Authors: Lauren B Hendricks*, University of Oregon, Gusti Z Anshari, Universitas Tanjungpura, Daniel G Gavin, University of Oregon
Topics: Paleoenvironmental Change, Human-Environment Geography, Physical Geography
Keywords: fire, Borneo, Southeast Asia, charcoal, radiocarbon dating
Session Type: Guided Poster
Start / End Time: 8:00 AM / 9:40 AM
Room: Roosevelt 3.5, Marriott, Exhibition Level
Presentation File: Download
Multiple studies have found evidence of past fire in tropical forests—including on Borneo—but the prevalence and spatial patterns of fire in the tropical rainforests of Borneo before the modern era is not well understood. Borneo’s indigenous groups have been using fire to clear land for centuries, and charcoal is abundant in low elevation areas with humid, multi-story forests that would have been suitable for agriculture. However, charcoal is also present in steep, high elevation areas that would not have been suitable for agriculture but are more susceptible to natural fires. Fire regimes dominated by human-caused fire would likely have a different spatial occurrence of fire than fire regimes dominated by natural fire. To understand the influence of human vs. natural fires and the historical resilience of tropical rainforest to fire we are using radiocarbon dating and relative abundance of charcoal in different forest types to examine the historical pattern of fire and pyrogenic-carbon content of soils in primary rainforest in Indonesia’s Gunung Palung National Park (GPNP). Initial counts of soil charcoal >2mm and radiocarbon dates across all sites sampled suggest that charcoal is both more abundant and younger (no older than 2500 calibrated years before present) in lowland forest types, with the oldest charcoal is found in upland sites (12,500-12,700 calibrated years before present). These results suggest that land clearance was a major source of fire in GPNP, and that these tropical rainforests were resilient to fires earlier in the Holocene.