FOG INTERCEPTION IN MONTANE FOREST ACROSS THE CENTRAL CORDILLERA OF PANAMA

Fog interception and rainfall were measured at 14 stations across the Central Cordillera in western Panama. Fog interception and rainfall we re measured monthly during 1988-1989 with artificial fog catchers and rain gauges, respectively. Fog interception was highest on ridges and increased with increasing altitude. Fog interception contributed betwe en 2.4 and 60.6% of the total water input, depending on altitude and e xposure to the prevailing winds. Absolute amounts of annual fog interc eption ranged from 142 to 2295 mm. Although low clouds were more frequ ent in montane forests, clouds close to the ground also occurred in th e lowlands. During the study period, there was a gradient of increasin g total rainfall from the Caribbean (3355 mm) to the Pacific side (575 9 mm) of the Central Cordillera. Nevertheless, rainfall was more seaso nal on the leeward side of the mountain range. Seasonal variation in f og intereption was different from rainfall patterns and no correlation was found between monthly (or annual) rainfall and fog interception. The results of this study showed the importance of montane forests for the preservation of water sources, particularly along ridges of the F ortuna drainage basin that provides more than 50% of the electricity o f the Republic of Panama.