Fig. 2
From: General principles in the community ecology of ectomycorrhizal fungi
As a result of variation in protease activity (the functional trait, see Fig. 1), different species exhibit unique distributions along a mineral N availability gradient. The vertical axis is a measure of success (abundance, etc.). For a community existing along a portion of this gradient (as indicated by the wide, vertical bar), species A is most abundant and species C is least abundant. At the higher end of the mineral N availability, the reverse would be true