Macroinvertebrate community succession in Wolf Point Creek, Glacier Bay National Park, Alaska

1. Macroinvertebrate community development in Wolf Point Creek in Glacier Bay National Park, Alaska formed by ice recession was investigated from 1991 to 1994 as part of a long-term study of colonization now exceeding 20 years. Chironomidae, the first taxon to colonize the stream, still dominated the community comprising 75-95% by number, but species succession was apparent. 2. Species richness in August increased from five species in 1978 to 11 in 1991 and 16 in 1994. 3. Diamesa species, abundant in 1978 at densities exceeding 2 750 m(-2), were not collected in 1994, while Pagastia partica dominated the community with densities exceeding 10 000 m(-2) 4. Sixteen taxa, never previously collected, colonized the stream between 1991 and 1994 including representatives of Coleoptera, Muscidae, Trichoptera, and the first noninsect taxon, Oligochaeta. Colonization by new taxa was associated with an increase in summer water temperature and the development of riparian vegetation. 5. Inter-specific competition is suggested as a possible factor in species succession and is incorporated into a taxa richness model of community development in postglacial streams incorporating stable and unstable channels.