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The utilization of bicarbonate ions by the macroalga Ascophyllum nodosum (L.) Le Jolis
Author(s) -
JOHNSTON A. M.,
RAVEN J. A.
Publication year - 1986
Publication title -
plant, cell and environment
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.646
H-Index - 200
eISSN - 1365-3040
pISSN - 0140-7791
DOI - 10.1111/1365-3040.ep11611615
Subject(s) - ascophyllum , bicarbonate , alkalinity , photosynthesis , chemistry , total inorganic carbon , ion , compensation point , carbon fibers , environmental chemistry , botany , carbon dioxide , algae , inorganic chemistry , materials science , biology , biochemistry , organic chemistry , transpiration , composite number , composite material
A comparison of some of the methods used to determine whether aquatic plants have the ability to utilize bicarbonate ions as a source of inorganic carbon for photosynthesis has been applied to the intertidal macroalga Ascophyllum nodosum . These include: observing photosynthesis at a high pH (below the alga's CO 2 compensation point), pH compensation point determinations, comparing the photosynthetic characteristics at low pH (5.20) and at high pH (7.95), estimating the maximal rates at which CO 2 can diffuse through the unstirred layer and the rate at which CO 2 can be produced from bicarbonate dehydration in the unstirred layer. All indicated that Ascophyllum nodosum can use bicarbonate ions for photosynthesis, though some were not always consistent. Calculating the total inorganic carbon concentration from pH measurements and acidification CO 2 determinations revealed that the assumption that the alkalinity remains constant during pH drift experiments is not always valid.