Early Holocene vegetation, human activity and climate from Sarawak, Malaysian Borneo

A 40 m core from Loagan Bunut, Malaysian Borneo, yielded a high-resolution early Holocene (11.3-6.75 ka) sequence of marginal-marine deposits. Palynological analysis showed relatively stable fire-regulated lowland forest through this time, with the local development and regression of mangrove vegetation. A general trend of rising rainfall and thus strengthening North East monsoonal circulation linked to the migration of the mean position of the ICTZ was interrupted by what may be episodes of drier climate and weakening monsoonal activity at 9250-8890, 7900 and 7600-7545 cal. BP. Magnetic susceptibility peaks suggest marked short-term ENSO-style activity superimposed upon this record. Repeated markers for open and disturbed habitats, plus occasional imported and probably-cultivated taxa, point towards human impact from the earliest Holocene on the wet tropical forest at Loagan Bunut.