EVENTS

Webinar Details:

Title:

What are the causes and consequences of past wildfires in Hawaiʻi? A network of new sedimentary charcoal archives records the last 2,000 years of fire history across the Hawaiian Islands

Webinar Description:

The August 2023 fires in Lāhainā and Kula, Maui are testaments to the rapidly changing fire regimes occurring across the Hawaiian Islands. Existing sedimentary evidence suggests wildfire was infrequent in Hawai‘i prior to the arrival of humans and introduction of invasive species. However, due to disparate methodologies and limited number of previous charcoal reconstructions, it is unclear how widespread and variable changes in fire regimes have been within and across the islands, particularly following settlement by Polynesians. Factors that influence fire regimes are unique on tropical Pacific Islands in terms of fuel (e.g., plant species, diversity, and degree of invasion), fire weather (e.g., trade winds and tropical cyclones), and natural ignition sources (e.g., infrequent lightning strikes and localized lava flows). Additional high-resolution, charcoal-based fire reconstructions from wetland and lake sediment cores are therefore greatly needed to assess the timing, geographic patterns, and ecosystem consequences of past fires in Hawai‘i. Here we present the first high-resolution charcoal accumulation rate records from our new inter-island network of sediment cores that document the last 2,000 years of fire history. Charcoal records island- and site-specific changes in the timing of past fire disturbance, even in wet, high elevation forests. We discuss developing future sediment-based fire reconstructions across the islands to refine our understanding of the causes and consequences of past fire regimes in Hawai‘i.

Speaker details:

Dr. David Pompeani attended the University of Pittsburgh, where he earned his B.S. (2009) and Ph.D. (2015) degrees in geology. His research has led to publications in journals such as Scientific Reports, Geology, and Quaternary Science Reviews. His NSF-funded postdoctoral position focused on studying the biogeochemical impacts of wildfires using lake sediment records. Currently, David works at the University of Hawai‘i at Mānoa, focusing on the wildfire history of the Hawaiian Islands.