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Large variation in whole‐plant water‐use efficiency among tropical tree species
Author(s) -
Cernusak Lucas A.,
Aranda Jorge,
Marshall John D.,
Winter Klaus
Publication year - 2007
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/j.1469-8137.2006.01913.x
Subject(s) - transpiration , stomatal conductance , photosynthesis , δ13c , botany , water use efficiency , isotopes of carbon , tectona , biology , stable isotope ratio , panama , horticulture , ecology , total organic carbon , physics , quantum mechanics
Summary• It is well known that whole‐plant water‐use efficiency (transpiration efficiency of carbon gain, TE C ) varies among plant species with different photosynthetic pathways. However, less is known of such variation among tree species within the C 3 group. Here we measured the TE C of seven C 3 tropical tree species. Isotopic analyses (δ 13 C, δ 18 O, and δ 15 N) and elemental analyses (carbon and nitrogen) were undertaken to provide insight into sources of variation in TE C . • Plants were grown over several months in approx. 80% full sunlight in individual 38‐l containers in the Republic of Panama. Soil moisture content was nonlimiting. • Significant variation was observed in TE C among the C 3 tree species. Values ranged from 1.6 mmol C mol −1 H 2 O for teak ( Tectona grandis ) to 4.0 mmol C mol −1 H 2 O for a legume, Platymiscium pinnatum . • Variation in TE C was correlated with both leaf N concentration, a proxy for photosynthetic capacity, and oxygen‐isotope enrichment, a proxy for stomatal conductance. The TE C varied with C‐isotope discrimination within species, but the relationship broke down among species, reflecting the existence of species‐specific offsets.