A 700-YEAR RECORD ON THE EFFECTS OF CLIMATE
AND HUMAN IMPACT ON THE SOUTHERN CAPE COAST
INFERRED FROM LAKE SEDIMENTS OF EILANDVLEI,
WILDERNESS EMBAYMENT, SOUTH AFRICA
BASTIAN REINWARTH
1
, SARAH FRANZ
1
, JUSSI BAADE
1
, TORSTEN HABERZETTL
1
,
THOMAS KASPER
1
, GERHARD DAUT
1
, JÖRG HELMSCHROT
2
, KELLY L. KIRSTEN
3
, LYNNE J. QUICK
3
,
MICHAEL E. MEADOWS
3
and ROLAND MÄUSBACHER
1
1
Physische Geographie, Institut für Geographie, Friedrich-Schiller-Universität Jena, Germany
2
Biozentrum Klein Flottbek & Botanischer Garten, Universität Hamburg, Germany
3
Department of Environmental & Geographical Science, University of Cape Town, South Africa
Reinwarth, B., Franz, S., Baade, J., Haberzettl, T., Kasper,
T., Daut, G., Helmschrot, J., Kirsten, K.L., Quick, L.J.,
Meadows, M.E. and Mäusbacher, R., 2013. A 700-year
record on the effects of climate and human impact on the
southern Cape coast inferred from lake sediments of Eilan-
dvlei, Wilderness Embayment, South Africa. Geografiska
Annaler: Series A, Physical Geography, 95, 345–360. doi:
10.1111/geoa.12015
ABSTRACT. The southern Cape coast, South Africa, is
sensitive to climate fluctuations as it is influenced by differ-
ent atmospheric and oceanic circulation systems. Palaeoeco-
logical evidence of Holocene climate variations in this
region is presently limited. Here, we present a lake sediment
record spanning approximately the last 670 years from
Eilandvlei, a brackish coastal lake situated mid-way between
Cape Town and Port Elizabeth. The results from geochemi-
cal and sedimentological analyses point to an increase in
minerogenic sediment input from the catchment starting
around ad 1400. Changes in the seasonal distribution of
rainfall during the Little Ice Age may have altered river
discharge and increased erosion rates and fluvial sediment
transport in pre-colonial times. A rising mean lake level,
possibly associated with an altered water balance or relative
sea-level rise, may offer an explanation for the deposition of
finer sediments. After ad 1450, reduced burial flux of ele-
ments associated with autochthonous sediment formation
may have resulted from ecological changes in Eilandvlei.
Enhanced sedimentation rates, increasing carbon, nitrogen,
phosphorous and biogenic silica concentrations, as well as
high concentrations of proxies for allochthonous sediment
input (e.g. aluminium, titanium, zirconium) point to increas-
ing sediment and nutrient flux into Eilandvlei from the late
nineteenth century onwards. The most likely factor involved
in these recent changes is land-use change and other forms of
human impact.
Key words: South Africa, southern Cape, coastal lake, lake
sediments, geochemistry, sedimentology, Little Ice Age,
human impact
Introduction
South Africa is affected by tropical and subtropical,
atmospheric and oceanic circulation systems
leading to strong climatic and environmental gradi-
ents across the subcontinent (Scott and Lee-Thorp
2004). A long-term perspective on climatic oscilla-
tions and the effects of human interference are
essential for environmental management and mod-
elling of environmental and climate change sce-
narios. Unfortunately, climatic conditions often
constrain the preservation of sedimentary records
across much of the subcontinent, which partly
explains the scarcity of palaeoenvironmental data
from terrestrial archives (Chase and Meadows
2007).
Sediments of coastal lakes provide an opportu-
nity for palaeoecological research and were previ-
ously used to reconstruct the evolution of South
Africa’s coastal environments and its driving
forces, that is, climate, sea level fluctuations and
human impact (Baxter and Meadows 1999; Gordon
et al. 2012). Here, we present a sediment record
from Eilandvlei, a coastal lake located in the Wil-
derness Embayment at the southern Cape coast
(Fig. 1a). The sensitivity of this region to climate
and sea-level change throughout the Holocene has
already been demonstrated by studies of diatom,
pollen and charcoal assemblages from Groenvlei
(Martin 1959, 1968), palynological evidence from
the Norga peat (Scholtz 1986) and the examination
of large mammal remains at Nelson Bay Cave
(Klein 1983; Fig. 1a). Detailed evidence for late
Holocene temperature oscillations was inferred
from a stalagmite record of the Cango Caves,
© 2013 Swedish Society for Anthropology and Geography
DOI:10.1111/geoa.12015
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