{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,8]],"date-time":"2026-01-08T19:12:04Z","timestamp":1767899524108,"version":"3.49.0"},"reference-count":51,"publisher":"American Geophysical Union (AGU)","issue":"3","license":[{"start":{"date-parts":[[2000,9,1]],"date-time":"2000-09-01T00:00:00Z","timestamp":967766400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Global Biogeochemical Cycles"],"published-print":{"date-parts":[[2000,9]]},"abstract":"<jats:p>Ecosystem exchanges of CO<jats:sub>2<\/jats:sub> and CH<jats:sub>4<\/jats:sub> were studied by chamber techniques in five different vegetation types in a high arctic valley at Zackenberg, NE Greenland. The vegetation types were categorized as <jats:italic>Cassiope<\/jats:italic> heath, hummocky fen, continuous fen, grassland and <jats:italic>Salix arctica<\/jats:italic> snowbed. Integrated daytime fluxes for the different vegetation types of the valley showed that the fen areas and the grassland, were significant sources of CH<jats:sub>4<\/jats:sub> with a mean efflux of 6.3 mg CH<jats:sub>4<\/jats:sub> m<jats:sup>\u22122<\/jats:sup> hr<jats:sup>\u22121<\/jats:sup> and sinks for CO<jats:sub>2<\/jats:sub>, with almost \u2010170 mg CO<jats:sub>2<\/jats:sub> m<jats:sup>\u22122<\/jats:sup> hr<jats:sup>\u22121<\/jats:sup>. The heath and snowbed areas had much lower carbon sequestration rates of about \u221225 mg CO<jats:sub>2<\/jats:sub> m<jats:sup>\u22122<\/jats:sup> hr<jats:sup>\u22121<\/jats:sup> and were also sinks for CH<jats:sub>4<\/jats:sub>. Methane emissions from the valley dominated in the hummocky fens. Computation of area integrated mean daytime flux values across all vegetation types of the entire valley bottom revealed that it was a sink of CO<jats:sub>2<\/jats:sub> in the order of \u221296 \u00b1 33 mg CO<jats:sub>2<\/jats:sub> m<jats:sup>\u22122<\/jats:sup> hr<jats:sup>\u22121<\/jats:sup> and a source of 1.9 \u00b1 0.7 mg CH<jats:sub>4<\/jats:sub> m<jats:sup>\u22122<\/jats:sup> hr<jats:sup>\u22121<\/jats:sup>. These values were in accordance with eddy correlation measurements reported elsewhere in this issue and reflect a high\u2010carbon exchange despite the high arctic location. In the fens, where the water table was at or above the soil surface, methane emissions increased with net ecosystem CO<jats:sub>2<\/jats:sub> flux. In places with the water table below the soil surface, such as particularly in the hummocky parts of the fen, oxidation tended to become the dominant controlling factor on methane efflux.<\/jats:p>","DOI":"10.1029\/1999gb001134","type":"journal-article","created":{"date-parts":[[2004,2,4]],"date-time":"2004-02-04T03:05:32Z","timestamp":1075863932000},"page":"701-713","source":"Crossref","is-referenced-by-count":138,"title":["Trace gas exchange in a high\u2010Arctic valley: 1. Variationsin CO<sub>2<\/sub> and CH<sub>4<\/sub> Flux between tundra vegetation types"],"prefix":"10.1029","volume":"14","author":[{"given":"T. R.","family":"Christensen","sequence":"first","affiliation":[]},{"given":"T.","family":"Friborg","sequence":"additional","affiliation":[]},{"given":"M.","family":"Sommerkorn","sequence":"additional","affiliation":[]},{"given":"J.","family":"Kaplan","sequence":"additional","affiliation":[]},{"given":"L.","family":"Illeris","sequence":"additional","affiliation":[]},{"given":"H.","family":"Soegaard","sequence":"additional","affiliation":[]},{"given":"C.","family":"Nordstroem","sequence":"additional","affiliation":[]},{"given":"S.","family":"Jonasson","sequence":"additional","affiliation":[]}],"member":"13","published-online":{"date-parts":[[2000,9]]},"reference":[{"key":"e_1_2_1_2_1","doi-asserted-by":"publisher","DOI":"10.1038\/348711a0"},{"key":"e_1_2_1_3_1","unstructured":"Alm J. CO2and CH4fluxes and carbon balance in the atmospheric interaction of boreal peatlands Ph.D. thesis Univ. of Joensuu Joensuu Finland 1997."},{"key":"e_1_2_1_4_1","doi-asserted-by":"publisher","DOI":"10.1007\/s004420050177"},{"key":"e_1_2_1_5_1","doi-asserted-by":"publisher","DOI":"10.1029\/91JD00610"},{"key":"e_1_2_1_6_1","volume-title":"Vegetation mapping of Zackenberg Valley, Northeast Greenland","author":"Bay C.","year":"1998"},{"key":"e_1_2_1_7_1","doi-asserted-by":"publisher","DOI":"10.1029\/1998GB900021"},{"key":"e_1_2_1_8_1","doi-asserted-by":"publisher","DOI":"10.2307\/2261594"},{"key":"e_1_2_1_9_1","doi-asserted-by":"publisher","DOI":"10.2307\/1939577"},{"key":"e_1_2_1_10_1","doi-asserted-by":"publisher","DOI":"10.1029\/95GB02379"},{"key":"e_1_2_1_11_1","doi-asserted-by":"publisher","DOI":"10.1029\/96JD00219"},{"key":"e_1_2_1_12_1","doi-asserted-by":"publisher","DOI":"10.1007\/BF00000874"},{"key":"e_1_2_1_13_1","doi-asserted-by":"publisher","DOI":"10.1029\/95JD02145"},{"key":"e_1_2_1_14_1","doi-asserted-by":"crossref","first-page":"651","DOI":"10.3402\/tellusb.v48i5.15938","article-title":"Methane flux from northern wetlands and tundra: An ecosystem source modelling approach","volume":"48","author":"Christensen T. R.","year":"1996","journal-title":"Tellus Ser. B"},{"key":"e_1_2_1_15_1","doi-asserted-by":"publisher","DOI":"10.1029\/98JD00084"},{"key":"e_1_2_1_16_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0929-1393(98)00146-2"},{"key":"e_1_2_1_17_1","first-page":"239","article-title":"Carbon cycling and methane exchange in Eurasian tundra ecosystems","volume":"28","author":"Christensen T. R.","year":"1999","journal-title":"Ambio"},{"key":"e_1_2_1_18_1","doi-asserted-by":"publisher","DOI":"10.1191\/095968398666994797"},{"key":"e_1_2_1_19_1","first-page":"181","article-title":"Productivity of Sphagnum (bogmoss) and peat accumulation","volume":"12","author":"Clymo R. S.","year":"1971","journal-title":"Hydrobiologia"},{"key":"e_1_2_1_20_1","doi-asserted-by":"publisher","DOI":"10.1029\/GB002i004p00371"},{"key":"e_1_2_1_21_1","article-title":"Trace gas exchange in a high\u2010arctic valley 2; Landscape CH4 fluxes measured and modeled using eddy correlation data","author":"Friborg T.","journal-title":"Global Biogeochem. Cycles"},{"key":"e_1_2_1_22_1","doi-asserted-by":"publisher","DOI":"10.1029\/91JD01247"},{"key":"e_1_2_1_23_1","doi-asserted-by":"publisher","DOI":"10.2307\/1941811"},{"key":"e_1_2_1_24_1","doi-asserted-by":"publisher","DOI":"10.1016\/S0169-5347(99)01649-3"},{"key":"e_1_2_1_25_1","doi-asserted-by":"publisher","DOI":"10.1111\/j.1751-8369.1999.tb00296.x"},{"key":"e_1_2_1_26_1","first-page":"367","article-title":"Organic matter and phytomass on three north Swedish tundra sites, and some connections with adjacent tundra areas","volume":"5","author":"Jonasson S.","year":"1982","journal-title":"Holarctic Ecol."},{"key":"e_1_2_1_27_1","doi-asserted-by":"publisher","DOI":"10.1029\/96JD03873"},{"key":"e_1_2_1_28_1","doi-asserted-by":"publisher","DOI":"10.1029\/92JD00063"},{"key":"e_1_2_1_29_1","doi-asserted-by":"publisher","DOI":"10.1016\/0045-6535(93)90430-D"},{"key":"e_1_2_1_30_1","doi-asserted-by":"crossref","first-page":"1149","DOI":"10.2307\/2845930","article-title":"Emission of CH4, N2O and CO2 from a virgin fell and a fell drained for grassland in Finland","volume":"22","author":"Nyk\u00e4nen H.","year":"1995","journal-title":"J. Biogeography"},{"key":"e_1_2_1_31_1","doi-asserted-by":"publisher","DOI":"10.1016\/B978-0-12-168250-7.50013-4"},{"key":"e_1_2_1_32_1","doi-asserted-by":"publisher","DOI":"10.1038\/361520a0"},{"key":"e_1_2_1_33_1","doi-asserted-by":"publisher","DOI":"10.2307\/1941992"},{"key":"e_1_2_1_34_1","doi-asserted-by":"publisher","DOI":"10.1029\/96GB03035"},{"key":"e_1_2_1_35_1","doi-asserted-by":"publisher","DOI":"10.1029\/1998JD200015"},{"key":"e_1_2_1_36_1","doi-asserted-by":"publisher","DOI":"10.1007\/978-1-4615-2524-0_10"},{"key":"e_1_2_1_37_1","doi-asserted-by":"publisher","DOI":"10.2134\/jeq1985.00472425001400010008x"},{"key":"e_1_2_1_38_1","doi-asserted-by":"publisher","DOI":"10.2307\/1942997"},{"key":"e_1_2_1_39_1","doi-asserted-by":"publisher","DOI":"10.2307\/1552116"},{"key":"e_1_2_1_40_1","doi-asserted-by":"publisher","DOI":"10.1890\/0012-9615(1998)068[0075:BACFIW]2.0.CO;2"},{"key":"e_1_2_1_41_1","doi-asserted-by":"publisher","DOI":"10.2307\/2261357"},{"key":"e_1_2_1_42_1","doi-asserted-by":"publisher","DOI":"10.1046\/j.1365-2486.1999.00250.x"},{"key":"e_1_2_1_43_1","article-title":"Trace gas exchange in a high arctic valley, 3, Integrating and scaling CO2 fluxes from canopy to landscape using flux data, footprint modelling and remote sensing","author":"Soegaard H.","journal-title":"Global Biogeochem. Cycles"},{"key":"e_1_2_1_44_1","series-title":"Ecol. Bull.","first-page":"235","volume-title":"Ecology of a Subarctic Mire","author":"Svensson B. H.","year":"1980"},{"key":"e_1_2_1_45_1","doi-asserted-by":"publisher","DOI":"10.2307\/3546788"},{"key":"e_1_2_1_46_1","doi-asserted-by":"publisher","DOI":"10.2307\/2390217"},{"key":"e_1_2_1_47_1","doi-asserted-by":"publisher","DOI":"10.1029\/96JD02014"},{"key":"e_1_2_1_48_1","volume-title":"Climate Change 1995. Impacts, Adaptations and Mitigation of Climate Change: Scientific\u2010Technical Analyses","author":"Watson R. T.","year":"1996"},{"key":"e_1_2_1_49_1","doi-asserted-by":"publisher","DOI":"10.1034\/j.1600-0889.1990.t01-2-00002.x"},{"key":"e_1_2_1_50_1","doi-asserted-by":"publisher","DOI":"10.1029\/92GB00430"},{"key":"e_1_2_1_51_1","doi-asserted-by":"publisher","DOI":"10.1029\/92GB00710"},{"key":"e_1_2_1_52_1","doi-asserted-by":"publisher","DOI":"10.1038\/364794a0"}],"container-title":["Global Biogeochemical Cycles"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1029%2F1999GB001134","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/agupubs.onlinelibrary.wiley.com\/doi\/pdf\/10.1029\/1999GB001134","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,9,22]],"date-time":"2023-09-22T18:48:41Z","timestamp":1695408521000},"score":1,"resource":{"primary":{"URL":"https:\/\/agupubs.onlinelibrary.wiley.com\/doi\/10.1029\/1999GB001134"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2000,9]]},"references-count":51,"journal-issue":{"issue":"3","published-print":{"date-parts":[[2000,9]]}},"alternative-id":["10.1029\/1999GB001134"],"URL":"https:\/\/doi.org\/10.1029\/1999gb001134","archive":["Portico"],"relation":{},"ISSN":["0886-6236","1944-9224"],"issn-type":[{"value":"0886-6236","type":"print"},{"value":"1944-9224","type":"electronic"}],"subject":[],"published":{"date-parts":[[2000,9]]}}}