Details

Autor(en) / Beteiligte

• Punwong, Paramita
• Marchant, Rob
• Selby, Katherine

Titel

Holocene mangrove dynamics and environmental change in the Rufiji Delta, Tanzania

Ist Teil von

• Vegetation history and archaeobotany, 2013-09, Vol.22 (5), p.381-396

Ort / Verlag

Berlin/Heidelberg: Springer-Verlag

Erscheinungsjahr

2013

Link zum Volltext

Quelle

SpringerLink

Beschreibungen/Notizen

• Holocene mangrove dynamics are reconstructed from pollen, sediment and radiocarbon analyses of three cores (ANR, BNR, CNR) located across a 20 km transect in the Rufiji Delta, Tanzania. At the base of the sediment sequence, dated to about 5600 cal. year B.P., the mangroves which are present suggest a low intertidal ecosystem in response to wet conditions and a higher sea level than at the present day. After around 5600 cal. year B.P. in core BNR, mangroves retreated seaward probably due to a lower sea level and drier environmental conditions. At around 4640 cal. year B.P., mangroves shifted landward suggesting a phase of sea level rise. In the late Holocene, mangroves became established at higher elevations of the Rufiji Delta, which is now a paddy field. Mangrove taxa decreased after 1170 cal. year B.P., suggesting drier conditions and less inundation frequency, possibly due to a lower sea level. Marked vegetation changes from mangroves to terrestrial vegetation occurred after around 750 cal. year B.P., possibly related to sea level regression and/or a desiccation phase recorded during the late Holocene. Paddy fields replaced mangroves in the landward part of the transect, reflecting an increase in human settlement in this area, a trend that continues to the present day. The recent decrease of mangrove species, particularly Rhizophora mucronata, could suggest less inundation by saline water and a lower sea level, although these changes may also be due to human activities during the last millennia as indicated by charcoal analysis.