Fig. 1
From: Northern spotted owl nesting forests as fire refugia: a 30-year synthesis of large wildfires
The range of the northern spotted owl range in the USA. Map a: potential nesting forest (i.e., habitat capable forest) and coverage of large (> 200 ha) wildfires from 1987 to 2017. Potential nesting forests were those areas with environmental conditions of elevation (< 2000 m) and soil types that without disturbance (e.g., timber harvest) could develop into suitable forest for nesting and roosting by spotted owls given time for succession. Map b: the extent of three historical fire regimes modified from Spies et al. (2018). The high severity, infrequent regime are those areas that typically experience large to very large patches of high-severity fire on > 200-year return intervals. The mixed severity, frequent regime were those areas typically burning with a relatively even mix of severity and relatively frequent return interval (15–200 years). Prior to effective fire exclusion during the past century the low severity, very frequent regime areas would have experienced short return intervals (5–25 years) and were dominated by low-severity fire