Beitrag
Physical variability and phytoplankton communities: VI. Day to day changes in primary productivity and species abundance
Septhon, Dawn H.; Harris, Graham P.
Archiv für Hydrobiologie Volume 102 Number 2 (1984), p. 155 - 175
49 Literaturangaben
veröffentlicht: Dec 11, 1984
DOI: 10.1127/archiv-hydrobiol/102/1984/155
ArtNo. ESP141010202001, Preis: 29.00 €
Abstract
Daily rates of primary productivity in Hamilton Harbour (L. Ontario) during the summer of 1979 were more variable than anticipated (c. f. Harris et al., 1980 b). Day-to-day integral productivity was largely determined by changes in the maximum volumetric rate of photosynthesis and in the assimilation number or photosynthetic capacity. The values of the assimilation number, photosynthetic efficiency and the light saturation parameter of photosynthesis fluctuated from day to day and they were correlated with changing environmental parameters at scales of 1—7 days. Cross-covariance analysis showed that the assimilation number lagged behind changes in the water column stability by 7 days. Photosynthetic efficiency lagged behind changes in water column stability by 1 day. The light saturation parameter of photosynthesis responded to changes in the integral irradiance with a lag of 1 day. Time series analysis suggests that the resident algal species responded differently to environmental changes with different temporal lags. Statistically significant internal periods (auto-correlations) may reflect the generation times of several species. Cyclotella increased in abundance in response to increased vertical mixing while Stephanodiscus responded negatively to changes in water column stability. Rhodomonas and Cryptomonas responded negatively to environmental fluctuations with lags of 1—5 days, while Chlamydomonas> responded positively with a lag of 2 days. Oocystis and Scenedesmus were most abundant during periods of thermal stability and Coelastrum responded positively to changes in water column stability with a lag of 4 days. These lag periods may represent an adaptive response to environmental change or changes in the community.
Schlagworte
productivity • photosynthetic • assimilation • Hamilton Harbour • L. Ontario