PHENOLOGY OF AQUATIC MACROINVERTEBRATES IN AN ALPINE WETLAND

The temporal distribution of populations of aquatic macroinvertebrates have been extensively investigated in temperate arctic regions, but l ittle information is available for alpine regions in North America. Th is paper describes phenology patterns of the aquatic macroinvertebrate s of a high elevation wetland (3593 m) in the Green Lakes Valley, Colo rado Front Range. Abundant taxa were Chironomidae (primarily Orthoclad ius and the limnephilid trichopteran Asynarchus curtus (Banks). Temper ature patterns were related to the seasonal timing of life stages of m ost species. Phenology of most alpine aquatic macroinvertebrates appea rs to be controlled by seasonal climatic patterns, particularly temper ature patterns. All chironomid species and Asynarchus curtus (Banks) h ad univoltine life cycles. Multi-year life cycles were not observed at this alpine site, although they have been observed at some arctic sit es with colder temperature regimes than observed in this study.