Photosynthetic characteristics of dwarf and fringe Rhizophora mangle L. in a Belizean mangrove

CHEESEMAN, J. M. and LOVELOCK, C. E. (2004) Photosynthetic characteristics of dwarf and fringe Rhizophora mangle L. in a Belizean mangrove. Plant, Cell and Environment, 27 (6). pp. 769-780. ISSN 0140-7791

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    Abstract

    Twin Cays (Belize) is a highly oligotrophic mangrove archipelago dominated by Rhizophora mangle L. Ocean-fringing trees are 3–7 m tall with a leaf area index (LAI) of 2.3, whereas in the interior, dwarf zone, trees are 1.5 m or less, and the LAI is 0.7. P-fertilization of dwarf trees dramatically increases growth. As a partial explanation of these characteristics, it was hypothesized that differences in stature and growth rates would reflect differences in leaf photosynthetic capacity, as determined by the photochemical and biochemical characteristics at the chloroplast level. Gas exchange and chlorophyll fluorescence were used to compare photosynthesis of dwarf, fringe and fertilized trees. Regardless of zonation or treatment, net CO2 exchange (A) and photosynthetic electron transport were light saturated at less than 500 µmol photons m−2 s−1, and low-light quantum efficiencies were typical for healthy C3 plants. On the other hand, light-saturated A was linearly related to stomatal conductance (gs), with seasonal, zonal and treatment differences in photosynthesis corresponding linearly to differences in the mean gs. Overall, photosynthetic capacity appeared to be co-regulated with stomatal conductance, minimizing the variability of Ci at ambient CO2 (and hence, Ci/Ca). Based on the results of in vitro assays, regulation of photosynthesis in R. mangle appeared to be accomplished, at least in part, by regulation of Rubisco activity.

    Item Type: Peer-reviewed Journal Article
    Related URLs:
    Unique ID or DOI: 10.1111/j.1365-3040.2004.01181.x
    Publisher: Blackwell Publishing Ltd
    Keywords: oligotrophy; phosphorus fertilization; Rubisco; stomatal conductance
    Subjects: (A) Biodiversity > (AH) Plants
    (C) Ecosystems > (CB) Marine > (CBE) Mangroves
    Publication Sources: (3) Other Source > (3C) Other Universities
    Date Deposited: 01 Feb 2011 15:36
    Last Modified: 01 Feb 2011 15:36
    URI: http://eprints.uberibz.org/id/eprint/1261

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