Zur Phototsynthese antarktischer Kryptogamen unter besonderer Berücksichtigung von Photoinhibition
In polar regions high quantum flux densities occur regularly during springtime and summer due to the high albedo of the persisting snowcover. Strong irradiances in the visible wavelength band are known to induce photoinhibition of photosynthesis. This factor could, therefore, be relevant for the pri...
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ftunivkiel:oai:macau.uni-kiel.de:diss_mods_00000367 2024-09-15T17:47:51+00:00 Zur Phototsynthese antarktischer Kryptogamen unter besonderer Berücksichtigung von Photoinhibition Schlensog, Mark Schroeter, B. Kappen, L. 2000 https://nbn-resolving.org/urn:nbn:de:gbv:8-diss-3670 https://macau.uni-kiel.de/receive/diss_mods_00000367 https://macau.uni-kiel.de/servlets/MCRFileNodeServlet/dissertation_derivate_00000367/d367.pdf deu ger https://nbn-resolving.org/urn:nbn:de:gbv:8-diss-3670 https://macau.uni-kiel.de/receive/diss_mods_00000367 https://macau.uni-kiel.de/servlets/MCRFileNodeServlet/dissertation_derivate_00000367/d367.pdf https://rightsstatements.org/page/InC/1.0/ info:eu-repo/semantics/openAccess ddc:570 thesis Adelaideinsel Livingston Island Kryptogamen Photosynthese Photoinaktivierung Photoinhibition Antarctica Mosses Lichens Photosynthesis Xanthophyll-Cycle Chl-a-Fluorescence CO2-Gas-Exchange HPLC dissertation Text doc-type:PhDThesis 2000 ftunivkiel 2024-07-03T23:41:26Z In polar regions high quantum flux densities occur regularly during springtime and summer due to the high albedo of the persisting snowcover. Strong irradiances in the visible wavelength band are known to induce photoinhibition of photosynthesis. This factor could, therefore, be relevant for the primary productivity of mosses and lichens dominating the antarctic vegetation. Under controlled conditions in the laboratory a wide range of investigated species showed a reduced efficiency of photosystem II following an exposure to high quantum flux densities of 1500 µmol m-2 s-1. In mosses from shaded habitats like Pohlia cruda a treatment of two hours with strong light led to a reduction of gross photosynthesis and electron transport rate through photosystem II of 52%, that was not reversible within days. In the lichens Usnea aurantiaco-atra and Umbilicaria antarctica from dry, open exposed fellfield habitats even stronger effects were found. However, in the field these species experienced strong irradiance almost in the desiccated and highly resistant state only. Mosses as Sanionia uncinata, which dominate habitats with a constant water supply, did not desiccate in the field. Regularly occurring reductions of photosystem II efficiency in the field were quickly reversible. They seem to be part of protection mechanisms as the xanthophyll cycle that enable the organisms to perform photosynthesis at fluctuating light. The photosynthetic performance of all investigated organisms seems, therefore, to be well adapted to the light and temperature conditions in the antarctic summer. Doctoral or Postdoctoral Thesis Antarc* Antarctic Antarctica Antarktis* Livingston Island MACAU: Open Access Repository of Kiel University |
institution |
Open Polar |
collection |
MACAU: Open Access Repository of Kiel University |
op_collection_id |
ftunivkiel |
language |
German |
topic |
ddc:570 thesis Adelaideinsel Livingston Island Kryptogamen Photosynthese Photoinaktivierung Photoinhibition Antarctica Mosses Lichens Photosynthesis Xanthophyll-Cycle Chl-a-Fluorescence CO2-Gas-Exchange HPLC |
spellingShingle |
ddc:570 thesis Adelaideinsel Livingston Island Kryptogamen Photosynthese Photoinaktivierung Photoinhibition Antarctica Mosses Lichens Photosynthesis Xanthophyll-Cycle Chl-a-Fluorescence CO2-Gas-Exchange HPLC Schlensog, Mark Zur Phototsynthese antarktischer Kryptogamen unter besonderer Berücksichtigung von Photoinhibition |
topic_facet |
ddc:570 thesis Adelaideinsel Livingston Island Kryptogamen Photosynthese Photoinaktivierung Photoinhibition Antarctica Mosses Lichens Photosynthesis Xanthophyll-Cycle Chl-a-Fluorescence CO2-Gas-Exchange HPLC |
description |
In polar regions high quantum flux densities occur regularly during springtime and summer due to the high albedo of the persisting snowcover. Strong irradiances in the visible wavelength band are known to induce photoinhibition of photosynthesis. This factor could, therefore, be relevant for the primary productivity of mosses and lichens dominating the antarctic vegetation. Under controlled conditions in the laboratory a wide range of investigated species showed a reduced efficiency of photosystem II following an exposure to high quantum flux densities of 1500 µmol m-2 s-1. In mosses from shaded habitats like Pohlia cruda a treatment of two hours with strong light led to a reduction of gross photosynthesis and electron transport rate through photosystem II of 52%, that was not reversible within days. In the lichens Usnea aurantiaco-atra and Umbilicaria antarctica from dry, open exposed fellfield habitats even stronger effects were found. However, in the field these species experienced strong irradiance almost in the desiccated and highly resistant state only. Mosses as Sanionia uncinata, which dominate habitats with a constant water supply, did not desiccate in the field. Regularly occurring reductions of photosystem II efficiency in the field were quickly reversible. They seem to be part of protection mechanisms as the xanthophyll cycle that enable the organisms to perform photosynthesis at fluctuating light. The photosynthetic performance of all investigated organisms seems, therefore, to be well adapted to the light and temperature conditions in the antarctic summer. |
author2 |
Schroeter, B. Kappen, L. |
format |
Doctoral or Postdoctoral Thesis |
author |
Schlensog, Mark |
author_facet |
Schlensog, Mark |
author_sort |
Schlensog, Mark |
title |
Zur Phototsynthese antarktischer Kryptogamen unter besonderer Berücksichtigung von Photoinhibition |
title_short |
Zur Phototsynthese antarktischer Kryptogamen unter besonderer Berücksichtigung von Photoinhibition |
title_full |
Zur Phototsynthese antarktischer Kryptogamen unter besonderer Berücksichtigung von Photoinhibition |
title_fullStr |
Zur Phototsynthese antarktischer Kryptogamen unter besonderer Berücksichtigung von Photoinhibition |
title_full_unstemmed |
Zur Phototsynthese antarktischer Kryptogamen unter besonderer Berücksichtigung von Photoinhibition |
title_sort |
zur phototsynthese antarktischer kryptogamen unter besonderer berücksichtigung von photoinhibition |
publishDate |
2000 |
url |
https://nbn-resolving.org/urn:nbn:de:gbv:8-diss-3670 https://macau.uni-kiel.de/receive/diss_mods_00000367 https://macau.uni-kiel.de/servlets/MCRFileNodeServlet/dissertation_derivate_00000367/d367.pdf |
genre |
Antarc* Antarctic Antarctica Antarktis* Livingston Island |
genre_facet |
Antarc* Antarctic Antarctica Antarktis* Livingston Island |
op_relation |
https://nbn-resolving.org/urn:nbn:de:gbv:8-diss-3670 https://macau.uni-kiel.de/receive/diss_mods_00000367 https://macau.uni-kiel.de/servlets/MCRFileNodeServlet/dissertation_derivate_00000367/d367.pdf |
op_rights |
https://rightsstatements.org/page/InC/1.0/ info:eu-repo/semantics/openAccess |
_version_ |
1810497503688130560 |