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.
Species whose influence on ecosystem function and diversity are disproportionate to their numerical abundance. Although all species interact, the interactions of some species are more profound and far-reaching than others, such that their elimination from an ecosystem often triggers cascades of direct and indirect changes on more than a single trophic level, leading eventually to losses of habitats and extirpation of other species in the food web.
Soule & Noss 19981 as referenced in United Nations (UN) 20132