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

De-coupling seasonal changes in water content and dry matter to predict live conifer foliar moisture content

W. Matt Jolly A B , Ann M. Hadlow A and Kathleen Huguet A
+ Author Affiliations
- Author Affiliations

A US Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory, 5775 Highway 10 W, Missoula, MT 59808, USA.

B Corresponding author. Email: mjolly@fs.fed.us

International Journal of Wildland Fire 23(4) 480-489 https://doi.org/10.1071/WF13127
Submitted: 7 August 2013  Accepted: 4 February 2014   Published: 15 May 2014

Abstract

Live foliar moisture content (LFMC) significantly influences wildland fire behaviour. However, characterising variations in LFMC is difficult because both foliar mass and dry mass can change throughout the season. Here we quantify the seasonal changes in both plant water status and dry matter partitioning. We collected new and old foliar samples from Pinus contorta for two growing seasons and quantified their LFMC, relative water content (RWC) and dry matter chemistry. LFMC quantifies the amount of water per unit fuel dry weight whereas RWC quantifies the amount of water in the fuel relative to how much water the fuel can hold at saturation. RWC is generally a better indicator of water stress than is LFMC. We separated water mass from dry mass for each sample and we attempted to best explain the seasonal variations in each using our measured physiochemical variables. We found that RWC explained 59% of variation in foliar water mass. Additionally, foliar starch, sugar and crude fat content explained 87% of the variation in seasonal dry mass changes. These two models combined explained 85% of the seasonal variations in LFMC. These results demonstrate that changes to dry matter exert a stronger control on seasonal LFMC dynamics than actual changes in water content, and they challenge the assumption that LFMC variations are strongly related to water stress. This methodology could be applied across a range of plant functional types to better understand the factors that drive seasonal changes in LFMC and live fuel flammability.

Additional keywords: carbohydrates, crude fat, model, relative water content.


References

Ackley WB (1954) Seasonal and diurnal changes in the water contents and water deficits of Bartlett pear leaves. Plant Physiology 29, 445–448.
Seasonal and diurnal changes in the water contents and water deficits of Bartlett pear leaves.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD28zht12jug%3D%3D&md5=c9814f1dc684966241b6082e03ab714aCAS | 16654695PubMed |

Agee JK, Wright CS, Williamson N, Huff MH (2002) Foliar moisture content of Pacific Northwest vegetation and its relation to wildland fire behavior. Forest Ecology and Management 167, 57–66.
Foliar moisture content of Pacific Northwest vegetation and its relation to wildland fire behavior.Crossref | GoogleScholarGoogle Scholar |

Alexander ME, Cruz MG (2013) Assessing the effect of foliar moisture on the spread rate of crown fires. International Journal of Wildland Fire 22, 415–427.
Assessing the effect of foliar moisture on the spread rate of crown fires.Crossref | GoogleScholarGoogle Scholar |

Anderson HE, Rothermel RC (1965) Influence of moisture and wind upon the characteristics of free-burning fires. Symposium (International) on Combustion 10, 1009–1019.
Influence of moisture and wind upon the characteristics of free-burning fires.Crossref | GoogleScholarGoogle Scholar |

Andrews PL (2013) Current status and future needs of the BehavePlus Fire Modeling System. International Journal of Wildland Fire 23, 21–33.

AOAC (1984) ‘Official Methods of Analysis.’ (Association of Official Analytical Chemists: Washington, DC)

Barrs HD, Weatherley PE (1962) A re-examination of the relative turgidity technique for estimating water deficits in leaves. Australian Journal of Biological Sciences 15, 413–428.

Bowman DMJS, Balch JK, Artazo P, Bond WJ, Carlson JM, Cochrane MA, D’Antonio CM, DeFries RS, Doyle JC, Harrison SP, Johnston FH, Keely JE, Krawchuk MA, Kull CA, Marston JB, Moritz MA, Prentice IC, Roos CI, Scott AC, Swetnam TW, van der Werf GR, Pyne SJ (2009) Fire in the Earth System. Science 324, 481–484.
Fire in the Earth System.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXkvVGmtb8%3D&md5=7d355635183e478d3c504946e7a1f904CAS |

Bowyer P, Danson FM (2004) Sensitivity of spectral reflectance to variation in live fuel moisture content at leaf and canopy level. Remote Sensing of Environment 92, 297–308.
Sensitivity of spectral reflectance to variation in live fuel moisture content at leaf and canopy level.Crossref | GoogleScholarGoogle Scholar |

Brenner J (2002) Measuring live fuel moistures in Florida: standard methods and procedures, August 28, 2002. (Florida Division of Forestry, Department of Agriculture and Consumer Services) Available at http://www.freshfromflorida.com/content/download/4761/30337/procedures.pdf [Verified 10 March 2014]

Byram GM (1959) Combustion of forest fuels. In ‘Forest Fire: Control and Use’. (Eds KP Davis, GM Byram, WR Krumm). (McGraw-Hill Book Company: New York)

Castro FX, Tudela A, Sebastià MT (2003) Modeling moisture content in shrubs to predict fire risk in Catalonia (Spain). Agricultural and Forest Meteorology 116, 49–59.
Modeling moisture content in shrubs to predict fire risk in Catalonia (Spain).Crossref | GoogleScholarGoogle Scholar |

Chrosciewicz Z (1986) Foliar moisture content variations in four coniferous tree species of central Alberta. Canadian Journal of Forest Research 16, 157–162.
Foliar moisture content variations in four coniferous tree species of central Alberta.Crossref | GoogleScholarGoogle Scholar |

Chuvieco E, Cocero D, Riano D, Martin P, Martínez-Vega J, De La Riva J, Pérez F (2004) Combining NDVI and surface temperature for the estimation of live fuel moisture content in forest fire danger rating. Remote Sensing of Environment 92, 322–331.
Combining NDVI and surface temperature for the estimation of live fuel moisture content in forest fire danger rating.Crossref | GoogleScholarGoogle Scholar |

Cruz MG, Alexander ME, Wakimoto RH (2005) Development and testing of models for predicting crown fire rate of spread in conifer forest stands. Canadian Journal of Forest Research 35, 1626–1639.
Development and testing of models for predicting crown fire rate of spread in conifer forest stands.Crossref | GoogleScholarGoogle Scholar |

Danson FM, Bowyer P (2004) Estimating live fuel moisture content from remotely sensed reflectance. Remote Sensing of Environment 92, 309–321.
Estimating live fuel moisture content from remotely sensed reflectance.Crossref | GoogleScholarGoogle Scholar |

Dasgupta S, Qu JJ, Hao X, Bhoi S (2007) Evaluating remotely sensed live fuel moisture estimations for fire behavior predictions in Georgia, USA. Remote Sensing of Environment 108, 138–150.
Evaluating remotely sensed live fuel moisture estimations for fire behavior predictions in Georgia, USA.Crossref | GoogleScholarGoogle Scholar |

Davies GM, Legg CJ, Smith AA, MacDonald AJ (2009) Rate of spread of fires in Calluna vulgaris-dominated moorlands. Journal of Applied Ecology 46, 1054–1063.
Rate of spread of fires in Calluna vulgaris-dominated moorlands.Crossref | GoogleScholarGoogle Scholar |

Dennison PE, Roberts DA, Thorgusen SR, Regelbrugge JC, Weise D, Lee C (2003) Modeling seasonal changes in live fuel moisture and equivalent water thickness using a cumulative water balance index. Remote Sensing of Environment 88, 442–452.
Modeling seasonal changes in live fuel moisture and equivalent water thickness using a cumulative water balance index.Crossref | GoogleScholarGoogle Scholar |

Dennison PE, Roberts DA, Peterson SH, Rechel J (2005) Use of Normalized Difference Water Index for monitoring live fuel moisture. International Journal of Remote Sensing 26, 1035–1042.
Use of Normalized Difference Water Index for monitoring live fuel moisture.Crossref | GoogleScholarGoogle Scholar |

Dimitrakopoulos AP, Bemmerzouk AM (2003) Predicting live herbaceous moisture content from a seasonal drought index. International Journal of Biometeorology 47, 73–79.

Dimitrakopoulos AP, Papaioannou KK (2001) Flammability assessment of Mediterranean forest fuels. Fire Technology 37, 143–152.
Flammability assessment of Mediterranean forest fuels.Crossref | GoogleScholarGoogle Scholar |

Ericsson A (1978) Seasonal changes in translocation of 14C from different age-classes of needles on 20-year-old Scots pine trees (Pinus silvestris). Physiologia Plantarum 43, 351–358.
Seasonal changes in translocation of 14C from different age-classes of needles on 20-year-old Scots pine trees (Pinus silvestris).Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaE1cXlvFeqsb8%3D&md5=e261d52f377ac44d20046fc723503879CAS |

Finney MA, Cohen JD, McAllister SS, Jolly WM (2013) On the need for a theory of wildland fire spread. International Journal of Wildland Fire 22, 25–36.
On the need for a theory of wildland fire spread.Crossref | GoogleScholarGoogle Scholar |

Fons WL (1946) Analysis of fire spread in light forest fuels. Journal of Agricultural Research 72, 93–121.

Frankman D, Webb BW, Butler BW (2008) Influence of absorption by environmental water vapor on radiation transfer in wildland fires. Combustion Science and Technology 180, 509–518.
Influence of absorption by environmental water vapor on radiation transfer in wildland fires.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXps1Slsg%3D%3D&md5=c82bdb31696374e6bd432ed248e0d7dfCAS |

Gary HL (1971) Seasonal and diurnal changes in moisture contents and water deficits of Engelmann spruce needles. Botanical Gazette 132, 327–332.
Seasonal and diurnal changes in moisture contents and water deficits of Engelmann spruce needles.Crossref | GoogleScholarGoogle Scholar |

Gisborne HT (1936) ‘Measuring fire weather and forest inflammability.’ (US Dept. of Agriculture)

Gordon JC, Larson PR (1968) Seasonal course of photosynthesis, respiration, and distribution of C14 in young Pinus resinosa trees as related to wood formation. Plant Physiology 43, 1617–1624.
Seasonal course of photosynthesis, respiration, and distribution of C14 in young Pinus resinosa trees as related to wood formation.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BC3cngvFWhuw%3D%3D&md5=b31428ae6a7be50e04ae5134e4dcb002CAS | 16656946PubMed |

Hao X, Qu JJ (2007) Retrieval of real-time live fuel moisture content using MODIS measurements. Remote Sensing of Environment 108, 130–137.
Retrieval of real-time live fuel moisture content using MODIS measurements.Crossref | GoogleScholarGoogle Scholar |

Horwitz W, Latimer GW (2000) ‘Official methods of analysis of AOAC International.’ (AOAC International: Gaithersburg)

Keyes CR (2006) Foliar moisture contents of North American conifers. In ‘Fuels Management – How to Measure Success: Conference Proceedings’, 28–30 March 2006, Portland, OR. (Eds PL Andrews, BW Butler) USDA Forest Service, Rocky Mountain Research Station, Proceedings RMRS-P-41, pp. 395–399. (Fort Collins, CO)

Kozlowski TT, Clausen JJ (1965) Changes in moisture contents and dry weights of buds and leaves of forest trees. Botanical Gazette 126, 20–26.
Changes in moisture contents and dry weights of buds and leaves of forest trees.Crossref | GoogleScholarGoogle Scholar |

Kozlowski TT, Pallardy SG (1979) ‘The Physiology of Woody Plants.’ (Academic Press: San Diego)

Linn R, Reisner J, Colman JJ, Winterkamp J (2002) Studying wildfire behavior using FIRETEC. International Journal of Wildland Fire 11, 233–246.
Studying wildfire behavior using FIRETEC.Crossref | GoogleScholarGoogle Scholar |

Little CHA (1970) Seasonal changes in carbohydrate and moisture content in needles of balsam fire (Abies balsamea). Canadian Journal of Botany 48, 2021–2028.
Seasonal changes in carbohydrate and moisture content in needles of balsam fire (Abies balsamea).Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaE3MXjvFWgtQ%3D%3D&md5=dbe6524e092c62beee3ed518360fa8a9CAS |

Mell W, Jenkins MA, Gould J, Cheney P (2007) A physics-based approach to modelling grassland fires. International Journal of Wildland Fire 16, 1–22.
A physics-based approach to modelling grassland fires.Crossref | GoogleScholarGoogle Scholar |

Nelson RM (2000) Prediction of diurnal change in 10-h fuel stick moisture content. Canadian Journal of Forest Research 30, 1071–1087.
Prediction of diurnal change in 10-h fuel stick moisture content.Crossref | GoogleScholarGoogle Scholar |

Nelson RM Jr (2001) Water relations of forest fuels. In ‘Forest fires: Behavior and Ecological Effects’. (Eds EA Johnson, K Miyanishi) pp. 79–149. (Academic Press: London)

Pellizzaro G, Duce P, Ventura A, Zara P (2007a) Seasonal variations of live moisture content and ignitability in shrubs of the Mediterranean Basin. International Journal of Wildland Fire 16, 633–641.
Seasonal variations of live moisture content and ignitability in shrubs of the Mediterranean Basin.Crossref | GoogleScholarGoogle Scholar |

Pellizzaro G, Cesaraccio C, Duce P, Ventura A, Zara P (2007b) Relationships between seasonal patterns of live fuel moisture and meteorological drought indices for Mediterranean shrubland species. International Journal of Wildland Fire 16, 232–241.
Relationships between seasonal patterns of live fuel moisture and meteorological drought indices for Mediterranean shrubland species.Crossref | GoogleScholarGoogle Scholar |

Philpot CW (1969) Seasonal changes in heat content and ether extractive content of chamise. USDA Forest Service, Intermountain Forest and Range Research Station, Research Paper INT-61. (Ogden, UT)

Piñol J, Filella I, Ogaya R, Peñuelas J (1998) Ground-based spectroradiometric estimation of live fine fuel moisture of Mediterranean plants. Agricultural and Forest Meteorology 90, 173–186.
Ground-based spectroradiometric estimation of live fine fuel moisture of Mediterranean plants.Crossref | GoogleScholarGoogle Scholar |

Pook EW, Gill AM (1993) Variation of live and dead fine fuel moisture in Pinus radiata plantations of the Australian Capital Territory. International Journal of Wildland Fire 3, 155–168.
Variation of live and dead fine fuel moisture in Pinus radiata plantations of the Australian Capital Territory.Crossref | GoogleScholarGoogle Scholar |

Rothermel RC (1972) A mathematical model for predicting fire spread in wildland fuels. USDA Forest Service, Intermountain Forest and Range Research Station, Research Paper INT-115. (Odgen, UT)

Running SW (1980) Environmental and physiological control of water flux through Pinus contorta. Canadian Journal of Forest Research 10, 82–91.
Environmental and physiological control of water flux through Pinus contorta.Crossref | GoogleScholarGoogle Scholar |

Running SW, Hunt ER (1993) Generalization of a forest ecosystem process model for other biomes, BIOME-BGC, and an application for global-scale models. In ‘Scaling Physiological Processes: Leaf to Globe’. (Eds JR Ehleringer, CB Field) pp. 141–158. (Academic Press: New York)

Stonex S, Stewart C, Bastik R, Michaud K, Smith J, Sahd K, Halperin J, Kearny D, Roller T, Rodgers M, Dennett C, Swanson D, Gatewood R, Maxwell C, Ellington J (2004) Southwest area fuel moisture monitoring program: standard methods and procedures. USDA Forest Service, Southwest Region. (Albuquerque, NM).

Van Wagner CE (1977) Conditions for the start and spread of crown fire. Canadian Journal of Forest Research 7, 23–34.
Conditions for the start and spread of crown fire.Crossref | GoogleScholarGoogle Scholar |

Van Wilgen BW, Le Maitre DC, Kruger FJ (1985) Fire behaviour in South African fynbos (macchia) vegetation and predictions from Rothermel’s fire model. Journal of Applied Ecology 22, 207–216.
Fire behaviour in South African fynbos (macchia) vegetation and predictions from Rothermel’s fire model.Crossref | GoogleScholarGoogle Scholar |

Viegas DX, Piñol J, Ogaya R (2001) Estimating live fine fuels moisture content using meteorologically based indices. International Journal of Wildland Fire 10, 223–240.
Estimating live fine fuels moisture content using meteorologically based indices.Crossref | GoogleScholarGoogle Scholar |

Viney NR (1991) A review of fine fuel moisture modelling. International Journal of Wildland Fire 1, 215–234.
A review of fine fuel moisture modelling.Crossref | GoogleScholarGoogle Scholar |

Weise DR, Zhou X, Sun L, Mahalingam S (2005) Fire spread in chaparral – ‘go or no-go?’ International Journal of Wildland Fire 14, 99–106.
Fire spread in chaparral – ‘go or no-go?’Crossref | GoogleScholarGoogle Scholar |

Xanthopoulos G, Wakimoto RH (1993) A time to ignition – temperature–moisture relationship for branches of three western conifers. Canadian Journal of Forest Research 23, 253–258.
A time to ignition – temperature–moisture relationship for branches of three western conifers.Crossref | GoogleScholarGoogle Scholar |

Yebra M, Chuvieco E, Riaño D (2008) Estimation of live fuel moisture content from MODIS images for fire risk assessment. Agricultural and Forest Meteorology 148, 523–536.
Estimation of live fuel moisture content from MODIS images for fire risk assessment.Crossref | GoogleScholarGoogle Scholar |

Zahn S, Henson C (2011) A synthesis of fuel moisture collection methods and equipment: a desk guide. USDA Forest Service, National Technology and Development Program, San Dimas Technology and Development Center, 1151 1806P. (San Dimas, CA) Available at http://www.fs.fed.us/t-d/pubs/pdf/11511806.pdf [Verified 23 April 2014]