Effects of Nitrogen Supply on Canopy Structure and Leaf Nitrogen Distribution in Carex Species

• Rien Aerts

• Hannie de Caluwe

抄録

Optimization theory of leaf nitrogen distribution in canopies with respect to photosynthetic carbon gain predicts that vertical leaf nitrogen gradients are steeper in dense canopies than in more open canopies. We tested this prediction at the intraspecific and the interspecific level by studying the effects of two levels of nitrogen supply on canopy structure and vertical leaf nitrogen distribution in experimental populations of three Carex species that dominate in low—productivity fens (Carex diandra and Carex rostrata) and in high—productivity fens (Carex acutiformis), respectively. The high—productivity species had a significantly higher amount of leaf area per unit ground area, a higher absolute amount of nitrogen in the canopy, proportionally more leaf area in upper canopy regions, and steeper gradients of leaf nitrogen in the canopy than the low—productivity species. Similarly, increased nitrogen supply resulted for each species in a higher amount of leaf area per unit ground area and a higher absolute amount of nitrogen in the canopy. However, only in C. acutiformis did an enhanced N supply led to proportionally more leaf area in upper canopy regions and to steeper gradients of leaf nitrogen in the canopy. It is suggested that the observed patterns in Carex acutiformis (a very high canopy with a large amount of leaf area) are not directed towards maximization of photosynthetic carbon gain, but are also directed towards suppression of other species in the competition for light. The interspecific differences in canopy structure and leaf nitrogen distribution are in agreement with the optimization theory. However, at the phenotypic level the low—productivity species did not show proportionally more leaf area in upper canopy regions and steeper gradients of leaf nitrogen in the canopy upon enhanced N supply, despite a strong increase in the total amount of leaf area. This suggests that low—productivity species have a lower phenotypic plasticity with regards to their vertical leaf distribution pattern and their vertical leaf nitrogen distribution than high—productivity species.

収録刊行物

• Ecology

  Ecology 75 (5), 1482-1490, 1994-07

  Wiley

キーワード

• Ecology, Evolution, Behavior and Systematics

詳細情報

• CRID: 1361137045349185664
• NII論文ID: 30020886938
• DOI: 10.2307/1937471
• ISSN: 19399170
• ISSN: 00129658
• Web Site: https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.2307%2F1937471
• Web Site: https://esajournals.onlinelibrary.wiley.com/doi/pdf/10.2307/1937471
• データソース種別:
  • Crossref
  • CiNii Articles