Late Holocene palaeoenvironmental reconstruction on a peat sequence from northeastern South Africa, using grass phytoliths as main proxy

Abstract: Contemporary a geographical imbalance of where palaeoclimatological studies have been undertaken exists, where the majority of palaeodata is based on studies from the northernhemisphere. Multiproxy analysis was performed on a peat core from Lydenburg, north-eastern Mpumalanga, covering the last 1.600 years. Proxy focus was put on fossil grassphytoliths. A general drying trend can be noted from AD 400 to 1000, followed by moremesic conditions around AD 1200. The increasingly mesic conditions were interrupted by asignificantly drier period between c. AD 1250 to 1350. This part of the Lydenburg sequenceoccurs in the end of a climate event termed “Medieval warm period” (MWP), suggested tohave been warmer and variable but mostly wetter in southern Africa. The results are in lineregarding the increased temperature and suggested variability. However, in contrast withearlier findings, significantly drier conditions seem to have prevailed at the Lydenburg fenat the end of “MWP” as interpreted by multiple proxies. Following AD 1400 increasinglymesic conditions was recorded as interpreted by several of the analysed proxies. Morepalaeoenvironmental studies needs to be performed in the area in order to elaborate on thedriving factors of palaeoenvironmental change in the region, as well as to establish if thesignals from the Lydenburg fen record local or regional changes. The results support earlierphytolith studies suggesting that small rondels should be excluded from phytolithassemblages in tropical and sub-tropical areas in Africa.