Distribution and ecology of dictyostelid cellular slime molds in Great Smoky Mountains National Park

Great Smoky Mountains National Park encompasses an area of 2080 km2 in eastern Tennessee and western North Carolina between 35 degrees 28' and 35 degrees 47' N. Elevations are 270-2000 m above sea level, and the topography and vegetation are as diverse as any region of eastern North America. In 1998-2004 soil/litter samples for isolation of dictyostelid cellular slime molds were collected throughout the park. Collecting sites included examples of all major forest types along with the more common types of nonforest vegetation. More than 2300 clones of dictyostelids were recovered from 412 samples. These clones included representatives of 20 described species together with at least 10 species new to science. This total is higher than those reported for other temperate regions of the world. In general both numbers of species and numbers of clones/g of sample material decreased with increasing elevation and several species displayed a distinct preference for either the low or high end of the elevation gradient. The relatively high number of new species recovered from samples collected at high elevations is an important new finding for dictyostelid ecology and distribution.