. Author manuscript; available in PMC: 2017 Jun 28.

Published in final edited form as: Trends Ecol Evol. 2017 Apr 4;32(5):356–367. doi: 10.1016/j.tree.2017.02.002

Table 1.

The 12 forms of functional rarity.

			Species frequency
			Geographically Restricted		Geographically Widespread
			Locally Scarce	Locally Abundant	Locally Scarce	Locally Abundant
Species Traits	Geographically Unique	Locally Distinct	Rare traits whatever the scale and the species pool	Specialized traits supported by few species	Widespread traits supported by few scarce species	Traits supported by few common species
	Geographically Unique	Locally Redundant	Impossible	Impossible	Impossible	Impossible
	Geographically Shared	Locally Distinct	Traits supported by many rare species that do not co-occur	Specialized traits supported by many species	Traits supported by many widespread but locally sparse species that do not co-occur	Traits supported by many common species that do not co-occur
	Geographically Shared	Locally Redundant	Traits supported by many rare species	Specialized traits supported by many species	Traits supported by many widespread but locally sparse species	Common traits whatever the scale and the species pool