Predation and competition drive trait diversity across space and time.

Area of Science:

• Ecology
• Community Ecology
• Biodiversity Science

Background:

• Competition is theorized to shape community assembly and biodiversity patterns.
• Identifying competition's role in natural communities is complex due to varied theoretical outcomes.
• Previous studies often infer competition indirectly from diversity patterns.

Purpose of the Study:

• To investigate the role of competition in shaping trait diversity patterns in odonate communities.
• To compare trait diversity across spatial and temporal scales along a natural competition-predation gradient.
• To understand the interplay between competition and predation in structuring biodiversity.

Main Methods:

• Compared trait diversity patterns in odonate communities.
• Analyzed data across local, spatial, and temporal scales.
• Utilized a natural gradient of competition and predation intensity.

Main Results:

• Local trait diversity increased with predator size, suggesting competitive exclusion reduces diversity.
• Spatial and temporal trait variation peaked with intermediate predators, indicating trait convergence.
• Competition acts as a deterministic force reducing trait diversity at multiple scales.

Conclusions:

• Competition is a deterministic force that reduces trait diversity at local, regional, and temporal scales.
• The interaction between competition and predation shapes biodiversity patterns.
• Findings offer new insights into the mechanisms driving biodiversity across scales.