Surface fires returned every 36 years on average in surviving pine stands.

Evidence

In addition to the fires severe enough to introduce the new stands reflected in Table 4, many surface fires in red and white pine stands killed few trees. The average return interval for fires in pine stands where some or all trees survived was 36 yr, based on ring counts for 190 scars from 76 trees with multiple scars. These intervals were extremely variable, however, with some stands showing repeat burns as close as 5 yr and others as long as 100 yr. Many of these fires burned in the same major fire years that elsewhere killed entire stands, while some occurred in years that are seldom reflected in new stand origins. — Miron L. Heinselman, Fire in the Virgin Forests of the…, 163

Categorization

• DEFINE: Distinguishes stand-replacing fires (dating new stands) from surface fires (scarring survivors) — a core disturbance-ecology method distinction.
• XREF: connects to: Tree species evolved distinct reproductive adaptations to fire — Miron L. Heinselman, Fire in the Virgin Forests of the…, 44; Letting all lightning fires run is unsafe in flat Canoe Area terrain — Miron L. Heinselman, Fire in the Virgin Forests of the…, 455; Natural fire rotation in the BWCA was about 100 years — Miron L. Heinselman, Fire in the Virgin Forests of the…, 2 (+1 more)

Related

• Five fire years created nearly three-quarters of today’s forest stands. (similarity 0.85)
• Natural fire rotation in the BWCA was about 100 years (similarity 0.84)
• Virtually every BWCA virgin forest stand burned since 1595. (similarity 0.84)
• Virtually every BWCA forest stand regenerated after fire since 1595 (similarity 0.84)
• The Canoe Area burned and regenerated on about a 100-year rotation. (similarity 0.84)
• Documented fire history undercounts actual fires due to evidence decay. (similarity 0.83)
• Natural fire rotation quantifies fire’s role and grounds fire-management targets. (similarity 0.83)
• The BWCA still has a roughly 60-year window before fire exclusion makes restoration impossible. (similarity 0.82)
• Restoring the natural regime means burning roughly 4,200 Canoe Area acres yearly (similarity 0.82)
• Coring dominant fire-adapted trees dates stand origin after burns. (similarity 0.82)
• No large BWCA burns since 1936 already eliminated early postfire communities. (similarity 0.80)
• The landscape mosaic remains fire-created even after sixty years of suppression. (similarity 0.80)
• Logging-era slash fires replaced red and white pine with aspen, birch, and jack pine (similarity 0.80)
• Tree species evolved distinct reproductive adaptations to fire (similarity 0.80)
• Contrasting stand ages let fire boundaries be traced on airphoto maps. (similarity 0.80)