Seasonal variation in enzyme activities and temperature sensitivities in Arctic tundra soils
Abstract Arctic soils contain large amounts of organic matter due to very slow rates of detritus decomposition. The first step in decomposition results from the activity of extracellular enzymes produced by soil microbes. We hypothesized that potential enzyme activities are low relative to the large...
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crwiley:10.1111/j.1365-2486.2008.01819.x 2024-09-30T14:29:54+00:00 Seasonal variation in enzyme activities and temperature sensitivities in Arctic tundra soils WALLENSTEIN, MATTHEW D. MCMAHON, SHAWNA K. SCHIMEL, JOSHUA P. 2009 http://dx.doi.org/10.1111/j.1365-2486.2008.01819.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1365-2486.2008.01819.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2486.2008.01819.x en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#vor Global Change Biology volume 15, issue 7, page 1631-1639 ISSN 1354-1013 1365-2486 journal-article 2009 crwiley https://doi.org/10.1111/j.1365-2486.2008.01819.x 2024-09-17T04:50:23Z Abstract Arctic soils contain large amounts of organic matter due to very slow rates of detritus decomposition. The first step in decomposition results from the activity of extracellular enzymes produced by soil microbes. We hypothesized that potential enzyme activities are low relative to the large stocks of organic matter in Arctic tundra soils, and that enzyme activity is low at in situ temperatures. We measured the potential activity of six hydrolytic enzymes at 4 and 20 °C on four sampling dates in tussock, intertussock, shrub organic, and shrub mineral soils at Toolik Lake, Alaska. Potential activities of N ‐acetyl glucosaminidase, β‐glucosidase, and peptidase tended to be greatest at the end of winter, suggesting that microbes produced enzymes while soils were frozen. In general, enzyme activities did not increase during the Arctic summer, suggesting that enzyme production is N‐limited during the period when temperatures would otherwise drive higher enzyme activity in situ . We also detected seasonal variations in the temperature sensitivity ( Q 10 ) of soil enzymes. In general, soil enzyme pools were more sensitive to temperature at the end of the winter than during the summer. We modeled potential in situ β‐glucosidase activities for tussock and shrub organic soils based on measured enzyme activities, temperature sensitivities, and daily soil temperature data. Modeled in situ enzyme activity in tussock soils increased briefly during the spring, then declined through the summer. In shrub soils, modeled enzyme activities increased through the spring thaw into early August, and then declined through the late summer and into winter. Overall, temperature is the strongest factor driving low in situ enzyme activities in the Arctic. However, enzyme activity was low during the summer, possibly due to N‐limitation of enzyme production, which would constrain enzyme activity during the brief period when temperatures would otherwise drive higher rates of decomposition. Article in Journal/Newspaper Arctic Tundra Alaska Wiley Online Library Arctic Global Change Biology 15 7 1631 1639 |
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Wiley Online Library |
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English |
description |
Abstract Arctic soils contain large amounts of organic matter due to very slow rates of detritus decomposition. The first step in decomposition results from the activity of extracellular enzymes produced by soil microbes. We hypothesized that potential enzyme activities are low relative to the large stocks of organic matter in Arctic tundra soils, and that enzyme activity is low at in situ temperatures. We measured the potential activity of six hydrolytic enzymes at 4 and 20 °C on four sampling dates in tussock, intertussock, shrub organic, and shrub mineral soils at Toolik Lake, Alaska. Potential activities of N ‐acetyl glucosaminidase, β‐glucosidase, and peptidase tended to be greatest at the end of winter, suggesting that microbes produced enzymes while soils were frozen. In general, enzyme activities did not increase during the Arctic summer, suggesting that enzyme production is N‐limited during the period when temperatures would otherwise drive higher enzyme activity in situ . We also detected seasonal variations in the temperature sensitivity ( Q 10 ) of soil enzymes. In general, soil enzyme pools were more sensitive to temperature at the end of the winter than during the summer. We modeled potential in situ β‐glucosidase activities for tussock and shrub organic soils based on measured enzyme activities, temperature sensitivities, and daily soil temperature data. Modeled in situ enzyme activity in tussock soils increased briefly during the spring, then declined through the summer. In shrub soils, modeled enzyme activities increased through the spring thaw into early August, and then declined through the late summer and into winter. Overall, temperature is the strongest factor driving low in situ enzyme activities in the Arctic. However, enzyme activity was low during the summer, possibly due to N‐limitation of enzyme production, which would constrain enzyme activity during the brief period when temperatures would otherwise drive higher rates of decomposition. |
format |
Article in Journal/Newspaper |
author |
WALLENSTEIN, MATTHEW D. MCMAHON, SHAWNA K. SCHIMEL, JOSHUA P. |
spellingShingle |
WALLENSTEIN, MATTHEW D. MCMAHON, SHAWNA K. SCHIMEL, JOSHUA P. Seasonal variation in enzyme activities and temperature sensitivities in Arctic tundra soils |
author_facet |
WALLENSTEIN, MATTHEW D. MCMAHON, SHAWNA K. SCHIMEL, JOSHUA P. |
author_sort |
WALLENSTEIN, MATTHEW D. |
title |
Seasonal variation in enzyme activities and temperature sensitivities in Arctic tundra soils |
title_short |
Seasonal variation in enzyme activities and temperature sensitivities in Arctic tundra soils |
title_full |
Seasonal variation in enzyme activities and temperature sensitivities in Arctic tundra soils |
title_fullStr |
Seasonal variation in enzyme activities and temperature sensitivities in Arctic tundra soils |
title_full_unstemmed |
Seasonal variation in enzyme activities and temperature sensitivities in Arctic tundra soils |
title_sort |
seasonal variation in enzyme activities and temperature sensitivities in arctic tundra soils |
publisher |
Wiley |
publishDate |
2009 |
url |
http://dx.doi.org/10.1111/j.1365-2486.2008.01819.x https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1365-2486.2008.01819.x https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2486.2008.01819.x |
geographic |
Arctic |
geographic_facet |
Arctic |
genre |
Arctic Tundra Alaska |
genre_facet |
Arctic Tundra Alaska |
op_source |
Global Change Biology volume 15, issue 7, page 1631-1639 ISSN 1354-1013 1365-2486 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1111/j.1365-2486.2008.01819.x |
container_title |
Global Change Biology |
container_volume |
15 |
container_issue |
7 |
container_start_page |
1631 |
op_container_end_page |
1639 |
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1811635063734927360 |