What does "Niche Complementarity" mean?
On this website they define "Niche Complementarity" as:
The tendency for coexisting species which occupy a similar position along one niche dimension
I don't quite understand this definition. The tendency to do what?
Notes:
I know what is an ecological niche and therefore what is a niche dimension. There is no need to define this.
I am particularly interested in the use of this concept in speciation and adaptive radiation.