New classes: soil layer, soil layer top, soil layer top depth, soil layer bottom, soil layer bottom depth

[celineaubert]

soil layer

• subclassOf layer; http://purl.obolibrary.org/obo/ENVO_01000281
• definition Layer in the soil which is parallel to the soil surface and possesses physical characteristics which differ from the layers above and beneath.
• database cross_reference:
  • http://www.cs.mcgill.ca/~rwest/link-suggestion/wpcd_2008-09_augmented/wp/s/Soil_horizon.htm
  • https://en.wikipedia.org/wiki/Soil_horizon
• exact_synonym soil horizon

  soil layer top

• subclassOf soil layer?;
• definition Superior limit of the soil layer.
• exact_synonym soil horizon top limit

  soil layer top depth

• subclassOf depthPATO_0000122
• subclassOf inheres in soil layer top;
• definition A depth which inheres in the top of a soil layer.

soil layer bottom

• subclassOf soil layer?;
• definition Inferior limit of the soil layer.
• exact_synonym soil horizon bottom limit

  soil layer bottom depth

• subclassOf depthPATO_0000122
• subclassOf inheres in soil layer bottom;
• definition ` A depth which inheres in the bottom of a soil layer.

[KrishnaTO]

soil layer was previously added

Remaining 4 need to be added

[dr-shorthair]

1. A soil horizon is a sub-class of soil layer, which is formed by a consistent genetic process or has a homogeneous composition - the ASLS says "with morphological properties different from layers below and above it".

The formal definition of soil horizon (sub-class of layer with differentia 'composed primarily of some soil') is actually OK for soil layer. However, the textual definition ("A layer which is parallel to the soil surface and which has roughly homogenous physical, chemical and biological properties relative to the soil layers above or beneath it. ") does better match soil horizon. Soil Layer is a more generic thing: some soil-layers are defined purely as a depth range, so are not necessarily homogeneous in their physical, chemical and biological properties.

2. New class required: Soil Contact - the interface between two horizons. A soil-layer-top of a soil-horizon, which is also a soil-layer-bottom with respect to an adjacent soil-horizon is called a Contact.

OK @meganrwong @ljgregory @abhritchie ?

[abhritchie]

Yes, this definition of soil layer suggests a horizon (horizons can be sub-typed, e.g. NZ: morphological horizon and functional horizon). Our experience is that soil layer is used to describe sampling artifacts whose extent is dictated by the sampling strategy, not the characteristics of the soil. The value of a soil layer class is debatable given ontologies like SOSA can carry the necessary information.

The value of soil layer top and soil layer bottom is unclear.

[abhritchie]

Agree with the need for soil contact. Horizon boundaries have their own characteristics (shape, distinctness).

Suggest soil horizon boundary instead of soil contact.

Contact implies the boundary between mappable soil units. Also, soil scientists may also accuse us of Geology.