A glossary of definitions for terms relating to biodiversity, ecosystems services and conservation.
All definitions are referenced, where possible preference has been given to internationally recognised definitions (for example those defined by international conventions or agreements). The terms have been chosen to support understanding of biodiversity and conservation issues, and terms relating to biodiversity loss are complemented by those relating to conservation responses supported by international conservation organisations, governments, scientists and business sectors.
More detailed explanations are provided for a number of key terms, to provide further background information.
The terms can be filtered by category to aid in the navigation of the many definitions.
Summit or boundary line separating adjacent drainage basins.
International Glossary of Hydrology, WMO/UNESCO, 20122
Note: the US use of the term generally refers to the area of land drained (which equates to ‘river/drainage basin’). The European use of the term ‘watershed’ refers to the boundary line (in the US this boundary line is known as the ‘water divide’).
Adapted from International Glossary of Hydrology, WMO/UNESCO, 20122