Functional diversity exhibits a diverse relationship with area, even a decreasing one

Area of Science:

• Ecology
• Trait-based ecology
• Island biogeography

Background:

• The species-area relationship is a fundamental ecological law.
• The relationship between area and functional diversity (FD) is less understood.
• Few studies explore the Functional Diversity-Area Relationship (FDAR).

Purpose of the Study:

• To investigate the Functional Diversity-Area Relationship (FDAR) using plant trait data.
• To determine how different facets of functional diversity change with area.
• To identify patterns in FDAR on the volcanic islands of Santorini.

Main Methods:

• Constructed species accumulation curves and functional diversity (FD) curves.
• Utilized plant diversity data from nested plots (1-128 m²).
• Calculated six multidimensional FD indices based on 26 plant traits.

Main Results:

• FDAR typology identified: positive for trait range, negative for trait abundance evenness, unclear for functional similarity, and idiosyncratic for functional divergence.
• Increasing area led to a wider range of traits but disproportionate increases in trait abundance.
• Dominance of certain traits emerged with increasing area, suggesting functional specialization.

Conclusions:

• The Functional Diversity-Area Relationship is complex and depends on the specific FD index used.
• Island plant communities exhibit distinct functional responses to increasing area.
• Community assembly processes influence the distribution of functional traits in relation to area.