Microsensor measurements in photosynthetic microbial mats

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Hauptverfasser: Al-Najjar, Mohammad A A, de Beer, Dirk, Kühl, Michael, Polerecky, Lubos
Format: Dataset Open Access
Sprache:en
Veröffentlicht: PANGAEA 2012
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author Al-Najjar, Mohammad A A
de Beer, Dirk
Kühl, Michael
Polerecky, Lubos
author_facet Al-Najjar, Mohammad A A
de Beer, Dirk
Kühl, Michael
Polerecky, Lubos
collection Datos científicos de ciencias marinas y ambientales
contents Based on combined microsensor measurements of irradiance, temperature and O2, we compared light energy budgets in photosynthetic microbial mats, with a special focus on the efficiency of light energy conservation by photosynthesis. The euphotic zones in the three studied mats differed in their phototrophic community structure, pigment concentrations and thickness. In all mats, < 1% of the absorbed light energy was conserved via photosynthesis at high incident irradiance, while the rest was dissipated as heat. Under light-limiting conditions, the photosynthetic efficiency reached a maximum, which varied among the studied mats between 4.5% and 16.2% and was significantly lower than the theoretical maximum of 27.7%. The maximum efficiency correlated linearly with the light attenuation coefficient and photopigment concentration in the euphotic zone. Higher photosynthetic efficiency was found in mats with a thinner and more densely populated euphotic zone. Microbial mats exhibit a lower photosynthetic efficiency compared with ecosystems with a more open canopy-like organization of photosynthetic elements, where light propagation is not hindered to the same extent by photosynthetically inactive components; such components contributed about 40-80% to light absorption in the investigated microbial mats, which is in a similar range as in oceanic planktonic systems.
format Dataset Open Access
id pangaea_https___doi_org_10_1594_PANGAEA_786792
institution PANGAEA
language en
publishDate 2012
publisher PANGAEA
record_format pangaea
spellingShingle Microsensor measurements in photosynthetic microbial mats
Al-Najjar, Mohammad A A
de Beer, Dirk
Kühl, Michael
Polerecky, Lubos

Based on combined microsensor measurements of irradiance, temperature and O2, we compared light energy budgets in photosynthetic microbial mats, with a special focus on the efficiency of light energy conservation by photosynthesis. The euphotic zones in the three studied mats differed in their phototrophic community structure, pigment concentrations and thickness. In all mats, < 1% of the absorbed light energy was conserved via photosynthesis at high incident irradiance, while the rest was dissipated as heat. Under light-limiting conditions, the photosynthetic efficiency reached a maximum, which varied among the studied mats between 4.5% and 16.2% and was significantly lower than the theoretical maximum of 27.7%. The maximum efficiency correlated linearly with the light attenuation coefficient and photopigment concentration in the euphotic zone. Higher photosynthetic efficiency was found in mats with a thinner and more densely populated euphotic zone. Microbial mats exhibit a lower photosynthetic efficiency compared with ecosystems with a more open canopy-like organization of photosynthetic elements, where light propagation is not hindered to the same extent by photosynthetically inactive components; such components contributed about 40-80% to light absorption in the investigated microbial mats, which is in a similar range as in oceanic planktonic systems.
title Microsensor measurements in photosynthetic microbial mats
topic
url https://doi.org/10.1594/PANGAEA.786792