Abstract:
East and West Usambara Mountain blocks are unique based on three characteristics. Firstly, they are connected blocks; secondly,
they have an oceanic-influenced climate; and thirdly, the rain seasons are not easily discernible due to their close proximity to
the Indian Ocean and Equator. Sediment cores were collected from peat bogs in Derema (DRM) and Mbomole (MBML) in East
Usambara and from Madumu (DUMU) in West Usambara. The multiproxy record provides an understanding on climate and
vegetation changes during the last 5000 years.DRMandMBMLcores result in radiocarbon ages and age-depth curvewhich showed
hiatus at 20 cm and 61 cm and huge inversion for DUMU core at 57 cm. Period 5000–4000 14C yr BP for DUMU core revealed
increased Montane forest indicative of relatively moist conditions. Periods 3000–2000 and 2000–1000 14C yr BP, DUMU core
demonstrated increased submontane and lowland forests. Period 1000–200 14C yr BP,DUMUcore signified increased coprophilous
fungi while DRM and MBML cores signified fluctuating herbaceous pollen spectra (wet-dry episodes). Period 200 14C yr BP to
present, all cores demonstrated stable recovery of forest types especially dominance of submontane forests. Abundant coprophilous
fungi indicated increased human impacts including forest fires, cultivation, and grazing.
