Sites, Zones, Areas, and other spatial entities

Frequently, environmental observers refer to areas, sites, zones, and similar entities. When handling these entities with OBO semantics, which rely on BFO for upper-level classes, a natural reflex is to represent such entities as subclasses of BFO:site, or an immaterial, spatial entity whose extent is defined by the material entities that 'frame' it (e.g. as the walls of a room delimit the spatial region inside the room).

However, there are several instances where the use of a term like "zone" is ambiguous. For example, does "ecozone" refer to a site or does it more directly refer to a collection of ecosystems? Many opinions may arise, and sometimes we must include both the BFO:site and the material entities (e.g. ecosystems) which frame it.

Thus, when adding such classes to ENVO, we attempt to link each type BFO:site to some material entity using the RO:overlaps relation. Thus, a "forest zone" will be a ENVO:'environmental zone' (a subclass of BFO:site) which overlaps with the material entity, ENVO:'forest ecosystem'. Linking these classes helps bring together content which may be siloed due to ambiguity in dealing with spatially focuses semantics in environmental terminology.