Niche divergence and competition
The present study showed that, at the local scale, sister species showed larger divergence than closely related species, almost all sister species pairs showed no overlap, and the overlaps between sister species were significantly less than those between closely related species, which is consistent with the competition exclusion principle. Niche divergence has been found to be important in maintaining diversity, initiating and completing speciation. The present results provide data well supporting the existing viewpoints.