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 patterns of dead organic matter in the canopy and of soil in the upper horizons 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 average of 1 degrees C of each other. Both canopy material and forest floor soils were moist throughout the wet and misty seasons (over 70% water content). Although canopy organic substrate experienced periods of rapid and severe dehydration during the dry season (20%-40% water content), forest floor soils remained at a consistently high water content (60%-70%). The more extreme and fluctuating moisture conditions of canopy organic material may be important in determining the distribution and activity of epiphytic plants and associated canopy organisms.