Mangrove pollen of Indonesia and its suitability as a sea-level indicator

Abstract

I investigated the mangroves of Southeast Sulawesi, Indonesia, to assess their potential as proxies for reconstructing sea-level during the Holocene. Initial investigations confirmed that the mangrove species demonstrate zonations parallel to the shoreline and are dominated by the family Rhizophoraceae with Avicennia, Heritiera and Sonneratia also important constituents of the mangroves. The vertical distributions of pollen assemblages were investigated at three sites in Southeast Sulawesi, Indonesia. Partial CCA analysis demonstrated that at all three sites, elevation was a significant control on the distribution of pollen assemblages in surface samples. The three contemporary transects were combined to develop a regional transfer function to elucidate the relationship between the surface assemblages and elevations using the Maximum Likelihood (ML) method. The developed transfer function indicated mangrove pollen can be utilised as a precise indicator of past sea-levels with an error of ±0.22m The transfer function was applied to two fossil cores from the Wakatobi Marine National Park and evaluated using the Modem Analogue Technique. Both cores showed similar patterns in changes of Reference Water Level and had modem analogues in the contemporary training set. I conclude that mangrove pollen is a suitable proxy for reconstructing sea-level in tropical environments.