Microbial carbon dynamics in nitrogen amended Arctic tundra soil: Measurement and model testing
We examined the responses of grazers (protozoa and nematodes) and their main food sources to low levels of nitrogen (N) fertilisation and applied carbon (C) flux models to our data. Replicate plots of tundra soil adjacent to the Kongsfjorden (Svalbard 78°N) were amended with ammonium and nitrate at...
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ftulundlup:oai:lup.lub.lu.se:2850a66b-9804-4713-8c41-d32aeb24f5cc 2023-05-15T15:12:07+02:00 Microbial carbon dynamics in nitrogen amended Arctic tundra soil: Measurement and model testing Stapleton, L M Crout, N M J Säwström, Christin Marshall, W A Poulton, P R Tye, A M Laybourn-Parry, J 2005 https://lup.lub.lu.se/record/150691 https://doi.org/10.1016/j.soilbio.2005.03.016 eng eng Elsevier https://lup.lub.lu.se/record/150691 http://dx.doi.org/10.1016/j.soilbio.2005.03.016 wos:000233501100012 scopus:27444433912 Soil Biology & Biochemistry; 37(11), pp 2088-2098 (2005) ISSN: 0038-0717 Environmental Sciences Ecology contributiontojournal/article info:eu-repo/semantics/article text 2005 ftulundlup https://doi.org/10.1016/j.soilbio.2005.03.016 2023-02-01T23:28:00Z We examined the responses of grazers (protozoa and nematodes) and their main food sources to low levels of nitrogen (N) fertilisation and applied carbon (C) flux models to our data. Replicate plots of tundra soil adjacent to the Kongsfjorden (Svalbard 78°N) were amended with ammonium and nitrate at concentrations of 1 and 5 kg N ha−1 to assess the impact of anthropogenic N deposition over three summers. Bacterial abundance as determined using the fluorochrome SYBR Green and epifluorescence microscopy ranged between 9.73×108 and 102.49×108 cells/g dry wt of soil, with a significant response to N addition occurring only during the second sampling in 2001. Despite little change in bacterial biomass, bacterial production (measured by the incorporation of 3H thymidine into DNA) during the second sampling in 2002, increased in NH4 enriched plots compared to control and NO3 amended plots, indicating that NH4 was the preferred source of inorganic N. The main bacterial predators were heterotrophic flagellates (HNAN) and naked amoebae, which showed no significant response to the N addition. HNAN showed a correlation with bacterial abundance suggesting a dependence on bacteria as a food source. The inability of a microbial C flux model to fit our data (RWSS/data=18.6, r2=0.088) was at least partly due to insufficient bacterial production to meet the C demands of predator taxa, and high variability in the data over time. This is reflected in the performance statistics for model variants where select microbial taxa and data were removed. The optimal model in terms of predictive utility was a model with data from 2002 only, minus naked amoebae (RWSS/data=2.45, r2=0.806). Article in Journal/Newspaper Arctic Kongsfjord* Kongsfjorden Svalbard Tundra Lund University Publications (LUP) Arctic Svalbard Soil Biology and Biochemistry 37 11 2088 2098 |
institution |
Open Polar |
collection |
Lund University Publications (LUP) |
op_collection_id |
ftulundlup |
language |
English |
topic |
Environmental Sciences Ecology |
spellingShingle |
Environmental Sciences Ecology Stapleton, L M Crout, N M J Säwström, Christin Marshall, W A Poulton, P R Tye, A M Laybourn-Parry, J Microbial carbon dynamics in nitrogen amended Arctic tundra soil: Measurement and model testing |
topic_facet |
Environmental Sciences Ecology |
description |
We examined the responses of grazers (protozoa and nematodes) and their main food sources to low levels of nitrogen (N) fertilisation and applied carbon (C) flux models to our data. Replicate plots of tundra soil adjacent to the Kongsfjorden (Svalbard 78°N) were amended with ammonium and nitrate at concentrations of 1 and 5 kg N ha−1 to assess the impact of anthropogenic N deposition over three summers. Bacterial abundance as determined using the fluorochrome SYBR Green and epifluorescence microscopy ranged between 9.73×108 and 102.49×108 cells/g dry wt of soil, with a significant response to N addition occurring only during the second sampling in 2001. Despite little change in bacterial biomass, bacterial production (measured by the incorporation of 3H thymidine into DNA) during the second sampling in 2002, increased in NH4 enriched plots compared to control and NO3 amended plots, indicating that NH4 was the preferred source of inorganic N. The main bacterial predators were heterotrophic flagellates (HNAN) and naked amoebae, which showed no significant response to the N addition. HNAN showed a correlation with bacterial abundance suggesting a dependence on bacteria as a food source. The inability of a microbial C flux model to fit our data (RWSS/data=18.6, r2=0.088) was at least partly due to insufficient bacterial production to meet the C demands of predator taxa, and high variability in the data over time. This is reflected in the performance statistics for model variants where select microbial taxa and data were removed. The optimal model in terms of predictive utility was a model with data from 2002 only, minus naked amoebae (RWSS/data=2.45, r2=0.806). |
format |
Article in Journal/Newspaper |
author |
Stapleton, L M Crout, N M J Säwström, Christin Marshall, W A Poulton, P R Tye, A M Laybourn-Parry, J |
author_facet |
Stapleton, L M Crout, N M J Säwström, Christin Marshall, W A Poulton, P R Tye, A M Laybourn-Parry, J |
author_sort |
Stapleton, L M |
title |
Microbial carbon dynamics in nitrogen amended Arctic tundra soil: Measurement and model testing |
title_short |
Microbial carbon dynamics in nitrogen amended Arctic tundra soil: Measurement and model testing |
title_full |
Microbial carbon dynamics in nitrogen amended Arctic tundra soil: Measurement and model testing |
title_fullStr |
Microbial carbon dynamics in nitrogen amended Arctic tundra soil: Measurement and model testing |
title_full_unstemmed |
Microbial carbon dynamics in nitrogen amended Arctic tundra soil: Measurement and model testing |
title_sort |
microbial carbon dynamics in nitrogen amended arctic tundra soil: measurement and model testing |
publisher |
Elsevier |
publishDate |
2005 |
url |
https://lup.lub.lu.se/record/150691 https://doi.org/10.1016/j.soilbio.2005.03.016 |
geographic |
Arctic Svalbard |
geographic_facet |
Arctic Svalbard |
genre |
Arctic Kongsfjord* Kongsfjorden Svalbard Tundra |
genre_facet |
Arctic Kongsfjord* Kongsfjorden Svalbard Tundra |
op_source |
Soil Biology & Biochemistry; 37(11), pp 2088-2098 (2005) ISSN: 0038-0717 |
op_relation |
https://lup.lub.lu.se/record/150691 http://dx.doi.org/10.1016/j.soilbio.2005.03.016 wos:000233501100012 scopus:27444433912 |
op_doi |
https://doi.org/10.1016/j.soilbio.2005.03.016 |
container_title |
Soil Biology and Biochemistry |
container_volume |
37 |
container_issue |
11 |
container_start_page |
2088 |
op_container_end_page |
2098 |
_version_ |
1766342847613632512 |