Sattler and others that indicates the presence of contemporary permafrost in debris-mantled slopes above *2000 m
elevation in the central Southern Alps, and above *2150 m
in the northern Kaikoura ranges. These altitudinal limits are
considered highly unusual for permafrost globally, and
Sattler and others emphasise that such permafrost may relate
to reduced ice loss because of maritime New Zealand’s
moderate summer temperatures. Relict periglacial features,
including patterned ground such as stone stripes, occur in
upland Central Otago and active solifluction deposits are
commonplace on slopes in central and southern New Zealand. Ploughing boulders on the Rock and Pillar Range also
indicate that periglacial processes remain active in some
areas at elevations of *1500 m. Gelisols form the main soil
order in the Ross Sea region of Antarctica (Chap. 17).
The diversity of soils in the relatively small area of New
Zealand provides some unique challenges because high soil
diversity has implications for management decision making.
For example, when a predictive model is developed at a
particular place, and then applied in other areas, confidence
in the results is enhanced if it is known that the soils are
similar and thus likely to behave in a similar way. Thus,
considerable work is needed to provide confidence in the
predictive capacity of a model, such as “Overseer”, when
applied over a heterogeneous range of soils.
Soil diversity at the paddock scale may be managed using
precision agricultural techniques. Where the diversity is well
mapped, and the soil well characterised, then the techniques
of precision agriculture can provide production and environmental benefits. However, in areas where soil investigations show low paddock-scale diversity, the investment in
precision agriculture techniques may not be worthwhile.
18.2.3 Global Relatives of New Zealand Soils
The New Zealand soil-landscape can be divided into four
broad regions (Fig. 18.1). The relatively tectonically stable
Northland area is dominated by Ultic Soils, Granular Soils,
and Oxidic Soils. We expect to find related soils in parts of
the world that are relatively tectonically stable, have warm,
generally wet, climates, and have missed the major disturbances of late Quaternary volcanism and associated mantling
of tephra deposits (Table 18.2). Although temperatures were
lower during the last glacial period, Northland remained
under forest cover, unlike the rest of New Zealand.
Correlatives of the Oxidic Soils are distributed globally in
the tropics typically on stable landforms of continental
shields, but they also occur in orogenic belts on highly
weatherable basic rocks, as is the case in northern New
Zealand. Although Oxidic Soils in New Zealand are generally similar to their international correlatives, equivalent
soils elsewhere are typically bioturbated by termites. The
apparent lack of termites in pre-human times in New Zealand suggests that our soils are much less bioturbated and
may differ biologically in some way.
Soils similar to both Granular and Ultic Soils are well
represented, on old landscapes, in many parts of the world.
However, some of the Ultic Soils in northern New Zealand
show strong podzol morphological features, despite being
enriched in clay, because of the potency of the kauri tree
(Agathis australis) as a scattered podzolising agent in the
region’s pre-human forests. The Densipan Ultic Soils are
also globally uncommon.
The widespread tephras in the central North Island are
dominated by Pumice Soils and Allophanic Soils. Similar
soils form in other parts of the world where tephra from
rhyolitic and andesitic volcanoes dominate the soil parent
materials (e.g. Japan and Oregon, USA). However, substantial proportions of the Allophanic Soils in North Island
are dominated by silica-rich rhyolitic tephras and are consequently less fertile, chemically, than the main andesite- to
basalt-dominated equivalent tephra-derived soils elsewhere
in the world. Essentially unlimited Al availability means that
so-called ‘non-allophanic’ Andisols (i.e. soils on tephra
dominated by Al-humus complexes rather than allophane, as
found in parts of Japan, for example) are probably not present in New Zealand. Based on a soil profile about 1 m deep,
New Zealand has a much wider range of ages on Andisols
than elsewhere. Most of the Pumice Soils (Vitrands in Soil
Taxonomy) are 700 or 1800 years old. The Allophanic
Soils (Udands in Soil Taxonomy) are formed mostly by developmental upbuilding pedogenesis and date back
20,000–25,000 years with some as old as 50,000 years
(composite ages for 1.0–1.5-m deep soil profiles). Thus,
New Zealand has possibly the oldest Andisols in the world
on this basis. The rhyolitic Pumice Soils (Vitrands) are
exceptionally siliceous and glassy, and lack macro- and
micronutrients (including Cu, Se, Co, B, and I).
Soils similar to the Semiarid Soils are common in low
rainfall areas throughout the world. A feature of the New
Zealand Semiarid Soils is that they generally have no lime
(calcium carbonate) inherited directly from the parent
materials. The lime accumulated in the profiles is not from
limestone or other calcareous rocks but formed instead as a
result of weathering processes in the soil, i.e. the lime is
secondary in origin. In mid- and western USA, Mollisols
(soils with deep (>25 cm), dark, organic matter-rich topsoils,
i.e. mollic epipedons) occur in similar semiarid and marginally moister environments. However, Mollisols are relatively rare in New Zealand. One reason is that their
formation may have been suppressed by the lack of natural
lime (to help stabilise organic carbon). Other inhibiting
factors for Mollisol formation include the overwhelming
predominance of podocarp-broadleaf forest vegetation,
rather than grasslands, from postglacial (Holocene) times
18.2 New Zealand Soils in a Global Context
291
elevation in the central Southern Alps, and above *2150 m
in the northern Kaikoura ranges. These altitudinal limits are
considered highly unusual for permafrost globally, and
Sattler and others emphasise that such permafrost may relate
to reduced ice loss because of maritime New Zealand’s
moderate summer temperatures. Relict periglacial features,
including patterned ground such as stone stripes, occur in
upland Central Otago and active solifluction deposits are
commonplace on slopes in central and southern New Zealand. Ploughing boulders on the Rock and Pillar Range also
indicate that periglacial processes remain active in some
areas at elevations of *1500 m. Gelisols form the main soil
order in the Ross Sea region of Antarctica (Chap. 17).
The diversity of soils in the relatively small area of New
Zealand provides some unique challenges because high soil
diversity has implications for management decision making.
For example, when a predictive model is developed at a
particular place, and then applied in other areas, confidence
in the results is enhanced if it is known that the soils are
similar and thus likely to behave in a similar way. Thus,
considerable work is needed to provide confidence in the
predictive capacity of a model, such as “Overseer”, when
applied over a heterogeneous range of soils.
Soil diversity at the paddock scale may be managed using
precision agricultural techniques. Where the diversity is well
mapped, and the soil well characterised, then the techniques
of precision agriculture can provide production and environmental benefits. However, in areas where soil investigations show low paddock-scale diversity, the investment in
precision agriculture techniques may not be worthwhile.
18.2.3 Global Relatives of New Zealand Soils
The New Zealand soil-landscape can be divided into four
broad regions (Fig. 18.1). The relatively tectonically stable
Northland area is dominated by Ultic Soils, Granular Soils,
and Oxidic Soils. We expect to find related soils in parts of
the world that are relatively tectonically stable, have warm,
generally wet, climates, and have missed the major disturbances of late Quaternary volcanism and associated mantling
of tephra deposits (Table 18.2). Although temperatures were
lower during the last glacial period, Northland remained
under forest cover, unlike the rest of New Zealand.
Correlatives of the Oxidic Soils are distributed globally in
the tropics typically on stable landforms of continental
shields, but they also occur in orogenic belts on highly
weatherable basic rocks, as is the case in northern New
Zealand. Although Oxidic Soils in New Zealand are generally similar to their international correlatives, equivalent
soils elsewhere are typically bioturbated by termites. The
apparent lack of termites in pre-human times in New Zealand suggests that our soils are much less bioturbated and
may differ biologically in some way.
Soils similar to both Granular and Ultic Soils are well
represented, on old landscapes, in many parts of the world.
However, some of the Ultic Soils in northern New Zealand
show strong podzol morphological features, despite being
enriched in clay, because of the potency of the kauri tree
(Agathis australis) as a scattered podzolising agent in the
region’s pre-human forests. The Densipan Ultic Soils are
also globally uncommon.
The widespread tephras in the central North Island are
dominated by Pumice Soils and Allophanic Soils. Similar
soils form in other parts of the world where tephra from
rhyolitic and andesitic volcanoes dominate the soil parent
materials (e.g. Japan and Oregon, USA). However, substantial proportions of the Allophanic Soils in North Island
are dominated by silica-rich rhyolitic tephras and are consequently less fertile, chemically, than the main andesite- to
basalt-dominated equivalent tephra-derived soils elsewhere
in the world. Essentially unlimited Al availability means that
so-called ‘non-allophanic’ Andisols (i.e. soils on tephra
dominated by Al-humus complexes rather than allophane, as
found in parts of Japan, for example) are probably not present in New Zealand. Based on a soil profile about 1 m deep,
New Zealand has a much wider range of ages on Andisols
than elsewhere. Most of the Pumice Soils (Vitrands in Soil
Taxonomy) are 700 or 1800 years old. The Allophanic
Soils (Udands in Soil Taxonomy) are formed mostly by developmental upbuilding pedogenesis and date back
20,000–25,000 years with some as old as 50,000 years
(composite ages for 1.0–1.5-m deep soil profiles). Thus,
New Zealand has possibly the oldest Andisols in the world
on this basis. The rhyolitic Pumice Soils (Vitrands) are
exceptionally siliceous and glassy, and lack macro- and
micronutrients (including Cu, Se, Co, B, and I).
Soils similar to the Semiarid Soils are common in low
rainfall areas throughout the world. A feature of the New
Zealand Semiarid Soils is that they generally have no lime
(calcium carbonate) inherited directly from the parent
materials. The lime accumulated in the profiles is not from
limestone or other calcareous rocks but formed instead as a
result of weathering processes in the soil, i.e. the lime is
secondary in origin. In mid- and western USA, Mollisols
(soils with deep (>25 cm), dark, organic matter-rich topsoils,
i.e. mollic epipedons) occur in similar semiarid and marginally moister environments. However, Mollisols are relatively rare in New Zealand. One reason is that their
formation may have been suppressed by the lack of natural
lime (to help stabilise organic carbon). Other inhibiting
factors for Mollisol formation include the overwhelming
predominance of podocarp-broadleaf forest vegetation,
rather than grasslands, from postglacial (Holocene) times
18.2 New Zealand Soils in a Global Context
291