Virapongse, Arika , 2019. Integrating subjective and objective dimensions of resilience in fire-prone landscapes
    Shearman, Timothy M.; Varner, J. Morgan; Hood, Sharon M.; Canslera, C. Alina; Hiers, J. Kevin. , 2019. Modelling post-fire tree mortality: Can random forest improve discrimination of imbalanced data?
    Grayson, Lindsay M.; Cluck, Daniel R.; Hood, Sharon M. , 2019. Persistence of fire-killed conifer snags in California, USA
    Hood, Sharon M.; Varner, J. Morgan. , 2019. Post-fire tree mortality
    Watts, Andrea; Hood, Sharon M.; Smith, Sheri; Bush, Renate; Huynh, Maurice , 2019. Science You Can Use (SYCU) - Is that tree dead? Quantifying fire-killed trees to inform salvage and forest management
    Axelson, Jodi; Battles, John; Bulaon, Beverly; Cluck, Danny; Cousins, Stella; Cox, Lauren; Estes, Becky; Fettig, Chris; Hefty, Andrea; Hishinuma, Stacy; Hood, Sharon M.; Kocher, Susie; Mortenson, Leif; Koltunov, Alexander; Kuskulis, Elliot; Poloni, Adrian; Ramirez, Carlos; Restaino, Christina; Slaton, Michele; Smith, Sheri; Tubbesing, Carmen , 2019. The California Tree Mortality Data Collection Network - Enhanced communication and collaboration among scientists and stakeholders
    Guney, Coskun Okan; Ryan, Kevin C.; Guney, Aylin; Hood, Sharon M. , 2019. Wildfire in Turkey: Fire management challenges at an ancient crossroads of nature and culture
    Progar, Robert A.; Ganio, Lisa; Grayson, Lindsay; Hood, Sharon M. , 2018. Chapter 9 - Monitoring survival of fire-injured trees in Oregon and Washington (Project WC-F-08-03)
    Hood, Sharon M.; Varner, J. Morgan; van Mantgem, Phillip; Cansler, C. Alina. , 2018. Fire and tree death: Understanding and improving modeling of fire-induced tree mortality
    Crotteau, Justin S.; Keyes, Christopher R.; Hood, Sharon M.; Affleck, David L. R.; Sala, Anna , 2018. Fuel dynamics after a bark beetle outbreak impacts experimental fuel treatments
    Retzlaff, Molly L.; Keane II, Robert E.; Affleck, David L.; Hood, Sharon M. , 2018. Growth response of whitebark pine (Pinus albicaulis Engelm) regeneration to thinning and prescribed burn treatments
    Crotteau, Justin S.; Hood, Sharon M.; Lutes, Duncan C.; Keyes, Christopher R.; Sala, Anna; Harrington, Michael G. , 2018. Management and succession at the Lick Creek Demonstration/Research Forest, Montana
    Crotteau, Justin S.; Keyes, Christopher R.; Hood, Sharon M.; Larson, Andrew J.; Sutherland, Elaine K.; Wright, David K.; Egan, Joel M. , 2018. Stand dynamics 11 years after retention harvest in a lodgepole pine forest
    Williams, Howard; Hood, Sharon M.; Keyes, Christopher R.; Egan, Joel M.; Negron, Jose , 2018. Subwatershed-level lodgepole pine attributes associated with a mountain pine beetle outbreak
    Hudak, Andrew T.; Freeborn, Patrick; Lewis, Sarah A.; Hood, Sharon M.; Smith, Helen Y.; Hardy, Colin C.; Kremens, Robert J.; Butler, Bret W.; Teske, Casey; Tissell, Robert G.; Queen, Lloyd P.; Nordgren, Bryce L.; Bright, Benjamin C.; Morgan, Penelope; Riggan, Philip J.; Macholz, Lee; Lentile, Leigh B.; Riddering, James P.; Mathews, Edward E. , 2018. The Cooney Ridge Fire Experiment: An early operation to relate pre-, active, and post-fire field and remotely sensed measurements
    Keane II, Robert E.; Loehman, Rachel A.; Holsinger, Lisa M.; Falk, Donald A.; Higuera, Philip; Hood, Sharon M.; Hessburg, Paul F. , 2018. Use of landscape simulation modeling to quantify resilience for ecological applications
    Hood, Sharon M.; Cluck, Daniel R.; Jones, Bobette E.; Pinnell, Sean , 2017. Radial and stand-level thinning treatments: 15-year growth response of legacy ponderosa and Jeffrey pine trees
    Bentz, Barbara J.; Hood, Sharon M.; Hansen, Matt; Vandygriff, James C.; Mock, Karen E. , 2016. Defense traits in the long-lived Great Basin bristlecone pine and resistance to the native herbivore mountain pine beetle
    Quentin, Audrey G.; Pinkard, Elizabeth A.; Ryan, Michael G.; Tissue, David T.; Baggett, L. Scott; Adams, Henry D.; Maillard, Pascale; Marchand, Jacqueline; Landhausser, Simon M.; Lacointe, Andre; Gibon, Yves; Anderegg, William R. L.; Asao, Shinichi; Atkin, Owen K.; Bonhomme, Marc; Claye, Caroline; Chow, Pak S.; Clement-Vidal, Anne; Davies, Noel W.; Dickman, L. Turin; Dumbur, Rita; Ellsworth, David S.; Falk, Kristen; Galiano, Lucía; Grunzweig, Jose M.; Hartmann, Henrik; Hoch, Gunter; Hood, Sharon M.; Jones, Joanna E.; Koike, Takayoshi; Kuhlmann, Iris; Lloret, Francisco; Maestro, Melchor; Mansfield, Shawn D.; Martinez-Vilalta, Jordi; Maucourt, Mickael; McDowell, Nathan G.; Moing, Annick; Muller, Bertrand; Nebauer, Sergio G.; Niinemets, Ulo; Palacio, Sara; Piper, Frida; Raveh, Eran; Richter, Andreas; Rolland, Gaelle; Rosas, Teresa; Joanis, Brigitte Saint; Sala, Anna; Smith, Renee A.; Sterck, Frank; Stinziano, Joseph R.; Tobias, Mari; Unda, Faride; Watanabe, Makoto; Way, Danielle A.; Weerasinghe, Lasantha K.; Wild, Birgit; Wiley, Erin; Woodruff, David R. , 2016. Non-structural carbohydrates in woody plants compared among laboratories
    Hood, Sharon M.; Sala, Anna; Heyerdahl, Emily K.; Boutin, Marion , 2015. Low-severity fire increases tree defense against bark beetle attacks
    Hood, Sharon M.; Sala, Anna , 2015. Ponderosa pine resin defenses and growth: Metrics matter
    Ryan, Michael G.; Sapes, Gerard; Sala, Anna; Hood, Sharon M. , 2015. Tree physiology and bark beetles
    Davis, Ryan S.; Hood, Sharon M.; Bentz, Barbara J. , 2012. Fire-injured ponderosa pine provide a pulsed resource for bark beetles
    Hood, Sharon M.; Smith, Helen Y.; Wright, David K.; Glasgow, Lance , 2012. Management guide to ecosystem restoration treatments: two-aged lodgepole pine forests of central Montana, USA
    Lewis, Sarah A.; Hudak, Andrew T.; Ottmar, Roger D.; Robichaud, Peter R.; Lentile, Leigh B.; Hood, Sharon M.; Cronan, James B.; Morgan, Penny , 2011. Using hyperspectral imagery to estimate forest floor consumption from wildfire in boreal forests of Alaska, USA
    Noonan-Wright, Erin; Hood, Sharon M.; Cluck, Danny R. , 2010. Does raking basal duff affect tree growth rates or mortality?
    Hood, Sharon M.; Smith, Sheri L.; Cluck, Daniel R. , 2010. Predicting mortality for five California conifers following wildfire
    Belote, R. Travis; Jones, Robert H.; Hood, Sharon M.; Wender, Bryan W. , 2008. Diversity-invasibility across an experimental disturbance gradient in Appalachian forests
    Hood, Sharon M.; Cluck, Danny R.; Smith, Sheri L.; Ryan, Kevin C. , 2008. Using bark char codes to predict post-fire cambium mortality
    Hood, Sharon M.; Bentz, Barbara J.; Gibson, Ken; Ryan, Kevin; DeNitto, Gregg , 2007. Assessing post-fire Douglas-fir mortality and Douglas-fir beetle attacks in the northern Rocky Mountains
    Hood, Sharon M.; Smith, Sheri L.; Cluck, Daniel R. , 2007. Delayed conifer tree mortality following fire in California
    Hood, Sharon M.; McHugh, Charles W.; Ryan, Kevin C.; Reinhardt, Elizabeth; Smith, Sheri L. , 2007. Evaluation of a post-fire tree mortality model for western US conifers
    Hood, Sharon M.; Long, Donald; Miller, Melanie; Ryan, Kevin C. , 2007. Introduction [Chapter 1]
    ; Hood, Sharon M. , 2007. Pinyon/juniper woodlands [Chapter 4]
    Hood, Sharon M.; Wu, Ros , 2006. Estimating Fuel Bed Loadings in Masticated Areas
    Hood, Sharon M.; Bentz, Barbara J.; Ryan, Kevin C. , 2003. Douglas-fir beetle attack and tree mortality following wildfire
    Wender, Bryan W.; Hood, Sharon M.; Smith, David W.; Zedaker, Shepard M.; Loftis, David L. , 1999. Response of Vascular Plant Communities to Harvest in Southern Appalachian Mixed-Oak Forests: Two-Year Results
    Risk factors for tree mortality in boxes, with color of boxes indicating species. Grouped by site and stand, radial growth, carbon isotopes, tree size, resin ducts, BAI-Δ13C relationships, and climate relationships.
    Determining why some trees die while others survive both drought and insect outbreaks is valuable for forecasting tree mortality events, which are expected to become more frequent with further climate change. We collected stand and tree-level data on the Sierra and Los Padres National Forests in Central and Southern California, where tree mortality from the combination of drought and bark beetles was widespread. 
    A picture of a pine tree core with visible tree rings, and resin ducts visible as small dots within the rings.
    Resin ducts are formed in the wood of pine trees and are a measure of the level of tree defense from insects and pathogens. We developed methods and software code to allow researchers to more easily quantify resin ducts.
    A ponderosa pine forest with mature trees in the background and seedlings in the foreground.
    Lick Creek is the longest running fuel treatment and restoration study of ponderosa pine forests in the northern U.S. Rocky Mountains. Through repeat photography and numerous published studies, we show how fuels and vegetation have changed over the 25 years since treatment and compare the effects of mechanical harvesting with and without prescribed burning.
    An eight-panel image of forest plots. Columns are 2005 and 2015; rows are control, burn-only, thin-only, and thin and burn.
    Fuel treatments are important to restore vegetation structure and composition in dry forests, imbuing ecological resistance to future wildfire. But ecosystem benefits may change after treatment as forests regrow, especially if disturbances such as mountain pine beetle outbreak intervene. We found post-treatment growth plus beetle-caused mortality in thinning-only or burning-only strategies erased comparative benefits, and only combined thinning and burning treatments provided the unique structural and compositional outcomes expected of restoration.
    Prescribed crown fire at Manning Creek, Fishlake National Forest. Photo credit: Roger Ottmar. Photo taken: June 2019
    The broad consensus among fire and fuel scientists and managers is that we need to reduce hazardous fuel accumulations on many more acres to mitigate the risk and severity of wildfires. But mechanical fuel treatments are expensive! Prescribed fire is a more cost effective tool to reduce fuel loads and to restore and maintain fuel conditions to something closer to the historical norm.
    During and after fire
    Each year wildland fires kill and injure trees on millions of forested hectares globally, causing both positive and negative impacts to plant and animal biodiversity, carbon storage, hydrologic processes, and ecosystem services. Understanding the underlying mechanisms of fire-caused tree mortality is important to accurately predict mortality, estimate fire-driven feedbacks to the global carbon cycle, extrapolate to novel future conditions, and implement appropriate management actions to increase forest resilience to wildfire.
    stand-level thinning
    Large, old trees, often called legacy trees, serve a foundational role in old-growth forests. Restoration efforts to improve vigor of legacy trees and decrease risk to high-intensity wildland fire and drought-mediated insect mortality often include reductions in stand density. However, sometimes regulatory and social constraints limit stand-level thinning options by requiring maintenance of closed canopies.
    The frequency of fire in low-elevation coniferous forests in western North America has greatly declined since the late 1800s. In many areas, this has increased tree density, increased the proportion of shade-tolerant species, reduced resource availability, and increased forest susceptibility to forest insect pests and high-severity wildfire. This study investigated how low-intensity fire affects tree defenses and whether fuel treatments impact resistance to a mountain pine beetle outbreak.
    We are developing a product and methodology that allows rapid assessment of fuels and potential fire hazard in forests impacted by the non-native balsam woolly adelgid (BWA) to better protect and improve the health of western America’s high-elevation fir forests. We will 1) compare fuel metrics derived from standard field procedures with aerial and terrestrial lidar-derived fuel metrics and 2) use physics-based fire behavior models to simulate fire behavior in stands spanning a range of BWA severities, allowing fuel hazard quantification in BWA-impacted forests across a range of weather scenarios. The results will be compiled into a photoguide to allow users to rapidly assess BWA severity, fuel conditions, and potential fire behavior. 
    Lick Creek Demonstration-Research Forest: 25-year fire and cutting effects on vegetation and fuels.
    Open oak and pine forests, which typically have a treed overstory and grasslands understory, historically were abundant across the United States. Agency investment in large-scale restoration programs begs the question: Do changes of ecological processes follow restoration of structure? 
    There is widespread interest in understanding the effectiveness of fuel treatments in mitigating the trajectory of wildfire suppression costs and how their effectiveness and longevity can be extended over large areas and landscapes. To date, there have been several studies that used a modeling approach to evaluate fuel treatment effectiveness at the landscape scale. However, empirical studies at this scale are rare because landscape-scale fuel treatment strategies have not been fully implemented or wildfires have not burned through implemented landscape fuel treatments. A thorough evaluation of what is currently available in the literature and lessons learned from forest and rangeland managers has not yet been conducted.
    The Fire and Smoke Model Evaluation Experiment (FASMEE) is a large-scale interagency effort to identify how fuels, fire behavior, fire energy and meteorology interact to determine the dynamics of smoke plumes, the long-range transport of smoke and local fire effects such as soil heating and vegetative response. FASMEE is designed to collect observations from large prescribed fires by combining Light Detection and Ranging (LiDAR), radar, ground monitoring, aircraft and satellite imagery, and weather and atmospheric measurements. Knowing more about how wildland fire operates helps land managers better predict fire behavior, smoke impacts, and the short- to long-term effects of fire. It also promotes increased public and firefighter safety and aids in the allocation of firefighting resources.
    Grand fir and western hemlock mortality and regeneration dynamics after wildfire and salvage.
    Long-term growth responses to stand density reduction treatments in mature pine forests of California
    Fuel treatment impacts in ponderosa pine - Douglas-fir forests in the Northern Rockies.
    The impact of fire on conifer defenses.
    Mortality reconsidered: Testing and extending models of fire–induced tree mortality across the United States.

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