Fjölrit RALA - 05.12.1999, Page 135

KevinF. O’Conncr etal.
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Hakatere and Craigiebum values. However, results varied extravagantly, apparently
affected by the substantial range between sites in mass of litter. As nutrient concentra-
tions in litter varied greatly from the concentrations in live shoots, even at the sites
where both had been measured, we abandoned the estimation procedure as unreliable.
Soils have been named in the list of localities above, according to the soil set to
which they correspond in the Soil Bureau (1968b) “General Survey of Soils of the
South Island”, except for the central Otago localities where soils of the tall tussock
sites were named by Molloy and Blakemore (1974). Carbon and nutrient levels re-
ported from such sources have been, where necessary, summed over 0-200 mm and
200-400 mm depth to allow ready comparison with other sites. Methods of analyses
for new soil data not previously reported have followed those of Soil Bureau, as used
in Forest Research Institute (Kelland 1978). Unless otherwise stated, four replicate
samples of soils have been taken from the field at each site and separately analysed.
Results
Tall tussock grassland biomass
Considerable variability in tall tussock grassland biomass is indicated in Table 1. Soil
carbon is less variable than phytomass compartments. There is a two-fold difference
in magnitude of live shoot biomass between the Canterbury and Otago studies
Table 1. Biomass (tonnes ha“') of tall tussock (Chionochloa) grasslands and soil carbon (tonnes
ha') in 0-200 mm layer at nine localities in South Island high country. Numbers (la, lb, etc.) refer
to localities described in text. Superscripts indicate values which include supplementing estimates
noted below.
Location Above-ground Live tissue Dead (incl. litter) Below-ground Roots SoilC 0-200 mm
Craigieburn Mountains
la. Chionochloapallens 7.9 47.1 19.0a) 86.7
lb. C. macra 8.9b) c) 33.4 8.5 80.9
lc. C. rubrcf1 14.4 40.6 13.0d) 88.1
Hakatere Basin
2a. C. macra 4.5C) 12.2 22.0 61.7
2b. C. rigida 10.3C) 30.6 31.4 90.6
Tekapo, Mackenzie Basin
3. C. rubrcF1 11.4 18.8 16.0d) 74.8
Old Man Range, Otago
4a. C. macra 16.9 25.1 24.2 95.2e) f) g)
4b. C. macra/C. rigida 16.5 16.5 15.7 52.5e)
4c. C. rigida 21.3 44.9 21.0 63.2e,f)
CV (%) 42.2 42.4 35.3 19.3
a) Value includes supplement for incomplete recovery of fme roots.
b) Value includes supplement for measured amount of pedestalled roots and rhizomes.
c) Values include supplements for intertussock live biomass, estimated from height intercept data.
d) Values estimated on the basis of core samples only.
e) Values calculated from analytical data but with guesstimates of soil bulk density.
f) Soil reference site some km distant from biomass reference site.
g) AIl values ffom duplicate samples only.