Responses of shallow sediment ecosystems to environmental alterations
Shallow-water sediment systems are continuously exposed to a range of anthropogenic stressors, including increased nutrient loading, physical disturbance and toxicants. Superimposed on these local stressors are stressors related to the on-going climate change. Interacting stressors may strengthen or...
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ftunivgoeteborg:oai:gupea.ub.gu.se:2077/31468 2023-10-29T02:39:16+01:00 Responses of shallow sediment ecosystems to environmental alterations Alsterberg, Christian 2013-02-14 application/pdf http://hdl.handle.net/2077/31468 eng eng I. Alsterberg, C., Hulth, S., Sundbäck, K. 2011. Response of a shallow-water sediment system to warming. Limnology and Oceanography, 56(6), 2147–2160.::doi::10.4319/lo.2011.56.6.2147 II. Alsterberg, C., Sundbäck, K., Hulth, S. 2012. Functioning of a shallow-water sediment system during experimental warming and nutrient enrichment. PLoS ONE 7(12): e51503.::doi::10.1371/journal.pone.0051503 III. Alsterberg, C. and Sundbäck, K. Experimental warming and toxicant exposure can result in antagonistic effects in a shallow-water sediment system. Revised manuscript submitted to Marine Ecology Progress Series. IV. Sundbäck, K., Alsterberg, C., Larson, F. 2010. Effects of multiple stressors on marine shallow-water sediments: Response of microalgae and meiofauna to toxicant–nutrient exposure. Journal of Experimental Marine Biology and Ecology. 388, 39-50.::doi::10.1016/j.jembe.2010.03.007 V. Alsterberg, C., Eklöf, J.S., Havenhand, J.N., Gamfeldt, L., Sundbäck, K. Consumers mediate the effects of experimental warming and ocean acidification on primary producers. Submitted Manuscript. 91-89677-55-2 http://hdl.handle.net/2077/31468 Shallow-water sediments microphytobenthos multiple stressors global warming eutrophication ocean acidification grazing trophic interactions biogeochemistry structural equation modeling meiofauna mesograzers Zostera marina primary production Text Doctoral thesis Doctor of Philosophy 2013 ftunivgoeteborg 2023-10-04T21:14:48Z Shallow-water sediment systems are continuously exposed to a range of anthropogenic stressors, including increased nutrient loading, physical disturbance and toxicants. Superimposed on these local stressors are stressors related to the on-going climate change. Interacting stressors may strengthen or weaken effects of individual stressors, resulting in – often unexpected – non-additive effects. Thus, the combined effect from several simultaneous stressors in shallow-water sediment systems is the main topic of this thesis. Individual and combined stressor effects were studied on intact sediment cores placed in an outdoor flow-through facility and in the laboratory. Both functional (primary and bacterial production, community respiration, meiofaunal grazing, denitrification, nitrogen mineralization and sediment-water fluxes of oxygen and nutrients) and structural (biomass and composition of microphytobenthos and meiofauna) were studied in order to assess effects of multiple stressors. It has been suggested that global warming can shift the trophic status of ecosystems from net autotrophy to net heterotrophy. A spring experiment (Paper I) showed, however, that the presence and activity of a well-developed microphytobenthic mat already in early spring sustained net autotrophy during simulated warming. The effects of increased temperature on the structure and function of the sediment systems were generally rather moderate. Consequently, it is possible that the presence and activity of microphytobenthos can buffer changes induced by seawater temperature. An autumn experiment (Paper II) suggested that warming combined with nutrient enrichment can induce shorter, intensive, heterotrophic periods that can be followed by longer autotrophic periods because initially increased mineralization induces a shortage of labile organic matter. Even though warming increased nutrient availability through increased mineralization, warming did not exacerbate the stimulatory effects of nutrient enrichment. The lack of interactive ... Doctoral or Postdoctoral Thesis Ocean acidification University of Gothenburg: GUPEA (Gothenburg University Publications Electronic Archive) |
institution |
Open Polar |
collection |
University of Gothenburg: GUPEA (Gothenburg University Publications Electronic Archive) |
op_collection_id |
ftunivgoeteborg |
language |
English |
topic |
Shallow-water sediments microphytobenthos multiple stressors global warming eutrophication ocean acidification grazing trophic interactions biogeochemistry structural equation modeling meiofauna mesograzers Zostera marina primary production |
spellingShingle |
Shallow-water sediments microphytobenthos multiple stressors global warming eutrophication ocean acidification grazing trophic interactions biogeochemistry structural equation modeling meiofauna mesograzers Zostera marina primary production Alsterberg, Christian Responses of shallow sediment ecosystems to environmental alterations |
topic_facet |
Shallow-water sediments microphytobenthos multiple stressors global warming eutrophication ocean acidification grazing trophic interactions biogeochemistry structural equation modeling meiofauna mesograzers Zostera marina primary production |
description |
Shallow-water sediment systems are continuously exposed to a range of anthropogenic stressors, including increased nutrient loading, physical disturbance and toxicants. Superimposed on these local stressors are stressors related to the on-going climate change. Interacting stressors may strengthen or weaken effects of individual stressors, resulting in – often unexpected – non-additive effects. Thus, the combined effect from several simultaneous stressors in shallow-water sediment systems is the main topic of this thesis. Individual and combined stressor effects were studied on intact sediment cores placed in an outdoor flow-through facility and in the laboratory. Both functional (primary and bacterial production, community respiration, meiofaunal grazing, denitrification, nitrogen mineralization and sediment-water fluxes of oxygen and nutrients) and structural (biomass and composition of microphytobenthos and meiofauna) were studied in order to assess effects of multiple stressors. It has been suggested that global warming can shift the trophic status of ecosystems from net autotrophy to net heterotrophy. A spring experiment (Paper I) showed, however, that the presence and activity of a well-developed microphytobenthic mat already in early spring sustained net autotrophy during simulated warming. The effects of increased temperature on the structure and function of the sediment systems were generally rather moderate. Consequently, it is possible that the presence and activity of microphytobenthos can buffer changes induced by seawater temperature. An autumn experiment (Paper II) suggested that warming combined with nutrient enrichment can induce shorter, intensive, heterotrophic periods that can be followed by longer autotrophic periods because initially increased mineralization induces a shortage of labile organic matter. Even though warming increased nutrient availability through increased mineralization, warming did not exacerbate the stimulatory effects of nutrient enrichment. The lack of interactive ... |
format |
Doctoral or Postdoctoral Thesis |
author |
Alsterberg, Christian |
author_facet |
Alsterberg, Christian |
author_sort |
Alsterberg, Christian |
title |
Responses of shallow sediment ecosystems to environmental alterations |
title_short |
Responses of shallow sediment ecosystems to environmental alterations |
title_full |
Responses of shallow sediment ecosystems to environmental alterations |
title_fullStr |
Responses of shallow sediment ecosystems to environmental alterations |
title_full_unstemmed |
Responses of shallow sediment ecosystems to environmental alterations |
title_sort |
responses of shallow sediment ecosystems to environmental alterations |
publishDate |
2013 |
url |
http://hdl.handle.net/2077/31468 |
genre |
Ocean acidification |
genre_facet |
Ocean acidification |
op_relation |
I. Alsterberg, C., Hulth, S., Sundbäck, K. 2011. Response of a shallow-water sediment system to warming. Limnology and Oceanography, 56(6), 2147–2160.::doi::10.4319/lo.2011.56.6.2147 II. Alsterberg, C., Sundbäck, K., Hulth, S. 2012. Functioning of a shallow-water sediment system during experimental warming and nutrient enrichment. PLoS ONE 7(12): e51503.::doi::10.1371/journal.pone.0051503 III. Alsterberg, C. and Sundbäck, K. Experimental warming and toxicant exposure can result in antagonistic effects in a shallow-water sediment system. Revised manuscript submitted to Marine Ecology Progress Series. IV. Sundbäck, K., Alsterberg, C., Larson, F. 2010. Effects of multiple stressors on marine shallow-water sediments: Response of microalgae and meiofauna to toxicant–nutrient exposure. Journal of Experimental Marine Biology and Ecology. 388, 39-50.::doi::10.1016/j.jembe.2010.03.007 V. Alsterberg, C., Eklöf, J.S., Havenhand, J.N., Gamfeldt, L., Sundbäck, K. Consumers mediate the effects of experimental warming and ocean acidification on primary producers. Submitted Manuscript. 91-89677-55-2 http://hdl.handle.net/2077/31468 |
_version_ |
1781066026683727872 |