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PHOTOSYNTHESIS IN THE SNOW: THE ALGA CHLAMYDOMONAS NIVALIS (CHLOROPHYCEAE) 1
Author(s) -
Mosser J. L.,
Mosser A. G.,
Brock T. D.
Publication year - 1977
Publication title -
journal of phycology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.85
H-Index - 127
eISSN - 1529-8817
pISSN - 0022-3646
DOI - 10.1111/j.1529-8817.1977.tb02881.x
Subject(s) - chlamydomonas , algae , photosynthesis , snow , chlorophyceae , biology , botany , environmental chemistry , ecology , chlorophyta , physics , chemistry , meteorology , biochemistry , gene , mutant
Red blooms of snow algae consisting almost exclusively of large spherical red cells of Chlamydomonas nivalis (Bauer) Wille are widespread during the summer in the Beartooth Mountains in Montana and Wyoming. Field studies designed to examine the effects of temperature, light, and water potential on algal activity were performed with natural populations using photosynthetic 14 C‐HCO 3 ‐ or 14 CO 2 incorporation as a measure of activity. The algae photo‐synthesized optimally at 5.4 × 10 4 lx, but were not inhibited by increased light intensity up to 8.6 × 10 4 lx, the maximum observed in the field. Photosynthesis was sensitive to a reduction in water potential, and since low water potentials develop in snow at temperatures below 0 C, it is unlikely that significant algal activity occurs at the sub‐0 temperatures which occur throughout winter. Photosynthesis was much lower following melting of the snow, but this was probably due to decreased diffusion of CO 2 . The optimal temperatures varied considerably among the different algal populations. Most samples photo‐synthesized optimally at 10 or 20 C but retained substantial activity at temperatures as low as 0 or ‐3 C. Exceptional samples photosynthesized optimally at 0 or ‐3 C. It is proposed that the varied temperature responses reflect the presence of different temperature strains. Taken together, the data suggest that development of the snow algae can occur only during the summer months.