<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE article PUBLIC "-//NLM//DTD Journal Publishing DTD v3.0 20080202//EN" "https://jats.nlm.nih.gov/nlm-dtd/publishing/3.0/journalpublishing3.dtd">
<article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" article-type="research-article" dtd-version="3.0" xml:lang="en">
<front>
<journal-meta>
<journal-id journal-id-type="publisher">BG</journal-id>
<journal-title-group>
<journal-title>Biogeosciences</journal-title>
<abbrev-journal-title abbrev-type="publisher">BG</abbrev-journal-title>
<abbrev-journal-title abbrev-type="nlm-ta">Biogeosciences</abbrev-journal-title>
</journal-title-group>
<issn pub-type="epub">1726-4189</issn>
<publisher><publisher-name>Copernicus Publications</publisher-name>
<publisher-loc>Göttingen, Germany</publisher-loc>
</publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="doi">10.5194/bg-9-2259-2012</article-id>
<title-group>
<article-title>Activity and diversity of methane-oxidizing bacteria in glacier forefields on siliceous and calcareous bedrock</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Nauer</surname>
<given-names>P. A.</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Dam</surname>
<given-names>B.</given-names>
</name>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Liesack</surname>
<given-names>W.</given-names>
</name>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Zeyer</surname>
<given-names>J.</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Schroth</surname>
<given-names>M. H.</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>Institute of Biogeochemistry and Pollutant Dynamics, ETH Zurich, 8092 Zurich, Switzerland</addr-line>
</aff>
<aff id="aff2">
<label>2</label>
<addr-line>Max-Planck-Institute for Terrestrial Microbiology, 35043 Marburg, Germany</addr-line>
</aff>
<pub-date pub-type="epub">
<day>25</day>
<month>06</month>
<year>2012</year>
</pub-date>
<volume>9</volume>
<issue>6</issue>
<fpage>2259</fpage>
<lpage>2274</lpage>
<permissions>
<copyright-statement>Copyright: &#x000a9; 2012 P. A. Nauer et al.</copyright-statement>
<copyright-year>2012</copyright-year>
<license license-type="open-access">
<license-p>This work is licensed under the Creative Commons Attribution 3.0 Unported License. To view a copy of this licence, visit <ext-link ext-link-type="uri"  xlink:href="https://creativecommons.org/licenses/by/3.0/">https://creativecommons.org/licenses/by/3.0/</ext-link></license-p>
</license>
</permissions>
<self-uri xlink:href="https://bg.copernicus.org/articles/9/2259/2012/bg-9-2259-2012.html">This article is available from https://bg.copernicus.org/articles/9/2259/2012/bg-9-2259-2012.html</self-uri>
<self-uri xlink:href="https://bg.copernicus.org/articles/9/2259/2012/bg-9-2259-2012.pdf">The full text article is available as a PDF file from https://bg.copernicus.org/articles/9/2259/2012/bg-9-2259-2012.pdf</self-uri>
<abstract>
<p>The global methane (CH&lt;sub&gt;4&lt;/sub&gt;) cycle is largely driven by methanogenic
archaea and methane-oxidizing bacteria (MOB), but little is known about
their activity and diversity in pioneer ecosystems. We conducted a field
survey in forefields of 13 receding Swiss glaciers on both siliceous and
calcareous bedrock to investigate and quantify CH&lt;sub&gt;4&lt;/sub&gt; turnover based on
soil-gas CH&lt;sub&gt;4&lt;/sub&gt; concentration profiles, and to characterize the MOB
community by sequencing and terminal restriction fragment length
polymorphism (T-RFLP) analysis of &lt;i&gt;pmoA&lt;/i&gt;. Methane turnover was fundamentally
different in the two bedrock categories. Of the 36 CH&lt;sub&gt;4&lt;/sub&gt; concentration
profiles from siliceous locations, 11 showed atmospheric CH&lt;sub&gt;4&lt;/sub&gt;
consumption at concentrations of ~1–2 μL L&lt;sup&gt;−1&lt;/sup&gt; with
soil-atmosphere CH&lt;sub&gt;4&lt;/sub&gt; fluxes of –0.14 to –1.1 mg m&lt;sup&gt;−2&lt;/sup&gt; d&lt;sup&gt;−1&lt;/sup&gt;.
Another 11 profiles showed no apparent activity, while the remaining 14
exhibited slightly increased CH&lt;sub&gt;4&lt;/sub&gt; concentrations of ~2–10 μL L&lt;sup&gt;−1&lt;/sup&gt; , most likely due to microsite methanogenesis. In
contrast, all profiles from calcareous sites suggested a substantial, yet
unknown CH&lt;sub&gt;4&lt;/sub&gt; source below our sampling zone, with soil-gas CH&lt;sub&gt;4&lt;/sub&gt;
concentrations reaching up to 1400 μL L&lt;sup&gt;−1&lt;/sup&gt;. Remarkably, most
soils oxidized ~90 % of the deep-soil CH&lt;sub&gt;4&lt;/sub&gt;, resulting
in soil-atmosphere fluxes of 0.12 to 31 mg m&lt;sup&gt;−2&lt;/sup&gt; d&lt;sup&gt;−1&lt;/sup&gt;. MOB showed
limited diversity in both siliceous and calcareous forefields: all
identified &lt;i&gt;pmoA&lt;/i&gt; sequences formed only 5 operational taxonomic units (OTUs) at
the species level and, with one exception, could be assigned to either
&lt;i&gt;Methylocystis&lt;/i&gt; or the as-yet-uncultivated Upland Soil Cluster &amp;gamma; (USC&amp;gamma;).
The latter dominated T-RFLP patterns of all siliceous and most calcareous
samples, while &lt;i&gt;Methylocystis&lt;/i&gt; dominated in 4 calcareous samples. Members of Upland Soil
Cluster &amp;alpha; (USC&amp;alpha;) were not detected. Apparently, USC&amp;gamma; adapted best to the oligotrophic cold climate conditions at the investigated
pioneer sites.</p>
</abstract>
<counts><page-count count="16"/></counts>
</article-meta>
</front>
<body/>
<back>
<ref-list>
<title>References</title>
<ref id="ref1">
<label>1</label><mixed-citation publication-type="other" xlink:type="simple">Adamsen, A. P. S. and King, G. M.: Methane consumption in temperate and subarctic forest soils: Rates, vertical zonation, and responses to water and nitrogen, Appl. Environ. Microb., 59, 485–490, 1993.</mixed-citation>
</ref>
<ref id="ref2">
<label>2</label><mixed-citation publication-type="other" xlink:type="simple">Andersen, B. L., Bidoglio, G., Leip, A., and Rembges, D.: A new method to study simultaneous methane oxidation and methane production in soils, Global Biogeochem. Cy., 12, 587–594, 1998.</mixed-citation>
</ref>
<ref id="ref3">
<label>3</label><mixed-citation publication-type="other" xlink:type="simple">Auman, A. J., Speake, C. C., and Lidstrom, M. E.: &lt;i&gt;nifH&lt;/i&gt; sequences and nitrogen fixation in type I and type II methanotrophs, Appl. Environ. Microb., 67, 4009–4016, 2001.</mixed-citation>
</ref>
<ref id="ref4">
<label>4</label><mixed-citation publication-type="other" xlink:type="simple">Baani, M. and Liesack, W.: Two isozymes of particulate methane monooxygenase with different methane oxidation kinetics are found in &lt;i&gt;Methylocystis&lt;/i&gt; sp. strain SC2, P. Natl. Acad. Sci. USA, 105, 10203–10208, 2008.</mixed-citation>
</ref>
<ref id="ref5">
<label>5</label><mixed-citation publication-type="other" xlink:type="simple">Barbier, B. A., Dziduch, I., Liebner, S., Ganzert, L., Lantuit, H., Pollard, W., and Wagner, D.: Methane-cycling communities in a permafrost-affected soil on Herschel Island, Western Canadian Arctic: Active layer profiling of &lt;i&gt;mcrA&lt;/i&gt; and &lt;i&gt;pmoA&lt;/i&gt; genes, FEMS Microbiol. Ecol., &lt;a href=&quot;http://dx.doi.org/10.1111/j.1574-6941.2012.01332.x&quot;&gt;https://doi.org/10.1111/j.1574-6941.2012.01332.x&lt;/a&gt;, 2012.</mixed-citation>
</ref>
<ref id="ref6">
<label>6</label><mixed-citation publication-type="other" xlink:type="simple">Bárcena, T. G., Yde, J. C., and Finster, K. W.: Methane flux and high-affinity methanotrophic diversity along the chronosequence of a receding glacier in Greenland, Ann. Glaciol., 51, 23–31, 2010.</mixed-citation>
</ref>
<ref id="ref7">
<label>7</label><mixed-citation publication-type="other" xlink:type="simple">Bárcena, T., Finster, K., and Yde, J.: Spatial patterns of soil development, methane oxidation, and methanotrophic diversity along a receding glacier forefield, southeast Greenland, Arct. Antarct. Alp. Res., 43, 178–188, 2011.</mixed-citation>
</ref>
<ref id="ref8">
<label>8</label><mixed-citation publication-type="other" xlink:type="simple">Bender, M. and Conrad, R.: Kinetics of CH&lt;sub&gt;4&lt;/sub&gt; oxidation in oxic soils exposed to ambient air or high CH&lt;sub&gt;4&lt;/sub&gt; mixing ratios, FEMS Microbiol. Lett., 101, 261–270, 1992.</mixed-citation>
</ref>
<ref id="ref9">
<label>9</label><mixed-citation publication-type="other" xlink:type="simple">Bernasconi, S. M., Bauder, A., Bourdon, B., Brunner, I., Bünemann, E., Chris, I., Derungs, N., Edwards, P., Farinotti, D., Frey, B., Frossard, E., Furrer, G., Gierga, M., Göransson, H., Gülland, K., Hagedorn, F., Hajdas, I., Hindshaw, R., Ivy-Ochs, S., Jansa, J., Jonas, T., Kiczka, M., Kretzschmar, R., Lemarchand, E., Luster, J., Magnusson, J., Mitchell, E. A. D., Venterink, H. O., Plötze, M., Reynolds, B., Smittenberg, R. H., Stähli, M., Tamburini, F., Tipper, E. T., Wacker, L., Welc, M., Wiederhold, J. G., Zeyer, J., Zimmermann, S., and Zumsteg, A.: Chemical and biological gradients along the Damma glacier soil chronosequence, Switzerland, Vadose Zone J, 10, 867–883, 2011.</mixed-citation>
</ref>
<ref id="ref10">
<label>10</label><mixed-citation publication-type="other" xlink:type="simple">Boetius, A., Ravenschlag, K., Schubert, C. J., Rickert, D., Widdel, F., Gieseke, A., Amann, R., Jorgensen, B. B., Witte, U., and Pfannkuche, O.: A marine microbial consortium apparently mediating anaerobic oxidation of methane, Nature, 407, 623–626, 2000.</mixed-citation>
</ref>
<ref id="ref11">
<label>11</label><mixed-citation publication-type="other" xlink:type="simple">Born, M., Dörr, H., and Levin, I.: Methane consumption in aerated soils of the temperate zone, Tellus B, 42, 2–8, 1990.</mixed-citation>
</ref>
<ref id="ref12">
<label>12</label><mixed-citation publication-type="other" xlink:type="simple">Bourne, D. G., McDonald, I. R., and Murrell, J. C.: Comparison of &lt;i&gt;pmoA&lt;/i&gt; PCR primer sets as tools for investigating methanotroph diversity in three Danish soils, Appl. Environ. Microbiol., 67, 3802–3809, 2001.</mixed-citation>
</ref>
<ref id="ref13">
<label>13</label><mixed-citation publication-type="other" xlink:type="simple">Brankatschk, R., Towe, S., Kleineidam, K., Schloter, M., and Zeyer, J.: Abundances and potential activities of nitrogen cycling microbial communities along a chronosequence of a glacier forefield, ISME J., 2010.</mixed-citation>
</ref>
<ref id="ref14">
<label>14</label><mixed-citation publication-type="other" xlink:type="simple">Conrad, R.: Soil microorganisms as controllers of atmospheric trace gases (H&lt;sub&gt;2&lt;/sub&gt;, CO, CH&lt;sub&gt;4&lt;/sub&gt;, OCS, N&lt;sub&gt;2&lt;/sub&gt;O, and NO), Microbiol. Mol. Biol. R., 60, 609, 1996.</mixed-citation>
</ref>
<ref id="ref15">
<label>15</label><mixed-citation publication-type="other" xlink:type="simple">Conrad, R.: The global methane cycle: Recent advances in understanding the microbial processes involved, Environ. Microbiol. Reports, 1, 285–292, 2009.</mixed-citation>
</ref>
<ref id="ref16">
<label>16</label><mixed-citation publication-type="other" xlink:type="simple">Costello, A. M. and Lidstrom, M. E.: Molecular characterization of functional and phylogenetic genes from natural populations of methanotrophs in lake sediments, Appl. Environ. Microbiol., 65, 5066–5074, 1999.</mixed-citation>
</ref>
<ref id="ref17">
<label>17</label><mixed-citation publication-type="other" xlink:type="simple">De Visscher, A., Boeckx, P., and van Cleemput, O.: Artificial methane sinks, in: Greenhouse gas sinks, edited by: Reay, D. S., Hewitt, C. N., Smith, K. A., and Grace, J., CABI, Wallingford, 184–200, 2007.</mixed-citation>
</ref>
<ref id="ref18">
<label>18</label><mixed-citation publication-type="other" xlink:type="simple">Dedysh, S. N., Ricke, P., and Liesack, W.: NifH and NifD phylogenies: an evolutionary basis for understanding nitrogen fixation capabilities of methanotrophic bacteria, Microbiology (SGM), 150, 1301–11313, 2004.</mixed-citation>
</ref>
<ref id="ref19">
<label>19</label><mixed-citation publication-type="other" xlink:type="simple">Degelmann, D. M., Borken, W., Drake, H. L., and Kolb, S.: Different atmospheric methane-oxidizing communities in European beech and Norway spruce soils, Appl. Environ. Microbiol., 76, 3228–3235, 2010.</mixed-citation>
</ref>
<ref id="ref20">
<label>20</label><mixed-citation publication-type="other" xlink:type="simple">Dlugokencky, E., Bruhwiler, L., White, J., Emmons, L., Novelli, P., Montzka, S., Masarie, K., Lang, P., Crotwell, A., and Miller, J.: Observational constraints on recent increases in the atmospheric CH&lt;sub&gt;4&lt;/sub&gt; burden, Geophys. Res. Lett., 36, L18803, https://doi.org/10.1029/2009GL039780, 2009.</mixed-citation>
</ref>
<ref id="ref21">
<label>21</label><mixed-citation publication-type="other" xlink:type="simple">Duc, L., Noll, M., Meier, B., Bürgmann, H., and Zeyer, J.: High diversity of diazotrophs in the forefield of a receding alpine glacier, Microb. Ecol., 57, 179–190, 2009.</mixed-citation>
</ref>
<ref id="ref22">
<label>22</label><mixed-citation publication-type="other" xlink:type="simple">Dunbar, J., Ticknor, L. O., and Kuske, C. R.: Phylogenetic specificity and reproducibility and new method for analysis of terminal restriction fragment profiles of 16S rRNA genes from bacterial communities, Appl. Environ. Microbiol., 67, 190–197, 2001.</mixed-citation>
</ref>
<ref id="ref23">
<label>23</label><mixed-citation publication-type="other" xlink:type="simple">Dunfield, P., Knowles, R., Dumont, R., and Moore, T. R.: Methane production and consumption in temperate and subarctic peat soils: Response to temperature and pH, Soil Biol. Biochem., 25, 321–326, 1993.</mixed-citation>
</ref>
<ref id="ref24">
<label>24</label><mixed-citation publication-type="other" xlink:type="simple">Dunfield, P. F.: The soil methane sink, in: Greenhouse gas sinks, edited by: Reay, D., Hewitt, K., Smith, K., and Grace, J., CABI, Wallingford, 152–170, 2007.</mixed-citation>
</ref>
<ref id="ref25">
<label>25</label><mixed-citation publication-type="other" xlink:type="simple">Egli, M., Wernli, M., Kneisel, C., and Haeberli, W.: Melting glaciers and soil development in the proglacial area Morteratsch (Swiss Alps): I. Soil type chronosequence, Arct. Antarct. Alp. Res., 38, 499–509, 2006.</mixed-citation>
</ref>
<ref id="ref26">
<label>26</label><mixed-citation publication-type="other" xlink:type="simple">Etiope, G., and Klusman, R. W.: Geologic emissions of methane to the atmosphere, Chemosphere, 49, 777–789, 2002.</mixed-citation>
</ref>
<ref id="ref27">
<label>27</label><mixed-citation publication-type="other" xlink:type="simple">Ettwig, K. F., Butler, M. K., Le Paslier, D., Pelletier, E., Mangenot, S., Kuypers, M. M. M., Schreiber, F., Dutilh, B. E., Zedelius, J., de Beer, D., Gloerich, J., Wessels, H. J. C. T., van Alen, T., Luesken, F., Wu, M. L., van de Pas-Schoonen, K. T., Op den Camp, H. J. M., Janssen-Megens, E. M., Francoijs, K.-J., Stunnenberg, H., Weissenbach, J., Jetten, M. S. M., and Strous, M.: Nitrite-driven anaerobic methane oxidation by oxygenic bacteria, Nature, 464, 543–548, 2010.</mixed-citation>
</ref>
<ref id="ref28">
<label>28</label><mixed-citation publication-type="other" xlink:type="simple">Fechner, E. J. and Hemond, H. F.: Methane transport and oxidation in the unsaturated zone of a Sphagnum peatland, Global Biogeochem. Cy., 6, 33–44, 1992.</mixed-citation>
</ref>
<ref id="ref29">
<label>29</label><mixed-citation publication-type="other" xlink:type="simple">Flessa, H., Rodionov, A., Guggenberger, G., Fuchs, H., Magdon, P., Shibistova, O., Zrazhevskaya, G., Mikheyeva, N., Kasansky, O. A., and Blodau, C.: Landscape controls of CH&lt;sub&gt;4&lt;/sub&gt; fluxes in a catchment of the forest tundra ecotone in northern Siberia, Glob. Change Biol., 14, 2040–2056, 2008.</mixed-citation>
</ref>
<ref id="ref30">
<label>30</label><mixed-citation publication-type="other" xlink:type="simple">Forster, P., Ramaswamy, V., Artaxo, P., Berntsen, T., Betts, R., Fahey, D. W., Haywood, J., Lean, J., Lowe, D. C., Myhre, G., Nganga, J., Prinn, R., Raga, G., Schulz, M., and Van Dorland, R.: Changes in atmospheric constituents and in radiative forcing, in: Climate change 2007: The physical science basis. Contribution of working group I to the fourth assessment report of the intergovernmental panel on climate change, edited by: Solomon, S., Qin, D., Manning, Z., Chen, Z., Marquis, M., Averyt, K. B., Tignor, M., and Miller, H. L., Cambridge University Press, Cambridge, UK and New York, NY, USA, 2007.</mixed-citation>
</ref>
<ref id="ref31">
<label>31</label><mixed-citation publication-type="other" xlink:type="simple">Friborg, T., Christensen, T. R., and Søgaard, H.: Rapid response of greenhouse gas emission to early spring thaw in a subarctic mire as shown by micrometeorological techniques, Geophys. Res. Lett., 24, 3061–3064, 1997.</mixed-citation>
</ref>
<ref id="ref32">
<label>32</label><mixed-citation publication-type="other" xlink:type="simple">Fuller, E. N., Schettler, P. D., and Giddings, J. C.: New method for prediction of binary gas-phase diffusion coefficients, Ind. Eng. Chem., 58, 18–27, 1966.</mixed-citation>
</ref>
<ref id="ref33">
<label>33</label><mixed-citation publication-type="other" xlink:type="simple">Hanson, R. and Hanson, T.: Methanotrophic bacteria, Microbiol. Mol. Biol. R., 60, 439–471, 1996.</mixed-citation>
</ref>
<ref id="ref34">
<label>34</label><mixed-citation publication-type="other" xlink:type="simple">Hartmann, A., Buchmann, N., and Niklaus, P.: A study of soil methane sink regulation in two grasslands exposed to drought and N fertilization, Plant Soil, 1–11, 2010.</mixed-citation>
</ref>
<ref id="ref35">
<label>35</label><mixed-citation publication-type="other" xlink:type="simple">Henckel, T., Jackel, U., Schnell, S., and Conrad, R.: Molecular analyses of novel methanotrophic communities in forest soil that oxidize atmospheric methane, Appl. Env. Microbiol., 66, 1801–1808, 2000.</mixed-citation>
</ref>
<ref id="ref36">
<label>36</label><mixed-citation publication-type="other" xlink:type="simple">Hendriks, D. M. D., van Huissteden, J., and Dolman, A. J.: Multi-technique assessment of spatial and temporal variability of methane fluxes in a peat meadow, Agr. Forest Meteorol., 150, 757–774, 2010.</mixed-citation>
</ref>
<ref id="ref37">
<label>37</label><mixed-citation publication-type="other" xlink:type="simple">Henneberger, R., Lüke, C., Mosberger, L., and Schroth, M. H.,: Structure and function of methanotrophic communities in a landfill-cover soil. FEMS Microbiol. Ecol., &lt;a href=&quot;http://dx.doi.org/10.1111/j.1574-6941.2011.01278.x&quot;&gt;https://doi.org/10.1111/j.1574-6941.2011.01278.x&lt;/a&gt;, 2012.</mixed-citation>
</ref>
<ref id="ref38">
<label>38</label><mixed-citation publication-type="other" xlink:type="simple">Hinkel, K. M., Paetzold, F., Nelson, F. E., and Bockheim, J. G.: Patterns of soil temperature and moisture in the active layer and upper permafrost at Barrow, Alaska: 1993–1999, Global Planet. Change, 29, 293–309, 2001.</mixed-citation>
</ref>
<ref id="ref39">
<label>39</label><mixed-citation publication-type="other" xlink:type="simple">Hodson, A., Boggild, C., Hanna, E., Huybrechts, P., Langford, H., Cameron, K., and Houldsworth, A.: The cryoconite ecosystem on the greenland ice sheet, Ann. Glaciol., 51, 123–129, 2010.</mixed-citation>
</ref>
<ref id="ref40">
<label>40</label><mixed-citation publication-type="other" xlink:type="simple">Holmes, A. J., Costello, A., Lidstrom, M. E., and Murrell, J. C.: Evidence that particulate methane monooxygenase and ammonia monooxygenase may be evolutionarily related, FEMS Microbiol. Lett., 132, 203–208, 1995.</mixed-citation>
</ref>
<ref id="ref41">
<label>41</label><mixed-citation publication-type="other" xlink:type="simple">Holmes, A. J., Roslev, P., McDonald, I. R., Iversen, N., Henriksen, K., and Murrell, J. C.: Characterization of methanotrophic bacterial populations in soils showing atmospheric methane uptake, Appl. Env. Microbiol., 65, 3312–3318, 1999.</mixed-citation>
</ref>
<ref id="ref42">
<label>42</label><mixed-citation publication-type="other" xlink:type="simple">Hormes, A., Müller, B. U., and Schlüchter, C.: The Alps with little ice: Evidence for eight holocene phases of reduced glacier extent in the central Swiss Alps, The Holocene, 11, 255–265, 2001.</mixed-citation>
</ref>
<ref id="ref43">
<label>43</label><mixed-citation publication-type="other" xlink:type="simple">IUSS Working Group WRB: World reference base for soil resources 2006, World Soil Resources Reports No.&amp;nbsp;103. FAO, Rome, 2006.</mixed-citation>
</ref>
<ref id="ref44">
<label>44</label><mixed-citation publication-type="other" xlink:type="simple">Joerin, U. E., Stocker, T. F., and Schlüchter, C.: Multicentury glacier fluctuations in the Swiss Alps during the Holocene, The Holocene, 16, 697–704, 2006.</mixed-citation>
</ref>
<ref id="ref45">
<label>45</label><mixed-citation publication-type="other" xlink:type="simple">Kammann, C., Grünhage, L., Jäger, H. J., and Wachinger, G.: Methane fluxes from differentially managed grassland study plots: The important role of CH&lt;sub&gt;4&lt;/sub&gt; oxidation in grassland with a high potential for CH&lt;sub&gt;4&lt;/sub&gt; production, Environ. Pollut., 115, 261–273, 2001.</mixed-citation>
</ref>
<ref id="ref46">
<label>46</label><mixed-citation publication-type="other" xlink:type="simple">Kammann, C., Hepp, S., Lenhart, K., and Müller, C.: Stimulation of methane consumption by endogenous CH&lt;sub&gt;4&lt;/sub&gt; production in aerobic grassland soil, Soil Biol. Biochem., 41, 622–629, 2009.</mixed-citation>
</ref>
<ref id="ref47">
<label>47</label><mixed-citation publication-type="other" xlink:type="simple">Klusman, R. W., Leopold, M. E., and LeRoy, M. P.: Seasonal variation in methane fluxes from sedimentary basins to the atmosphere: Results from chamber measurements and modeling of transport from deep sources, J. Geophys. Res., 105, 24661–24670, 2000.</mixed-citation>
</ref>
<ref id="ref48">
<label>48</label><mixed-citation publication-type="other" xlink:type="simple">Knief, C. and Dunfield, P. F.: Response and adaptation of different methanotrophic bacteria to low methane mixing ratios, Environ. Microbiol., 7, 1307–1317, 2005.</mixed-citation>
</ref>
<ref id="ref49">
<label>49</label><mixed-citation publication-type="other" xlink:type="simple">Knief, C., Lipski, A., and Dunfield, P. F.: Diversity and activity of methanotrophic bacteria in different upland soils, Appl. Environ. Microbiol., 69, 6703–6714, 2003.</mixed-citation>
</ref>
<ref id="ref50">
<label>50</label><mixed-citation publication-type="other" xlink:type="simple">Knief, C., Kolb, S., Bodelier, P. L. E., Lipski, A., and Dunfield, P. F.: The active methanotrophic community in hydromorphic soils changes in response to changing methane concentration, Environ. Microbiol., 8, 321–333, 2006.</mixed-citation>
</ref>
<ref id="ref51">
<label>51</label><mixed-citation publication-type="other" xlink:type="simple">Kolb, S., Knief, C., Dunfield, P. F., and Conrad, R.: Abundance and activity of uncultured methanotrophic bacteria involved in the consumption of atmospheric methane in two forest soils, Environ. Microbiol., 7, 1150–1161, 2005.</mixed-citation>
</ref>
<ref id="ref52">
<label>52</label><mixed-citation publication-type="other" xlink:type="simple">Kolb, S.: The quest for atmospheric methane oxidizers in forest soils, Environ. Microbiol. Reports, 1, 336–346, 2009.</mixed-citation>
</ref>
<ref id="ref53">
<label>53</label><mixed-citation publication-type="other" xlink:type="simple">Kristensen, A. H., Thorbjørn, A., Jensen, M. P., Pedersen, M., and Moldrup, P.: Gas-phase diffusivity and tortuosity of structured soils, J. Contam. Hydrol., 115, 26–33, 2010.</mixed-citation>
</ref>
<ref id="ref54">
<label>54</label><mixed-citation publication-type="other" xlink:type="simple">Lacelle, D.: Environmental setting, (micro)morphologies and stable C–O isotope composition of cold climate carbonate precipitates – A review and evaluation of their potential as paleoclimatic proxies, Quaternary Sci. Rev., 26, 1670–1689, 2007.</mixed-citation>
</ref>
<ref id="ref55">
<label>55</label><mixed-citation publication-type="other" xlink:type="simple">Lafrenière, M. and Sharp, M.: The concentration and fluorescence of dissolved organic carbon (DOC) in glacial and nonglacial catchments: Interpreting hydrological flow routing and DOC sources, Arct. Antarct. Alp. Res., 36, 156–165, 2004.</mixed-citation>
</ref>
<ref id="ref56">
<label>56</label><mixed-citation publication-type="other" xlink:type="simple">Lane, J. D.: 16s/23s rRNA sequencing, in: Nucleic acid techniques in bacterial systematics, edited by: Stackebrandt, E., and Goodfellow, M., John Wiley and Sons, New York, NY, 115–175, 1991.</mixed-citation>
</ref>
<ref id="ref57">
<label>57</label><mixed-citation publication-type="other" xlink:type="simple">Lazzaro, A., Abegg, C., and Zeyer, J.: Bacterial community structure of glacier forefields on siliceous and calcareous bedrock, Eur. J. Soil Sci., 60, 860–870, 2009.</mixed-citation>
</ref>
<ref id="ref58">
<label>58</label><mixed-citation publication-type="other" xlink:type="simple">Lazzaro, A., Gauer, A., and Zeyer, J.: A field-scale transplantation experiment to investigate structures of soil bacterial communities at pioneering sites, Appl. Environ. Microbiol., &lt;a href=&quot;http://dx.doi.org/10.1128/AEM.05778-11&quot;&gt;https://doi.org/10.1128/AEM.05778-11&lt;/a&gt;, 2011.</mixed-citation>
</ref>
<ref id="ref59">
<label>59</label><mixed-citation publication-type="other" xlink:type="simple">Le Mer, J. and Roger, P.: Production, oxidation, emission and consumption of methane by soils: A review, Eur. J. Soil Biol., 37, 25-5-0, 2001.</mixed-citation>
</ref>
<ref id="ref60">
<label>60</label><mixed-citation publication-type="other" xlink:type="simple">Liebner, S. and Wagner, D.: Permafrost – current and future challenges to study methanotrophy in permafrost-affected tundra and wetlands, in: Handbook of hydrocarbon and lipid microbiology, edited by: Timmis, K. N., Springer Berlin Heidelberg, 2173–2179, 2010.</mixed-citation>
</ref>
<ref id="ref61">
<label>61</label><mixed-citation publication-type="other" xlink:type="simple">Ludwig, W., Strunk, O., Westram, R., Richter, L., Meier, H., Yadhukumar, Buchner, A., Lai, T., Steppi, S., Jobb, G., Förster, W., Brettske, I., Gerber, S., Ginhart, A. W., Gross, O., Grumann, G., Hermann, S., Jost, R., König, A., Liss, T., Lü{ß}mann, R., May, M., Nonhoff, B., Reichel, B., Strehlow, R., Stamatakis, A., Stuckmann, N., Vilbig, A., Lenke, M., Ludwig, T., Bode, A., and Schleifer, K.-H.: ARB: A software environment for sequence data. Nucl. Acids Res., 32, 1363–1371, 2004.</mixed-citation>
</ref>
<ref id="ref62">
<label>62</label><mixed-citation publication-type="other" xlink:type="simple">Maisch, M., Wipf, A., Denneler, B., Battaglia, J., and Benz, C.: Die Gletscher der Schweizer Alpen: Gletscherhochstand 1850, aktuelle Vergletscherung, Gletscherschwund-Szenarien, vdf Hochschulverlag AG an der ETH Zürich, Zürich, 2000.</mixed-citation>
</ref>
<ref id="ref63">
<label>63</label><mixed-citation publication-type="other" xlink:type="simple">Martineau, C., Whyte, L. G., and Greer, C. W.: Stable isotope probing analysis of the diversity and activity of methanotrophic bacteria in soils from the Canadian High Arctic, Appl. Environ. Microbiol., 76, 5773–5784, 2010.</mixed-citation>
</ref>
<ref id="ref64">
<label>64</label><mixed-citation publication-type="other" xlink:type="simple">Matthews, M. D.: Migration – a view from the top, in: Hydrocarbon migration and its near-surface expression, edited by: Schumacher, D., and Abrams, M. A., Amer. Assoc. Petrol. Geol., Tulsa, OK, 139–155, 1996.</mixed-citation>
</ref>
<ref id="ref65">
<label>65</label><mixed-citation publication-type="other" xlink:type="simple">McDonald, I. R., Bodrossy, L., Chen, Y., and Murrell, J. C.: Molecular ecology techniques for the study of aerobic methanotrophs, Appl. Environ. Microbiol., 74, 1305–1315, 2008.</mixed-citation>
</ref>
<ref id="ref66">
<label>66</label><mixed-citation publication-type="other" xlink:type="simple">Moldrup, P., Olesen, T., Gamst, J., Schjonning, P., Yamaguchi, T., and Rolston, D. E.: Predicting the gas diffusion coefficient in repacked soil: Water-induced linear reduction model, Soil Sci. Soc. Am. J., 64, 1588–1594, 2000.</mixed-citation>
</ref>
<ref id="ref67">
<label>67</label><mixed-citation publication-type="other" xlink:type="simple">Moore, T. R. and Knowles, R.: Methane emissions from fen, bog and swamp peatlands in Quebec, Biogeochemistry, 11, 45–61, 1990.</mixed-citation>
</ref>
<ref id="ref68">
<label>68</label><mixed-citation publication-type="other" xlink:type="simple">Muller, R. N. and Hamilton, M. E.: A simple, effective method for determining the bulk density of stony soils, Commun. Soil Sci. Plan., 23, 313–319, 1992.</mixed-citation>
</ref>
<ref id="ref69">
<label>69</label><mixed-citation publication-type="other" xlink:type="simple">Nauer, P. A. and Schroth, M. H.: In situ quantification of atmospheric methane oxidation in near-surface soils, Vadose Zone J., 9, 1052–1062, 2010.</mixed-citation>
</ref>
<ref id="ref70">
<label>70</label><mixed-citation publication-type="other" xlink:type="simple">Nemergut, D., Anderson, S., Cleveland, C., Martin, A., Miller, A., Seimon, A., and Schmidt, S.: Microbial community succession in an unvegetated, recently deglaciated soil, Microb. Ecol., 53, 110–122, 2007.</mixed-citation>
</ref>
<ref id="ref71">
<label>71</label><mixed-citation publication-type="other" xlink:type="simple">Orphan, V. J., House, C. H., Hinrichs, K.-U., McKeegan, K. D., and DeLong, E. F.: Multiple archaeal groups mediate methane oxidation in anoxic cold seep sediments, P. Natl. Acad. Sci. USA, 99, 7663–7668, 2002.</mixed-citation>
</ref>
<ref id="ref72">
<label>72</label><mixed-citation publication-type="other" xlink:type="simple">Sawstrom, C., Mumford, P., Marshall, W., Hodson, A., and Laybourn-Parry, J.: The microbial communities and primary productivity of cryoconite holes in an arctic glacier (Svalbard 79\textdegree N), Polar Biol., 25, 591–596, 2002.</mixed-citation>
</ref>
<ref id="ref73">
<label>73</label><mixed-citation publication-type="other" xlink:type="simple">Shrestha, P. M., Kammann, C., Lenhart, K., Dam, B., and Liesack, W.: Linking activity, composition, and seasonal dynamics of atmospheric methane oxidizers in a meadow soil, ISME J., &lt;a href=&quot;http://dx.doi.org/10.1038/ismej.2011.179&quot;&gt;https://doi.org/10.1038/ismej.2011.179&lt;/a&gt;, 2011.</mixed-citation>
</ref>
<ref id="ref74">
<label>74</label><mixed-citation publication-type="other" xlink:type="simple">Sigler, W. V., and Zeyer, J.: Microbial diversity and activity along the forefields of two receding glaciers, Microb. Ecol., 43, 397–407, 2002.</mixed-citation>
</ref>
<ref id="ref75">
<label>75</label><mixed-citation publication-type="other" xlink:type="simple">Sims, G. K., Ellsworth, T. R., and Mulvaney, R. L.: Microscale determination of inorganic nitrogen in water and soil extracts, Commun. Soil Sci. Plan., 26, 303–316, 1995.</mixed-citation>
</ref>
<ref id="ref76">
<label>76</label><mixed-citation publication-type="other" xlink:type="simple">Smith, K. A., Dobbie, K. E., Ball, B. C., Bakken, L. R., Sitaula, B. K., Hansen, S., Brumme, R., Borken, W., Christensen, S., Priemé, A., Fowler, D., Macdonald, J. A., Skiba, U., Klemedtsson, L., Kasimir-Klemedtsson, A., Degórska, A., and Orlanski, P.: Oxidation of atmospheric methane in northern European soils, comparison with other ecosystems, and uncertainties in the global terrestrial sink, Glob. Change Biol., 6, 791–803, 2000.</mixed-citation>
</ref>
<ref id="ref77">
<label>77</label><mixed-citation publication-type="other" xlink:type="simple">Soil Survey Staff: Soil survey laboratory information manual. Soil survey investigations report no.&amp;nbsp;45, Version 2.0, edidet by: Burt, R., U.S. Department of Agriculture, Natural Resources Conservation Service, Lincoln, Nebraska, 2011.</mixed-citation>
</ref>
<ref id="ref78">
<label>78</label><mixed-citation publication-type="other" xlink:type="simple">Stibal, M., Lawson, E. C., Lis, G. P., Mak, K. M., Wadham, J. L., and Anesio, A. M.: Organic matter content and quality in supraglacial debris across the ablation zone of the greenland ice sheet, Ann. Glaciol., 51, 1–8, 2010.</mixed-citation>
</ref>
<ref id="ref79">
<label>79</label><mixed-citation publication-type="other" xlink:type="simple">Tchawa Yimga, M., Dunfield, P. F., Ricke, P., Heyer, J., and Liesack, W.: Wide distribution of a novel &lt;i&gt;pmoA&lt;/i&gt;-like gene copy among type II methanotrophs, and its expression in &lt;i&gt;Methylocystis&lt;/i&gt; strain SC2, Appl. Environ. Microbiol., 69, 5593–5602, 2003.</mixed-citation>
</ref>
<ref id="ref80">
<label>80</label><mixed-citation publication-type="other" xlink:type="simple">Urmann, K., Gonzalez-Gil, G., Schroth, M. H., and Zeyer, J.: Quantification of microbial methane oxidation in an alpine peat bog, Vadose Zone J., 6, 705–712, 2007.</mixed-citation>
</ref>
<ref id="ref81">
<label>81</label><mixed-citation publication-type="other" xlink:type="simple">Wadham, J. L., Cooper, R. J., Tranter, M., and Bottrell, S.: Evidence for widespread anoxia in the proglacial zone of an arctic glacier, Chem. Geol., 243, 1–15, 2007.</mixed-citation>
</ref>
<ref id="ref82">
<label>82</label><mixed-citation publication-type="other" xlink:type="simple">Wang, F. L. and Bettany, J. R.: Methane emission from canadian prairie and forest soils under short term flooding conditions, Nutr. Cycl. Agroecosys., 49, 197–202, 1997.</mixed-citation>
</ref>
<ref id="ref83">
<label>83</label><mixed-citation publication-type="other" xlink:type="simple">Whalen, S. C. and Reeburgh, W. S.: Consumption of atmospheric methane by tundra soils, Nature, 346, 160–162, 1990.</mixed-citation>
</ref>
<ref id="ref84">
<label>84</label><mixed-citation publication-type="other" xlink:type="simple">Whalen, S. C., Reeburgh, W. S., and Barber, V. A.: Oxidation of methane in boreal forest soils: A comparison of seven measures, Biogeochemistry, 16, 181–211, 1992.</mixed-citation>
</ref>
<ref id="ref85">
<label>85</label><mixed-citation publication-type="other" xlink:type="simple">Yavitt, J. B., Downey, D. M., Lang, G. E., and Sexston, A. J.: Methane consumption in two temperate forest soils, Biogeochemistry, 9, 39–52, 1990.</mixed-citation>
</ref>
<ref id="ref86">
<label>86</label><mixed-citation publication-type="other" xlink:type="simple">Yergeau, E., Hogues, H., Whyte, L. G., and Greer, C. W.: The functional potential of high arctic permafrost revealed by metagenomic sequencing, qPCR and microarray analyses, ISME J., 4, 1206–1214, 2010.</mixed-citation>
</ref>
<ref id="ref87">
<label>87</label><mixed-citation publication-type="other" xlink:type="simple">Zheng, Y., Yang, W., Sun, X., Wang, S.-P., Rui,Y. C., Luo, C. Y., and Guo, L. D.: Methanotrophic community structure and activity under warming and grazing of alpine meadow on the Tibetan Plateau. Appl. Microbiol. Biotechnol., &lt;a href=&quot;http://dx.doi.org/10.1007/s00253-011-3535-5&quot;&gt;https://doi.org/10.1007/s00253-011-3535-5&lt;/a&gt;, 2011.</mixed-citation>
</ref>
</ref-list>
</back>
</article>