Phylogenetic Diversity Outperforms Functional Diversity in Predicting Aboveground Biomass Across Tree Strata in a...

Area of Science:

• Ecology
• Forest Science
• Biodiversity Research

Background:

• Forest aboveground biomass (AGB) is vital for global carbon balance.
• The relationship between biodiversity and AGB is complex and not fully understood.
• Mechanisms linking biodiversity dimensions to AGB productivity require further elucidation.

Purpose of the Study:

• To investigate the impact of functional and phylogenetic diversity on AGB in subtropical forest overstory and understory.
• To determine which dimension of biodiversity (functional or phylogenetic) has a more prominent effect on AGB.
• To assess the role of functional traits and evolutionary relatedness in AGB accumulation.

Main Methods:

• Field measurements of AGB, functional traits, and evolutionary relatedness in a subtropical forest.
• Application of partial least squares (PLS) regression to assess the predictive importance of diversity indices.
• Analysis across distinct tree layers (overstory and understory).

Main Results:

• Overstory AGB was positively associated with resource-acquisitive traits and higher phylogenetic diversity.
• Understory AGB was enhanced by conservative strategies, mean nearest taxon distance, and higher phylogenetic and functional richness.
• Phylogenetic diversity explained more AGB variation than functional diversity across tree strata.

Conclusions:

• Functional identity plays a key role in regulating AGB.
• Phylogenetic diversity is a more significant predictor of AGB accumulation than functional diversity in this subtropical forest.
• Incorporating phylogenetic diversity is crucial for understanding biodiversity and ecosystem function (BEF) relationships.