Fog- and rainwater chemistry in the tropical seasonal rain forest of Xishuangbanna, Southwest China

• Published in: Water, air, and soil pollution air, and soil pollution, 2005-10, Vol.167 (1-4), p.295-309
• Main Authors: Liu, W.J, Zhang, Y.P, Li, H.M, Meng, F.R, Liu, Y.H, Wang, C.M
• Format: Article
• Language: English
• Subjects: air pollution; Alkaline soils; atmospheric deposition; chemical composition; Convection, turbulence, diffusion. Boundary layer structure and dynamics; Dry season; Earth, ocean, space; Environmental monitoring; Exact sciences and technology; External geophysics; Fog; fog (meteorology); hydrochemistry; Leaves; Meteorology; Rain; Rainforests; Rainy season; Seasons; Tropical forests; tropical rain forests; Washout; Water in the atmosphere (humidity, clouds, evaporation, precipitation)
• ISSN: 0049-6979; 1573-2932
• DOI: 10.1007/s11270-005-0080-9

Fogwater, fog drip and rainwater chemistry were examined at a tropical seasonal rain forest in Xishuangbanna, southwest China between November 2001 and October 2002. During the period of observation, 204 days with the occurrence of radiation fog were observed and the total duration of fog was 1949 h, of which 1618 h occurred in the dry season (November to April), accounting for 37.0% of the time during the season. The mean pH of fogwater, fog drip and rainwater were 6.78, 7.30, and 6.13, respectively. The ion with the highest concentration for fog- and rainwater was HCO^sub 3^^sup -^, which amounted to 85.2 and 37.3 μeq l^sup -1^, followed by Ca^sup 2+^, Mg^sup 2+^ and NH^sub 4^^sup +^. Concentrations of NO^sub 3^^sup -^, HCO^sub 3^^sup -^, NH^sub 4^^sup +^, Ca^sup 2+^, and K^sup +^ in fogwater samples collected in the dry season were significantly greater when compared to those collected in the rainy season. It was found that the ionic concentrations in fog drip were higher than those in fogwater, except for NH^sub 4^^sup +^ and H^sup +^, which was attributed to the washout of the soil- and ash-oriented ions deposited on the leaves and the alkaline ionic emissions by the leaves, since biomass burns are very common in the region and nearby road was widening.[PUBLICATION ABSTRACT]