Carbon isotopic signature reveals the geographical trend in methane consumption and production pathways in alpine ecosystems over the Qinghai–Tibetan Plateau. Issue 6 (2nd November 2017)

• Record Type: Journal Article
• Authors: Kato, Tomomichi; Yamada, Keita; Tang, Yanhong; Yoshida, Naohiro; Wada, Eitaro
• Is Part Of: Isotopes in environmental and health studies. Volume 53:Issue 6(2017)
• Page Start: 597
• Page End: 609
• Publication Date: 2017-11-02
• Subjects: Carbon-13 -- grassland -- isotope ecology -- isotope fractionation -- methane oxidation -- methane production -- Qinghai–Tibetan Plateau -- soil C/N -- wetland; Isotopes -- Periodicals; Radioisotopes -- Periodicals; Environment -- Periodicals; Isotopes -- Periodicals; Medicine -- Periodicals; Radioisotopes -- Periodicals; 541.388
• DOI: 10.1080/10256016.2017.1326916
• Languages: English
• ISSNs: 1025-6016

Abstract

ABSTRACT: On the Qinghai–Tibetan Plateau, isotopic signatures in soil–atmosphere CH4 fluxes were investigated in nine grasslands and three wetlands. In the grasslands, the fractionation factor for soil CH4 uptake, α soil, was much smaller than the usually reported value of 0.9975–1.0095. Stepwise multiple variation analysis indicates that α soil is higher for higher soil water contents but is lower for higher C/N ratios of soil surface biomass. In the three wetlands, the soil-emitted δ 13 C–CH4 was similar (−55.3 ± 5.5 ‰ and −53.0 ± 5.5 ‰) in two bogs separated by >1000 km but was lower (−63.4 ± 6.3 ‰) in a marsh. Environmental factors related to intrasite variations in soil-emitted δ 13 C–CH4 include the soil C/N ratio, oxidation–reduction potential, soil C concentration and soil water contents. Geographical isotopic surveys revealed environmental constraints on the CH4 consumption pathways in grasslands and the biome type-specific consistency in CH4 production pathways in wetlands.