Protostelids, dictyostelids, and myxomycetes in the litter microhabitat ofthe Luquillo Experimental Forest, Puerto Rico

Protostelids, dictyostelids and myxomycetes are well known from terrestrial ecosystems in temperate regions but poorly known from the tropics. This st udy examined the distribution and ecology of these three groups of 'slime m oulds' in the forest floor litter microhabitat of five different forest typ es (tabonuco forest, secondary tabonuco forest, pale colorado forest, palm forest, and elfin forest) within the Luquillo Experimental Forest in Puerto Rico. Protostelids associated with aerial litter (dead but still attached plant parts) also were studied. At least 13 species of protostelids, 13 spe cies of dictyostelids and 24 species of myxomycetes were recovered. Both sp ecies richness and abundance of dictyostelids and myxomycetes were higher i n the secondary tabonuco forest than in any of the other forest types. The tabonuco forest yielded the most species of protostelids, but the next high est total was recorded from the secondary tabonuco forest. Both of these fo rest types are located at the low end of the elevation gradient. Lowest lev els of species richness and abundance occurred in the elfin forest, located at the high end of the elevation gradient. The general pattern observed wa s that of decreasing diversity with increasing elevation.