How does forest recovery following moderate-severity fire influence effects of subsequent wildfire in mixed-conifer forests?

Fire Ecology

Brandon M. Collins¹  Scott L. Stephens²  Jamie M. Lydersen³  Richard G. Everett³ 

[1] Center for Fire Research and Outreach, University of California, Berkeley, USA;Department of Natural Resources, Salish Kootenai College, Pablo, USA;Ecosystem Sciences Division, Department of Environmental Science, Policy, and Management, University of California, Berkeley, USA

关键词: Departure;    Fire exclusion;    Forest restoration;    Fire suppression;    Mixed conifer forest;   

DOI  :  10.1186/s42408-018-0004-x

学科分类：生态、进化、行为和系统

来源: Springer

【 摘 要 】

Given regional increases in fire activity in western North American forests, understanding how fire influences the extent and effects of subsequent fires is particularly relevant. Remotely sensed estimates of fire effects have allowed for spatial portioning into different severity categories based on the degree of fire-caused vegetation change. Fire effects between minimal overstory tree mortality (< 20%) and complete (or nearly complete) overstory tree mortality (> 95%) are often lumped into a single category referred to as moderate severity. In this paper, we investigated how burned areas in this broad category of moderate-severity fire fared when reburned by a subsequent fire. Specifically, we examined the influence of forest structure, tree species composition, and shrub cover 9–17 yr following moderate-severity fire on the severity of a subsequent large wildfire event. We used plot-based measurements of trees and shrub cover to develop 15 forest structure and composition variables to attempt to explain observed reburn severity. Only live Abies Mill. species basal area and dead standing biomass were identified as significant predictors of reburn severity using conditional inference tree analysis, both of which were positively related to reburn severity. Our findings emphasize that the wide range of fire effects in the moderate-severity category can contribute to highly variable responses to subsequent wildfire.

【 授权许可】

CC BY