MOISTURE AND TEMPERATURE PATTERNS OF CANOPY HUMUS AND FOREST FLOOR SOIL OF A MONTANE CLOUD FOREST, COSTA-RICA

Accumulations of organic material can be found in the crowns of trees in tropical wet forests. We investigated moisture and temperature patt erns of dead organic matter in the canopy and of soil in the upper hor izons of the forest floor over a 42-month period. Temperatures of the canopy material and forest floor soil fluctuated throughout the year ( range = 11.5 degrees C to 21.0 degrees C), but remained within an aver age of 1 degrees C of each other. Both canopy material and forest floo r soils were moist throughout the wet and misty seasons (over 70% wate r content). Although canopy organic substrate experienced periods of r apid and severe dehydration during the dry season (20%-40% water conte nt), forest floor soils remained at a consistently high water content (60%-70%). The more extreme and fluctuating moisture conditions of can opy organic material may be important in determining the distribution and activity of epiphytic plants and associated canopy organisms.