Dictyostelids from aerial “canopy soil” microhabitats

The leaf litter decomposition zone of forest soils is generally considered as the primary microhabitat for dictyostelid cellular slime molds (dictyostelids), but these organisms also occur in other types of soils and are sometimes coprophilous. The occurrence of dictyostelids in aerial microhabitats has received relatively little study. However, they can be surprisingly abundant in the mantle of dead organic matter (literally a “canopy soil”) often found at the bases of epiphytes that grow on the larger branches and trunks of trees in moist temperate and tropical forests. More than 400 samples collected from the canopy soil microhabitat in 11 localities in several different regions of the world yielded at least 37 species of dictyostelids. Some of the species recovered from canopy soil have been described as new to science, and three of these are not yet known from ground soil.