Environmental filtering explains a U-shape latitudinal pattern in regional β-deviation for eastern North American...

Area of Science:

• Ecology
• Biodiversity Science
• Biogeography

Background:

• Understanding latitudinal gradients in biodiversity is crucial for ecological theory.
• Previous research on beta-diversity (β-diversity) has primarily focused on local scales, limiting insights into regional patterns.
• The relative importance of species range size versus environmental filtering in shaping β-diversity gradients remains debated.

Discussion:

• This study reveals scale-dependent drivers of β-diversity gradients using US Forest Inventory Analysis Program data.
• At local scales, species spatial patterns had minimal impact on β-diversity.
• At regional scales, spatial patterns dominated, and a U-shaped latitudinal relationship for standardized β-diversity deviation was observed.

Key Insights:

• Regional β-diversity gradients are significantly influenced by spatial variations in climate and soil texture, supporting the environmental filtering hypothesis.
• The findings contradict Rapoport's rule, which posits a relationship between range size and β-diversity gradients.
• Species spatial distributions play a critical role in regional β-diversity patterns.

Outlook:

• Future research should explore the interplay of multiple environmental factors across different spatial scales.
• Investigating the mechanisms behind the U-shaped latitudinal relationship can refine biodiversity models.
• This work highlights the importance of considering scale when assessing biodiversity patterns and drivers.