This report presents the findings of an assessment of the ecological role and integrity of fire regimes across the lower 48 states of the U.S. Frequent fire return intervals dominate fire regimes across the assessment area.

Approximately 80% of ecosystems, major habitat types, Nature Conservancy regions and the Conservancy’s portfolio of conservation areas of biodiversity significance (conservation areas) are moderately to highly departed from their ecological reference conditions. Fire regime conditions do not differ substantially within versus outside the Conservancy’s conservation areas, nor within versus outside federally-administered lands.

Technical fire capacity and conservation actions targeted at abating fire-related threats across the Conservancy and partner organizations vary considerably and do not necessarily parallel the degree and extent of altered fire regime conditions across the U.S. nor within the Conservancy’s priority conservation areas.

Fire’s ecological roles and sources of its alteration must be considered in conservation planning, prioritization, partnerships, taking action and measuring results. Maintaining and restoring fire’s ecological roles in areas of high biodiversity value is tantamount to effective conservation wherever the Conservancy works.