table_name	description
taxon	"Identifying information about a taxon (e.g. name, id and system)."
observation	"This is the core table, which holds the observations being analyzed (e.g. organism abundance or density). Observations must be linked to a taxon and to a location. Linking to ancillary observations (via observation_id) is optional. The event_id column is a placeholder that will link to a sampling events model in the future."
location_ancillary	"Additional information about a place that does not change frequently (e.g. lake area or depth, experimental treatment). Features that change frequently are more closely related to the observational event, and are thus kept in the observation_ancillary table. Ancillary observations are linked through the location_id, and one location_id may have many ancillary observations about it."
taxon_ancillary	"Additional info about an organism that does not change frequently (e.g. trophic level). Features that change frequently are probably observations. Ancillary observations are linked through the taxon_id, which may have many ancillary observations about it."
observation_ancillary	"Ancillary information about an observational event for context. These are very often environmental driver data in analyses (e.g. water depth, height of a tower, temperature of medium)."
dataset_summary	Summary info about the dataset.
variable_mapping	Information linking a variable_name used in a table to an external definition.
location	"Identifying information about a place (lonitude, latitude, elevation). The table is self-referencing so that sites can be nested."