Geoscience Reference
In-Depth Information
A. Kandihumults, A. Kanhaplohumults). The plaggen epipedon is recognized at the
great-group level (Plagganthrepts) and at the subgroup level (Plagganthreptic
Udipsamments, P., Fragiaquods, P. Haplohumods, P. Alorthods, P. Fragiorthods).
However, to date no soil series containing an anthropic or plaggen epipedon has
been included in the OSDs. Of course many topsoils have been cultivated, but a key
criterion of ST is that normal soil mixing will not change a soil taxon. Anthropo-
genic soils will soon be differentiated in ST at the subgroup level.
A plaggen epipedon from the Bulkhead Archaeological site in lower Manhattan,
New York, is shown in the upper panel of Fig.
3.1
. This site contains a buried ship
from the time of Dutch settlement in the New York harbor area in 1624. An
anthropic epipedon from the Turtle Mound site in Florida is shown in the lower
panel of Fig.
3.1
. The mound is 15 m tall, contains an estimated 27,000 m
3
of shells,
and recent radiocarbon dates suggest that it dates to around 1,000 BCE.
3.2 Properties of Soils with Anthropic
and Plaggen Epipedons
Based on the specific requirements for the anthropic and plaggen epipedons (Soil
Survey Staff
2010
), three of the pedons in Table
3.1
would contain neither
epipedon. Pedons 2 and 5 appear to have plaggen epipedons, and pedon 6 may
have an anthropic epipedon.
3.3 Classification of Soils with Anthropic and Plaggen
Epipedons in ST
The classification of soils with anthropic and plaggen epipedons as of 2013 is given
in Table
3.2
. Anthropic epipedons are anticipated in four orders, the Aridisols,
Entisols, Inceptisols, and Ultisols; the plaggen epipedon is anticipated in the
Entisols, Inceptisols, and Spodosols. Allowance is made in ST for one suborder,
the Anthrepts;
three great groups,
the Anthracambids, Plagganthrepts, and
Haplanthreps; and eight subgroups.
3.4 Soil-Forming Factors and Development of Anthropic
and Plaggen Epipedons
The dominant factor in the development of anthropic and plaggen epipedons is
human activity. The expression of human effects is controlled by the other soil-
forming factors, particularly the time factor.
Search WWH ::
Custom Search