Journal of the Royal Society of New Zealand abstracts
A Holocene pollen and sediment record of Whangape Harbour, far
northern New Zealand
M. Horrocks*, S. L. Nichol+, M. R.
Gregory**, R.
Creese++, P. C.
Augustinus+**
*Centre for Archaeological Research, University of Auckland, Private
Bag 92019, Auckland, New Zealand.
+Department of Geography, University of Auckland, Private Bag
92019, Auckland, New Zealand.
**Department of Geology, University of Auckland, Private
Bag 92019, Auckland, New Zealand.
++School of Environmental and Marine Sciences,
University of Auckland, Private Bag 92019, Auckland, New Zealand.
The sediment record of Whangape Harbour shows that there were significant
fluctuations in depositional energy in the harbour during the period from c.
>8000 cal. yr B.P. to some time within the last millenium, and that fluvial
influences increased as the harbour infilled. The pollen record (highly
discontinuous) from Whangape Harbour indicates that conifer-hardwood forest
covered the hills surrounding the harbour during this period. The main canopy
conifers were
Dacrydium and
Prumnopitys taxifolia, with
some
Libocedrus,
Dacrycarpus,
and
Phyllocladus.
Agathis was also present. Common canopy hardwoods were
Metrosideros and, in the latter part of the period,
Elaeocarpus.
Ascarina and
Cyathea were abundant in the sub-canopy.
Leptospermum grew on disturbed areas fringing the estuary. Marsh or
swamp environments probably never developed on a large scale in the harbour.
Avicennia, extremely under-represented in the pollen flora, has been
present on tidal flats in the harbour since at least c. 2500 cal. yr B.P.
Large-scale anthropogenic deforestation by burning commenced in the Whangape
catchment some time during or since 700-430 cal. yr B.P. The associated
increase in erosion rates in the catchment resulted in a change towards a
sandier sediment regime in the harbour which has continued to the present day.
Weinmannia and
Ackama, previously rare in the catchment, expanded
in remaining forest.
Keywords palynology; sedimentology; Holocene; disturbance;
Northland
R00004. Received 6 March 2000; accepted 26 July 2000
(c) Journal of The Royal Society of New Zealand,
Volume 31, Number 2, June 2001, pp 411-424
PDF file of entire paper: medium quality (903K); (scanned from paper original: notes about this process)
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