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Constraints on physiological function associated with branch architecture and wood density in tropical forest trees

Informally Refereed

Abstract

This study examined how leaf and stem functional traits related to gas exchange and water balance scale with two potential proxies for tree hydraulic architecture: the leaf area:sapwood area ratio (AL:AS) and wood density (ρW). We studied the upper crowns of individuals of 15 tropical forest tree species at two sties in Panama with contrasting moisture regimes and forest types. Transpiration and maximum photosynthetic electron transport rate (ETRmax) per unit leaf area declined sharply with increasing AL:AS as did the ratio of ETRmax to leaf N content, an index of photosynthetic nitrogen-use efficiency. Midday leaf water potential, bulk leaf osmotic potential at zero turgor, branch xylem specific conductivity, leaf-specific conductivity, and stem and leaf capacitance all declined with increasing ρW. At the branch scale, AL:AS and total leaf N content per unit sapwood area increased with ρW resulting in a 30-percent increase in ETRmax per unit sapwood area with a doubling of ρW.

Keywords

Capacitance, functional convergence, hydraulic architecture, osmotic potential, photsynthesis, transpiration, water potential

Citation

Meinzer, Frederick C.; Campanello, Paula I.; Domec, Jean-Christophe; Gatti, M. Genoveva; Goldstein, Guillermo; Villalobos-Vega, Randol; Woodruff, David R. 2008. Constraints on physiological function associated with branch architecture and wood density in tropical forest trees. Tree Physiology. 28: 1609-1617
Citations
https://www.fs.usda.gov/research/treesearch/33191