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Organic Acids and Aldehydes in Throughfall and Dew in a Japanese Pine Forest
Author(s) -
Chiwa Masaaki,
Miyake Takayuki,
Kimura Nobuhito,
Sakugawa Hiroshi
Publication year - 2008
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq2007.0559
Subject(s) - throughfall , dew , chemistry , environmental chemistry , oxalate , leaching (pedology) , soil water , environmental science , organic chemistry , soil science , physics , condensation , thermodynamics
We analyzed low molecular weight organic acids and aldehydes in throughfall under pine forest, and organic acids in dew on chemically inert surfaces and pine needle surfaces at urban‐ and mountain‐facing sites of pine forest in western Japan. Low molecular weight organic acids and aldehydes accounted for less than 5% of the dissolved organic carbon in throughfall at both sites. Formaldehyde at both sites and formate at the mountain‐facing site were found at significantly lower concentrations in throughfall than in rainfall, which may be explained by the degradation and/or retention of these components by the pine canopy as the incident precipitation passed through it. The oxalate concentration in throughfall was significantly higher than those in rainfall at both sites, suggesting that oxalate was derived from leaching from the pine foliage. At both sites, organic acid concentrations were higher in dew on the pine needles than in throughfall or dew on chemically inert surfaces. This could be due to the long contact time of dew on pine needles, during which leached substances from pine needles and dry deposits accumulated on their surfaces can dissolve into the small volume of dew. The role of enhanced concentrations of oxalate in an aqueous phase on the plant surfaces (e.g., dew) is discussed in relation to hydroxyl radical formation via the photo‐Fenton reaction.