fire severity

Mature and old-growth forests (MOG) provide essential ecosystem services, yet they face increasing threats. Currently, high-intensity, high-severity wildfires are the main driver for loss of MOG on federally managed forests across the United States. Quantifying MOG forests with greatest exposure to stand-replacing wildfires provides essential information for land managers.

Background

In historically frequent fire forests, wildfires are burning larger areas and driving forest loss across western North America, yet they also produce extensive low- to moderate-severity effects that can be leveraged to harden landscapes against future high-severity fire.

Reducing fuel densities is the primary tool available to improve forest resilience to intensifying disturbance, but implementation is constrained by concern of effects to mature-forest associated species, such as spotted owls (Strix occidentalis).

Background

Phenological correction of pre- and post-fire imagery is used to improve remotely sensed burn severity evaluations. Unburned offset values standardize greenness between image pairs; however, efficacy across diverse scenarios remains underexplored.

Aims

Biological legacies (i.e., materials that persist following disturbance; “legacies”) shape ecosystem functioning and feedbacks to future disturbances, yet how legacies are driven by pre-disturbance ecosystem state and disturbance severity is poorly understood—especially in ecosystems influenced by infrequent and severe disturbances.

Wildfires are increasing in severity, frequency and size, potentially threatening freshwater species that adapted under different disturbance regimes. However, few wildfire studies have comprehensively evaluated freshwater populations and assemblages following wildfire over broad spatial scales while accounting for post-fire salvage practices in the watershed.

Background

Climate change in boreal regions is leading to warmer, drier conditions which amplify wildfire activity by altering fuel moisture, weather conditions, as well as the timing and duration of snow cover. Reduced snowpack and earlier snowmelt can lower fuel moisture, extend wildfire seasons, and increase burn severity.