PT  - JOURNAL ARTICLE
AU  - Masatoshi Katabuchi
AU  - Kaoru Kitajima
AU  - S. Joseph Wright
AU  - Sunshine A. Van Bael
AU  - Jeanne L. D. Osnas
AU  - Jeremy W. Lichstein
TI  - Decomposing leaf mass into photosynthetic and structural components explains divergent patterns of trait variation within and among plant species
AID  - 10.1101/116855
DP  - 2017 Jan 01
TA  - bioRxiv
PG  - 116855
4099  - http://biorxiv.org/content/early/2017/03/30/116855.short
4100  - http://biorxiv.org/content/early/2017/03/30/116855.full
AB  - Across the global flora, photosynthetic and metabolic rates depend more strongly on leaf area than leaf mass. In contrast, intraspecific variation in these rates is strongly mass-dependent. These contrasting patterns suggest that the causes of variation in leaf mass per area (LMA) may be fundamentally different within vs. among species.We used statistical methods to decompose LMA into two conceptual components – ‘photosynthetic’ LMAp (which determines photosynthetic capacity and metabolic rates, and also affects optimal leaf lifespan) and ‘structural’ LMAs (which determines leaf toughness and potential leaf lifespan) using leaf trait data from tropical forest sites in Panama and a global leaf-trait database.Statistically decomposing LMA into LMAp and LMAs provides improved predictions of trait variation (photosynthesis, respiration, and lifespan) across the global flora, and within and among tropical plant species in Panama. Our analysis shows that most interspecific LMA variation is due to LMAs (which explains why photosynthetic and metabolic traits are area-dependent across species) and that intraspecific LMA variation is due to changes in both LMAp and LMAs (which explains why photosynthetic and metabolic traits are mass-dependent within species).Our results suggest that leaf trait variation is multi-dimensional and is not well-represented by the one-dimensional leaf economics spectrum.