Protostelids from boreal forest and tundra ecosystems in Alaska

Six species of protostelids were recovered from litter samples collected fr om four study sites in Alaska. No protostelids were isolated from aerial li tter (dead but still attached plant parts) collected in two boreal forest s tudy sites, but four species were isolated from ground litter collected in these same sites. Two tundra study sites yielded all of the species recorde d for forest study sites plus two additional species. At one of the boreal forest sites, substrate colonization rates for protostelids were obtained o n sterile wheat straws in the two different litter microhabitats. Straws fr om aerial litter yielded four species of protostelids, whereas straws from ground litter yielded six species. In general, species richness of protoste lids appears to be lower in high-latitude ecosystems than in the temperate forests and grasslands thus far examined.