Cloud Forest Extension and its Contribution of Occult Rain to the Total Precipitation in the Uyuca Biological Reserve, Honduras

Abstract

It has been assumed that the zone impacted by clouds and mists on the Uyuca Mountain begins at 1,700 m for an area of 237 ha. Mature multistratified broadleaf forest covers 52 ha whereas 185 ha are covered by secondary forest formed by pure and mixed groves of Pinus maximinoi and broadleaf forests. Due to the importance of cloud forests as water collectors, occult precipitation o fog dip was quantified at the mature broadleaf forest over five years (1987-1992). A network of 12 funnel type pluviometers of 52 cm of diameter was installed at different altitudes inside the forest. Three pluviometers were placed as control in a 2.7 ha open area adjacent to the mature forest. Data were taken daily about rainfall, cloudiness, visibility, wind speed and direction, throughout the five years of the study. Monthly average rainfall varied between 62.3 mm and 276.3 mm. Average total annual rainfall inside the forest was 2,021.6 mm, whereas it was 2,360 mm estimated by the Thiessen's polygons method. A total annual average of 978 was registered at the open area. Consequently horizontal rainfall was 1,382.2 mm; a 141.3% contribution of the forest to the normal rainfall. It was determined that the very humid mountainous low subtropical forest zone begins at 1,600 msnm in Uyuca. As a result, the area covered by cloud forest at the Uyuca mountain measures 556 ha. Consequently, this additional sector, or at least the most feasible parts of it, must be strictly preserved to protect an area of cloud forest of great importance. This is essential especially if we take in account that due to its delicate dependence on local climate, cloud forests will be strongly affected by global climate change. The inclusion on the reserve zoning of a Climate Change Adaptation Subzone is an excellent first step in working to counteract the impacts of climate change and the effect of this compounded with other factors that threat biodiversity.

Ceiba 2012, Vol.53(2):109-123