Does trait variation within broadly distributed species mirror patterns across species? A case study in Puerto Rico

Area of Science:

• Ecology
• Plant Functional Trait Variation
• Evolutionary Biology

Background:

• Traditional trait-based studies often prioritize interspecific differences over intraspecific variation.
• This approach assumes species differences consistently outweigh within-species variation.
• Broadly distributed species experience diverse environments, potentially leading to significant intraspecific trait divergence.

Purpose of the Study:

• To characterize leaf trait variation patterns across ecological scales for broadly distributed species.
• To assess trait variance and covariance across elevation, species, populations, and individuals.
• To investigate how leaf traits related to photosynthesis, display, and stomatal conductance vary.

Main Methods:

• Examined seven key leaf traits in broadly distributed plant species along an elevational gradient.
• Quantified trait variance at multiple ecological scales: elevation, species, populations, and individuals.
• Analyzed trait covariance both within and across species along the gradient.

Main Results:

• Intraspecific leaf trait variation was comparable to interspecific variation for broadly distributed species.
• Trait variance structure exhibited high variability among different species.
• Trait coordination was observed across species along the gradient, but not consistently within species.

Conclusions:

• Species-specific trait coordination and covariance patterns are idiosyncratic, challenging single-optimum trait value assumptions.
• Broadly distributed species can fulfill similar functional roles despite phenotypic differences.
• Future functional ecology studies must incorporate both interspecific and intraspecific trait variation across environmental gradients.