The Numbers and Proportions of Testacea and Ciliates in Litters and Soils

SYNOPSIS. The numbers and kinds of testacea and ciliates were studied in the litters and soils of 23 sites, from temperate and subtropical coniferous and deciduous forests, and grasslands. In coniferous forests, testacea were 10 times or more abundant than ciliates, and numbered 10,000–24,000/g (wet weight) in litters and up to 8,000/g in soils. Ciliates numbered up to 1,500/g, but averaged less than 600/g in litters and less than 300/g in soils. Under deciduous vegetation, ciliates approached, equaled, or exceeded testacea, and numbered 1,000–5,000/g in litters, while remaining about the same in soils. Temperature and soil influence vegetation types, and their rates of litter decay affect the protozoa. Moisture favors numerical dominance of certain species. Among testacea, several species dominate in a particular habitat; among ciliates, the genus Colpoda dominates in almost all litter and soil habitats.