Fire–climate–human interactions during the Holocene: insights from sediment records in southwestern Türkiye

Fire is a major driver of Mediterranean ecosystems, yet the long-term interactions between fire, vegetation dynamics, and human land use in southwestern Türkiye remain poorly understood. Unlike previous Mediterranean studies, which have tended to focus on individual records or assume direct links between vegetation and fire, this study explicitly compares charcoal, pollen, and anthropogenic indicators. This allows the relative roles of climate, vegetation structure, and human activity in shaping fire regimes to be disentangled. In this study, we use a lacustrine sediment record spanning the last 12,000 years to reconstruct Holocene fire history and its environmental controls, employing charcoal, deciduous Quercus pollen, cultivated trees pollen (Olea, Castanea, and Pistacia), and anthropogenic pollen indicators (Asteraceae Cichorioideae, Amaranthaceae, Ranunculaceae, Artemisia, and Plantago). Charcoal concentrations show some variability over time, reflecting changes in fire activity and discrete fire episodes associated with forest growth and increasing human influence. However, these variations do not consistently align with changes in vegetation, suggesting that fire regimes were influenced by several interacting factors rather than one dominant driver. During the Early Holocene, low charcoal influx and low percentages of deciduous Quercus pollen suggest weak, climate-driven fire regimes with limited fuel availability. After 9000 years BP, the rapid expansion of oak-dominated forests led to sustained increases in fire activity and fire episode frequency, peaking during the Middle Holocene between 8500 and 4500 years BP. The close correspondence between high Quercus abundances and charcoal peaks highlights the primary role of forest structure in regulating fire regimes. From around 7500 years BP onwards, increasing anthropogenic pollen indicators (Asteraceae Cichorioideae, Amaranthaceae, Ranunculaceae, Artemisia, and Plantago) and cultivated tree (Castanea, Olea, and Pistacia) pollen demonstrate the emergence of arboriculture and managed landscapes, indicating growing human influence on fire activity. During the Late Holocene, declining charcoal accumulation, moderate oak percentages, and the persistence of cultivated trees reflect a transition towards controlled burning and stable agricultural systems. These results demonstrate a progressive shift from predominantly climate- and vegetation-controlled fire regimes in the Early Holocene to increasingly human-modified systems after 7500 years BP, culminating in fully established, managed fire regimes with reduced large-scale burning during the Late Holocene (after 3000 years BP).