ISSN:
1573-5117
Keywords:
Mono Lake
;
photosynthesis
;
salt lake
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract The photosynthetic activity of phytoplankton in hypersaline Mono Lake, California was measured over the three year period, 1983–1985. The maximum chlorophyll-specific rate of carbon uptake (Pm B) and the light-limited slope (alpha) were derived from laboratory measurements of photosynthesis vs. irradiance (P-I) relationships. Annual estimates of primary production were 340–540 g C m-2 yr-1. Production was two to three times higher during the spring of 1983 than in the springs of 1984 and 1985; higher standing biomass of algae occurred in 1983. While Pm B rates followed water temperatures and varied over 40-fold over the year, integral primary production varied less since periods of high Pm B occurred when algal biomass was low. Sixty-eight percent of the seasonal variation in the Pm B was explained by a regression on temperature (53%), chlorophyll a (12%), and the carbon:chlorophyll a ratio (3%). Light-saturated and light-limited rates of photosynthesis generally covaried, evidenced by the strong seasonal correlation between Pm B and alpha. Sixty-one percent of variation in alpha was explained by a regression on Pm B, temperature, grazing, water column stability, and self-shading. There was no correlation of carbon uptake with ambient levels of inorganic nitrogen. The regression coefficient of the dependence of Pm B on the seasonal temperature trend was much larger than that determined from individual samples incubated at several different temperatures; this indicates that uptake is limited by more than low temperatures in the spring. Regression equations including only temperature, chlorophyll and depth were sufficient to estimate patterns of seasonal and year to year variation in integral primary productivity.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00026267
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