Periodic coupling of anthropogenic fire patterns and East Asian monsoon variability over the past 4000 years

Discrepancies among fire proxies have long hindered integrated reconstructions of prehistoric anthropogenic burning and its climatic feedbacks. We analyzed a 490-cm terrestrial sedimentary profile from Guangrao, Shandong Province (GR section; 4000–0 yr BP) within the East Asian monsoon domain. By integrating fecal stanols with black carbon, polycyclic aromatic hydrocarbons (PAHs), and paleoecological proxies, we reconstruct fire regime dynamics and human responses to monsoon variability over the past four millennia. Spectral analysis of char and 5-ring PAHs concentrations, combined with Redfit and Multi-Taper Method (MTM) analyses, delineates a three-phase evolution of anthropogenic fire regimes over the past 4000 years:(1) 4000–2500 yr BP (Yueshi Culture to Warring States), characterized by low-intensity smoldering with ∼500-year quasi-periodicity linked to agricultural clearance; (2) 2500–300 yr BP (Warring States to late Ming–early Qing), dominated by high-intensity flaming with ∼280-year quasi-periodicity associated with warfare-related burning; and (3) the past 300 years (Qing to present), marked by pervasive biomass burning under anthropogenic climate influence at centennial-to-decadal scales.Cross-Wavelet Transform (XWT) and Wavelet Transform Coherence (WTC) analyses indicate that the periodic changes in the fire regime are significantly correlated with the quasi-periods of the East Asian Summer Monsoon (EASM) at the centennial scale (∼500 years) and (∼ 200–300 years), respectively.XGBoost–SHAP analyses show that the contribution of anthropogenic burning to fire regimes has increased progressively over the past 4000 years, rising from ∼23 % to more than 51 %. These shifts in fire regime periodicity were mainly governed by seasonal hydrothermal changes induced by the weakening of the EASM, together with increasing spatial heterogeneity in anthropogenic fire patterns.Concurrently, in the mid-to-late Holocene, the use of different biomass-burning practices by ancient human progressively altered the regional ecological landscape.Therefore,Over 4000 years, anthropogenic fire practices have both mirrored centennial-scale monsoon variability and reflected adaptive shifts in production systems and social structures. In the lower Yellow River, sustained land reclamation promoted persistent smoldering fires, leading to landscape fragmentation, ecological degradation, and marking a critical threshold in anthropogenic mediated climate transformation.