WHAT THE EVIDENCE SAYS
Researchers combined 1986–2022 California spotted-owl detections, a statewide fuels-management database and remotely sensed predictors in random-forest habitat models. Nesting/roosting habitat declined 54% since 1986, with 92% of remaining habitat concentrated in San Bernardino National Forest. Of attributable post-2006 nesting/roosting habitat losses, wildfire accounted for about 80%, drought/other disturbance 14% and fuels management 6%. Potential territories meeting both nesting/roosting and prey-acquisition habitat thresholds declined 73%.
WHY IT MATTERS / OUR READ
The result complicates the idea that fuels treatment is the dominant driver of old-forest habitat loss in this system. It supports evaluating treatment effects against the larger counterfactual risk from severe wildfire while still protecting the habitat features owls require.
CAVEATS / UNCERTAINTY
Attribution comes from remote-sensing and statistical habitat models rather than a randomized treatment experiment. Habitat suitability is not the same as owl demography, treatment intensity and placement matter, and the percentages are specific to this Southern California landscape and study period.
SOURCE
Forest Ecology and Management / USDA Forest Service — primary study
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USDA Forest Service Treesearch
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