New Zealand Journal of Botany abstracts
Distribution of native forest in the upper Clutha district, Otago, New
Zealand
PETER WARDLE
Landcare Research
P.O. Box 69
Lincoln, New Zealand
Abstract The upper Clutha district extends from steep,
glaciated mountains along the South Island Main Divide to broad plateaus and
terraced valleys further downstream, and covers an annual precipitation
gradient from 4000 mm to 400 mm. Tall forest prevails from the valley
floors to the subalpine tree limit in north-western headwaters, but southwards
down the rainfall gradient becomes increasingly confined to small pockets.
Nothofagus is overwhelmingly dominant, with
N. menziesii
prevailing in the north-west and
N. solandri var.
cliffortioides
in drier country to the east. Pockets of forest in the south of the district
can consist of either species.
Nothofagus fusca co-dominates with the
other
Nothofagus species at low altitudes through part of the Matukituki
catchment, and over a small area by Lake Hawea. Low-altitude
N.
menziesii forest in the Makarora Valley has a similar composition to
forests west of the Main Divide, and includes several conifer species and a
wide range of broad-leaved trees, notably
Weinmannia racemosa. The
hardiest conifers,
Podocarpus hallii and
Phyllocladus alpinus,
are widely distributed in the
Nothofagus forests of the district and
also dominate small stands of native trees on otherwise treeless mountains. In
the moister part of the district
Kunzea ericoides and
Leptospermum
scoparium are successional to broad-leaved forest, whereas in the drier
parts they are self-perpetuating. Grey scrub, dominated mainly by
Discaria
toumatou, is widespread on slopes where rainfall is low, and on river flats
under higher rainfall. Small trees of
Sophora microphylla and
Olearia spp. occur locally in this scrub
.
Keywords forest distribution; Nothofagus; Phyllocladus
alpinus; Podocarpus hallii; precipitation gradient
B00021
Received 22 June 2000; accepted 22 May 2001
New Zealand Journal of Botany, 2001, Vol. 39: 435-446
0028-825X/01/3903-0435 $7.00 (c) The Royal Society of New Zealand 2001
PDF file of entire paper: medium quality (7907K); (scanned from paper original: notes about this process)
This year's abstracts |
Journal home page |
All abstracts |
Publishing home page
