Cloud water deposition to forest canopies of Cryptomeria japonica at Mt. Rokko, Kobe, Japan

Cloud water deposition to canopies of Cryptomeria japonica at Mt.Rokko, Kob e, Japan, was estimated from throughfall measurements and fog water collect ions carried out during a full year. Annual cloud frequency was 11.5-15.5% and liquid water content (LWC) was 0.059 g/m(3). Since cloud water depositi on on to forest canopies was significantly correlated with the amount of fo g water collected, the former parameter could be quantitatively derived fro m throughfall measurements. Annual cloud water deposition on to Cryptomeria canopies was 1420-2860 mm (Av. 2140 mm), corresponding to 90-180% (Av. 122 %) of annual rainfall. The rate of deposition was higher at the mountain ri dge and the forest edge than at the mountain side and the forest interior. Annual deposition of SO42-, NO3-, H+ and NH4+ from cloud water was estimate d as 204,153, 2.5 and 58 kg/ha, respectively, equivalent to 5.8-11.7 times the corresponding deposition via rain. The values are equal to, or exceed, the maximum deposition reported for Appalachian forests in the eastern Unit ed States. Multiple regression analyses indicate that cloud water depositio n on to Cryptomeria canopies was significantly correlated with the followin g three parameters: cloud frequency, LWC, and wind speed. Thus, these three factors apparently control cloud water deposition on to forest canopies.