New Zealand Journal of Botany abstracts
Deschampsia cespitosa subalpine tussockland on the Green Lake
landslide, Hunter Mountains, Fiord Ecological Region, New Zealand
ALAN F. MARK
KATHARINE J. M. DICKINSON
Botany Department
University of Otago,
P.O. Box 56
Dunedin, New Zealand
Email: kath.dickinson@botany.otago.ac.nz
Abstract The tussock grass
Deschampsia cespitosa,
considered to be conspecific with the very polymorphic taxon which is
cosmopolitan in temperate and cold regions, is currently classed amongst the 62
"vulnerable" indigenous vascular species for New Zealand. Previously more
widespread here, the species' demise in certain regions within the last century
has been attributed to grazing and/or competition from aggressive introduced
grasses. This study provides the first quantification of the flora, vegetation,
and soil of an indigenous grassland stand dominated by
D. cespitosa.
Cover-abundance data were recorded from 15 randomly placed quadrats in a
localised intact stand of
D. cespitosa subalpine tussockland, occupying
an ancient landslide depression in eastern Fiordland. These data are related to
comparable information gathered from adjacent, more extensive,
Chionochloa
rubra ssp.
cuprea (copper) tussockland. Multivariate analysis
confirmed the distinction of the two stands in terms of species abundance but
indicated continuous floristic variation among the 51 plant taxa recorded. The
floristic similarity for the two stands was 49%, which was not statistically
significant, whereas that for the cover-abundance data was only 5%. Soils under
the site-specific
D.
cespitosa stand were classified as silt
loams while those of the
C. rubra ssp.
cuprea (copper)
tussockland are sandy clay loams with water content, organic matter, and root
mass all much higher in the former. The Fiordland population showed no signs of
grazing use despite the presence of introduced herbivores. Only one
non-aggressive grass, amongst the three exotic species, was recorded. On the
basis of this study,
D. cespitosa tussockland is proposed as a new
indigenous vegetation type for New Zealand.
Keywords Deschampsia cespitosa; Chionochloa
rubra ssp. cuprea; grasslands; indigenous tussocklands; floristics;
soil factors
B01022
Received 23 May 2001; accepted 14 September 2001
New Zealand Journal of Botany, 2001, Vol. 39: 577-585
0028-825X/01/3904-0577 $7.00 (c) The Royal Society of New Zealand 2001
PDF file of entire paper: medium quality (2352K); (scanned from paper original: notes about this process)
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