COS 35-3 - Leaf economics fundamentals explained by optimality principles

Monday, August 7, 2023

4:00 PM – 4:15 PM PDT

Location: D139

Presenting Author(s)

HW

Han Wang

Tsinghua University, China (People's Republic)

Coauthor(s)

IP

Iain Colin C. Prentice

Department of Biological Sciences, Macquarie University, North Ryde, NSW 2109, Australia, Australia
IW

Ian Wright

Western Sydney University, Australia
DW

David Warton

UNSW Sydney, Australia
SQ

Shengchao Qiao

Tsinghua University, China (People's Republic)
XX

Xiangtao Xu

Cornell University, United States
JZ

Jian Zhou

Tsinghua University, China (People's Republic)
KK

Kihachiro Kikuzawa

Ishikawa Prefectural University,, Japan
NS

Nils Stenseth

Tsinghua University, China (People's Republic)

Abstract: The life span of leaves increases with their mass per unit area (LMA). It is unclear why. Here, we show that this empirical generalization (the foundation of the worldwide leaf economics spectrum) is a consequence of natural selection, maximizing average net carbon gain over the leaf life cycle. Analyzing two large leaf trait datasets, we show that evergreen and deciduous species with diverse construction costs (assumed proportional to LMA) are selected by light, temperature, and growing-season length in different, but predictable, ways. We quantitatively explain the observed divergent latitudinal trends in evergreen and deciduous LMA and show how local distributions of LMA arise by selection under different environmental conditions acting on the species pool. These results illustrate how optimality principles can underpin a new theory for plant geography and terrestrial carbon dynamics.