Intraspecific Trait Variation in Tree Species Responds to Environmental Heterogeneity at Range-Wide but Not Local...

Area of Science:

• Ecology
• Plant Ecology
• Trait-Based Ecology

Background:

• Intraspecific trait variation (ITV) is increasingly recognized for its role in ecological communities.
• ITV may be influenced by environmental variability across spatial and temporal scales.
• Understanding ITV's link to species distributions is crucial for predicting ecological responses to environmental change.

Purpose of the Study:

• To investigate the relationship between ITV, environmental heterogeneity, and species distribution breadth in Puerto Rican trees.
• To determine if within-site ITV correlates with local spatial and temporal environmental variation.
• To assess how across-site ITV relates to the breadth of species' environmental distributions.

Main Methods:

• Studied 33 tree species across eight sites in Puerto Rico along environmental gradients.
• Measured leaf mass per area (LMA) and wood density as key plant traits to represent ITV.
• Employed statistical models to analyze associations between ITV, site-level environmental variability (topography, rainfall), and species' island-wide environmental ranges.

Main Results:

• No significant correlation was found between within-site ITV and site-level temporal or spatial environmental variability.
• Higher ITV in LMA and wood density was significantly associated with broader environmental ranges for species.
• Species with high wood density exhibited narrower climatic ranges, unlike those with high LMA.

Conclusions:

• The relationship between ITV and species distributions is complex and scale-dependent.
• ITV, particularly in traits like wood density, can influence species' ability to occupy diverse environments.
• Findings highlight the importance of considering ITV in ecological research on species distributions and range dynamics.