HR: 1330h
AN: C42A-1014    [PDF]
TI: Seasonal variation of a snow algal community on an Alaskan glacier
AU: * Takeuchi, N
EM: takeuchi@chikyu.ac.jp
AF: Research Institute for Humanity and Nature, 335 Takashimacho Kamigyoku, Kyoto, 602-0878 Japan
AB: There are cold tolerant algae (snow algae) growing on the surface of glaciers. Several species of snow algae have been reported on Alaskan glaciers. Seasonal variation of the snow algal community was investigated on Gulkana Glacier in the Alaska Range from May to September, 2001. Chlorophyll, nutrients, and stable isotope for carbon and nitrogen (particulate organic matter) were also measured. The snow algal community on this glacier varied with time, in particular changed with snow melting and nutrients in the snow. When the glacier is covered with snow (May), the algal community consisted of mainly only one species of alga (Chlamydomonas nivalis, alga of red snow). The algal biomass and chlorophyll concentration increased with snow melting in early summer. When the glacial ice surface appeared, the community structure changed drastically. The community on the ice consisted of some of different species. The community structure and biomass kept almost constant after the ice surface appeared. Nutrients measurements showed that nitrogen was likely limited on the algal growth rather than phosphate. Especially, the nitrate was depleted from August to September. Results of stable isotope measurements also support the nitrogen limitation of the snow algae in late summer.
DE: 1045 Low-temperature geochemistry
DE: 1615 Biogeochemical processes (4805)
DE: 1827 Glaciology (1863)
DE: 4870 Stable isotopes
DE: 9350 North America
SC: Cryosphere [C]
MN: 2003 Fall Meeting