Beyond Fuel Treatment Effectiveness: Characterizing Interactions between Fire and Treatments in the US

Kevin Barnett,Helen Naughton,Sean Parks,Carol Miller

doi:10.3390/f7100237

Abstract

In the United States, fuel reduction treatments are a standard land management tool to restore the structure and composition of forests that have been degraded by past management. Although treatments can have multiple purposes, their principal objective is to create landscape conditions where wildland fire can be safely managed to help achieve long-term land management goals. One critique is that fuel treatment benefits are unlikely to transpire due to the low probability that treated areas will be burned by a subsequent fire within a treatment’s lifespan, but little quantitative information exists to corroborate this argument. We summarized the frequency, extent, and geographic variation of fire and fuel treatment interactions on federal lands within the conterminous United States (CONUS). We also assessed how the encounters between fuel treatments and fires varied with treatment size, treatment age, and number of times treated. Overall, 6.8% of treatment units evaluated were encountered by a subsequent fire during the study period, though this rate varied among ecoregions across the CONUS. Larger treatment units were more likely to be encountered by a fire, and treatment units were most frequently burned within one year of the most recent treatment, the latter of which is likely because of ongoing maintenance of existing treatments. Our results highlight the need to identify and prioritize additional opportunities to reduce fuel loading and fire risk on the millions of hectares of federal lands in the CONUS that are in need of restoration.

Highlights

Interactions between historical fire exclusion, land use changes, and a warming climate have increased fuel loading and fire hazard across millions of hectares of federal forested lands in the United States [1]
We focused on fire and fuel treatment interactions outside of the wildland–urban interface (WUI), where forest restoration goals are assumed to supersede other potential fuel treatment objectives [31]
A total of 9249 of the 136,483 treatment units were encountered by subsequent fire, resulting in an overall encounter rate of 6.8% (Table S1)

Summary

Introduction

Interactions between historical fire exclusion, land use changes, and a warming climate have increased fuel loading and fire hazard across millions of hectares of federal forested lands in the United States [1]. Fuel treatments can moderate subsequent fire behavior [4,5], mitigate fire severity [6,7], and increase forest resilience to subsequent disturbances [8,9]. Fuel treatment effects vary according to treatment type, size, and age [10], while their spatial arrangement and rate of implementation can affect outcomes at the landscape level [11,12]. One principal critique of fuel treatments is that their benefits are rarely realized because of the low likelihood that an unplanned fire will encounter a previously treated area during its effective lifespan [13,14,15], though the rate and extent to which this occurs remains largely unknown.

Results

Discussion

Conclusion