Rainfall, fog and throughfall dynamics in a subtropical ridge top cloud forest, National Park of Garajonay (La Gomera, Canary Islands, Spain)

✍ Scribed by G. García-Santos; L. A. Bruijnzeel

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 188 KB
• Volume: 25
• Category: Article
• ISSN: 0885-6087
• DOI: 10.1002/hyp.7760

✦ Synopsis

Abstract

Mixed tree‐heath/beech forest is a type of subtropical montane cloud forest found on wind‐ and fog‐exposed ridges in the Canary Islands. With a dry season of 5 months and an annual precipitation of 600–700 mm, the extra water inputs through fog interception assume particular importance in this environment. Measurements were made of rainfall, fog occurrence, wind speed and direction as well as of throughfall (TF) in a ridge top cloud forest located near the centre of the National Park of Garajonay on the island of La Gomera. Measured amounts of incident rainfall were corrected for wind‐induced losses around the gauge and for topographic effects. Amounts of fog water as collected by a 0·25‐m^2^ fog screen were corrected for changes in effective screen surface collection area depending on wind direction. No such corrections were taken into account in most if not all previous studies of rainfall and fog water inputs in the Canary Islands. TF fractions differed between events with rain‐only (87% of wind‐corrected rainfall), fog‐only (∼6% of wind‐corrected fog) and mixed precipitation (110%). It is concluded that the fog screen was more efficient at capturing fog water than the forest canopy, whereas previous wetting of the canopy and bryophytes by rain may have caused the higher TF fraction found on days with rainfall and fog. Copyright © 2010 John Wiley & Sons, Ltd.