Species niches, not traits, determine abundance and occupancy patterns: a multi-site synthesis

 

Aim: Locally abundant species are usually widespread, and such pattern has been related to properties of the niches and traits of species. However, such explanations fail to account for the potential of traits to determine species niches, and often overlook statistical artifacts. Here we examine how trait distinctiveness determines species abilities to exploit either common habitats (niche position) or a range of habitats (niche breadth), and how niche position and breadth in turn affect abundance and occupancy. We also examine how statistical artifacts moderate these relations.
Location: Sixteen sites in the Neotropics.
Time period: 1993-2014.
Major taxa studied: Aquatic invertebrates from tank bromeliads.
Methods: We measured the environmental niche position and breadth of each species and calculated its trait distinctiveness, as the average trait difference with all other species at each site. Then, we used a combination of Structural Equations Models and a meta-analytic app...