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TEMPERATURE AND IRRADIANCE EFFECTS ON GROWTH OF PITHOPHORA OEDOGONIA (CHLOROPHYCEAE) AND SPIROGYRA SP. (CHAROPHYCEAE) 1
Author(s) -
O'Neal Steven W.,
Lembi Carole A.
Publication year - 1995
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.0022-3646.1995.00720.x
Subject(s) - spirogyra , chlorophyceae , biology , photon flux , growth rate , chlorophyll , botany , algae , chlorophyta , chlorophyll a , zoology , photon , physics , geometry , mathematics , quantum mechanics
Growth responses of Pithophora oedogonia ( Mont.) Wittr. and Spirogyra sp. to nine combinations of temperature (15°, 25°, and 35°C) and photon flux rate (50, 100, and 500 μmol·m −2 ·s −1 ) were determined using a three‐factorial design. Maximum growth rates were measured at 35°C and 500 pmol·m −2 ·s −1 for P. oedogonia ( 0.247 d −1 ) and 25°C and 500 μmol·m −2 ·s −1 for Spirogyra sp. (0.224 d −1 ). Growth rates of P . oedogonia were strongly inhibited at 15°C (average decrease = 89% of maximum rate), indicating that this species is warm stenothermal. Growth rates of Spirogyra sp. were only moderately inhibited at 15° and 35°C (average decrease = 36 and 30%, respectively), suggesting that this species is eurythermal over the temperature range employed. Photon flux rate had a greater influence on growth of Spirogyra sp. (31% reduction at 50 pmol·m −2 ·s −1 and 25°C) than it did on growth of P. oedogonia ( 16% reduction at 50 μmol·m −2 ·s −1 and 35°C ). Spirogyra sp. also exhibited much greater adjustments to its content of chlorophyll a ( 0.22–3.34 μg·mg fwt −1 ) than did P. oedogonia ( 1.35–3.08 μg·mg fwt −1 ). The chlorophyll a content of Spirogyra sp. increased in response to both reductions in photon flux rate and high temperatures (35°C). Observed species differences are discussed with respect to in situ patterns of seasonal abundance in Surrey Lake, Indiana, the effect of algal mat anatomy on the internal light environment, and the process of acclimation to changes in temperature and irradiance conditions .