Water input from fog drip in the tropical seasonal rain forest of Xishuangbanna, South-West China

Fog drip and related microclimatic factors were measured between January 1999 and December 2002 at a tropical seasonal rain forest in Xishuangbanna, South-West China. During the study period, the annual average fog drip was 89.4 +/- 13.5 mm (mean +/- 1SD). Fog drip contributes an estimated 5'% of the annual rainfall, with 86% of the fog drip occurring in the dry season (November-April). Annual fog drip was negatively correlated with annual rainfall. Monthly variation in fog drip was also negatively correlated with monthly rainfall. Average daily fog drip was 0.38 +/- 10.2 7 mm d(-1) for all days on which fog drip occurred. Daily fog drip was negatively correlated with minimum air temperature and positively correlated with mean above-canopy wind speed. The results indicate that fog drip is an important additional input of water to this seasonal rain forest during the dry season.