A general model for the light-use efficiency of primary production

A. Haxeltine*, I. C. Prentice

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

299 Citations (Scopus)

Abstract

1. Net primary production (NPP) by terrestrial ecosystems appears to be proportional to absorbed photosynthetically active radiation (APAR) on a seasonal and annual basis. This observation has been used in 'diagnostic' models that estimate NPP from remotely sensed vegetation indices. In 'prognostic' process-based models carbon fluxes are more commonly integrated with respect to leaf area index assuming invariant leaf photosynthetic parameters. This approach does not lead to a proportional relationship between NPP and APAR. However, leaf nitrogen content and Rubisco activity are known to vary seasonally and with canopy position, and there is evidence that this variation takes place in such a way as to nearly optimize total canopy net photosynthesis. 2. Using standard formulations for the instantaneous response of leaf net photosynthesis to APAR, we show that the optimized canopy net photosynthesis is proportional to APAR. This theory leads to reasonable values for the maximum (unstressed) light-use efficiency of gross and net primary production of C3 plants at current ambient CO2, comparable with empirical estimates for agricultural crops and forest plantations. 3. By relating the standard formulations to the Collatz-Farquhar model of photosynthesis, we show that a range of observed physiological responses to temperature and CO2 can be understood as consequences of the optimization. These responses include the CO2 fertilization response and stomatal closure in C2 plants, the increase of leaf N concentration with decreasing growing season temperature, and the downward acclimation of leaf respiration and N content with increasing ambient CO2. The theory provides a way to integrate diverse experimental observations into a general framework for modelling terrestrial primary production.

Original languageEnglish
Pages (from-to)551-561
Number of pages11
JournalFunctional Ecology
Volume10
Issue number5
Publication statusPublished - 1996
Externally publishedYes

Keywords

  • Climate change
  • net primary production
  • photosynthesis

Fingerprint Dive into the research topics of 'A general model for the light-use efficiency of primary production'. Together they form a unique fingerprint.

Cite this