envoEmpo.owl
type: Ontology
version IRI: envoEmpo.owl
version info: 2025-10-20

definition
type: AnnotationProperty

expand assertion to
type: AnnotationProperty

term replaced by
type: AnnotationProperty

plural form
type: AnnotationProperty
sub property of: synonym_type_property

EnvO-Lite-GSC
type: AnnotationProperty
comment: EnvO-Lite-GSC
sub property of: subset_property

disconnected_from
type: AnnotationProperty
definition: A is disconnected_from B if they have no parts in common.
expand assertion to: Class: <http://www.w3.org/2002/07/owl#Nothing> EquivalentTo: (BFO_0000050 some ?X) and (BFO_0000050 some ?Y)
has_exact_synonym: non_overlapping_with
has_obo_namespace: ENVO
id: disconnected_from
is class level: true
is metadata tag: true

Axiom
annotated source: disconnected_from
annotated property: definition
annotated target: A is disconnected_from B if they have no parts in common.
database_cross_reference: https://orcid.org/0000-0002-6601-2165

disposition slim
type: AnnotationProperty
comment: Disposition slim
sub property of: subset_property

environmental hazards
type: AnnotationProperty
comment: environmental_hazards
sub property of: subset_property

envoANZSoil
type: AnnotationProperty
comment: envoANZSoil
sub property of: subset_property

envoAstro
type: AnnotationProperty
comment: envoAstro
sub property of: subset_property

envoAtmo
type: AnnotationProperty
comment: envoAtmo
sub property of: subset_property

envoCesab
type: AnnotationProperty
comment: envoCesab
sub property of: subset_property

envoCmecs
type: AnnotationProperty
comment: envoCmecs
sub property of: subset_property

envoEOVs
type: AnnotationProperty
comment: envoEOVs
sub property of: subset_property

envoEmpo
type: AnnotationProperty
comment: envoEmpo
sub property of: subset_property

envoMarine
type: AnnotationProperty
comment: envoMarine
sub property of: subset_property

envoMeo
type: AnnotationProperty
comment: envoMeo
sub property of: subset_property

envoNceas
type: AnnotationProperty
comment: envoNceas
sub property of: subset_property

envoOmics
type: AnnotationProperty
comment: envoOmics
sub property of: subset_property

envoPlastics
type: AnnotationProperty
comment: envoPlastics
sub property of: subset_property

envoPolar
type: AnnotationProperty
comment: envoPolar
sub property of: subset_property

mpath slim
type: AnnotationProperty
comment: Pathology slim
sub property of: subset_property

nlcd2011
type: AnnotationProperty
comment: nlcd2011
sub property of: subset_property

relational slim
type: AnnotationProperty
comment: Relational slim: types of quality that require an additional entity in order to exist
sub property of: subset_property

ro-eco
type: AnnotationProperty
comment: ro-eco
sub property of: subset_property

scalar slim
type: AnnotationProperty
comment: Scalar slim
sub property of: subset_property

value slim
type: AnnotationProperty
comment: Value slim
sub property of: subset_property

wwfBiome
type: AnnotationProperty
comment: wwfBiome
sub property of: subset_property

subset_property
type: AnnotationProperty

synonym_type_property
type: AnnotationProperty

consider
type: AnnotationProperty

has_alternative_id
type: AnnotationProperty

has_broad_synonym
type: AnnotationProperty

database_cross_reference
type: AnnotationProperty

has_exact_synonym
type: AnnotationProperty

has_narrow_synonym
type: AnnotationProperty

has_obo_format_version
type: AnnotationProperty

has_obo_namespace
type: AnnotationProperty

has_related_synonym
type: AnnotationProperty

has_synonym_type
type: AnnotationProperty

in_subset
type: AnnotationProperty

shorthand
type: AnnotationProperty

BFO_0000050
type: ObjectProperty
database_cross_reference: BFO:0000050
has_obo_namespace: ENVO
id: part_of
shorthand: part_of

BFO_0000051
type: ObjectProperty
database_cross_reference: BFO:0000051
has_obo_namespace: ENVO
id: has_part
shorthand: has_part

BFO_0000054
type: ObjectProperty
database_cross_reference: BFO:0000054
has_obo_namespace: ENVO
id: realized_in
shorthand: realized_in

BFO_0000055
type: ObjectProperty
database_cross_reference: BFO:0000055
has_obo_namespace: ENVO
id: realizes
shorthand: realizes

BFO_0000062
type: ObjectProperty
database_cross_reference: BFO:0000062
has_obo_namespace: ENVO
id: preceded_by
shorthand: preceded_by

BFO_0000063
type: ObjectProperty
database_cross_reference: BFO:0000063
has_obo_namespace: ENVO
id: precedes
shorthand: precedes

BFO_0000066
type: ObjectProperty
database_cross_reference: BFO:0000066
has_obo_namespace: ENVO
id: occurs_in
shorthand: occurs_in

BFO_0000067
type: ObjectProperty
database_cross_reference: BFO:0000067
has_obo_namespace: ENVO
id: contains_process
shorthand: contains_process

partially_surrounded_by
type: ObjectProperty
IAO_0000112: A duck swimming in a pond is partially surrounded by air and partially surrounded by water.
definition: x partially_surrounded_by y if and only if (1) x is adjacent to y and for the region r that is adjacent to x, r partially overlaps y (2) the shared boundary between x and y occupies a non-trivial proportion of the outermost boundary of x
database_cross_reference: ENVO:01001307
has_obo_namespace: ENVO
id: partially_surrounded_by
shorthand: partially_surrounded_by
comment: Definition modified from 'surrounded by'.

derives from part of
type: ObjectProperty
definition: A relation between two distinct material entities, the new entity and the old entity, in which the new entity begins to exist through the separation or transformation of a part of the old entity, and the new entity inherits a significant portion of the matter belonging to that part of the old entity.
database_cross_reference: ENVO:01003004
has_obo_namespace: ENVO
id: derives_from_part_of
shorthand: derives_from_part_of

has increased levels of
type: ObjectProperty
sub property of: RO_0002180
definition: A has part relationship between a whole and a part, where the number of parts present in the whole is higher than in comparable entities.
see also: https://github.com/EnvironmentOntology/envo/issues/1380
database_cross_reference: ENVO:02000200
has_obo_namespace: ENVO
id: has_increased_levels_of
shorthand: has_increased_levels_of
comment: This relation is present in ENVO to support compositional classes such as "X-enriched soil". These will later be formalized, and a different relation from RO may be chosen.

results in transformation into
type: ObjectProperty
database_cross_reference: ENVO:02500006
has_obo_namespace: ENVO
id: results_in_transformation_into
shorthand: results_in_transformation_into

results in expansion of
type: ObjectProperty
IAO_0000112: Afforestation results in the expansion of a forest.
definition: A process, p, results in the expansion of a material entity, m, if the spatial extent of m is increased as a result of participating in p.
database_cross_reference: ENVO:02500016
has_obo_namespace: ENVO
id: results_in_expansion_of
shorthand: results_in_expansion_of

results in proliferation of
type: ObjectProperty
database_cross_reference: ENVO:02500020
has_obo_namespace: ENVO
id: results_in_proliferation_of
shorthand: results_in_proliferation_of
comment: To be ceded to RO

generates
type: ObjectProperty
definition: A relation between a process and a disposition such that the existence of the disposition is caused by the execution of the process.
IAO_0000116: Consider ceding to RO
created by: https://orcid.org/0000-0002-6601-2165
creation date: 2018-11-03T20:58:13Z
database_cross_reference: ENVO:2000036
has_obo_namespace: ENVO
id: generates
shorthand: generates

obsolete determined by
type: ObjectProperty
database_cross_reference: ENVO:2100001
has_obo_namespace: ENVO
id: obsolete_determined_by
shorthand: obsolete_determined_by
deprecated: true

obsolete determined by part of
type: ObjectProperty
database_cross_reference: ENVO:2100007
has_obo_namespace: ENVO
id: obsolete_determined_by_part_of
shorthand: obsolete_determined_by_part_of
deprecated: true

RO_0000052
type: ObjectProperty
database_cross_reference: RO:0000052
has_obo_namespace: ENVO
id: characteristic_of
shorthand: characteristic_of

RO_0000053
type: ObjectProperty
database_cross_reference: RO:0000053
has_obo_namespace: ENVO
id: has_characteristic
shorthand: has_characteristic

RO_0000056
type: ObjectProperty
database_cross_reference: RO:0000056
has_obo_namespace: ENVO
id: participates_in
shorthand: participates_in

RO_0000057
type: ObjectProperty
database_cross_reference: RO:0000057
has_obo_namespace: ENVO
id: has_participant
shorthand: has_participant

RO_0000059
type: ObjectProperty
database_cross_reference: RO:0000059
has_obo_namespace: ENVO
id: concretizes
shorthand: concretizes

RO_0000085
type: ObjectProperty
database_cross_reference: RO:0000085
has_obo_namespace: ENVO
id: has_function
shorthand: has_function

RO_0000086
type: ObjectProperty
database_cross_reference: RO:0000086
has_obo_namespace: ENVO
id: has_quality
shorthand: has_quality

RO_0000087
type: ObjectProperty
database_cross_reference: RO:0000087
has_obo_namespace: ENVO
id: has_role
shorthand: has_role

RO_0000091
type: ObjectProperty
database_cross_reference: RO:0000091
has_obo_namespace: ENVO
id: has_disposition
shorthand: has_disposition

RO_0001000
type: ObjectProperty
sub property of: derives from part of
database_cross_reference: RO:0001000
has_obo_namespace: ENVO
id: derives_from
shorthand: derives_from

RO_0001001
type: ObjectProperty
database_cross_reference: RO:0001001
has_obo_namespace: ENVO
id: derives_into
shorthand: derives_into

RO_0001015
type: ObjectProperty
database_cross_reference: RO:0001015
has_obo_namespace: ENVO
id: location_of
shorthand: location_of

RO_0001019
type: ObjectProperty
database_cross_reference: RO:0001019
has_obo_namespace: ENVO
id: obsolete_contains
shorthand: obsolete_contains

RO_0001025
type: ObjectProperty
database_cross_reference: RO:0001025
has_obo_namespace: ENVO
id: located_in
shorthand: located_in

RO_0002007
type: ObjectProperty
database_cross_reference: RO:0002007
has_obo_namespace: ENVO
id: bounding_layer_of
shorthand: bounding_layer_of

RO_0002084
type: ObjectProperty
database_cross_reference: RO:0002084
has_obo_namespace: ENVO
id: during_which_ends
shorthand: during_which_ends

RO_0002088
type: ObjectProperty
database_cross_reference: RO:0002088
has_obo_namespace: ENVO
id: during_which_starts
shorthand: during_which_starts

RO_0002091
type: ObjectProperty
database_cross_reference: RO:0002091
has_obo_namespace: ENVO
id: starts_during
shorthand: starts_during

RO_0002131
type: ObjectProperty
database_cross_reference: RO:0002131
has_obo_namespace: ENVO
id: overlaps
shorthand: overlaps

RO_0002150
type: ObjectProperty
database_cross_reference: RO:0002150
has_obo_namespace: ENVO
id: continuous_with
shorthand: continuous_with

RO_0002151
type: ObjectProperty
database_cross_reference: RO:0002151
has_obo_namespace: ENVO
id: partially_overlaps
shorthand: partially_overlaps

RO_0002170
type: ObjectProperty
database_cross_reference: RO:0002170
has_obo_namespace: ENVO
id: connected_to
shorthand: connected_to

connects
type: ObjectProperty
database_cross_reference: RO:0002176
has_obo_namespace: ENVO
id: connects
shorthand: connects

RO_0002180
type: ObjectProperty
database_cross_reference: RO:0002180
has_obo_namespace: ENVO
id: has_component
shorthand: has_component

regulates (processual)
type: ObjectProperty
database_cross_reference: RO:0002211
has_obo_namespace: ENVO
id: regulates_(processual)
shorthand: regulates_(processual)

RO_0002212
type: ObjectProperty
database_cross_reference: RO:0002212
has_obo_namespace: ENVO
id: negatively_regulates
shorthand: negatively_regulates

RO_0002215
type: ObjectProperty
database_cross_reference: RO:0002215
has_obo_namespace: ENVO
id: capable_of
shorthand: capable_of

surrounded by
type: ObjectProperty
database_cross_reference: RO:0002219
has_obo_namespace: ENVO
id: surrounded_by
shorthand: surrounded_by

RO_0002220
type: ObjectProperty
database_cross_reference: RO:0002220
has_obo_namespace: ENVO
id: adjacent_to
shorthand: adjacent_to

RO_0002229
type: ObjectProperty
database_cross_reference: RO:0002229
has_obo_namespace: ENVO
id: ends
shorthand: ends

RO_0002232
type: ObjectProperty
database_cross_reference: RO:0002232
has_obo_namespace: ENVO
id: has_end_location
shorthand: has_end_location

RO_0002233
type: ObjectProperty
database_cross_reference: RO:0002233
has_obo_namespace: ENVO
id: has_input
shorthand: has_input

RO_0002234
type: ObjectProperty
database_cross_reference: RO:0002234
has_obo_namespace: ENVO
id: has_output
shorthand: has_output

RO_0002297
type: ObjectProperty
database_cross_reference: RO:0002297
has_obo_namespace: ENVO
id: results_in_formation_of_anatomical_entity
shorthand: results_in_formation_of_anatomical_entity

has habitat
type: ObjectProperty
database_cross_reference: RO:0002303
has_obo_namespace: ENVO
id: has_habitat
shorthand: has_habitat

RO_0002314
type: ObjectProperty
database_cross_reference: RO:0002314
has_obo_namespace: ENVO
id: characteristic_of_part_of
shorthand: characteristic_of_part_of

RO_0002331
type: ObjectProperty
database_cross_reference: RO:0002331
has_obo_namespace: ENVO
id: involved_in
shorthand: involved_in

RO_0002350
type: ObjectProperty
database_cross_reference: RO:0002350
has_obo_namespace: ENVO
id: member_of
shorthand: member_of

RO_0002351
type: ObjectProperty
database_cross_reference: RO:0002351
has_obo_namespace: ENVO
id: has_member
shorthand: has_member

RO_0002352
type: ObjectProperty
database_cross_reference: RO:0002352
has_obo_namespace: ENVO
id: input_of
shorthand: input_of

RO_0002353
type: ObjectProperty
database_cross_reference: RO:0002353
has_obo_namespace: ENVO
id: output_of
shorthand: output_of

RO_0002354
type: ObjectProperty
database_cross_reference: RO:0002354
has_obo_namespace: ENVO
id: formed_as_result_of
shorthand: formed_as_result_of

RO_0002371
type: ObjectProperty
database_cross_reference: RO:0002371
has_obo_namespace: ENVO
id: attached_to
shorthand: attached_to

RO_0002376
type: ObjectProperty
database_cross_reference: RO:0002376
has_obo_namespace: ENVO
id: tributary_of
shorthand: tributary_of

RO_0002377
type: ObjectProperty
database_cross_reference: RO:0002377
has_obo_namespace: ENVO
id: distributary_of
shorthand: distributary_of

RO_0002411
type: ObjectProperty
database_cross_reference: RO:0002411
has_obo_namespace: ENVO
id: causally_upstream_of
shorthand: causally_upstream_of

RO_0002418
type: ObjectProperty
database_cross_reference: RO:0002418
has_obo_namespace: ENVO
id: causally_upstream_of_or_within
shorthand: causally_upstream_of_or_within

RO_0002427
type: ObjectProperty
database_cross_reference: RO:0002427
has_obo_namespace: ENVO
id: causally_downstream_of_or_within
shorthand: causally_downstream_of_or_within

RO_0002430
type: ObjectProperty
database_cross_reference: RO:0002430
has_obo_namespace: ENVO
id: involved_in_negative_regulation_of
shorthand: involved_in_negative_regulation_of

RO_0002473
type: ObjectProperty
database_cross_reference: RO:0002473
has_obo_namespace: ENVO
id: composed_primarily_of
shorthand: composed_primarily_of

RO_0002479
type: ObjectProperty
database_cross_reference: RO:0002479
has_obo_namespace: ENVO
id: has_part_that_occurs_in
shorthand: has_part_that_occurs_in

RO_0002500
type: ObjectProperty
database_cross_reference: RO:0002500
has_obo_namespace: ENVO
id: causal_agent_in_process
shorthand: causal_agent_in_process

RO_0002503
type: ObjectProperty
database_cross_reference: RO:0002503
has_obo_namespace: ENVO
id: towards
shorthand: towards

RO_0002507
type: ObjectProperty
database_cross_reference: RO:0002507
has_obo_namespace: ENVO
id: determined_by
shorthand: determined_by

RO_0002509
type: ObjectProperty
database_cross_reference: RO:0002509
has_obo_namespace: ENVO
id: determined_by_part_of
shorthand: determined_by_part_of

RO_0002608
type: ObjectProperty
database_cross_reference: RO:0002608
has_obo_namespace: ENVO
id: process_has_causal_agent
shorthand: process_has_causal_agent

particle of sand
type: Class
subclass of: particle
disjoint with: sand
definition: A particle which 1) is composed primarily of and derived from rock or mineral sources and 2) is or was part of a portion of sand.
has_exact_synonym: grain of sand
has_exact_synonym: granule of sand
has_exact_synonym: sand granule
has_obo_namespace: ENVO
id: ENVO:00000340
comment: In general, sand grains are larger than those of silt, but finer than those of gravel.

Axiom
annotated source: particle of sand
annotated property: definition
annotated target: A particle which 1) is composed primarily of and derived from rock or mineral sources and 2) is or was part of a portion of sand.
database_cross_reference: https://en.wikipedia.org/wiki/Sand

particle of silt
type: Class
subclass of: particle
definition: A particle which 1) is primarily composed of quartz or feldspar and 2) is or was part of a portion of silt.
has_exact_synonym: grain of silt
has_exact_synonym: granule of silt
has_obo_namespace: ENVO
id: ENVO:00000343
comment: The distinction between silt and clay varies by discipline. Geologists and soil scientists usually consider the separation to occur at a particle size of 2 μm (clays being finer than silts), sedimentologists often use 4–5 μm, and colloid chemists use 1 μm. Geotechnical engineers distinguish between silts and clays based on the plasticity properties of the soil, as measured by the soils' Atterberg limits. ISO 14688 grades clay particles as being smaller than 2 μm and silt particles as being larger. Mixtures of sand, silt and less than 40% clay are called loam.

Axiom
annotated source: particle of silt
annotated property: comment
annotated target: The distinction between silt and clay varies by discipline. Geologists and soil scientists usually consider the separation to occur at a particle size of 2 μm (clays being finer than silts), sedimentologists often use 4–5 μm, and colloid chemists use 1 μm. Geotechnical engineers distinguish between silts and clays based on the plasticity properties of the soil, as measured by the soils' Atterberg limits. ISO 14688 grades clay particles as being smaller than 2 μm and silt particles as being larger. Mixtures of sand, silt and less than 40% clay are called loam.
database_cross_reference: Properties

soil
type: Class
subclass of: environmental material
subclass of: Restriction
  on property: BFO_0000050
  some values from: pedosphere
subclass of: Restriction
  on property: BFO_0000051
  some values from: clay
subclass of: Restriction
  on property: BFO_0000051
  some values from: silt
subclass of: Restriction
  on property: BFO_0000051
  some values from: sand
subclass of: Restriction
  on property: BFO_0000051
  some values from: organic material
subclass of: Restriction
  on property: BFO_0000051
  some values from: mineral material
subclass of: Restriction
  on property: RO_0000091
  some values from: water-holding capacity of soil
definition: An environmental material which is primarily composed of minerals, varying proportions of sand, silt, and clay, organic material such as humus, interstitial gases, liquids, and a broad range of resident micro- and macroorganisms.
IAO_0000116: The various 'has part' and 'has quality' relations may not hold true for all soils; however, I have yet to find counter examples. Require input from a pedologist or similar. [pbuttigieg]
has_broad_synonym: regolith
database_cross_reference: LTER:535
database_cross_reference: SPIRE:Soil
database_cross_reference: SWEETRealm:Soil
database_cross_reference: https://en.wikipedia.org/wiki/Soil
has_obo_namespace: ENVO
id: ENVO:00001998
in_subset: ENVO_03605015
in_subset: EnvO-Lite-GSC
comment: 'In engineering terms, soil is referred to as regolith, or loose rock material that lies above the 'solid geology'. Soil is commonly referred to as "earth" or "dirt"; technically, the term "dirt" should be restricted to displaced soil.' https://en.wikipedia.org/wiki/Soil " The upper limit of soil is the boundary between soil and air, shallow water, live plants, or plant materials that have not begun to decompose. Areas are not considered to have soil if the surface is permanently covered by water too deep (typically more than 2.5 meters) for the growth of rooted plants. The lower boundary that separates soil from the nonsoil underneath is most difficult to define. Soil consists of horizons near the Earth's surface that, in contrast to the underlying parent material, have been altered by the interactions of climate, relief, and living organisms over time. Commonly, soil grades at its lower boundary to hard rock or to earthy materials virtually devoid of animals, roots, or other marks of biological activity. For purposes of classification, the lower boundary of soil is arbitrarily set at 200 cm." Soil taxonomy, 2nd Ed., quoted in http://www.nrcs.usda.gov/wps/portal/nrcs/detail/soils/edu/?cid=nrcs142p2_054280

Axiom
annotated source: soil
annotated property: definition
annotated target: An environmental material which is primarily composed of minerals, varying proportions of sand, silt, and clay, organic material such as humus, interstitial gases, liquids, and a broad range of resident micro- and macroorganisms.
database_cross_reference: https://en.wikipedia.org/wiki/Soil

liquid water
type: Class
subclass of: liquid environmental material
definition: An environmental material primarily composed of dihydrogen oxide in its liquid form.
has_broad_synonym: water
database_cross_reference: EcoLexicon:water
database_cross_reference: LTER:617
database_cross_reference: https://en.wikipedia.org/wiki/Water
has_obo_namespace: ENVO
id: ENVO:00002006
in_subset: ENVO_03605019

Axiom
annotated source: liquid water
annotated property: definition
annotated target: An environmental material primarily composed of dihydrogen oxide in its liquid form.
database_cross_reference: MA:ma

sediment
type: Class
subclass of: particulate environmental material
definition: Particulate environmental material which is formed as a result of the transport and deposition of particles by flowing liquid.
database_cross_reference: EcoLexicon:sediment
database_cross_reference: EcoLexicon:sedimentation
database_cross_reference: LTER:492
database_cross_reference: LTER:493
database_cross_reference: SWEETRealm:Sediment
database_cross_reference: https://en.wikipedia.org/wiki/Sediment
has_obo_namespace: ENVO
id: ENVO:00002007
in_subset: ENVO_03605026
in_subset: EnvO-Lite-GSC
in_subset: envoPolar
comment: Sediment is typically deposited on the bed or bottom of a body of water or other liquid.

Axiom
annotated source: sediment
annotated property: definition
annotated target: Particulate environmental material which is formed as a result of the transport and deposition of particles by flowing liquid.
database_cross_reference: https://en.wikipedia.org/wiki/Sediment

saline water
type: Class
subclass of: liquid water
definition: Water which contains a significant concentration of dissolved salts.
database_cross_reference: EcoLexicon:saltwater
database_cross_reference: SWEETRealm:SalineWater
database_cross_reference: SWEETRealm:SaltWater
database_cross_reference: https://en.wikipedia.org/wiki/Saline_water
has_exact_synonym: salt water
has_obo_namespace: ENVO
id: ENVO:00002010
in_subset: ENVO_03605019
comment: The threshold salt concentration for classifying water as saline varies, but typically begins at about 1,000 to 3,000 parts salt per million parts water or 0.1–0.3% salt by weight.

fresh water
type: Class
subclass of: liquid water
definition: Water which has a low concentration of dissolved solutes, particularly that of sodium chloride.
database_cross_reference: EcoLexicon:fresh_water
database_cross_reference: LTER:216
database_cross_reference: SWEETRealm:FreshWater
database_cross_reference: https://en.wikipedia.org/wiki/Fresh_water
has_exact_synonym: freshwater
has_obo_namespace: ENVO
has_related_synonym: sweet water
id: ENVO:00002011
in_subset: ENVO_03605019
in_subset: envoEmpo
in_subset: envoPolar
comment: The lower bound of solute concentration required for water to be considered freshwater is variable, but is always less than that of seawater, and often cited as less than 1 gram of solutes per 1 litre of water.

clay
type: Class
subclass of: particulate environmental material
subclass of: Restriction
  on property: BFO_0000051
  some values from: particle of clay
disjoint with: silt
definition: Particulate environmental material which 1) is composed primarily of clay particles, with only minor proportions of other materials, 2) demonstrates plasticity when wet, and 3) is capable of hardening when dried or fired.
IAO_0000116: Do not oversimplify the particulate environmental material subclasses with design patterns or similar. The materials have properties that their components do not - write full definitions including these where possible.
database_cross_reference: EcoLexicon:clay
database_cross_reference: SWEETRealm:Clay
has_obo_namespace: ENVO
id: ENVO:00002982
comment: This definition is intentionally ambiguous to support the multiple thresholds set by different authorities.The distinction between silt and clay varies by discipline. Geologists and soil scientists usually consider the separation to occur at a particle size of 2 μm (clays being finer than silts), sedimentologists often use 4–5 μm, and colloid chemists use 1 μm. Geotechnical engineers distinguish between silts and clays based on the plasticity properties of the soil, as measured by the soils' Atterberg limits. ISO 14688 grades clay particles as being smaller than 2 μm and silt particles as being larger. Mixtures of sand, silt and less than 40% clay are called loam. Similar mixtures with greater than 40% clay are often considered clay soils.

Axiom
annotated source: clay
annotated property: definition
annotated target: Particulate environmental material which 1) is composed primarily of clay particles, with only minor proportions of other materials, 2) demonstrates plasticity when wet, and 3) is capable of hardening when dried or fired.
database_cross_reference: https://en.wikipedia.org/wiki/Clay

Axiom
annotated source: clay
annotated property: comment
annotated target: This definition is intentionally ambiguous to support the multiple thresholds set by different authorities.The distinction between silt and clay varies by discipline. Geologists and soil scientists usually consider the separation to occur at a particle size of 2 μm (clays being finer than silts), sedimentologists often use 4–5 μm, and colloid chemists use 1 μm. Geotechnical engineers distinguish between silts and clays based on the plasticity properties of the soil, as measured by the soils' Atterberg limits. ISO 14688 grades clay particles as being smaller than 2 μm and silt particles as being larger. Mixtures of sand, silt and less than 40% clay are called loam. Similar mixtures with greater than 40% clay are often considered clay soils.
database_cross_reference: https://en.wikipedia.org/wiki/Clay

sterile water
type: Class
subclass of: liquid water
definition: Sterile water is water which does not contain lliving organisms.
has_obo_namespace: ENVO
id: ENVO:00005791
in_subset: ENVO_03605019

rhizosphere
type: Class
subclass of: ecosystem
subclass of: Restriction
  on property: BFO_0000050
  some values from: soil
definition: The narrow region of soil that is directly influenced by root secretions and associated soil microorganisms.
database_cross_reference: LTER:472
has_obo_namespace: ENVO
id: ENVO:00005801
in_subset: ENVO_03605014
in_subset: ENVO_03605024

Axiom
annotated source: rhizosphere
annotated property: definition
annotated target: The narrow region of soil that is directly influenced by root secretions and associated soil microorganisms.
database_cross_reference: https://en.wikipedia.org/wiki/Rhizosphere_%28ecology%29

environmental material
type: Class
definition: A material entity which other material entities in an environmental system are primarily or partially composed of.
has_exact_synonym: portion of environmental material
has_obo_namespace: ENVO
id: ENVO:00010483
comment: Everything under this parent must be a mass noun (i.e. not countable). All subclasses are to be understood as being composed primarily of the named entity, rather than restricted to that entity. For example, "ENVO:water" is to be understood as "environmental material composed primarly of some CHEBI:water".
comment: Instances of this class are portions of environmental materials, such as seawater in bucket, a water parcel in the photic zone of a lake, or the concrete that composes a building part. Instances of these portions may have fiat or non-fiat boundaries. For example, a water parcel has not physical boundaries, while the seawater in a bucket is bounded by the internal surfaces of the bucket.

Axiom
annotated source: environmental material
annotated property: definition
annotated target: A material entity which other material entities in an environmental system are primarily or partially composed of.
database_cross_reference: http://ontology.buffalo.edu/smith/articles/niches.html
database_cross_reference: https://dx.doi.org/10.1186/2041-1480-4-43
database_cross_reference: https://en.wikipedia.org/wiki/Material

silt
type: Class
subclass of: particulate environmental material
subclass of: Restriction
  on property: BFO_0000051
  some values from: particle of silt
disjoint with: sand
definition: Particulate environmental material which is primarily composed of silt particles.
IAO_0000116: Do not oversimplify the particulate environmental material subclasses with design patterns or similar. The materials have properties that their components do not - write full definitions including these where possible.
database_cross_reference: EcoLexicon:silt
database_cross_reference: SWEETRealm:Silt
database_cross_reference: https://en.wikipedia.org/wiki/Silt
has_obo_namespace: ENVO
id: ENVO:01000016
comment: This definition is intentionally ambiguous to support the multiple thresholds set by different authorities. Some authorities consider this soil material that contains 80% or more silt and less than 12% clay. In the Udden-Wentworth scale (due to Krumbein), silt particles range between 0.0039 to 0.0625 mm, larger than clay but smaller than sand particles. ISO 14688 grades silts between 0.002 mm and 0.063 mm. In actuality, silt is chemically distinct from clay, and unlike clay, grains of silt are approximately the same size in all dimensions; furthermore, their size ranges overlap. Clays are formed from thin plate-shaped particles held together by electrostatic forces, so present a cohesion. According to the U.S. Department of Agriculture Soil Texture Classification system, the sand-silt distinction is made at the 0.05 mm particle size. The USDA system has been adopted by the Food and Agriculture Organization (FAO). In the Unified Soil Classification System (USCS) and the AASHTO Soil Classification system, the sand-silt distinction is made at the 0.075 mm particle size (i.e., material passing the #200 sieve). Silts and clays are distinguished mechanically by their plasticity.

Axiom
annotated source: silt
annotated property: definition
annotated target: Particulate environmental material which is primarily composed of silt particles.
database_cross_reference: https://en.wikipedia.org/wiki/Silt

Axiom
annotated source: silt
annotated property: comment
annotated target: This definition is intentionally ambiguous to support the multiple thresholds set by different authorities. Some authorities consider this soil material that contains 80% or more silt and less than 12% clay. In the Udden-Wentworth scale (due to Krumbein), silt particles range between 0.0039 to 0.0625 mm, larger than clay but smaller than sand particles. ISO 14688 grades silts between 0.002 mm and 0.063 mm. In actuality, silt is chemically distinct from clay, and unlike clay, grains of silt are approximately the same size in all dimensions; furthermore, their size ranges overlap. Clays are formed from thin plate-shaped particles held together by electrostatic forces, so present a cohesion. According to the U.S. Department of Agriculture Soil Texture Classification system, the sand-silt distinction is made at the 0.05 mm particle size. The USDA system has been adopted by the Food and Agriculture Organization (FAO). In the Unified Soil Classification System (USCS) and the AASHTO Soil Classification system, the sand-silt distinction is made at the 0.075 mm particle size (i.e., material passing the #200 sieve). Silts and clays are distinguished mechanically by their plasticity.
database_cross_reference: https://en.wikipedia.org/wiki/Silt
database_cross_reference: https://sis.agr.gc.ca/cansis/glossary/t/index.html

sand
type: Class
subclass of: particulate environmental material
subclass of: Restriction
  on property: BFO_0000051
  some values from: particle of sand
definition: Particulate environmental material which is composed primarily of particles of sand with only minor proportions of other substances.
IAO_0000116: Do not oversimplify the particulate environmental material subclasses with design patterns or similar. The materials have properties that their components do not - write full definitions including these where possible.
database_cross_reference: EcoLexicon:sand
database_cross_reference: LTER:484
database_cross_reference: SWEETRealm:Sand
database_cross_reference: https://en.wikipedia.org/wiki/Sand
has_obo_namespace: ENVO
id: ENVO:01000017
comment: This definition is intentionally ambiguous to support the multiple thresholds set by different authorities. Some authorities consider as sands soil material that contains 85% or more sand; the percentage of silt plus 1.5 times the percentage of clay does not exceed 15. coarse sand (sable grossier) 25% or more very coarse and coarse sand, and less than 50% any other one grade of sand.

Axiom
annotated source: sand
annotated property: definition
annotated target: Particulate environmental material which is composed primarily of particles of sand with only minor proportions of other substances.
database_cross_reference: https://en.wikipedia.org/wiki/Sand

Axiom
annotated source: sand
annotated property: comment
annotated target: This definition is intentionally ambiguous to support the multiple thresholds set by different authorities. Some authorities consider as sands soil material that contains 85% or more sand; the percentage of silt plus 1.5 times the percentage of clay does not exceed 15. coarse sand (sable grossier) 25% or more very coarse and coarse sand, and less than 50% any other one grade of sand.
database_cross_reference: https://sis.agr.gc.ca/cansis/glossary/t/index.html

particulate environmental material
type: Class
subclass of: environmental material
subclass of: Restriction
  on property: BFO_0000051
  some values from: particle
definition: An environmental material which is composed primarily of particles.
IAO_0000116: Do not oversimplify this branch with design patterns or similar. The materials have properties that their components do not - write full definitions including these where possible.
IAO_0000231: IAO_0000227
term replaced by: ENVO_00000369
has_broad_synonym: particulate matter
has_obo_namespace: ENVO
id: ENVO:01000060
in_subset: envoAtmo
in_subset: envoPolar
deprecated: true

organic material
type: Class
subclass of: environmental material
definition: Environmental material derived from living organisms and composed primarily of one or more biomacromolecules.
created by: ORCID:0000-0002-4366-3088
creation date: 2010-03-20T08:40:04Z
database_cross_reference: EcoLexicon:organic_material
has_exact_synonym: biomass
has_obo_namespace: ENVO
id: ENVO:01000155

Axiom
annotated source: organic material
annotated property: definition
annotated target: Environmental material derived from living organisms and composed primarily of one or more biomacromolecules.
database_cross_reference: ISBN:978-0-618-45504-1
database_cross_reference: ORCID:0000-0002-4366-3088

environmental system
type: Class
definition: A system which has the disposition to environ one or more material entities.
creation date: 2013-09-23T16:04:08Z
database_cross_reference: EcoLexicon:environment
has_exact_synonym: environment
has_obo_namespace: ENVO
id: ENVO:01000254
comment: In ENVO's alignment with the Basic Formal Ontology, this class is being considered as a subclass of a proposed BFO class "system". The relation "environed_by" is also under development. Roughly, a system which includes a material entity (at least partially) within its site and causally influences that entity may be considered to environ it. Following the completion of this alignment, this class' definition and the definitions of its subclasses will be revised.

Axiom
annotated source: environmental system
annotated property: definition
annotated target: A system which has the disposition to environ one or more material entities.
database_cross_reference: DOI:10.1186/2041-1480-4-43

mineral material
type: Class
subclass of: environmental material
definition: A mineral material is an environmental material which is primarily composed of some substance that is naturally occurring, solid and stable at room temperature, representable by a chemical formula, usually abiogenic, and that has an ordered atomic structure.
IAO_0000116: Look for "mineral" in a chemical or geochemical ontology to formalise the composed primarily of link. From https://en.wikipedia.org/wiki/ [A mineral] is different from a rock, which can be an aggregate of minerals or non-minerals and does not have a specific chemical composition. The exact definition of a mineral is under debate, especially with respect to the requirement a valid species be abiogenic, and to a lesser extent with regards to it having an ordered atomic structure.
created by: ORCID:0000-0002-4366-3088
creation date: 2013-10-05T12:37:41Z
database_cross_reference: LTER:341
has_obo_namespace: ENVO
id: ENVO:01000256

Axiom
annotated source: mineral material
annotated property: definition
annotated target: A mineral material is an environmental material which is primarily composed of some substance that is naturally occurring, solid and stable at room temperature, representable by a chemical formula, usually abiogenic, and that has an ordered atomic structure.
database_cross_reference: https://en.wikipedia.org/wiki/Mineral

atmosphere
type: Class
subclass of: fluid layer
subclass of: Restriction
  on property: RO_0002220
  some values from: astronomical body
definition: An atmosphere is a layer of gases surrounding a material body of sufficient mass that is held in place by the gravity of the body.
created by: ORCID:0000-0002-4366-3088
creation date: 2013-10-10T08:14:50Z
database_cross_reference: LTER:48
has_obo_namespace: ENVO
id: ENVO:01000267

Axiom
annotated source: atmosphere
annotated property: definition
annotated target: An atmosphere is a layer of gases surrounding a material body of sufficient mass that is held in place by the gravity of the body.
database_cross_reference: https://en.wikipedia.org/wiki/Atmosphere
database_cross_reference: https://en.wikipedia.org/wiki/Physical_geography

layer
type: Class
definition: A material entity which 1) is spatially continuous, 2) is composed of material of comparable thickness, composition, and physical properties, and 3) is physically distinct from adjacent portions of environmental material.
created by: https://orcid.org/0000-0002-4366-3088
creation date: 2013-10-15T16:42:02Z
has_obo_namespace: ENVO
id: ENVO:01000281
in_subset: envoPolar

Axiom
annotated source: layer
annotated property: definition
annotated target: A material entity which 1) is spatially continuous, 2) is composed of material of comparable thickness, composition, and physical properties, and 3) is physically distinct from adjacent portions of environmental material.
database_cross_reference: https://en.wiktionary.org/wiki/layer

freshwater environment
type: Class
equivalent class: Class
  intersection of: aquatic environment
  intersection of: Restriction
    on property: RO_0002507
    some values from: fresh water
subclass of: aquatic environment
definition: An aquatic environment which is determined by freshwater.
IAO_0000118: Water (non-saline)
has_exact_synonym: fresh water environment
has_obo_namespace: ENVO
id: ENVO:01000306
in_subset: envoEmpo
in_subset: envoOmics
in_subset: envoPolar

Axiom
annotated source: freshwater environment
annotated property: IAO_0000118
annotated target: Water (non-saline)
database_cross_reference: http://press.igsb.anl.gov/earthmicrobiome/protocols-and-standards/emp-ontology-empo/

saline water environment
type: Class
equivalent class: Class
  intersection of: aquatic environment
  intersection of: Restriction
    on property: RO_0002507
    some values from: saline water
subclass of: aquatic environment
definition: An environmental system which has its properties and dynamics determined by saline water.
IAO_0000118: Water (saline)
has_obo_namespace: ENVO
id: ENVO:01000307
in_subset: envoEmpo
in_subset: envoOmics
in_subset: envoPolar

Axiom
annotated source: saline water environment
annotated property: IAO_0000118
annotated target: Water (saline)
database_cross_reference: http://press.igsb.anl.gov/earthmicrobiome/protocols-and-standards/emp-ontology-empo/

aquatic environment
type: Class
equivalent class: Class
  intersection of: environmental system
  intersection of: Restriction
    on property: RO_0002507
    some values from: liquid water
subclass of: environmental system
definition: An environment whose dynamics are strongly influenced by water.
has_obo_namespace: ENVO
id: ENVO:01000317

outer space
type: Class
subclass of: environmental material
definition: Outer space is a hard vacuum containing a low density of particles, predominantly a plasma of hydrogen and helium as well as electromagnetic radiation, magnetic fields, neutrinos, dust and cosmic rays that exists between celestial bodies.
has_broad_synonym: space
has_obo_namespace: ENVO
id: ENVO:01000637
in_subset: envoAstro

Axiom
annotated source: outer space
annotated property: definition
annotated target: Outer space is a hard vacuum containing a low density of particles, predominantly a plasma of hydrogen and helium as well as electromagnetic radiation, magnetic fields, neutrinos, dust and cosmic rays that exists between celestial bodies.
database_cross_reference: https://en.wikipedia.org/wiki/Outer_space

planetary crust
type: Class
subclass of: planetary structural layer
definition: A planetary crust is the outermost solid shell of a rocky planet or natural satellite, which is chemically distinct from the underlying mantle.
has_broad_synonym: crust
has_obo_namespace: ENVO
id: ENVO:01000638
comment: This class is meant to be applicable accross planets. Earth's crust would be an instance.

Axiom
annotated source: planetary crust
annotated property: definition
annotated target: A planetary crust is the outermost solid shell of a rocky planet or natural satellite, which is chemically distinct from the underlying mantle.
database_cross_reference: https://en.wikipedia.org/wiki/Crust_(geology)

planetary structural layer
type: Class
subclass of: layer
subclass of: Restriction
  on property: BFO_0000050
  some values from: planet
definition: A planetary structural layer is laminar part of a terrestrial planet or other rocky body large enough to have differentiation by density. Planetary layers have differing physicochemical properties and composition.
IAO_0000116: Label should be improved to match definition.
has_obo_namespace: ENVO
id: ENVO:01000639

lithosphere
type: Class
subclass of: planetary structural layer
subclass of: Restriction
  on property: BFO_0000051
  some values from: planetary crust
subclass of: Restriction
  on property: RO_0002473
  some values from: solid environmental material
definition: A lithosphere is the outermost shell of a terrestrial-type planet or natural satellite that is defined by its rigid mechanical properties.
has_obo_namespace: ENVO
id: ENVO:01000646
comment: Earth's lithosphere includes the crust and uppermost mantle.

Axiom
annotated source: lithosphere
annotated property: definition
annotated target: A lithosphere is the outermost shell of a terrestrial-type planet or natural satellite that is defined by its rigid mechanical properties.
database_cross_reference: https://en.wikipedia.org/wiki/Lithosphere

astronomical body
type: Class
subclass of: astronomical object
definition: An object which is naturally occuring, bound together by gravitational or electromagnetic forces, and surrounded by space.
has_obo_namespace: ENVO
has_related_synonym: celestial body
id: ENVO:01000799
in_subset: envoAstro
comment: Astronomical bodies are usually cohesive, thus the use of the term 'object' sensu BFO 'object'.

Axiom
annotated source: astronomical body
annotated property: definition
annotated target: An object which is naturally occuring, bound together by gravitational or electromagnetic forces, and surrounded by space.
database_cross_reference: https://en.wikipedia.org/wiki/Astronomical_object

planet
type: Class
subclass of: astronomical body
definition: A planet is an astronomical body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared its neighbouring region of planetesimals.
has_obo_namespace: ENVO
id: ENVO:01000800
in_subset: envoAstro
in_subset: envoPolar
comment: Considerable debate on the definition of planet exists.

Axiom
annotated source: planet
annotated property: definition
annotated target: A planet is an astronomical body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared its neighbouring region of planetesimals.
database_cross_reference: http://solarsystem.nasa.gov/planets/whatisaplanet
database_cross_reference: https://en.wikipedia.org/wiki/Planet

astronomical object
type: Class
subclass of: Restriction
  on property: BFO_0000051
  some values from: astronomical body
subclass of: Restriction
  on property: RO_0000086
  some values from: geodiversity
subclass of: Restriction
  on property: surrounded by
  some values from: outer space
definition: An object which is composed of one or more gravitationally bound structures that are associated with a position in space.
has_obo_namespace: ENVO
has_related_synonym: celestial object
id: ENVO:01000804
in_subset: envoAstro
comment: If there is only one astronomical body involved, this class is equivalent to ENVO:01000799. This may be problematic with reasoning, but it seems to be true to the rather fuzzy definitions found thus far.

Axiom
annotated source: astronomical object
annotated property: definition
annotated target: An object which is composed of one or more gravitationally bound structures that are associated with a position in space.
database_cross_reference: https://en.wikipedia.org/wiki/Astronomical_object

astronomical body part
type: Class
subclass of: Restriction
  on property: BFO_0000050
  some values from: astronomical body
definition: A material part of an astronomical body.
IAO_0000116: Also note that some astronomical body parts (ABPs) may have fiat boundaries: if there's strong debate about where an ABP begins or ends (over and above fuzzy boundaries), with different official classifications setting different thresholds or limits, axiomatise the class with fiat boundaries of the appropriate dimension.
IAO_0000116: Note that material entities may have immaterial entities (e.g. sites) as parts.
IAO_0000116: This class includes material parts of astronomical bodies. Immaterial parts, such as magnetospheres, are represented as sites under the influence of magnetic fields.Please post countercases in the ENVO tracker for revision of this hierarchy if needed.
has_obo_namespace: ENVO
id: ENVO:01000813
in_subset: envoAstro
in_subset: envoPolar
comment: Material parts of astronomical bodies generally have boundaries formed by discontinuities in qualities, composition, or other physical characterisitcs. These boundaries are sometimes sharp, and sometimes diffuse, with different classification systems and communities declaring varying thresholds (e.g. for where a shoreline, forest, or other entity begins and ends). However, some boundaries are declared by fiat - that is, by arbitrary human convention or decree - particularly by regulatory or other authorities and communities of practice. The classes in this hierarchy attempt to offer generalisable definitions that allow multiple classfiication systems to map to and interoperate through. If desired, we can create classes that declare thresholds used by a given authority or community under the more generic ones, annotated with source information.

solid environmental material
type: Class
subclass of: environmental material
definition: An environmental material which is in a solid state.
has_obo_namespace: ENVO
id: ENVO:01000814
comment: This is a defined class: its subclasses will not be asserted, but filled by inference.

liquid environmental material
type: Class
subclass of: fluid environmental material
definition: An environmental material which is in a liquid state.
has_obo_namespace: ENVO
id: ENVO:01000815
in_subset: envoPolar
comment: This is a defined class: most of its subclasses will not be asserted, but filled by inference.

biosphere
type: Class
subclass of: astronomical body part
definition: An astronomical body part which includes all the living entities within the gravitational sphere of influence of that body, as well as the non-living and dead entities with which they interact.
IAO_0000116: Whether this class should be grouped with classes such as "hydrosphere" and "cryosphere" requires some discussion.
has_obo_namespace: ENVO
id: ENVO:01000817
in_subset: envoAstro
in_subset: envoPolar
comment: The gravitational sphere of influence referenced in this class' definition is the Hill sphere: a region in which an object dominates the attraction of satellites despite gravitational perturbations.

Axiom
annotated source: biosphere
annotated property: definition
annotated target: An astronomical body part which includes all the living entities within the gravitational sphere of influence of that body, as well as the non-living and dead entities with which they interact.
database_cross_reference: http://www.biology-online.org/dictionary/Biosphere
database_cross_reference: https://en.wikipedia.org/wiki/Biosphere

hydrosphere
type: Class
subclass of: liquid astronomical body part
subclass of: Restriction
  on property: RO_0002473
  some values from: liquid water
definition: An astronomical body part which is composed of the combined mass of water found on, under, and over the surface of a planet.
has_obo_namespace: ENVO
id: ENVO:01000819
in_subset: envoAstro
in_subset: envoPolar
comment: This is a very broad and, in practice, poorly defined term. Please consider using or requesting a more specific class.

Axiom
annotated source: hydrosphere
annotated property: definition
annotated target: An astronomical body part which is composed of the combined mass of water found on, under, and over the surface of a planet.
database_cross_reference: https://en.wikipedia.org/wiki/Hydrosphere

pedosphere
type: Class
subclass of: astronomical body part
subclass of: Restriction
  on property: RO_0002131
  some values from: atmosphere
subclass of: Restriction
  on property: RO_0002131
  some values from: lithosphere
subclass of: Restriction
  on property: RO_0002131
  some values from: biosphere
subclass of: Restriction
  on property: RO_0002131
  some values from: hydrosphere
subclass of: Restriction
  on property: RO_0002473
  some values from: soil
definition: An astronomical body part which is composed of soil, subject to soil formation processes, and found on the surface of a lithosphere.
has_obo_namespace: ENVO
id: ENVO:01000820
in_subset: envoAstro
comment: This is a very broad and, in practice, poorly defined term. Please consider using or requesting a more specific class.

Axiom
annotated source: pedosphere
annotated property: definition
annotated target: An astronomical body part which is composed of soil, subject to soil formation processes, and found on the surface of a lithosphere.
database_cross_reference: https://en.wikipedia.org/wiki/Pedosphere

environmental system determined by a quality
type: Class
subclass of: environmental system
definition: An environmental system which is determined by materials bearing roughly homogeneous qualities.
has_obo_namespace: ENVO
id: ENVO:01000997
comment: Organisational class. Not intended for annotation.

rhizosphere environment
type: Class
subclass of: environmental system
subclass of: Restriction
  on property: RO_0002131
  some values from: rhizosphere
subclass of: Restriction
  on property: RO_0002131
  some values from: plant-associated environment
definition: An environmental system determined by the presence of a plant rhizosphere.
IAO_0000118: Plant rhizosphere
has_obo_namespace: ENVO
id: ENVO:01000999
in_subset: envoEmpo
in_subset: envoOmics

Axiom
annotated source: rhizosphere environment
annotated property: IAO_0000118
annotated target: Plant rhizosphere
comment: http://press.igsb.anl.gov/earthmicrobiome/protocols-and-standards/emp-ontology-empo/

environmental system determined by an organism
type: Class
subclass of: environmental system
definition: An environmental system which is determined by a living organism.
has_obo_namespace: ENVO
has_related_synonym: host-associated environment
id: ENVO:01001000
in_subset: envoEmpo
in_subset: envoOmics

plant-associated environment
type: Class
definition: An environmental system determined by a green plant.
IAO_0000118: Plant
has_broad_synonym: plant environment
has_exact_synonym: Viridiplantae-associated environment
has_obo_namespace: ENVO
id: ENVO:01001001
in_subset: envoEmpo
in_subset: envoOmics

Axiom
annotated source: plant-associated environment
annotated property: IAO_0000118
annotated target: Plant
database_cross_reference: http://press.igsb.anl.gov/earthmicrobiome/protocols-and-standards/emp-ontology-empo/

animal-associated environment
type: Class
definition: An environmental system determined by an animal.
IAO_0000118: Animal
has_broad_synonym: animal environment
has_exact_synonym: Metazoan-associated environment
has_obo_namespace: ENVO
id: ENVO:01001002
in_subset: envoEmpo
in_subset: envoMeo
in_subset: envoOmics

Axiom
annotated source: animal-associated environment
annotated property: IAO_0000118
annotated target: Animal
database_cross_reference: http://press.igsb.anl.gov/earthmicrobiome/protocols-and-standards/emp-ontology-empo/

non-saline environment
type: Class
subclass of: environmental system determined by a quality
IAO_0000118: Non-saline
has_obo_namespace: ENVO
id: ENVO:01001003
in_subset: envoEmpo
comment: This class (term) is defined by the lack of a quality (i.e. the lack of salinity or increased osmolarity), which is not best-practice ontologically. Use for annotation is generally discouraged and users should use classes which positively describe the material or environment sampled (i.e. stating the qualities the entity has, rather than those it does not).

Axiom
annotated source: non-saline environment
annotated property: IAO_0000118
annotated target: Non-saline
database_cross_reference: http://press.igsb.anl.gov/earthmicrobiome/protocols-and-standards/emp-ontology-empo/

sediment permeated by freshwater
type: Class
subclass of: sediment
subclass of: Restriction
  on property: surrounded by
  some values from: fresh water
definition: Sediment which has its porespace filled by water which has very low levels of sodium chloride and/or other salts.
has_obo_namespace: ENVO
id: ENVO:01001028
in_subset: envoEmpo
in_subset: envoOmics
comment: We do not specify numeric thresholds for saline vs. non-saline here, as this is variable. Consider specifying this on the information and/or data layer for your purposes. If you require an ENVO class with a fixed threshold, please request one using our issue tracker.

fecal environment
type: Class
subclass of: environmental system
definition: An environmental system which has its properties and dynamics determined by feces.
IAO_0000118: Animal distal gut
has_obo_namespace: ENVO
id: ENVO:01001029
in_subset: envoEmpo
in_subset: envoMeo
in_subset: envoOmics

Axiom
annotated source: fecal environment
annotated property: IAO_0000118
annotated target: Animal distal gut
database_cross_reference: http://press.igsb.anl.gov/earthmicrobiome/protocols-and-standards/emp-ontology-empo/
comment: The label of this EMPO class is ambiguous, but pers. comm. with L Thompson (http://orcid.org/0000-0002-3911-1280) reveals that this is essentially limited to fecal samples.

environment determined by a metazoan secretion
type: Class
subclass of: environmental system
definition: An environmental system which has its properties and dynamics determined by a bodily secretion of a metazoan.
IAO_0000118: Animal secretion
has_obo_namespace: ENVO
id: ENVO:01001030
in_subset: envoEmpo
in_subset: envoMeo
in_subset: envoOmics

Axiom
annotated source: environment determined by a metazoan secretion
annotated property: IAO_0000118
annotated target: Animal secretion
database_cross_reference: http://press.igsb.anl.gov/earthmicrobiome/protocols-and-standards/emp-ontology-empo/

environment determined by a plant substance
type: Class
subclass of: environmental system
definition: An environmental system which has its properties and dynamics determined by a substance produced by a plant.
IAO_0000118: Plant secretion
has_obo_namespace: ENVO
id: ENVO:01001031
in_subset: envoEmpo
in_subset: envoMeo
in_subset: envoOmics

Axiom
annotated source: environment determined by a plant substance
annotated property: IAO_0000118
annotated target: Plant secretion
database_cross_reference: http://press.igsb.anl.gov/earthmicrobiome/protocols-and-standards/emp-ontology-empo/

environment determined by a biofilm on a plant surface
type: Class
definition: An environmental system which has its properties and dynamics determined by a biofilm on the surface of a plant.
IAO_0000118: Plant surface
has_obo_namespace: ENVO
id: ENVO:01001032
in_subset: envoEmpo
in_subset: envoMeo
in_subset: envoOmics

Axiom
annotated source: environment determined by a biofilm on a plant surface
annotated property: IAO_0000118
annotated target: Plant surface
database_cross_reference: http://press.igsb.anl.gov/earthmicrobiome/protocols-and-standards/emp-ontology-empo/

digestive tract environment
type: Class
subclass of: anatomical entity environment
definition: An environmental system which has its properties and dynamics determined by a digestive tract.
IAO_0000118: Animal proximal gut
has_obo_namespace: ENVO
id: ENVO:01001033
in_subset: envoEmpo
in_subset: envoMeo
in_subset: envoOmics

Axiom
annotated source: digestive tract environment
annotated property: IAO_0000118
annotated target: Animal proximal gut
database_cross_reference: http://press.igsb.anl.gov/earthmicrobiome/protocols-and-standards/emp-ontology-empo/
comment: This EMPO class includes examples of microbial environments determined by the "gut intestine, gizzard, crop, lumen, [and] mucosa".

environment determined by a biofilm on an animal surface
type: Class
definition: An environmental system which has its properties and dynamics determined by a biofilm on the surface of a animal.
IAO_0000118: Animal surface
has_obo_namespace: ENVO
id: ENVO:01001034
in_subset: envoEmpo
in_subset: envoMeo
in_subset: envoOmics

Axiom
annotated source: environment determined by a biofilm on an animal surface
annotated property: IAO_0000118
annotated target: Animal surface
database_cross_reference: http://press.igsb.anl.gov/earthmicrobiome/protocols-and-standards/emp-ontology-empo/

environment determined by a biofilm on a fungal surface
type: Class
definition: An environmental system which has its properties and dynamics determined by a biofilm on the surface of a fungus.
IAO_0000118: Fungus surface
has_obo_namespace: ENVO
id: ENVO:01001035
in_subset: envoEmpo
in_subset: envoMeo
in_subset: envoOmics

Axiom
annotated source: environment determined by a biofilm on a fungal surface
annotated property: IAO_0000118
annotated target: Fungus surface
database_cross_reference: http://press.igsb.anl.gov/earthmicrobiome/protocols-and-standards/emp-ontology-empo/

sediment permeated by saline water
type: Class
subclass of: sediment
subclass of: Restriction
  on property: surrounded by
  some values from: saline water
definition: Sediment which has its porespace filled by water with increased levels of sodium chloride and other salts.
has_obo_namespace: ENVO
id: ENVO:01001036
in_subset: ENVO_03605026
in_subset: envoEmpo
in_subset: envoOmics
comment: We do not specify numeric thresholds for saline vs. non-saline here, as this is variable. Consider specifying this on the information and/or data layer for your purposes. If you require an ENVO class with a fixed threshold, please request one using our issue tracker.

saline environment
type: Class
subclass of: environmental system determined by a quality
definition: An environment which is determined by materials which bear significant concentrations of salts.
IAO_0000118: Saline
has_obo_namespace: ENVO
id: ENVO:01001040
in_subset: envoEmpo
comment: The thresholds for "significant" concentrations of salts vary widely and thus no committment is made in this class. Subclasses with more explicit thresholds can be made upon request.

Axiom
annotated source: saline environment
annotated property: IAO_0000118
annotated target: Saline
database_cross_reference: http://press.igsb.anl.gov/earthmicrobiome/protocols-and-standards/emp-ontology-empo/

fungi-associated environment
type: Class
definition: An environmental system determined by a fungal structure.
IAO_0000118: Fungus
has_broad_synonym: fungus environment
has_exact_synonym: fungus-associated environment
has_obo_namespace: ENVO
id: ENVO:01001041
in_subset: envoEmpo
in_subset: envoMeo
in_subset: envoOmics

Axiom
annotated source: fungi-associated environment
annotated property: IAO_0000118
annotated target: Fungus
database_cross_reference: http://press.igsb.anl.gov/earthmicrobiome/protocols-and-standards/emp-ontology-empo/

sterile water environment
type: Class
equivalent class: Class
  intersection of: aquatic environment
  intersection of: Restriction
    on property: RO_0002507
    some values from: sterile water
subclass of: aquatic environment
subclass of: Restriction
  on property: RO_0002473
  some values from: sterile water
definition: An environmental system which has its properties and dynamics determined by sterile water.
IAO_0000118: Negative
has_obo_namespace: ENVO
id: ENVO:01001042
in_subset: envoEmpo
in_subset: envoOmics
comment: This term can be understood as a negative experimental control primarily composed of sterile water. The quantity of sterile water used may be contaminated; to express pure sterile water, please use http://purl.obolibrary.org/obo/ENVO_00005791

Axiom
annotated source: sterile water environment
annotated property: IAO_0000118
annotated target: Negative
database_cross_reference: http://press.igsb.anl.gov/earthmicrobiome/protocols-and-standards/emp-ontology-empo/

hypersaline water environment
type: Class
subclass of: saline water environment
definition: An environmental system which has its properties and dynamics determined by hypersaline water.
IAO_0000118: Hypersaline (saline)
has_obo_namespace: ENVO
id: ENVO:01001043
in_subset: envoEmpo
in_subset: envoOmics
in_subset: envoPolar

Axiom
annotated source: hypersaline water environment
annotated property: IAO_0000118
annotated target: Hypersaline (saline)
database_cross_reference: http://press.igsb.anl.gov/earthmicrobiome/protocols-and-standards/emp-ontology-empo/
comment: Examples inlcude water from hypersaline samples or brines (>50 psu)

soil environment
type: Class
equivalent class: Class
  intersection of: environmental system
  intersection of: Restriction
    on property: RO_0002507
    some values from: soil
subclass of: environmental system
definition: An environmental system which has its properties and dynamics determined by soil.
IAO_0000118: Soil (non-saline)
has_obo_namespace: ENVO
id: ENVO:01001044
in_subset: envoEmpo
in_subset: envoOmics

Axiom
annotated source: soil environment
annotated property: IAO_0000118
annotated target: Soil (non-saline)
database_cross_reference: http://press.igsb.anl.gov/earthmicrobiome/protocols-and-standards/emp-ontology-empo/

planetary subsurface environment
type: Class
subclass of: environmental system
definition: An environmental system which has its properties and dynamics determined by the subsurface zone of a planet.
has_obo_namespace: ENVO
id: ENVO:01001046
in_subset: envoEmpo
in_subset: envoMeo
in_subset: envoOmics

non-saline planetary subsurface environment
type: Class
subclass of: planetary subsurface environment
definition: An environmental system which has its properties and dynamics determined by those parts of a planetary subsurface zone which are not saline.
IAO_0000118: Subsurface (non-saline)
has_obo_namespace: ENVO
id: ENVO:01001047
in_subset: envoEmpo
in_subset: envoMeo
in_subset: envoOmics

Axiom
annotated source: non-saline planetary subsurface environment
annotated property: IAO_0000118
annotated target: Subsurface (non-saline)
database_cross_reference: http://press.igsb.anl.gov/earthmicrobiome/protocols-and-standards/emp-ontology-empo/

sediment environment
type: Class
equivalent class: Class
  intersection of: environmental system
  intersection of: Restriction
    on property: RO_0002507
    some values from: sediment
subclass of: environmental system
definition: An environmental system which has its properties and dynamics determined by sediment.
has_obo_namespace: ENVO
id: ENVO:01001048
in_subset: envoEmpo
in_subset: envoOmics

non-saline sediment environment
type: Class
equivalent class: Class
  intersection of: sediment environment
  intersection of: Restriction
    on property: RO_0002507
    some values from: sediment permeated by freshwater
subclass of: sediment environment
definition: An environmental system which has its properties and dynamics determined by sediment permeated by non-saline water.
IAO_0000118: Sediment (non-saline)
has_obo_namespace: ENVO
id: ENVO:01001049
in_subset: envoEmpo
in_subset: envoOmics

Axiom
annotated source: non-saline sediment environment
annotated property: IAO_0000118
annotated target: Sediment (non-saline)
database_cross_reference: http://press.igsb.anl.gov/earthmicrobiome/protocols-and-standards/emp-ontology-empo/

saline sediment environment
type: Class
equivalent class: Class
  intersection of: sediment environment
  intersection of: Restriction
    on property: RO_0002507
    some values from: sediment permeated by saline water
subclass of: sediment environment
definition: An environmental system which has its properties and dynamics determined by sediment permeated by saline water.
IAO_0000118: Sediment (saline)
has_obo_namespace: ENVO
id: ENVO:01001050
in_subset: envoEmpo
in_subset: envoOmics

Axiom
annotated source: saline sediment environment
annotated property: IAO_0000118
annotated target: Sediment (saline)
database_cross_reference: http://press.igsb.anl.gov/earthmicrobiome/protocols-and-standards/emp-ontology-empo/

environment determined by a biofilm on a non-saline surface
type: Class
definition: An environmental system which has its properties and dynamics determined by a biofilm on a surface which is exposed to non-saline materials.
IAO_0000118: Surface (non-saline)
has_obo_namespace: ENVO
id: ENVO:01001051
in_subset: envoEmpo
in_subset: envoMeo
in_subset: envoOmics

Axiom
annotated source: environment determined by a biofilm on a non-saline surface
annotated property: IAO_0000118
annotated target: Surface (non-saline)
database_cross_reference: http://press.igsb.anl.gov/earthmicrobiome/protocols-and-standards/emp-ontology-empo/

aerosol environment
type: Class
subclass of: environmental system
definition: An environmental system which has its properties and dynamics determined by an aerosol.
has_obo_namespace: ENVO
id: ENVO:01001052
in_subset: envoEmpo
in_subset: envoOmics

saline aerosol environment
type: Class
subclass of: aerosol environment
definition: An environmental system which has its properties and dynamics determined by a saline aerosol.
IAO_0000118: Aerosol (saline)
has_obo_namespace: ENVO
id: ENVO:01001053
in_subset: envoEmpo
in_subset: envoOmics

Axiom
annotated source: saline aerosol environment
annotated property: IAO_0000118
annotated target: Aerosol (saline)
database_cross_reference: http://press.igsb.anl.gov/earthmicrobiome/protocols-and-standards/emp-ontology-empo/
comment: seaspray or other aerosolized saline material (>5 psu)

non-saline aerosol environment
type: Class
subclass of: aerosol environment
definition: An environmental system which has its properties and dynamics determined by an aerosol with a low concentration of dissolved solutes.
IAO_0000118: Aerosol (non-saline)
has_obo_namespace: ENVO
id: ENVO:01001054
in_subset: envoEmpo
in_subset: envoOmics

Axiom
annotated source: non-saline aerosol environment
annotated property: IAO_0000118
annotated target: Aerosol (non-saline)
database_cross_reference: http://press.igsb.anl.gov/earthmicrobiome/protocols-and-standards/emp-ontology-empo/
comment: aerosolized dust or liquid

environment associated with an animal part or small animal
type: Class
subclass of: ecosystem
definition: An environmental system determined by part of a living or dead animal, or a whole small animal.
IAO_0000118: Animal corpus
has_obo_namespace: ENVO
id: ENVO:01001055
in_subset: envoEmpo
in_subset: envoMeo
in_subset: envoOmics

Axiom
annotated source: environment associated with an animal part or small animal
annotated property: IAO_0000118
annotated target: Animal corpus
database_cross_reference: http://press.igsb.anl.gov/earthmicrobiome/protocols-and-standards/emp-ontology-empo/

environment determined by a biofilm on a saline surface
type: Class
definition: An environmental system which has its properties and dynamics determined by a biofilm on a surface which is exposed to saline materials.
IAO_0000118: Surface (saline)
has_obo_namespace: ENVO
id: ENVO:01001056
in_subset: envoEmpo
in_subset: envoMeo
in_subset: envoOmics

Axiom
annotated source: environment determined by a biofilm on a saline surface
annotated property: IAO_0000118
annotated target: Surface (saline)
database_cross_reference: http://press.igsb.anl.gov/earthmicrobiome/protocols-and-standards/emp-ontology-empo/

environment associated with a plant part or small plant
type: Class
definition: An environmental system determined by part of a living or dead plant, or a whole small plant.
IAO_0000118: Plant corpus
has_obo_namespace: ENVO
id: ENVO:01001057
in_subset: envoEmpo
in_subset: envoMeo
in_subset: envoOmics

Axiom
annotated source: environment associated with a plant part or small plant
annotated property: IAO_0000118
annotated target: Plant corpus
database_cross_reference: http://press.igsb.anl.gov/earthmicrobiome/protocols-and-standards/emp-ontology-empo/

environment associated with a fungal tissue
type: Class
definition: An environmental system determined by part of a living or dead fungus.
IAO_0000118: Fungus corpus
has_obo_namespace: ENVO
id: ENVO:01001058
in_subset: envoEmpo
in_subset: envoMeo
in_subset: envoOmics

Axiom
annotated source: environment associated with a fungal tissue
annotated property: IAO_0000118
annotated target: Fungus corpus
database_cross_reference: http://press.igsb.anl.gov/earthmicrobiome/protocols-and-standards/emp-ontology-empo/

mock community culture
type: Class
subclass of: cell culture
definition: A cell culture which is composed of a microbial community of known composition.
IAO_0000118: Mock community
has_obo_namespace: ENVO
id: ENVO:01001059
in_subset: envoEmpo
in_subset: envoOmics
comment: Mock communities are typically used as positive controls in experiments.

Axiom
annotated source: mock community culture
annotated property: IAO_0000118
annotated target: Mock community
database_cross_reference: http://press.igsb.anl.gov/earthmicrobiome/protocols-and-standards/emp-ontology-empo/

single strain cell culture
type: Class
subclass of: cell culture
definition: A cell culture which is composed of a single population of bacterial or archaeal cells.
IAO_0000118: Single strain
has_obo_namespace: ENVO
id: ENVO:01001060
in_subset: envoEmpo
in_subset: envoOmics

Axiom
annotated source: single strain cell culture
annotated property: IAO_0000118
annotated target: Single strain
database_cross_reference: http://press.igsb.anl.gov/earthmicrobiome/protocols-and-standards/emp-ontology-empo/

ecosystem
type: Class
subclass of: environmental system
definition: An environmental system which includes both living and non-living components.
database_cross_reference: LTER:173
has_obo_namespace: ENVO
id: ENVO:01001110
comment: This class will be primarily filled by inference, any environmental system which necessarily includes living parts should be autoclassified here.

Axiom
annotated source: ecosystem
annotated property: definition
annotated target: An environmental system which includes both living and non-living components.
database_cross_reference: https://en.wikipedia.org/wiki/Ecosystem

Axiom
annotated source: ecosystem
annotated property: database_cross_reference
annotated target: LTER:173
database_cross_reference: https://vocab.lternet.edu/vocab/vocab/index.php

geodiversity
type: Class
definition: A quality which inheres in a astronomical body or astronomical body part by virtue of the variation in its material composition, participation in geological processes, and the variation in is land- and hydroforms.
has_obo_namespace: ENVO
id: ENVO:01001164
comment: Materials which are usually assessed when appraising geodiversity include minerals, rocks, sediments, fossils, soils and water. Landforms factored into geodiversity metrics typically include folds, faults, and other expressions of morphology or relations between units of earth material. Natural processes that are included in measures of geodiversity are those which either maintain or change materials or geoforms, including tectonics, sediment transport, and pedogenesis. Geodiversity does not usually factor in anthropogenic entities.

Axiom
annotated source: geodiversity
annotated property: definition
annotated target: A quality which inheres in a astronomical body or astronomical body part by virtue of the variation in its material composition, participation in geological processes, and the variation in is land- and hydroforms.
database_cross_reference: https://en.wikipedia.org/wiki/Geodiversity

Axiom
annotated source: geodiversity
annotated property: comment
annotated target: Materials which are usually assessed when appraising geodiversity include minerals, rocks, sediments, fossils, soils and water. Landforms factored into geodiversity metrics typically include folds, faults, and other expressions of morphology or relations between units of earth material. Natural processes that are included in measures of geodiversity are those which either maintain or change materials or geoforms, including tectonics, sediment transport, and pedogenesis. Geodiversity does not usually factor in anthropogenic entities.

liquid astronomical body part
type: Class
equivalent class: Class
  intersection of: fluid astronomical body part
  intersection of: Restriction
    on property: RO_0002473
    some values from: liquid environmental material
subclass of: fluid astronomical body part
definition: A part of an astronomical body which is primarily composed of liquid material.
created by: https://orcid.org/0000-0002-4366-3088
has_obo_namespace: ENVO
id: ENVO:01001477

fluid astronomical body part
type: Class
equivalent class: Class
  intersection of: astronomical body part
  intersection of: Restriction
    on property: RO_0002473
    some values from: fluid environmental material
subclass of: astronomical body part
definition: A part of an astronomical body which is primarily composed of fluid.
created by: https://orcid.org/0000-0002-4366-3088
creation date: 2018-10-04T13:59:22Z
has_obo_namespace: ENVO
id: ENVO:01001479

Axiom
annotated source: fluid astronomical body part
annotated property: definition
annotated target: A part of an astronomical body which is primarily composed of fluid.
database_cross_reference: https://en.wikipedia.org/wiki/Fluid

fluid layer
type: Class
subclass of: layer
definition: A layer which is composed primarily of some fluid.
creator: https://orcid.org/0000-0002-4366-3088
date: 2019-07-22T17:35:08Z
has_obo_namespace: ENVO
id: ENVO:01001678

mass of environmental material
type: Class
definition: An object which is composed primarily of an environmental material
creator: https://orcid.org/0000-0002-4366-3088
date: 2019-08-20T09:38:29Z
has_obo_namespace: ENVO
id: ENVO:01001686
comment: This class and its subclasses refer to objects that are discrete accumulations of environmental materials, generally primarily composed of one or a few main material types.

mass of solid material
type: Class
equivalent class: Class
  intersection of: mass of environmental material
  intersection of: Restriction
    on property: RO_0002473
    some values from: solid environmental material
subclass of: mass of environmental material
definition: An mass of environmental material which is composed primarily of a solid environmental material
creator: https://orcid.org/0000-0002-4366-3088
date: 2019-08-20T09:41:27Z
has_obo_namespace: ENVO
id: ENVO:01001687
comment: This class and its subclasses refer to objects that are discrete accumulations of environmental materials, generally primarily composed of one or a few main material types.

water-holding capacity
type: Class
definition: A disposition of a material entity which is realised when it is saturated with liquid water.
creator: https://orcid.org/0000-0002-4366-3088
has_obo_namespace: ENVO
id: ENVO:01003001

particle
type: Class
subclass of: mass of solid material
subclass of: Restriction
  on property: BFO_0000050
  some values from: particulate environmental material
definition: A mass of solid material which is either 1) a minute fragment of a larger mass or 2) one of a collection of small masses composing an aggregate.
has_obo_namespace: ENVO
has_related_synonym: grain
id: ENVO:01003002

Axiom
annotated source: particle
annotated property: definition
annotated target: A mass of solid material which is either 1) a minute fragment of a larger mass or 2) one of a collection of small masses composing an aggregate.
database_cross_reference: https://en.wiktionary.org/wiki/particle

particle of clay
type: Class
subclass of: particle
definition: A particle which 1) is composed primarily of hydrous aluminium phyllosilicate minerals, in turn composed of aluminium and silicon ions bonded into tiny, thin plates by interconnecting oxygen and hydroxide ions, and 2) is or was part of a portion of clay.
has_exact_synonym: clay particle
has_obo_namespace: ENVO
id: ENVO:01003003
comment: The distinction between silt and clay varies by discipline. Geologists and soil scientists usually consider the separation to occur at a particle size of 2 μm (clays being finer than silts), sedimentologists often use 4–5 μm, and colloid chemists use 1 μm. Geotechnical engineers distinguish between silts and clays based on the plasticity properties of the soil, as measured by the soils' Atterberg limits. ISO 14688 grades clay particles as being smaller than 2 μm and silt particles as being larger. Mixtures of sand, silt and less than 40% clay are called loam.

Axiom
annotated source: particle of clay
annotated property: definition
annotated target: A particle which 1) is composed primarily of hydrous aluminium phyllosilicate minerals, in turn composed of aluminium and silicon ions bonded into tiny, thin plates by interconnecting oxygen and hydroxide ions, and 2) is or was part of a portion of clay.
database_cross_reference: https://en.wikipedia.org/wiki/Clay#Properties

Axiom
annotated source: particle of clay
annotated property: comment
annotated target: The distinction between silt and clay varies by discipline. Geologists and soil scientists usually consider the separation to occur at a particle size of 2 μm (clays being finer than silts), sedimentologists often use 4–5 μm, and colloid chemists use 1 μm. Geotechnical engineers distinguish between silts and clays based on the plasticity properties of the soil, as measured by the soils' Atterberg limits. ISO 14688 grades clay particles as being smaller than 2 μm and silt particles as being larger. Mixtures of sand, silt and less than 40% clay are called loam.
database_cross_reference: Properties

cell culture
type: Class
subclass of: organic material
definition: A cell culture is a growth of cells in vitro in an artificial medium for experimental research.
database_cross_reference: https://en.wikipedia.org/wiki/Cell_culture
has_obo_namespace: ENVO
id: ENVO:02000008

Axiom
annotated source: cell culture
annotated property: definition
annotated target: A cell culture is a growth of cells in vitro in an artificial medium for experimental research.

fluid environmental material
type: Class
subclass of: environmental material
definition: An environmental material which is unable to resist shear forces and continuously deforms when subject to them.
has_narrow_synonym: fluid
has_obo_namespace: ENVO
id: ENVO:02000140

Axiom
annotated source: fluid environmental material
annotated property: definition
annotated target: An environmental material which is unable to resist shear forces and continuously deforms when subject to them.
database_cross_reference: https://en.wikipedia.org/wiki/Fluid
database_cross_reference: https://github.com/EnvironmentOntology/envo/issues/940

water-holding capacity of soil
type: Class
subclass of: water-holding capacity
subclass of: Restriction
  on property: RO_0000052
  some values from: soil
definition: Water-holding capacity which inheres in some soil.
creator: http://orcid.org/0000-0002-8461-9745
creator: https://orcid.org/0000-0001-6284-4821
has_exact_synonym: soil water-holding capacity
has_obo_namespace: ENVO
id: ENVO:06105304

Axiom
annotated source: water-holding capacity of soil
annotated property: definition
annotated target: Water-holding capacity which inheres in some soil.
database_cross_reference: https://www.canr.msu.edu/news/why_is_soil_water_holding_capacity_important

anatomical entity environment
type: Class
subclass of: environmental system
subclass of: Restriction
  on property: BFO_0000050
  some values from: environmental system determined by an organism
definition: An environment which is determined by an anatomical entity.
has_obo_namespace: ENVO
id: ENVO:2100000