Global reef fish richness gradients emerge from divergent and scale-dependent component changes

Area of Science:

• Ecology
• Biogeography
• Biodiversity Science

Background:

• Biodiversity patterns vary geographically due to environmental and historical influences.
• Species richness, a common metric, has limitations in explaining these variations.
• A deeper understanding requires dissecting species richness into its core components.

Purpose of the Study:

• To investigate how scale-dependent components of species richness (total abundance, relative abundances, spatial aggregation) explain known biogeographic gradients.
• To differentiate the underlying processes shaping latitudinal and longitudinal species richness patterns in reef fish.

Main Methods:

• Scale-dependent analysis of species richness components: total abundance, species relative abundances, and spatial aggregations.
• Comparison of component patterns underlying latitudinal and longitudinal reef fish species richness gradients.

Main Results:

• Latitudinal species richness gradients are driven by scale-independent patterns in total and relative abundances, suggesting ecological constraints.
• Longitudinal gradients emerge at larger scales, linked to relative abundances and spatial aggregation, indicating beta-diversity influences.

Conclusions:

• Deconstructing species richness into components reveals distinct processes underlying different biodiversity gradients.
• This approach enhances our ability to identify the ecological and historical factors shaping biodiversity patterns.