Solar UV-B decreases decomposition in herbaceous plant litter in Tierra del Fuego, Argentina: Potential role of an altered decomposer community

Tierra del Fuego, Argentina (55°S), receives increased solar ultraviolet-B radiation (UV-B) as a result of Antarctic stratospheric ozone depletion. We conducted a field study to examine direct and indirect effects of solar UV-B radiation on decomposition of Gunnera magellanica, a native perennial he...

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Publicado: 2003
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Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_13541013_v9_n10_p1465_Pancotto
http://hdl.handle.net/20.500.12110/paper_13541013_v9_n10_p1465_Pancotto
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spelling paper:paper_13541013_v9_n10_p1465_Pancotto2023-06-08T16:11:05Z Solar UV-B decreases decomposition in herbaceous plant litter in Tierra del Fuego, Argentina: Potential role of an altered decomposer community Decomposer community composition Decomposition Gunnera magellanica Litter quality Ozone depletion Ultraviolet-B solar radiation community composition decomposition litter microbial community ozone depletion ultraviolet B radiation Argentina Bassiana Beauveria Cladosporium Cordyceps bassiana Davidiella tassiana Gunnera magellanica Hypocrea pachybasioides Penicillium chrysogenum Penicillium glabrum Penicillium thomii Trichoderma Tierra del Fuego, Argentina (55°S), receives increased solar ultraviolet-B radiation (UV-B) as a result of Antarctic stratospheric ozone depletion. We conducted a field study to examine direct and indirect effects of solar UV-B radiation on decomposition of Gunnera magellanica, a native perennial herb, and on the native community of decomposer organisms. In general, indirect effects of UV-B mostly occur due to changes in the chemical composition of litter, whereas direct effects during decomposition result from changes in decomposer organisms and/or differences in the photochemical breakdown of litter. We designed a full-factorial experiment using senescent leaves that had received either near-ambient or attenuated UV-B during growth. The leaves were distributed in litterbags and allowed to decompose under near-ambient or reduced solar UV-B during the growing season. We evaluated initial litter quality, mass loss, and nutrient release of decomposing litter, and microbial colonization of both initial litter and decomposed litter. We found that litter that decomposed under near-ambient UV-B had significantly less mass loss than litter that decomposed under reduced UV-B. The UV-B conditions received by plants during growth, which did not affect mass loss and nutrient composition of litter, affected fungal species composition but in different ways throughout the decomposition period. Before the decomposition trial, Beauveria bassiana and Penicillium frequentans were higher under reduced UV-B, whereas Cladosporium herbarum and pigmented bacteria were more common under the near-ambient compared to the reduced UV-B treatment. After the decomposition period, leaves that had grown under reduced UV-B showed higher frequency of Penicillium thomii and lower frequency of Trichoderma polysporum than leaves that had grown under near-ambient conditions. The UV-B condition received during decomposition also affected fungal colonization, with Penicillium chrysogenum being more frequent in leaves that had decomposed under reduced UV-B, while the other species were not affected. Our results demonstrate that, in this ecosystem, the effects of UV-B radiation on decomposition apparently occurred mostly through changes in the fungal community, while changes in photochemical breakdown appeared to be less important. 2003 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_13541013_v9_n10_p1465_Pancotto http://hdl.handle.net/20.500.12110/paper_13541013_v9_n10_p1465_Pancotto
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Decomposer community composition
Decomposition
Gunnera magellanica
Litter quality
Ozone depletion
Ultraviolet-B solar radiation
community composition
decomposition
litter
microbial community
ozone depletion
ultraviolet B radiation
Argentina
Bassiana
Beauveria
Cladosporium
Cordyceps bassiana
Davidiella tassiana
Gunnera magellanica
Hypocrea pachybasioides
Penicillium chrysogenum
Penicillium glabrum
Penicillium thomii
Trichoderma
spellingShingle Decomposer community composition
Decomposition
Gunnera magellanica
Litter quality
Ozone depletion
Ultraviolet-B solar radiation
community composition
decomposition
litter
microbial community
ozone depletion
ultraviolet B radiation
Argentina
Bassiana
Beauveria
Cladosporium
Cordyceps bassiana
Davidiella tassiana
Gunnera magellanica
Hypocrea pachybasioides
Penicillium chrysogenum
Penicillium glabrum
Penicillium thomii
Trichoderma
Solar UV-B decreases decomposition in herbaceous plant litter in Tierra del Fuego, Argentina: Potential role of an altered decomposer community
topic_facet Decomposer community composition
Decomposition
Gunnera magellanica
Litter quality
Ozone depletion
Ultraviolet-B solar radiation
community composition
decomposition
litter
microbial community
ozone depletion
ultraviolet B radiation
Argentina
Bassiana
Beauveria
Cladosporium
Cordyceps bassiana
Davidiella tassiana
Gunnera magellanica
Hypocrea pachybasioides
Penicillium chrysogenum
Penicillium glabrum
Penicillium thomii
Trichoderma
description Tierra del Fuego, Argentina (55°S), receives increased solar ultraviolet-B radiation (UV-B) as a result of Antarctic stratospheric ozone depletion. We conducted a field study to examine direct and indirect effects of solar UV-B radiation on decomposition of Gunnera magellanica, a native perennial herb, and on the native community of decomposer organisms. In general, indirect effects of UV-B mostly occur due to changes in the chemical composition of litter, whereas direct effects during decomposition result from changes in decomposer organisms and/or differences in the photochemical breakdown of litter. We designed a full-factorial experiment using senescent leaves that had received either near-ambient or attenuated UV-B during growth. The leaves were distributed in litterbags and allowed to decompose under near-ambient or reduced solar UV-B during the growing season. We evaluated initial litter quality, mass loss, and nutrient release of decomposing litter, and microbial colonization of both initial litter and decomposed litter. We found that litter that decomposed under near-ambient UV-B had significantly less mass loss than litter that decomposed under reduced UV-B. The UV-B conditions received by plants during growth, which did not affect mass loss and nutrient composition of litter, affected fungal species composition but in different ways throughout the decomposition period. Before the decomposition trial, Beauveria bassiana and Penicillium frequentans were higher under reduced UV-B, whereas Cladosporium herbarum and pigmented bacteria were more common under the near-ambient compared to the reduced UV-B treatment. After the decomposition period, leaves that had grown under reduced UV-B showed higher frequency of Penicillium thomii and lower frequency of Trichoderma polysporum than leaves that had grown under near-ambient conditions. The UV-B condition received during decomposition also affected fungal colonization, with Penicillium chrysogenum being more frequent in leaves that had decomposed under reduced UV-B, while the other species were not affected. Our results demonstrate that, in this ecosystem, the effects of UV-B radiation on decomposition apparently occurred mostly through changes in the fungal community, while changes in photochemical breakdown appeared to be less important.
title Solar UV-B decreases decomposition in herbaceous plant litter in Tierra del Fuego, Argentina: Potential role of an altered decomposer community
title_short Solar UV-B decreases decomposition in herbaceous plant litter in Tierra del Fuego, Argentina: Potential role of an altered decomposer community
title_full Solar UV-B decreases decomposition in herbaceous plant litter in Tierra del Fuego, Argentina: Potential role of an altered decomposer community
title_fullStr Solar UV-B decreases decomposition in herbaceous plant litter in Tierra del Fuego, Argentina: Potential role of an altered decomposer community
title_full_unstemmed Solar UV-B decreases decomposition in herbaceous plant litter in Tierra del Fuego, Argentina: Potential role of an altered decomposer community
title_sort solar uv-b decreases decomposition in herbaceous plant litter in tierra del fuego, argentina: potential role of an altered decomposer community
publishDate 2003
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_13541013_v9_n10_p1465_Pancotto
http://hdl.handle.net/20.500.12110/paper_13541013_v9_n10_p1465_Pancotto
_version_ 1768545751217995776