Jesada Luangjame

Salinity effects in Eucalyptus camaldulensis and Combretum quadrangulare: ecophysiological and morphological studies

Luangjame J. (1990). Salinity effects in Eucalyptus camaldulensis and Combretum quadrangulare: ecophysiological and morphological studies. Acta Forestalia Fennica no. 214 article id 7661. https://doi.org/10.14214/aff.7661

Abstract

The aim of this study was to investigate the ecophysiological and morphological characteristics of two salt-tolerant tree species, Eucalyptus camaldulensis Dehn. and Combretum quadrangulare Kurz. A greenhouse experiment with different levels of NaCl salinity (0, 0.5, 1.0, 1.5, and 2.0%) was set up and the results were compared with those of a field study on non-saline and saline soils. The determination of optimum gas exchange and the development and evaluation of photosynthetic models with and without water deficit were also included in this study.

Morphological characteristics under saline conditions showed that shoot height and diameter growth, shoot internode length, root length/biomass, leaf width and length, leaf area, number and biomass, and shoot/root and leaf/root ratios decreased with salinity, while leaf thickness increased with salinity. More growth was allocated to the roots than to the leaf canopy. Ecophysiological studies in laboratory showed that photosynthesis, stomatal conductance and water potential decreased with salinity, while the CO₂ compensation point increased with salinity. Transpiration, dark respiration and photorespiration increased at low salinity but decreased at high salinity levels. In the field study, however, there were no significant differences in stomatal conductance and opening between saline and non-saline soils. Model predictions supported the results of the field measurements. Adaptation to salinity was reflected in an acclimatization of tree structure in the field study. There were both functioning and structural changes of seedlings in the greenhouse experiment

In terms of ecophysiological and morphological characteristics, E. Camaldulensis showed better salt tolerance than C. Quadragulare both in the greenhouse experiment and field study

The PDF includes a summary in Finnish.

Keywords
biomass; photosynthesis; allocation; photorespiration; transpiration; respiration; water deficit; salinity; carbon dioxide compensation point; leaf resistance; water-use efficiency; stomatal resistance; stomatal movement; Eucalyptus camaldulensis; Combretum quadrangulare

Published in 1990

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Available at https://doi.org/10.14214/aff.7661 | Download PDF