The effects of past erosion would appear to be borne out
by the apparently denuded appearance of many parts of the
semiarid landscape. However, the overall removal of sediment exported from the region by large rivers is low compared to the sediment volumes removed by large rivers
draining the heavily bush-clad, hill and mountain slopes of
catchments in South Westland. The West Coast rivers deliver about two and a half times more sediment than the
Clutha River, which drains the Central Otago catchments.
The higher sediment loads in South Westland are attributed
to the high, and often intense rainfall (>7,000 mm yr
−1 in
many places), steep slopes, and rapid tectonic uplift in the
Westland catchments.
Many soils in the Semiarid Soil landscapes of Central
Otago have thin, poorly aggregated topsoils. Soil organic
matter is low, especially where not irrigated or well vegetated. Are these a fair representation of the soils and landscapes prior to human occupation? Probably not, given the
unequivocal evidence from prehistoric pollen records that
show essentially continuous forest cover (apart from montane or alpine areas) since c. 8500 years ago. Soil quality is
partly a function of healthy vigorous vegetation. Loss of
plant vigour impacts on soil organic matter levels and the
protective, insulating effects of ground surface litter. Large
accumulations of moa bones have been discovered in some
of the basins, prompting a question: what was the carrying
capacity of the land to support a sizable grazing population
of these large birds? The questions remain: are the soils in a
generally depleted state, and could land management and
ecosystem restoration return the soils to a higher level of soil
quality and ecosystem functioning? Soil organic carbon
modelling by Aroon Parshotam shows that, given good
vegetation cover, soil organic carbon is capable of
improvement, and suggests that, given ideal conditions, the
soil organic matter levels may have once been higher and
could potentially be returned to that state.
Further Reading
Allen RB, McIntosh PD (1994) Soils and plant communities and their
management, Pisa Flats. Central Otago. Landcare Research Contract Report, Landcare Research New Zealand Ltd, Dunedin
Anderson A (2013) A fragile plenty: pre-European Maori and the New
Zealand environment. In: Pawson E, Brooking T (eds) Making a
new land—environmental histories of New Zealand, new edn.
Otago University Press, Dunedin, pp 35–51
Balks MR, Hewitt AE (1987) The prospects for maintaining saline soils
for Lepidium kirkii.N.Z. Soil Bureau Contract Report 87/197
Balks MR, Beecroft FG (1985) Soil, irrigation suitability and drainage
information for selected irrigation schemes in Otago, 1985. Bound
soil data file No. 5. DSIR Soil Bureau, Dunedin
Barrell DJA, Cox SC, Greene S, Townsend DB (2009) Otago Alluvial
Fans Project: Supplementary maps and information on fans in
selected areas of Otago. GNS Science Consultancy Report
2009/052. Prepared for Otago Regional Council
Basher LR (1998) Surface erosion assessment in New Zealand using
caesium-137. In: Proceedings of SPERA98, environmental radioactivity and its application in environmental studies, 5th biennial
conference of the South Pacific environmental radioactivity association, Christchurch, 16-19 February, pp 31–38
Basher LR (2000) Surface erosion assessment using
137 Cs: examples
from New Zealand. Acta Geologica Hispanica 35:219–228
Basher LR, Webb TH (1997) Wind erosion rates on terraces in the
Mackenzie Basin. J Roy Soc New Zealand 27:499–512
Basher LR, Meurk CD, Tate KR (1990) The effects of burning on soil
properties and vegetation: a review of the scientific evidence
relating to the sustainability of ecosystems and land use in the
eastern South Island hill and high country. DSIR Land Resources
Technical Record 18, 93 p
Beecroft FG, Balks MR (1986) The drainage of land suitable for
orcharding, Blackmans Road area, Earnscleugh irrigation scheme,
Central Otago. N.Z. Soil Bureau Contract Report 86/05
Beecroft FG, Balks MR (1985) Examination of the Kohine and
Galloway soils for orchard suitability, Earnscleugh irrigation
scheme. Central Otago, Soil Bureau District Office Report DN, 28 p
Beecroft FG (1978) Gleying induced by irrigation in two Central Otago
soils. In: Rijske WC (ed) Soil groups of New Zealand: part 3. New
Zealand Society of Soil Science, Gley soils, pp 42–43
Brash DW, Beecroft FG (1987) Soil resources of Central Otago. Proc
New Zealand Grassland Assoc 48:23–30
Brook MS, Ferrar S (2019) Hartley Travers Ferrar (1879–1932) and his
geological legacy in Antarctica, Egypt and New Zealand. Earth Sci
Hist 38:43–58
Chen L, Arimoto R, Duce RA (1985) The sources and forms of
phosphorus in marine aerosol particles and rain from northern New
Zealand. Atmos Environ 19:779–787
Cook FJ, Beecroft FG, Joe EN, Balks MR (1986) Flow of water in a
gravelly sandy loam soil from a point source. N.Z. Soil Bureau
Contract Report 86/06
Fahey BD (1981) Origin and age of upland schist tors in Central Otago,
New Zealand. New Zealand J Geol Geophys 24(3):399–413
Fieldes M (1968) Clay mineralogy. In: Soils of New Zealand (Part 2).
NZ Soil Bureau Bull 26(2):22–39
Fieldes M (1971) Clay mineralogy of Brown-grey Earths. In:
Miller RB, Willoughby J (compilers) Soil Groups of New Zealand
(second printing). NZ Society of Soil Science, Lower Hutt, pp
17–18
Fieldes M, Perrott KW (1966) The nature of allophane in soils. Part 3.
Rapid field and laboratory test for allophane. NZ J Sci 4:623–629
Grab SW, Dickinson KJM, Mark AF et al (2008) Ploughing boulders
on the Rock and Pillar Range, south-central New Zealand: their
geomorphology and alpine plant associations. J Roy Soc New
Zealand 38:51–70
Hewitt AE (1982) Soils of Waipori farm settlement, east Otago. New
Zealand, NZ Soil Survey Report, 65 p
Hewitt AE (1984) Review of the brown-grey earths. NZ Soil Resources
Report SR2. Landcare Research
Hewitt AE (1994) A soil-landscape model for the Conroy land system.
In: Webb TH (ed) Soil-landscape modelling in New Zealand,
Landcare Research Science Series 5:80–86
Hewitt AE (1995) Soils of the Conroy land system, Central Otago.
Landcare Research Science Series 13, 56 p
Hewitt AE (1996) Estimating surface erosion using
137 Cs at a semiarid
site in Central Otago, New Zealand. J Roy Soc New Zealand
26:107–118
Hewitt AE, Balks MR (1988) Review of some halophyte habitats,
Central Otago. N.Z.Soil Bureau Contract Report 88/07
246
15 Semiarid Soils
by the apparently denuded appearance of many parts of the
semiarid landscape. However, the overall removal of sediment exported from the region by large rivers is low compared to the sediment volumes removed by large rivers
draining the heavily bush-clad, hill and mountain slopes of
catchments in South Westland. The West Coast rivers deliver about two and a half times more sediment than the
Clutha River, which drains the Central Otago catchments.
The higher sediment loads in South Westland are attributed
to the high, and often intense rainfall (>7,000 mm yr
−1 in
many places), steep slopes, and rapid tectonic uplift in the
Westland catchments.
Many soils in the Semiarid Soil landscapes of Central
Otago have thin, poorly aggregated topsoils. Soil organic
matter is low, especially where not irrigated or well vegetated. Are these a fair representation of the soils and landscapes prior to human occupation? Probably not, given the
unequivocal evidence from prehistoric pollen records that
show essentially continuous forest cover (apart from montane or alpine areas) since c. 8500 years ago. Soil quality is
partly a function of healthy vigorous vegetation. Loss of
plant vigour impacts on soil organic matter levels and the
protective, insulating effects of ground surface litter. Large
accumulations of moa bones have been discovered in some
of the basins, prompting a question: what was the carrying
capacity of the land to support a sizable grazing population
of these large birds? The questions remain: are the soils in a
generally depleted state, and could land management and
ecosystem restoration return the soils to a higher level of soil
quality and ecosystem functioning? Soil organic carbon
modelling by Aroon Parshotam shows that, given good
vegetation cover, soil organic carbon is capable of
improvement, and suggests that, given ideal conditions, the
soil organic matter levels may have once been higher and
could potentially be returned to that state.
Further Reading
Allen RB, McIntosh PD (1994) Soils and plant communities and their
management, Pisa Flats. Central Otago. Landcare Research Contract Report, Landcare Research New Zealand Ltd, Dunedin
Anderson A (2013) A fragile plenty: pre-European Maori and the New
Zealand environment. In: Pawson E, Brooking T (eds) Making a
new land—environmental histories of New Zealand, new edn.
Otago University Press, Dunedin, pp 35–51
Balks MR, Hewitt AE (1987) The prospects for maintaining saline soils
for Lepidium kirkii.N.Z. Soil Bureau Contract Report 87/197
Balks MR, Beecroft FG (1985) Soil, irrigation suitability and drainage
information for selected irrigation schemes in Otago, 1985. Bound
soil data file No. 5. DSIR Soil Bureau, Dunedin
Barrell DJA, Cox SC, Greene S, Townsend DB (2009) Otago Alluvial
Fans Project: Supplementary maps and information on fans in
selected areas of Otago. GNS Science Consultancy Report
2009/052. Prepared for Otago Regional Council
Basher LR (1998) Surface erosion assessment in New Zealand using
caesium-137. In: Proceedings of SPERA98, environmental radioactivity and its application in environmental studies, 5th biennial
conference of the South Pacific environmental radioactivity association, Christchurch, 16-19 February, pp 31–38
Basher LR (2000) Surface erosion assessment using
137 Cs: examples
from New Zealand. Acta Geologica Hispanica 35:219–228
Basher LR, Webb TH (1997) Wind erosion rates on terraces in the
Mackenzie Basin. J Roy Soc New Zealand 27:499–512
Basher LR, Meurk CD, Tate KR (1990) The effects of burning on soil
properties and vegetation: a review of the scientific evidence
relating to the sustainability of ecosystems and land use in the
eastern South Island hill and high country. DSIR Land Resources
Technical Record 18, 93 p
Beecroft FG, Balks MR (1986) The drainage of land suitable for
orcharding, Blackmans Road area, Earnscleugh irrigation scheme,
Central Otago. N.Z. Soil Bureau Contract Report 86/05
Beecroft FG, Balks MR (1985) Examination of the Kohine and
Galloway soils for orchard suitability, Earnscleugh irrigation
scheme. Central Otago, Soil Bureau District Office Report DN, 28 p
Beecroft FG (1978) Gleying induced by irrigation in two Central Otago
soils. In: Rijske WC (ed) Soil groups of New Zealand: part 3. New
Zealand Society of Soil Science, Gley soils, pp 42–43
Brash DW, Beecroft FG (1987) Soil resources of Central Otago. Proc
New Zealand Grassland Assoc 48:23–30
Brook MS, Ferrar S (2019) Hartley Travers Ferrar (1879–1932) and his
geological legacy in Antarctica, Egypt and New Zealand. Earth Sci
Hist 38:43–58
Chen L, Arimoto R, Duce RA (1985) The sources and forms of
phosphorus in marine aerosol particles and rain from northern New
Zealand. Atmos Environ 19:779–787
Cook FJ, Beecroft FG, Joe EN, Balks MR (1986) Flow of water in a
gravelly sandy loam soil from a point source. N.Z. Soil Bureau
Contract Report 86/06
Fahey BD (1981) Origin and age of upland schist tors in Central Otago,
New Zealand. New Zealand J Geol Geophys 24(3):399–413
Fieldes M (1968) Clay mineralogy. In: Soils of New Zealand (Part 2).
NZ Soil Bureau Bull 26(2):22–39
Fieldes M (1971) Clay mineralogy of Brown-grey Earths. In:
Miller RB, Willoughby J (compilers) Soil Groups of New Zealand
(second printing). NZ Society of Soil Science, Lower Hutt, pp
17–18
Fieldes M, Perrott KW (1966) The nature of allophane in soils. Part 3.
Rapid field and laboratory test for allophane. NZ J Sci 4:623–629
Grab SW, Dickinson KJM, Mark AF et al (2008) Ploughing boulders
on the Rock and Pillar Range, south-central New Zealand: their
geomorphology and alpine plant associations. J Roy Soc New
Zealand 38:51–70
Hewitt AE (1982) Soils of Waipori farm settlement, east Otago. New
Zealand, NZ Soil Survey Report, 65 p
Hewitt AE (1984) Review of the brown-grey earths. NZ Soil Resources
Report SR2. Landcare Research
Hewitt AE (1994) A soil-landscape model for the Conroy land system.
In: Webb TH (ed) Soil-landscape modelling in New Zealand,
Landcare Research Science Series 5:80–86
Hewitt AE (1995) Soils of the Conroy land system, Central Otago.
Landcare Research Science Series 13, 56 p
Hewitt AE (1996) Estimating surface erosion using
137 Cs at a semiarid
site in Central Otago, New Zealand. J Roy Soc New Zealand
26:107–118
Hewitt AE, Balks MR (1988) Review of some halophyte habitats,
Central Otago. N.Z.Soil Bureau Contract Report 88/07
246
15 Semiarid Soils