gum-diggers sought kauri gum, miners sluiced or dredged
for gold in the nineteenth and early twentieth centuries, and
foresters have modified soils during tree planting and
harvesting.
Given the wide variety of activities that lead to development of Anthropic Soils there is no one set of typical
features. Anthropic Soil properties depend on the nature of
manufactured or natural materials and the nature of the soil
manipulation. Thus many Anthropic Soils may be recognised by their lack of the usual natural soil properties such as
distinct, naturally formed, horizons. In other cases the soil
features and landforms or landscapes do not conform with
natural patterns, and land surfaces can be artificial and
drainage modified. Some Anthropic Soils may be identifiable by odour (e.g. methane at landfill sites).
Conceptually, Anthropic Soils are soils in which the
original plant rooting environment and soil moisture regime
are changed to the degree that the new soil is distinctly
different from the original soil. The character of Anthropic
Soil lies in the contrast between the natural soil and
human-made soil.
3.1.2 Areas of Occurrence
Areas of Anthropic Soils are scattered throughout New
Zealand (Fig. 3.2). They are extensive in urban areas, land
that has been mined, areas of agricultural development
involving flipping or humping and hollowing activities, the
addition of material to the land surface, and highly disturbed
areas in forest plantations. In the South Island, areas of
Mixed Anthropic Soils occur on sites of former gold
dredging. For example, 1700 ha of Stony-tailings Fill
Anthropic Soils formed on tailings, left behind following
gold dredging, are mapped on the flood plains of the Waikaka Stream in Southland. Anthropic Soils are estimated to
cover <1% of New Zealand, but accurate identification of
Anthropic Soils can be difficult. For example, a restored soil
may become indistinguishable from undisturbed land once
the new soil surface is developed and new topsoil becomes
established. The extent of Anthropic Soils is continuing to
increase, particularly as a result of ongoing urban expansion.
3.1.3 Variation Within the Anthropic Soil Order
Four soil groups are recognised within the Anthropic Soil
order (Fig. 3.3):
Truncated Anthropic Soils—most of the pre-existing soil
profile has been removed,
Refuse Anthropic Soils—waste material that contains significant organic material has been added to the soil, for
instance in a landfill,
Mixed Anthropic Soils—severe disturbance and loss of
original character by mixing at depth. Currently no subgroups are recognised in this group but if the original soils
are known and evident then its classification may be
appended in parentheses (e.g. Fig. 3.1),
Fill Anthropic Soils—formed from deposited materials,
including reconstructed soils such as those formed following
urban development or mine rehabilitation.
Fig. 3.1 A soil mixed by ‘flipping’ near Murupara in the central North
Island. Left: the original Immature Orthic Pumice Soil profile with two
coarse pumice layers (Kahroa tephra overlying Taupo tephra) near the
surface. Centre: soil ‘flipping’ using a digger to bring underlying buried
soil horizons to the surface. Right: the resulting Mixed Anthropic Soil
([formerly] Immature Orthic Pumice Soil)—in this case the topsoil was
put to one side and replaced at the soil surface
42
3 Anthropic Soils
for gold in the nineteenth and early twentieth centuries, and
foresters have modified soils during tree planting and
harvesting.
Given the wide variety of activities that lead to development of Anthropic Soils there is no one set of typical
features. Anthropic Soil properties depend on the nature of
manufactured or natural materials and the nature of the soil
manipulation. Thus many Anthropic Soils may be recognised by their lack of the usual natural soil properties such as
distinct, naturally formed, horizons. In other cases the soil
features and landforms or landscapes do not conform with
natural patterns, and land surfaces can be artificial and
drainage modified. Some Anthropic Soils may be identifiable by odour (e.g. methane at landfill sites).
Conceptually, Anthropic Soils are soils in which the
original plant rooting environment and soil moisture regime
are changed to the degree that the new soil is distinctly
different from the original soil. The character of Anthropic
Soil lies in the contrast between the natural soil and
human-made soil.
3.1.2 Areas of Occurrence
Areas of Anthropic Soils are scattered throughout New
Zealand (Fig. 3.2). They are extensive in urban areas, land
that has been mined, areas of agricultural development
involving flipping or humping and hollowing activities, the
addition of material to the land surface, and highly disturbed
areas in forest plantations. In the South Island, areas of
Mixed Anthropic Soils occur on sites of former gold
dredging. For example, 1700 ha of Stony-tailings Fill
Anthropic Soils formed on tailings, left behind following
gold dredging, are mapped on the flood plains of the Waikaka Stream in Southland. Anthropic Soils are estimated to
cover <1% of New Zealand, but accurate identification of
Anthropic Soils can be difficult. For example, a restored soil
may become indistinguishable from undisturbed land once
the new soil surface is developed and new topsoil becomes
established. The extent of Anthropic Soils is continuing to
increase, particularly as a result of ongoing urban expansion.
3.1.3 Variation Within the Anthropic Soil Order
Four soil groups are recognised within the Anthropic Soil
order (Fig. 3.3):
Truncated Anthropic Soils—most of the pre-existing soil
profile has been removed,
Refuse Anthropic Soils—waste material that contains significant organic material has been added to the soil, for
instance in a landfill,
Mixed Anthropic Soils—severe disturbance and loss of
original character by mixing at depth. Currently no subgroups are recognised in this group but if the original soils
are known and evident then its classification may be
appended in parentheses (e.g. Fig. 3.1),
Fill Anthropic Soils—formed from deposited materials,
including reconstructed soils such as those formed following
urban development or mine rehabilitation.
Fig. 3.1 A soil mixed by ‘flipping’ near Murupara in the central North
Island. Left: the original Immature Orthic Pumice Soil profile with two
coarse pumice layers (Kahroa tephra overlying Taupo tephra) near the
surface. Centre: soil ‘flipping’ using a digger to bring underlying buried
soil horizons to the surface. Right: the resulting Mixed Anthropic Soil
([formerly] Immature Orthic Pumice Soil)—in this case the topsoil was
put to one side and replaced at the soil surface
42
3 Anthropic Soils