Daily timing of emersion and elevated atmospheric CO2 concentration affect photosynthetic performance of the intertidal macroalga Ulva lactuca (Chlorophyta) in sunlight
-
Dinghui Zou
Abstract
The lunar day differs in length from the solar day so that times of low tide vary from day to day. Thus, aerial exposure of intertidal seaweeds may be during the day or during the night. We measured photosynthetic CO2 assimilation rates of the intertidal green macroalga Ulva lactuca during exposures of varied daily timings during sunny days of summer to establish how photosynthetic performance responds to emersion timing under varied CO2 levels [at ambient (360 ppmv) and 2× ambient (720 ppmv) atmospheric CO2 concentrations]. There was an increase in net photosynthetic rates following some duration of exposure when the initial timing of exposure occurred during early morning (06.30 h) and late afternoon (17.15 h). In contrast, net rates exhibited a sharp decline with exposure duration when the initial timing of exposure occurred at 09.30 h, 15.30 h and especially at noon (12.30 h), implying the occurrence of a severe photoinhibition resulting from mid-day insolation. Doubled atmospheric CO2 concentration significantly enhanced the emersed photosynthetic rates, indicating that the emersed photosynthesis is CO2-limited at ambient CO2 levels. However, increasing CO2 barely stimulates the emersed photosynthetic rates during mid-day insolation.
©2007 by Walter de Gruyter Berlin New York
Artikel in diesem Heft
- Structure of this issue
- Is the cryptic alien seaweed Ulva pertusa (Ulvales, Chlorophyta) widely distributed along European Atlantic coasts?
- Daily timing of emersion and elevated atmospheric CO2 concentration affect photosynthetic performance of the intertidal macroalga Ulva lactuca (Chlorophyta) in sunlight
- Yucatán seaweeds from the offshore waters of Isla Mujeres, Quintana Roo, Mexico
- Dictyota dolabellana sp. nov. (Dictyotaceae, Phaeophyceae) based on morphological and chemical data
- Rostrupiella danica gen. et sp. nov., a Lulworthia-like marine lignicolous species from Denmark and the USA
- Ascoma development in the marine ascomycete Corollospora gracilis (Halosphaeriales, Hypocreomycetidae, Sordariomycetes)
- Low-molecular-mass carbohydrates and soluble polysaccharides of green and red morphs of Gracilaria domingensis (Gracilariales, Rhodophyta)
- Seaweed invasions: introduction and scope
- Introductions of seaweeds: accidental transfer pathways and mechanisms
- Intentional introductions of commercially harvested alien seaweeds
- Mechanisms of invasion: establishment, spread and persistence of introduced seaweed populations
- Mechanisms of invasions: can the recipient community influence invasion rates?
- Methods for identifying and tracking seaweed invasions
- Molecular approaches to the study of invasive seaweeds
- Impacts of introduced seaweeds
- Control of invasive seaweeds
- Invasive seaweeds: global and regional law and policy responses
- Seaweed invasions: conclusions and future directions
- Author information Special Issue Seaweed Invasions
- Subject index Special Issue Seaweed Invasions
- Reviewer acknowledgement Bot. Mar. volume 50 (2007)
- Contents index Bot. Mar. volume 50 (2007)
- Author index Bot. Mar. volume 50 (2007)
- Genus/Species index Bot. Mar. volume 50 (2007)
Artikel in diesem Heft
- Structure of this issue
- Is the cryptic alien seaweed Ulva pertusa (Ulvales, Chlorophyta) widely distributed along European Atlantic coasts?
- Daily timing of emersion and elevated atmospheric CO2 concentration affect photosynthetic performance of the intertidal macroalga Ulva lactuca (Chlorophyta) in sunlight
- Yucatán seaweeds from the offshore waters of Isla Mujeres, Quintana Roo, Mexico
- Dictyota dolabellana sp. nov. (Dictyotaceae, Phaeophyceae) based on morphological and chemical data
- Rostrupiella danica gen. et sp. nov., a Lulworthia-like marine lignicolous species from Denmark and the USA
- Ascoma development in the marine ascomycete Corollospora gracilis (Halosphaeriales, Hypocreomycetidae, Sordariomycetes)
- Low-molecular-mass carbohydrates and soluble polysaccharides of green and red morphs of Gracilaria domingensis (Gracilariales, Rhodophyta)
- Seaweed invasions: introduction and scope
- Introductions of seaweeds: accidental transfer pathways and mechanisms
- Intentional introductions of commercially harvested alien seaweeds
- Mechanisms of invasion: establishment, spread and persistence of introduced seaweed populations
- Mechanisms of invasions: can the recipient community influence invasion rates?
- Methods for identifying and tracking seaweed invasions
- Molecular approaches to the study of invasive seaweeds
- Impacts of introduced seaweeds
- Control of invasive seaweeds
- Invasive seaweeds: global and regional law and policy responses
- Seaweed invasions: conclusions and future directions
- Author information Special Issue Seaweed Invasions
- Subject index Special Issue Seaweed Invasions
- Reviewer acknowledgement Bot. Mar. volume 50 (2007)
- Contents index Bot. Mar. volume 50 (2007)
- Author index Bot. Mar. volume 50 (2007)
- Genus/Species index Bot. Mar. volume 50 (2007)
