The Quaternary pollen of Ntsikeni Wetland, KwaZulu-Natal, South Africa

Abstract

Ntsikeni wetland, one of the highest altitude wetlands (~1795 m.asl) in South Africa, is a Ramsar site. Data from Ntsikeni Wetland will add to the spatial and temporal palaeoclimate data for southern Africa. The CONISS analysis separates the sequence into four primary zones of statistically significant similarity: WNT4: 25,000-13,000 cal. yr BP; WNT3: 13,100-10,800 cal. yr BP; WNT2: 9,000-4,300 cal. yr BP; WNT1: 4,200-650 cal. yr BP. From 22,000-21,000 cal. yr BP an increase in temperature and moisture is observed, followed by an increase in temperature and a decrease in moisture from 21,000-18,750 cal. yr BP. At 17,000 cal. yr BP a short but sudden drop in temperature and moisture is recorded. The final two changes in Zone WNT1 are short and definitive shifts to colder temperatures; the first at 15,000-14,800 cal.yr BP, the second 14,000-13,200 cal. yr BP; at 13500 cal. yr BP it is possibly the coldest period. The entire Zone WNT1 points to an increase in precipitation during colder periods. The wetland continued to contract until 11,000 cal. yr BP. A hiatus in pollen 9,000-10,700 cal. yr BP is observed, followed by an increase in moisture 8,800-8,200 cal. yr BP, and a warm period, with a contraction of the wetland from 7,000-5,050 cal. yr BP. A very brief wet and warmer period from 4,300-4,100 cal. yr BP is recorded, as the wetland starts to expand. Temperatures continue to increase, with a short localised drying period (100 years) and evaporation.