Daily variation patterns in seagrass photosynthesis along a vertical gradient
Autor(a) principal: | |
---|---|
Data de Publicação: | 2003 |
Outros Autores: | |
Tipo de documento: | Artigo |
Idioma: | eng |
Título da fonte: | Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
Texto Completo: | http://hdl.handle.net/10400.1/12140 |
Resumo: | The relationship between the available photosynthetic active radiation (PAR) and the photosynthetic yield of Photosystem II (PSII), measured by chlorophyll a fluorescence, was assessed in the intertidal seagrasses of Ria Formosa, a coastal lagoon in southern Portugal. Most of the lagoon's intertidal is occupied by a monospecific population of Zostera noltii (Hornemann), which occupies a vertical gradient of about 2 m. The upper distribution limit of this species comprises the edge of a Spartina maritima (Curtis) Fernald saltmarsh and the lower limit the transition to the subtidal, dominated by Cymodocea nodosa (Ucria) Ascherson. Diurnal changes in the pattern of rapid-light curves (RLCs) was investigated with pulse amplitude-modulated (PAM) fluorometry in Z. noltii and in C. nodosa in the upper and lower intertidal. The light reactions of photosynthesis were assessed by fitting photosynthesis-irradiance (P-I) models to the RLCs. The photosynthetic parameters of Z noltii revealed that this plant species exhibits sun- and shade-type responses in its upper and lower vertical distribution limits, respectively. At the lower distribution limit in low light, the initial slopes of all RLCs were significantly higher than at the upper site, but decreased with increasing irradiances, while at the upper distribution limit, although lower, the slopes were unaffected by increasing irradiance. C. nodosa presented a typical shade-type response, as evidenced by the daily variation and light dependence of both photosynthetic efficiency and optimal quantum yield. The relationship between the maximum electron-transport rate and irradiance suggests that this species is strongly light-limited. We suggest that attempts to characterize the photosynthetic behaviour of an intertidal meadow should consider both diurnal fluctuations in the plants' photosynthetic activity as well as its vertical distribution frequency. |
id |
RCAP_fc1d91b40ba1ee9492f34c73d29771b0 |
---|---|
oai_identifier_str |
oai:sapientia.ualg.pt:10400.1/12140 |
network_acronym_str |
RCAP |
network_name_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository_id_str |
7160 |
spelling |
Daily variation patterns in seagrass photosynthesis along a vertical gradientModulated pam fluorometrySubmersed aquatic vegetationMeasured In-SituChlorophyll fluorescenceThalassia-testudinumCarbon assimilationZostera-marinaQuantum yieldWater-qualityLightThe relationship between the available photosynthetic active radiation (PAR) and the photosynthetic yield of Photosystem II (PSII), measured by chlorophyll a fluorescence, was assessed in the intertidal seagrasses of Ria Formosa, a coastal lagoon in southern Portugal. Most of the lagoon's intertidal is occupied by a monospecific population of Zostera noltii (Hornemann), which occupies a vertical gradient of about 2 m. The upper distribution limit of this species comprises the edge of a Spartina maritima (Curtis) Fernald saltmarsh and the lower limit the transition to the subtidal, dominated by Cymodocea nodosa (Ucria) Ascherson. Diurnal changes in the pattern of rapid-light curves (RLCs) was investigated with pulse amplitude-modulated (PAM) fluorometry in Z. noltii and in C. nodosa in the upper and lower intertidal. The light reactions of photosynthesis were assessed by fitting photosynthesis-irradiance (P-I) models to the RLCs. The photosynthetic parameters of Z noltii revealed that this plant species exhibits sun- and shade-type responses in its upper and lower vertical distribution limits, respectively. At the lower distribution limit in low light, the initial slopes of all RLCs were significantly higher than at the upper site, but decreased with increasing irradiances, while at the upper distribution limit, although lower, the slopes were unaffected by increasing irradiance. C. nodosa presented a typical shade-type response, as evidenced by the daily variation and light dependence of both photosynthetic efficiency and optimal quantum yield. The relationship between the maximum electron-transport rate and irradiance suggests that this species is strongly light-limited. We suggest that attempts to characterize the photosynthetic behaviour of an intertidal meadow should consider both diurnal fluctuations in the plants' photosynthetic activity as well as its vertical distribution frequency.Inter-ResearchSapientiaSilva, JoãoSantos, Rui2018-12-07T14:58:39Z20032003-01-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttp://hdl.handle.net/10400.1/12140eng0171-863010.3354/meps257037info:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2023-07-24T10:24:04Zoai:sapientia.ualg.pt:10400.1/12140Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T20:03:31.994501Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse |
dc.title.none.fl_str_mv |
Daily variation patterns in seagrass photosynthesis along a vertical gradient |
title |
Daily variation patterns in seagrass photosynthesis along a vertical gradient |
spellingShingle |
Daily variation patterns in seagrass photosynthesis along a vertical gradient Silva, João Modulated pam fluorometry Submersed aquatic vegetation Measured In-Situ Chlorophyll fluorescence Thalassia-testudinum Carbon assimilation Zostera-marina Quantum yield Water-quality Light |
title_short |
Daily variation patterns in seagrass photosynthesis along a vertical gradient |
title_full |
Daily variation patterns in seagrass photosynthesis along a vertical gradient |
title_fullStr |
Daily variation patterns in seagrass photosynthesis along a vertical gradient |
title_full_unstemmed |
Daily variation patterns in seagrass photosynthesis along a vertical gradient |
title_sort |
Daily variation patterns in seagrass photosynthesis along a vertical gradient |
author |
Silva, João |
author_facet |
Silva, João Santos, Rui |
author_role |
author |
author2 |
Santos, Rui |
author2_role |
author |
dc.contributor.none.fl_str_mv |
Sapientia |
dc.contributor.author.fl_str_mv |
Silva, João Santos, Rui |
dc.subject.por.fl_str_mv |
Modulated pam fluorometry Submersed aquatic vegetation Measured In-Situ Chlorophyll fluorescence Thalassia-testudinum Carbon assimilation Zostera-marina Quantum yield Water-quality Light |
topic |
Modulated pam fluorometry Submersed aquatic vegetation Measured In-Situ Chlorophyll fluorescence Thalassia-testudinum Carbon assimilation Zostera-marina Quantum yield Water-quality Light |
description |
The relationship between the available photosynthetic active radiation (PAR) and the photosynthetic yield of Photosystem II (PSII), measured by chlorophyll a fluorescence, was assessed in the intertidal seagrasses of Ria Formosa, a coastal lagoon in southern Portugal. Most of the lagoon's intertidal is occupied by a monospecific population of Zostera noltii (Hornemann), which occupies a vertical gradient of about 2 m. The upper distribution limit of this species comprises the edge of a Spartina maritima (Curtis) Fernald saltmarsh and the lower limit the transition to the subtidal, dominated by Cymodocea nodosa (Ucria) Ascherson. Diurnal changes in the pattern of rapid-light curves (RLCs) was investigated with pulse amplitude-modulated (PAM) fluorometry in Z. noltii and in C. nodosa in the upper and lower intertidal. The light reactions of photosynthesis were assessed by fitting photosynthesis-irradiance (P-I) models to the RLCs. The photosynthetic parameters of Z noltii revealed that this plant species exhibits sun- and shade-type responses in its upper and lower vertical distribution limits, respectively. At the lower distribution limit in low light, the initial slopes of all RLCs were significantly higher than at the upper site, but decreased with increasing irradiances, while at the upper distribution limit, although lower, the slopes were unaffected by increasing irradiance. C. nodosa presented a typical shade-type response, as evidenced by the daily variation and light dependence of both photosynthetic efficiency and optimal quantum yield. The relationship between the maximum electron-transport rate and irradiance suggests that this species is strongly light-limited. We suggest that attempts to characterize the photosynthetic behaviour of an intertidal meadow should consider both diurnal fluctuations in the plants' photosynthetic activity as well as its vertical distribution frequency. |
publishDate |
2003 |
dc.date.none.fl_str_mv |
2003 2003-01-01T00:00:00Z 2018-12-07T14:58:39Z |
dc.type.status.fl_str_mv |
info:eu-repo/semantics/publishedVersion |
dc.type.driver.fl_str_mv |
info:eu-repo/semantics/article |
format |
article |
status_str |
publishedVersion |
dc.identifier.uri.fl_str_mv |
http://hdl.handle.net/10400.1/12140 |
url |
http://hdl.handle.net/10400.1/12140 |
dc.language.iso.fl_str_mv |
eng |
language |
eng |
dc.relation.none.fl_str_mv |
0171-8630 10.3354/meps257037 |
dc.rights.driver.fl_str_mv |
info:eu-repo/semantics/openAccess |
eu_rights_str_mv |
openAccess |
dc.format.none.fl_str_mv |
application/pdf |
dc.publisher.none.fl_str_mv |
Inter-Research |
publisher.none.fl_str_mv |
Inter-Research |
dc.source.none.fl_str_mv |
reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação instacron:RCAAP |
instname_str |
Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
instacron_str |
RCAAP |
institution |
RCAAP |
reponame_str |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
collection |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) |
repository.name.fl_str_mv |
Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação |
repository.mail.fl_str_mv |
|
_version_ |
1799133269856354304 |