A high-resolution record of Holocene climate and vegetation dynamics from the southern Cape coast of South Africa: pollen and microcharcoal evidence from Eilandvlei

Abstract

The southern Cape is a particularly dynamic region of South Africa in terms of climate change as it is influenced by both temperate and tropical circulation systems. This paper presents pollen and microcharcoal data generated from a sediment core extracted from the coastal lake Eilandvlei spanning the last ∼8900 years. With an average sample resolution of 57 years, this record represents the highest resolution record of Holocene vegetation change from the region. The data indicate that cool, seasonal and moderately dry conditions characterized the Wilderness Embayment from ∼8900 to 8000 cal a BP. Afrotemperate forests expanded from ∼8000 cal a BP until 4700 cal a BP. This humid period is followed by indications of more arid and seasonal conditions until 3500 cal a BP. A long‐term increase in forest taxa suggests steadily increasing moisture availability across the late Holocene. Strong affinities are noted with records from more tropical regions of South Africa, suggesting that tropical systems are of importance in maintaining higher moisture availability in the region. An important mechanism of climate change is the Agulhas Current, which transmits what appears to be a localized signal of tropical variability to the southern Cape coast.

Are forest‐shrubland mosaics of the Cape Floristic Region an example of alternate stable states?

“…In our analysis, the Transition vegetation shared more floristic similarities with Fynbos than with Forest, is still far from the closed canopy and occurs on soils that are nutritionally intermediate, although more similar to Fynbos, particularly at Orange Kloof. Palynological records from a site in the CFR, where the contemporary vegetation consists of a mosaic of Forest, Fynbos and Strandveld, suggest that a shift from Fynbos to Forest takes at least 750 yr (Quick et al 2018). We thus suggest that this Transition vegetation zone is a relatively unstable intermediate zone with respect to fire, water and nutrients, in which regime shifts could occur and may therefore exist as a relatively open-or closedcanopy forms.…”

“…There is little information on the rate at which vegetation can alter soil chemical properties in the Fynbos sufficient to allow Forest closure. Palynological records from a site in the CFR, where the contemporary vegetation consists of a mosaic of Forest, Fynbos and Strandveld, suggest that a shift from Fynbos to Forest takes at least 750 yr (Quick et al 2018). In Orange Kloof, colonising Forest trees (e.g.…”

High-resolution record of Holocene climate change dynamics from southern Africa's temperate-tropical boundary, Baviaanskloof, South Africa

“…These data were later complimented by work on the Norga peats by Scholtz (1986), speleothems from Cango Cave by Talma and Vogel (1992), and most recently by evidence from rock hyrax middens from Seweweekspoort (Chase et al, 2013;Chase et al, 2017). Recent initiatives have also explored the potential of other lakes within the Wilderness region (Kirsten et al, 2018;Quick et al, 2018;Quick et al, 2016;Wündsch et al, 2018;Wündsch et al, 2016) and adjacent coastal margin (Carr et al, 2010b;Quick et al, 2015) (Figure 1b).…”

‘I Can Do It’ Becomes ‘We Do It’: Kimberley (Australia) and Still Bay (South Africa) Points Through a Socio-technical Framework Lens

“…It is understood that environmental/climatic conditions in southern Africa were more varied/complex than represented by these data sets, as illustrated by more fine-grained work for later periods (e.g. Chase and Meadows 2007;Chevalier and Chase 2016;Quick et al 2018). Here, we use these environmental data sets merely as illustration of how to incorporate a range of elements into socio-technical thinking and not as comprehensive analysis.…”