Relational hierarchical database = multiple layers arranged in tree-like database structure supporting one-to-many, one-to-one and many-to-one relationships
The Field-Map database is fully relational. The “plot” identification layer is used as the root of the database to which a number of layers can be connected. Each one of these layers may in turn be the root of an additional chain of related data layers. The relationship between layers can be one-to-many or one-to-one. For polygons a many-to-one relationship can be used as well (e.g. non-continuous patches of one vegetation type with a common description). In addition, user defined conditional relationships can be selectively activate or de-activate subordinate layers based on specific values entered into the parent table.