Dune advancement 1937—1977 at the Mlalazi Nature Reserve, Mtunzini, Natal, South Africa, and a preliminary vegetation-succession chronology

Abstract

Foredune advancement on a 2 km coastline north of the Siaya Lagoon Mouth was studied using air photos. Between 1937 and 1977 the dunes advanced about 95 m (2,4 m per year). Vegetation was dated according to its position on a  profile. If a 2,4 m per year seaward advancement of the dunes is assumed, the following succession chronology is  obtained: Scaevola thunbergii Foredunes from 0 to 30 years; Passerina rigida Open Dune Scrub 30 to60 years; Closed Dune Scrub 60 to 90 years and Dune Forest beginning at about 90 years. Variation in dune advancement rates on different coastal stretches and for different time intervals was observed and will be reported on later. This dune succession chronology should, therefore, only be seen as a first rough approximation.