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International Journal of Wildland Fire International Journal of Wildland Fire Society
Journal of the International Association of Wildland Fire
RESEARCH ARTICLE

Long-term changes in masticated woody fuelbeds in northern California and southern Oregon, USA

Warren P. Reed A B C F , J. Morgan Varner D , Eric E. Knapp E and Jesse K. Kreye B
+ Author Affiliations
- Author Affiliations

A Department of Forest Resources and Environmental Conservation, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA.

B Department of Ecosystem Science and Management, The Pennsylvania State University, University Park, PA 16802, USA.

C Intercollege Graduate Degree Program in Ecology, The Pennsylvania State University, University Park, PA 16802, USA.

D Tall Timbers Research Station, 13093 Henry Beadel Drive, Tallahassee, FL 32312, USA.

E USDA Forest Service Pacific Southwest Research Station, Redding, CA 96002, USA.

F Corresponding author. Email: wpr5005@psu.edu

International Journal of Wildland Fire 29(9) 807-819 https://doi.org/10.1071/WF19156
Submitted: 28 September 2019  Accepted: 15 May 2020   Published: 5 June 2020

Abstract

Mechanical mastication is a fuels treatment that shreds midstorey trees and shrubs into a compacted woody fuel layer to abate fire hazards in fire-prone ecosystems. Increased surface fuel loading from mastication may, however, lead to undesirable fire intensity, long-duration flaming or smouldering, and undesirable residual tree mortality. Two major questions facing fuels managers are: how long do masticated fuels persist, and how does the composition of masticated fuelbeds change over time? To evaluate these changes, we measured 25 masticated sites with a range of vegetation, species masticated and time since treatment (1–16 years) in the western US. Seven of the 25 sites were sampled nearly a decade earlier, providing a unique opportunity to document fuelbed changes. Woody fuel loading ranged from 12.1 to 91.9 Mg ha−1 across sites and was negatively related to time since treatment. At remeasured sites, woody fuel loads declined by 20%, with the greatest losses in 1- and 10-h woody fuels (69 and 33% reductions in mass respectively). Reductions were due to declines in number of particles and reduced specific gravity. Mastication treatments that generate greater proportions of smaller-diameter fuels may result in faster decomposition and potentially be more effective at mitigating fire hazard.

Additional keywords: decomposition, fire hazard reduction, fuel loading, fuels treatments, timelag, woody fuels.


References

Abatzoglou JT, Williams AP (2016) Impact of anthropogenic climate change on wildfire across western US forests. Proceedings of the National Academy of Sciences of the United States of America 113, 11770–11775.
Impact of anthropogenic climate change on wildfire across western US forests.Crossref | GoogleScholarGoogle Scholar | 27791053PubMed |

Agee JK, Skinner CN (2005) Basic principles of forest fuel reduction treatments. Forest Ecology and Management 211, 83–96.
Basic principles of forest fuel reduction treatments.Crossref | GoogleScholarGoogle Scholar |

ASTM (2002) Standard test methods for specific gravity of wood and wood-based materials, D2395–02. In ‘Annual book of ASTM standards’, Vol. 4.10, pp. 357–364. (American Society for Testing and Materials: Conshohocken, PA, USA)

Battaglia MA, Rocca ME, Rhoades CC, Ryan MG (2010) Surface fuel loadings within mulching treatments in Colorado coniferous forests. Forest Ecology and Management 260, 1557–1566.
Surface fuel loadings within mulching treatments in Colorado coniferous forests.Crossref | GoogleScholarGoogle Scholar |

Black DE, Arthur MA, Leuenberger W, Taylor DD, Lewis JF (2019) Alteration to woodland structure through midstory mastication increased fuel loading and cover of understory species in two upland hardwood stands. Forest Science 65, 344–354.
Alteration to woodland structure through midstory mastication increased fuel loading and cover of understory species in two upland hardwood stands.Crossref | GoogleScholarGoogle Scholar |

Bradley T, Gibson J, Bunn W (2006) Fire severity and intensity during spring burning in natural and masticated shrub woodlands. In ‘Fuels management – how to measure success’. (Eds PL Andrews, BW Butler) USDA Forest Service, Rocky Mountain Research Station, Proceedings RMRS-P-41, pp. 419–428. (Fort Collins, CO, USA)

Brennan T, Keeley J (2015) Effect of mastication and other mechanical fuel treatments on fuel structure in chaparral. International Journal of Wildland Fire 24, 949–969.
Effect of mastication and other mechanical fuel treatments on fuel structure in chaparral.Crossref | GoogleScholarGoogle Scholar |

Brown JK (1974) Handbook for inventorying downed woody material. USDA Forest Service, Intermountain Forest and Range Experiment Station, General Technical Report INT-16. (Ogden, UT, USA)

Busse MD, Hubbert KR, Fiddler GO, Shestak CJ, Powers RF (2005) Lethal soil temperatures during burning of masticated forest residues. International Journal of Wildland Fire 14, 267–276.
Lethal soil temperatures during burning of masticated forest residues.Crossref | GoogleScholarGoogle Scholar |

Busse MD, Shestak CJ, Hubbert KR, Knapp E (2010) Soil physical properties regulate lethal heating during burning of woody residues. Forest Range and Wildland Soils 74, 947–955.
Soil physical properties regulate lethal heating during burning of woody residues.Crossref | GoogleScholarGoogle Scholar |

Coop JD, Grant TA, Magee PA, Moore EA (2017) Mastication treatment effects on vegetation and fuels in pinon–juniper woodlands of central Colorado, USA. Forest Ecology and Management 396, 68–84.
Mastication treatment effects on vegetation and fuels in pinon–juniper woodlands of central Colorado, USA.Crossref | GoogleScholarGoogle Scholar |

Edmonds RL (1987) Decomposition rates and nutrient dynamics in small-diameter woody litter in four forest ecosystems in Washington, USA. Canadian Journal of Forest Research 17, 499–509.
Decomposition rates and nutrient dynamics in small-diameter woody litter in four forest ecosystems in Washington, USA.Crossref | GoogleScholarGoogle Scholar |

Edmonds RL, Vogt DJ, Sandberg DH, Driver CH (1986) Decomposition of Douglas-fir and red alder wood in clear-cuttings. Canadian Journal of Forest Research 16, 822–831.
Decomposition of Douglas-fir and red alder wood in clear-cuttings.Crossref | GoogleScholarGoogle Scholar |

Erickson HE, Edmonds RL, Peterson CE (1985) Decomposition of logging residues in Douglas-fir, western hemlock, Pacific silver fir, and ponderosa pine ecosystems. Canadian Journal of Forest Research 15, 914–921.
Decomposition of logging residues in Douglas-fir, western hemlock, Pacific silver fir, and ponderosa pine ecosystems.Crossref | GoogleScholarGoogle Scholar |

Fasth BG, Harmon ME, Sexton J, White P (2011) Decomposition of fine woody debris in a deciduous forest in North Carolina. The Journal of the Torrey Botanical Society 138, 192–206.
Decomposition of fine woody debris in a deciduous forest in North Carolina.Crossref | GoogleScholarGoogle Scholar |

Gartner TB, Cardon ZG (2004) Decomposition dynamics in mixed-species leaf litter. Oikos 104, 230–246.
Decomposition dynamics in mixed-species leaf litter.Crossref | GoogleScholarGoogle Scholar |

Glitzenstein JS, Streng DR, Achtemeier GL, Naeher LP, Wade DD (2006) Fuels and fire behavior in chipped and unchipped plots: implications for land management near the wildland/urban interface. Forest Ecology and Management 236, 18–29.
Fuels and fire behavior in chipped and unchipped plots: implications for land management near the wildland/urban interface.Crossref | GoogleScholarGoogle Scholar |

Hood S, Wu R (2006) Estimating fuel bed loadings in masticated areas. In ‘Fuels management – how to measure success’. (Eds PL Andrews, BW Butler) USDA Forest Service, Rocky Mountain Research Station, RMRS-P-41, pp. 333–340. (Portland, OR, USA)

Jain T, Sikkink, P, Keefe, R, Byrne, J (2018) To masticate or not: Useful tips for treating forests, woodland, and shrubland vegetation. USDA Forest Service, Rocky Mountain Research Station, General Technical Report RMRS-GTR-381. (Fort Collins, CO, USA)

Johnson EA, Miyanishi K (2008) Testing assumptions of chronosequences in succession. Ecology Letters 11, 419–431.
Testing assumptions of chronosequences in succession.Crossref | GoogleScholarGoogle Scholar | 18341585PubMed |

Kane JM, Varner JM, Knapp EE (2009) Novel fuelbed characteristics associated with mechanical mastication treatments in northern California and south-western Oregon, USA. International Journal of Wildland Fire 18, 686–697.
Novel fuelbed characteristics associated with mechanical mastication treatments in northern California and south-western Oregon, USA.Crossref | GoogleScholarGoogle Scholar |

Kane JM, Varner JM, Knapp EE, Powers RF (2010) Understory vegetation responses to mechanical mastication and other fuels treatments in a ponderosa pine forest. Applied Vegetation Science 13, 207–220.
Understory vegetation responses to mechanical mastication and other fuels treatments in a ponderosa pine forest.Crossref | GoogleScholarGoogle Scholar |

Keane RE, Sikkink PG, Jain TB (2018) Physical and chemical characteristics of surface fuels in masticated mixed-conifer stands of the US Rocky Mountains. USDA Forest Service, Rocky Mountain Research Station, General Technical Report RMRS-GTR-370. (Fort Collins, CO, USA)

Knapp EE, Varner JM, Busse MD, Skinner CN, Shestak CJ (2011) Behaviour and effects of prescribed fire in masticated fuelbeds. International Journal of Wildland Fire 20, 932–945.
Behaviour and effects of prescribed fire in masticated fuelbeds.Crossref | GoogleScholarGoogle Scholar |

Kreye JK, Varner JM, Knapp EE (2012) Moisture desorption in mechanically masticated fuels: effects of particle fracturing and fuelbed compaction. International Journal of Wildland Fire 21, 894–904.
Moisture desorption in mechanically masticated fuels: effects of particle fracturing and fuelbed compaction.Crossref | GoogleScholarGoogle Scholar |

Kreye JK, Kobziar LN, Zipperer WC (2013) Effects of fuel loading and moisture content on fire behaviour and heating in masticated litter-dominated fuels. International Journal of Wildland Fire 22, 440–445.
Effects of fuel loading and moisture content on fire behaviour and heating in masticated litter-dominated fuels.Crossref | GoogleScholarGoogle Scholar |

Kreye JK, Brewer NW, Morgan P, Varner JM, Smith AMS, Hoffman CM, Ottmar RD (2014a) Fire behavior in masticated fuels: a review. Forest Ecology and Management 314, 193–207.
Fire behavior in masticated fuels: a review.Crossref | GoogleScholarGoogle Scholar |

Kreye JK, Kobziar LN, Camp JM (2014b) Immediate and short-term response of understory fuels following mechanical mastication in a pine flatwoods site of Florida, USA. Forest Ecology and Management 313, 340–354.
Immediate and short-term response of understory fuels following mechanical mastication in a pine flatwoods site of Florida, USA.Crossref | GoogleScholarGoogle Scholar |

Kreye JK, Varner JM, Kane JM, Knapp EE, Reed WP (2016) The impact of aging on laboratory fire behaviour in masticated shrub fuelbeds of California and Oregon, USA. International Journal of Wildland Fire 25, 1002–1008.
The impact of aging on laboratory fire behaviour in masticated shrub fuelbeds of California and Oregon, USA.Crossref | GoogleScholarGoogle Scholar |

Lyon ZD, Morgan P, Stevens-Rumann CS, Sparks AM, Keefe RF, Smith AMS (2018) Fire behaviour in masticated forest fuels: lab and prescribed fire experiments. International Journal of Wildland Fire 27, 280–292.
Fire behaviour in masticated forest fuels: lab and prescribed fire experiments.Crossref | GoogleScholarGoogle Scholar |

Melillo JM, Aber JD, Muratore JF (1982) Nitrogen and lignin control of hardwood leaf litter decomposition dynamics. Ecology 63, 621–626.
Nitrogen and lignin control of hardwood leaf litter decomposition dynamics.Crossref | GoogleScholarGoogle Scholar |

PRISM Climate Group (2004) PRISM Climate Data. Northwest Alliance for Computational Science & Engineering at Oregon State University Available at http://prism.oregonstate.edu[verified 27 May 2020].

Quinn-Davidson LN, Varner JM (2012) Impediments to prescribed fire across agency, landscape and manager: an example from northern California. International Journal of Wildland Fire 21, 210–218.
Impediments to prescribed fire across agency, landscape and manager: an example from northern California.Crossref | GoogleScholarGoogle Scholar |

R Core Team (2018) A language and environment for statistical computing. (R Foundation for Statistical Computing: Vienna, Austria) Available at https://www.R-project.org

Radeloff VC, Hammer RB, Stewart SI, Fried JS, Holcomb SS, McKeefry JF (2005) The wildland–urban interface in the United States. Ecological Applications 15, 799–805.
The wildland–urban interface in the United States.Crossref | GoogleScholarGoogle Scholar |

Reiner AL, Vaillant NM, Fites-Kaufman J, Dailey SN (2009) Mastication and prescribed fire impacts on fuels in a 25-year old ponderosa pine plantation, southern Sierra Nevada. Forest Ecology and Management 258, 2365–2372.
Mastication and prescribed fire impacts on fuels in a 25-year old ponderosa pine plantation, southern Sierra Nevada.Crossref | GoogleScholarGoogle Scholar |

Sackett SS (1980) Woody fuel particle size and specific gravity of south-western tree species. USDA Forest Service, Rocky Mountain Forest and Range Experiment Station, Research Note RM-389. (Fort Collins, CO, USA)

Safford HD, Stevens JT, Merriam K, Meyer MD, Latimer AM (2012) Fuel treatment effectiveness in California yellow pine and mixed-conifer forests. Forest Ecology and Management 274, 17–28.
Fuel treatment effectiveness in California yellow pine and mixed-conifer forests.Crossref | GoogleScholarGoogle Scholar |

Scholl AE, Taylor AH (2010) Fire regimes, forest change, and self-organization in an old-growth mixed-conifer forest, Yosemite National Park, USA. Ecological Applications 20, 362–380.
Fire regimes, forest change, and self-organization in an old-growth mixed-conifer forest, Yosemite National Park, USA.Crossref | GoogleScholarGoogle Scholar | 20405793PubMed |

Sikkink PG, Jain TB, Reardon J, Heinsch FA, Keane RE, Butler B, Baggett LS (2017) Effect of particle aging on chemical characteristics, smoldering, and fire behavior in mixed-conifer masticated fuel. Forest Ecology and Management 405, 150–165.
Effect of particle aging on chemical characteristics, smoldering, and fire behavior in mixed-conifer masticated fuel.Crossref | GoogleScholarGoogle Scholar |

Stottlemyer AD, Waldrop TA, Wang GG (2015) Prescribed burning and mastication effects on surface fuels in southern pine beetle-killed loblolly pine plantations. Ecological Engineering 81, 514–524.
Prescribed burning and mastication effects on surface fuels in southern pine beetle-killed loblolly pine plantations.Crossref | GoogleScholarGoogle Scholar |

Syphard AD, Radeloff VC, Keeley JE, Hawbaker TJ, Clayton MK, Stewart SI, Hammer RB (2007) Human influence on California fire regimes. Ecological Applications 17, 1388–1402.
Human influence on California fire regimes.Crossref | GoogleScholarGoogle Scholar | 17708216PubMed |

Vitorelo B, Han HS, Varner JM (2009) Masticators for fuel reduction treatment: equipment options, effectiveness, costs, and environmental impacts. In ‘Proceedings of the 2006 Council on Forest Engineering (COFE) meeting’, pp. 11. (Lake Tahoe, CA, USA)