The Contemporary Scale and Context of Wildfire in Hawai‘i

Wildfire is a major threat to natural resources and native species in Hawai‘i, but the frequency and extent of wildfires across the archipelago has not been well quantified. Our objective was to summarize the available wildfire data for Hawai‘i and synthesize the social and ecological dimensions of wildfire drivers, impacts, and management responses. We constructed a 110-yr span of wildfire records for the state of Hawai‘i to examine historical trends (1904–2011) and summarized relationships between contemporary wildfire occurrence (2005–2011) and land use/land cover types and human population. Total area burned statewide increased more than fourfold from 1904 to 1959 to peaks in the 1960s–1970s and mid-1990s to present. From 2005 to 2011, on average, 1,007 wildfires were reported across the state per year (± 77 SE), burning an average of 8,427 ha yr⁻¹ (± 2,394 SE). Most fires (95%) were <4 ha, while most area burned (93%) was attributed to fires ≥ 40 ha. Ignition frequency was positively correlated with human population across islands. Wildfires were most frequent in developed areas, but most areas burned occurred in dry nonnative grasslands and shrublands that currently compose 24% of Hawai‘i’s total land cover. These grass-dominated landscapes allow wildfires to propagate rapidly from areas of high ignition frequencies into the forested margins of the state’s watersheds, placing native habitat, watershed integrity, and human safety at risk. There is an urgent need to better assess fire risk and impacts at landscape scales and increase the integration of prefire planning and prevention into existing land management goals.