| Abstract: | The short-term effects of simulated acid rain on Acer negundo L. have been investigated using photoacoustic spectroscopy and modulated fluorescence measurements. Three seeding groups of Acer negundo L. were treated with simulated acid rain at pH 3.0, 4.5 and 5.6 levels for three months. The results indicated the photosynthetic activity, expressed in terms of normalized oxygen evolution signal, photochemical energy storage, normalized variable fluorescence (Fv/Fm), photochemical and non-photochemical chlorophyll fluorescence quenching, ranges in the order pH 4.5 > pH 3.0 > pH 5.6. This stimulation effect has been confirmed by increased growth rate observed in relation with increased acidity levels. The nutritional aspects of this favorable effect of the acid rain on plant growth were discussed. |
