Microcharcoals Reveal More Grass Than Trees During the Mid-Holocene Optimum on the Chinese Loess Plateau

Microcharcoal morphology, which changes with biofuel type in the wildfire, can be used as an index for wildfire history and vegetation evolution. Here, five loess sites across the Chinese Loess Plateau were used to establish the biofuel history of the region during the Holocene based on microcharcoal morphological records. The results suggested that consistently increasing grass biofuel dominated the mid-Holocene (& SIM;7,500-3,000 yr BP), and the grassland or steppe expanded in the same interval. Since the climate conditions with simultaneous high precipitation and temperature of the mid-Holocene are the most recent paleoclimate analog for future warming, we argue that the humid and warm conditions expected under future global warming on the Loess Plateau might lead to an increase in the grass rather than trees.