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Photosynthetic differences between saplings and adult trees: an integration of field results by meta-analysis.

Publication ,  Journal Article
Thomas, SC; Winner, WE
Published in: Tree physiology
February 2002

Ontogenetic changes in gas exchange parameters provide both insight into mechanisms underlying tree growth patterns, and data necessary to scale environmental impacts on young trees to predict responses of older trees. We present a quantitative review and meta-analysis of field measurements of gas exchange parameters in saplings and mature trees of 35 tree species (seven conifers, seven temperate deciduous trees, and 21 tropical evergreen trees). Data for saplings were obtained in both understory environments and open areas or large gaps. We also present data on ontogenetic changes in photosynthesis for Pseudotsuga menziesii (Mirb.) Franco and Tsuga heterophylla (Raf.) Sarg., species of particular interest because of their large maximal heights and long life-spans. Among tree species, there is evidence for both ontogenetic increases and ontogenetic decreases in photosynthetic capacity on a leaf area basis (A(area)). Overall, A(area) is generally higher for upper-canopy leaves of adult trees than for saplings, especially in temperate deciduous trees. However, the pattern for photosynthetic capacity on a leaf mass basis (A(mass)) is the reverse of that observed for A(area). Saplings of both conifers and broad-leaved trees, even when acclimated to low-light conditions, characteristically have a higher A(mass) than adult trees. This pattern is driven largely by an ontogenetic increase in leaf mass per unit area (LMA), as found in 100% of studies reviewed. Data for Pacific Northwest conifers, although including measurements on some of the tallest trees studied, did not differ greatly from patterns found in other tree species. We conclude that ontogenetic changes in LMA are the single most consistent difference between saplings and adult trees, and that changes in LMA and related aspects of leaf morphology may be critical to understanding both variation in gas exchange during tree growth, and stage-dependent responses of trees to environmental change.

Duke Scholars

Published In

Tree physiology

DOI

EISSN

1758-4469

ISSN

0829-318X

Publication Date

February 2002

Volume

22

Issue

2-3

Start / End Page

117 / 127

Related Subject Headings

  • Washington
  • Tsuga
  • Trees
  • Pseudotsuga
  • Plant Biology & Botany
  • Photosynthesis
  • 4101 Climate change impacts and adaptation
  • 3108 Plant biology
  • 3103 Ecology
  • 0705 Forestry Sciences
 

Citation

APA
Chicago
ICMJE
MLA
NLM
Thomas, S. C., & Winner, W. E. (2002). Photosynthetic differences between saplings and adult trees: an integration of field results by meta-analysis. Tree Physiology, 22(2–3), 117–127. https://doi.org/10.1093/treephys/22.2-3.117
Thomas, Sean C., and William E. Winner. “Photosynthetic differences between saplings and adult trees: an integration of field results by meta-analysis.Tree Physiology 22, no. 2–3 (February 2002): 117–27. https://doi.org/10.1093/treephys/22.2-3.117.
Thomas, Sean C., and William E. Winner. “Photosynthetic differences between saplings and adult trees: an integration of field results by meta-analysis.Tree Physiology, vol. 22, no. 2–3, Feb. 2002, pp. 117–27. Epmc, doi:10.1093/treephys/22.2-3.117.
Journal cover image

Published In

Tree physiology

DOI

EISSN

1758-4469

ISSN

0829-318X

Publication Date

February 2002

Volume

22

Issue

2-3

Start / End Page

117 / 127

Related Subject Headings

  • Washington
  • Tsuga
  • Trees
  • Pseudotsuga
  • Plant Biology & Botany
  • Photosynthesis
  • 4101 Climate change impacts and adaptation
  • 3108 Plant biology
  • 3103 Ecology
  • 0705 Forestry Sciences