Estimating masticated and cone fuel loads using the Photoload method

Abstract

Recognizing the complexity and varied nature of forest fuelbeds is crucial in understanding fire behavior and effects on the landscape. While current modeling efforts often consider fine and coarse woody debris surface fuel loads, those options do not always provide the most complete description of the fuelbeds. Both masticated fuels and cones can be a significant part of the fuelbed, with the potential to influence fire behavior and effects, but they are not currently captured in planar intersect methods or Photoload fuel sampling methodology. Cones are prevalent in most forested conifer stands, while mastication is a type of fuel treatment used to compact fuelbeds by shredding or chipping small trees, shrubs, and down woody debris. The treatment creates nonuniform particle sizes that violate assumptions of the planar intersect method to estimate dead surface fuel loads. The Photoload method of fuel load estimation allows visual estimates of fuel loads by particle type and the flexibility to develop photosequences of new fuel types. We created Photoload mastication sequences for estimating loading of masticated fuels, as well as cone loading sequences. Our mastication photosequences were developed from Pinus ponderosa-Pseudotsuga menziesii forests in Montana, USA, but could be used to provide a relative estimate of load for any masticated material. The cones used for developing photosequences were gathered from several forest types in the Northern Rockies, USA. We created two masticated fuel photosequences—fine particles < 7.62 cm and coarse particles ≥ 7.62 cm in width and six cone photosequences—Larix occidentalis, P. ponderosa, Pinus monticola, Pinus flexilis, Picea engelmannii, and P. menziesii. The new mastication and cone loading photosequences can be used together with existing Photoload sequences to obtain total estimates of surface fuel loads. The 1-page sequences can be printed and used in the field to estimate these additional fuel type loads quickly and easily.