Shrub cover declined as Indigenous populations expanded across southeast Australia

• 成果类型: Article
• 署名作者: Mariani, Michela; Wills, Alastair; Herbert, Annika; Adeleye, Matthew; Florin, S. Anna; Cadd, Haidee; Connor, Simon; Kershaw, Peter; Theuerkauf, Martin; Stevenson, Janelle; Fletcher, Michael-Shawn; Mooney, Scott; Bowman, David; Haberle, Simon
• 署名单位: University of Nottingham; Australian National University; Australian National University; Australian National University; University of Cambridge; Australian National University; University of Wollongong; University of Wollongong; Monash University; Universitat Greifswald; Leuphana University Luneburg; University of Melbourne; University of Melbourne; University of Melbourne; University of New South Wales Sydney; University of Tasmania
• 刊物名称: SCIENCE
• ISSN/ISSBN: 0036-9150
• DOI: 10.1126/science.adn8668
• 发表日期: 2024-11-01
• 关键词: cultural landscape; fire; holocene; climate; pollen; vegetation; tasmania; dispersal; savanna; MODEL

摘要

Wildfires in forests globally have become more frequent and intense because of changes in climate and human management. Shrub layer fuels allow fire to spread vertically to forest canopy, creating high-intensity fires. Our research provides a deep-time perspective on shrub fuel loads in fire-prone southeastern Australia. Comparing 2833 records for vegetation cover, past climate, biomass burning, and human population size across different phases of human occupation, we demonstrated that Indigenous population expansion and cultural fire use resulted in a 50% reduction in shrub cover, from approximately 30% from the early to mid-Holocene (12 to 6 thousand years ago) to 15% during the late to mid-Holocene (6 to 1 thousand years ago). Since the start of British colonization to the present, shrub cover has increased to the highest ever recorded (mean of 35% land cover), increasing the risk of high-intensity fires.