Development of Anthropogenic Soil Classification - Virginia Tech

Dr. John M. Galbraith, Virginia Tech
Liasion: Joseph V. Chiaretti, USDA-NRCS, Lincoln, NE
Presented 6-12-2012
4th IUSS Conference for Soil Classification, Lincoln, NE

Thank you, Dr. Allen

Thank you, Hari

Naming Names
In summary, it would be impossible to mention all
names that contributed to this final proposal.
A short list includes: WRB and IUSS and FAO
Del Fanning International Participants
John Sencindiver Craig Ditzler
Ray Bryant Steve Fisher
Dick Arnold NYC Soil Survey
Alan Kosse (dec.) Horace Smith
Bob Ahrens Maxine Levin
Bob Engel Luis Hernandez
Pavel Krasilnikov John Kimble

Introduction
Anthropogenic (profoundly human-altered and
human-transported, or HAHT) soils are found
worldwide.
HAHT soils are pervasive in paddys/terraced land,
mine lands, intensive agriculture, and urban areas.
These may be called Anthoscapes (proposed).
Taxa have been included in many classification
systems at different levels, sometimes with diagnostic
horizons or characteristics with criteria.

Anthroscape

Mountaintop Removal

Urban Soils

L. Wilding and R. Ahrens, Euro.
Soil Bureau Research Rpt. 7
The charges of ICOMANTH in 1995 were to define
“anthropogenic” soils, differentiate them from other soils,
and add taxa to facilitate mapping and interpretation.
Challenges:
How much difference in soil properties does it take before one
recognizes anthropogenic effects (Bryant et al., 1999)?
Is simple plowing or more drastic disturbance required? Will
a few years of irrigation be sufficient to recognize significant
effects?
How does one recognize the effects due to anthropogenic
activities from those due to other non-anthropogenic
impacts?

Wilding and Ahrens
The human factor is certainly one of the biological
components but is human activity really a pedogenic
process that can be differentiated from other
pedogenic processes that are not humanly induced?
The proposals to this committee varied from
establishing a new soil order, to revising current Soil
Taxonomy provisions, designing new taxa based on
prior historic knowledge, and improving the design
and description of mapping units as soil complexes
(Kimble, et al., 1999).

Amending Soil Taxonomy
Hari Eswaran recommended defining diagnostic soil
materials.
Del Fanning proposed adding Urbents and Garbents
to the Entisols, John Sencindiver proposed adding
Spolents.
Ray Bryant proposed a new soil order of Anthrisols.
Landform cannot be used as a defining criteria.
All were considered, and seven Circular Letters used to
propose and revise the tasks for ICOMANTH.

Steps to add human-altered and human-
transported (HAHT) soils to the NCSS System
Identify the subject (what is a HAHT material and soil?)
Define general types of HAHT soils
Define the limits of soils considered
Identify the user needs
Begin to survey (New York City) HAHT soils
Tour the subject (NV, CA), later NYC
Invite international comment
Pose questions and provided answers to Circ. letters
Conducted literature review, post on CD and web site
Made proposals to amend the system for making
descriptions, database entries, new series and mapping

History
http://clic.cses.vt.edu/ICOMANTH/
Circular letter 1 (August, 1995) – Circular Letter 5 (March,
2005)
Then, with Circular Letter 6 (June, 2006)
Proposed new terms for HAHT soils to facilitate soil
mapping in New York City:
Human-transported Materials (HTM)
Constructional landforms
Anthropogenic features (now microfeatures)
Manufactured layers and material types …

Circular Letters 6 (continued)
Artifacts
Types
Sizes
Abundance
Rupture resistance
Added artifacts as a type of coarse fragment
Added “artifacts” and “manufactured layers” as terms in
lieu of texture

Circular Letters 6 (continued)
Horizon names:
Prefix – caret ^ used to identify horizons formed in
human-transported material (HTM)
Master horizon – M for manufactured layer (asphalt,
concrete, geotextile, plastic, rubber) used as a rootlimiting
subsurface layer. The upper surface is a rootlimiting
contact.
Suffix – u for the presence of artifacts

Challenges Identified by Circ. 6
These additions to the USDA soil survey system
allowed creation, mapping and interpretation of new
soil series
However, most series were classified as Udorthents
and came from the east and mined coal lands, or
mapped as Arents in the US midwest and California
(contained a few fragments of former diagnostic
horizons)
Other HAHT soils fell out of the existing key as Arents
or Fluvents. Inspection of Arents followed.

Questions Unresolved - Circular 7
Can HAHT soils be allocated consistently to
avoid being grouped together without specificity,
and to avoid including soils not profoundly
altered by humans?
Should taxa be added at the new order,
suborders, or lower levels?
Can we standardize what we already have (fill
empty taxa or replace them consistently without
adding more empty taxa)? Taxa were scattered
from suborder to subgroup levels, most empty.

Circular Letter 7
Can HAHT materials be defined as differentiae
using field evidence?
Can irregular carbon decreases be identified as
anthropogenic or natural?
Should we survey contaminated and landfill
soils?
Will we have to split existing series and remap
areas?

Heavy metals in the park
Lead

A horizon
B horizon
C horizon
^A
^Cu
^Ab
^Cb
Ab
Bwb
New A horizon
Cola can
Buried layers of fill
Buried A horizon
Buried B horizon

Solutions Proposed – Consistently
Identifying (allocating) HAHT Soils
Artifacts, Human-Altered Materials, Human-Transported
Materials, and manufactured layer contacts were defined in
Chapter 3 as diagnostic criteria.
Redefining the epipedons allows them to be consistent and
prevent overlapping properties with anthropic and plaggen
(see poster session).
Defining HTM as a type of mantle allows consistent
identification of buried soils. Three types of mantles now
all have defined, thickness proposed to make the mantle
thickness limit 50 cm (see poster session).

Artifacts, HTM,
deep-plowed soils, HAM

Solutions Proposed – Taxa Levels
We follow the guidelines of adding taxa: made soil
descriptions, sampled and analyzed lab data, and
estimated extent. Bottom-up approach.
Adding a set of specified taxa at the subgroup and family
level allows easy formation of series, identifies properties
critical to producing interpretive maps, and can be used in
any existing subgroup or great group without adding taxa
above.
Adding taxa at a high level such as soil order means you
have to predict what you might find and proliferate empty
“placeholder “ higher taxa and subgroups to get to the
family level, then series. This was rejected as inefficient.

Solutions- Allocating HAHT Soils
Added a new family class for soils with substantial
HAHT on top (50 cm or the whole soil over bedrock).
Removing empty taxa above the subgroup level.
Reclassify Arents, eliminate the suborder.
Added a specific set of subgroups suggested for HAHT
will allow us to pull a set of all HAHT soils from the official
series database.
Exclusion statements now prevent irregular carbon
distribution for allocating HAHT soils with Fluvents,
Fluventic, Fluvaquentic, and Cumulic subgroups.
Geomorphic properties, artifacts, and microfeatures can
now be used as soil properties, thus identification criteria.

Human-altered and -transported Soils
Bulldozed material
Dredge material

Excavated Soils,
Anthropogenic Landforms

Contaminated HAHT Soils
Should we survey contaminated and landfill soils? Only
when the health and safety of the surveyors and lab staff
can be protected.
The soils can be described using remote methods, sensors,
and ancillary data, or just avoided.
The soils should not be sampled and analyzed in the soils
lab unless pre-tested for dangerous pollutants.
Like it or not people live in, on, and grow gardens in
contaminated soils. We can no longer avoid giving soil
information to people in urban areas.

Urban Garden Concerns?

Classify Similar to Existing Taxa?
We considered existing “anthropogenic” taxa and
borrowed good ideas from other systems.
Our proposal will be at lower levels, and can be
delineated on very large order maps.
However, we can correlate to their orders by using the
specific taxa and family classes proposed.
And, later, higher taxa may be formed if there are a
cluster of associated lower taxa.

New Family Classes
A new family modifier to identify extreme
conditions or properties of HAHT that
profoundly affect use and management. Must
have at least 50 cm of HAHT materials or the
entire soil above bedrock.
Control section defined: 0 to 100 [200?] cm
Placed between Particle-size and Mineralogy

HAHT Material Class Examples
Methanogenic Subsidic
Bituminic Concretic
Spoliwastic Asphaltic
Gypsifactic Ashifactic
Combustic Megaartifactic
Medioartifactic Pauciartifactic
Aquadensic Metalic
Dredgic Spolic
Listed in sequence, open to adjustments, additions.
Heavy metals not included: may be dangerous to sample.

Other Changes Proposed
Modify the definition of “Fluvent__” and
“Cumulic ” subgroups to exclude irregular
decrease in OC with depth due to burial of
soil material by planned human activity.
A list of properties for HTM and HAM
given, use “accumulation of evidence”
(best professional judgment) for
identification.

Split Series and Remap?
NO. But, some series will be reallocated and renamed.
Some new series will be formed and consociations
remapped as complexes.
For example:

Comparisons – Former Arents
Before After
Fine-loamy, mixed, mesic Sodic
Torriarents
Coarse-loamy, mixed, mesic Alfic
Xeroarents
Loamy-skeletal, mixed, mesic Typic
Ustarents
Fine-loamy, araric, mixed, mesic Sodic
Anthralitic Torriorthents
Coarse-loamy, araric, mixed, mesic
Anthraltic Xerorthents
Loamy-skeletal, wastispolic, mixed,
calcareous, mesic Anthroportic
Ustorthents
Fine, mixed, thermic Alfic Udarents Fine, dredgic, mixed, acid, thermic
Anthroportic Udorthents

Pic of mine soils
Now we would
add a “^” in front
of all of these
names and a “d”
after the ^2C.
Mine Soil

Comparisons – Urban Soils
Before After
Coarse-loamy, mixed, acid, mesic Typic
Udorthents
Loamy-skeletal, mixed, calcareous,
mesic Typic Udorthents
Sandy or Sandy-skeletal, mixed, mesic
Typic Udipsamments
Coarse-loamy, spolic, mixed, acid,
mesic Anthroportic Udorthents
Loamy-skeletal, spolic, mixed,
calcareous mesic Anthroportic
Ustorthents
Sandy or Sandy-skeletal, combustic,
mixed, mesic Anthroportic
Udipsamments

Associated Changes to NSSH
Anthropogenic Features will be decommissioned as a broad
category (NASIS data element).
The term will be replaced by three new categories in NASIS
to describe geomorphic items at the earth’s surface or in
shallow water.
Anthroscape – A human-modified “landscape” of substantial
and permanent alterations
Anthropogenic Landform - A discrete, human-made
“landform” on the earth’s surface. Constructional and
excavated
Anthropogenic Microfeature - A discrete, individual,
human-derived form. Constructional, excavated, and buried

Anthraquic Soils

Specific Subgroups
Extragrade subgroup formative elements for use throughout
Soil Taxonomy. Humic, Dystric, or Eutric could be added to
Anthropic, Plaggic, or Plagghaplic if needed.
Anthraltic (from Gr. Anthropos, human and L. alterāre, to change)
Anthraquic (anthraquic conditions)
Anthropic (have an anthropic epipedon)
Anthroportic (from Gr. Anthropos human and L. portāre to carry)
Plaggic (have an plaggen epipedon)
Plagghaplic (upper 25-49 cm of material qualifies for plaggen)
Sulfuric (has a sulfuric horizon)

Anthroportic subgroup in
Urban Landscapes
Original soil surface

Conclusion?
Currently, the proposals (36) are making their way for
final review).
They were published for field testing, and have been
reviewed by existing soil survey crews in NYC and LA.
This is the 2 nd Approximation. It will be edited,
changed, tested, improved.
Your feedback is welcome through the established
system of USDA-NRCS explained by our host,
Cameron Loerch.