Diurnal variation of methane emissions from an alpine wetland on the eastern edge of Qinghai-Tibetan Plateau

Abstract

Alpine wetland is a source for CH 4 , but little is known about methane emission from such wetland, especially about its diurnal pattern. In this study we tried to probe the diurnal variation in methane emission from alpine wetland vegetation. The average methane emission rate was 9.6 ± 3.4 mg CH 4 m −2 h −1 . There was an apparent diurnal variation pattern in methane emission with one minor peak at 06:00 and a major one at 15:00. The sunrise peak was consistent with a two-way transport mechanism for plants (convective at daytime and diffusive at night-time). CH 4 emission was found significantly correlated with redox potentials. The afternoon peak could not be explained by diurnal variation in soil temperature, but could be attributable to changes in CH 4 oxidation and production driven by plant gas transport mechanism. The results have important implications for sampling and scaling strategies for estimating methane emission from alpine wetlands.

Effects of soil warming, rainfall reduction and water table level on CH 4 emissions from the Zoige peatland in China

“…Peatlands in this region have a depth of 0.3e10 m and a mean dry mass accumulation rate of 0.03 g m À2 yr À1 (Chen et al, 2010;Sun, 1992); an average pH of 6.6e7.0 Peat cores were collected from an open fen near Hongyuan County town using a stainless steel, cylindrical corer with a diameter of 25 cm and a height of 60 cm. After cutting the peat with the corer, the core was dug out with the vegetation of the peat surface intact.…”

Methane emissions from rice paddies natural wetlands, lakes in China: synthesis new estimate

“…However, due to high salinity and frequent tidal flooding (Bartlett et al ., ) (Van der Nat & Middelburg, ; Chang & Yan, ), coastal salt marshes showed small CH 4 emission fluxes in China (2.89 ± 3.97 mg CH 4 m −2 h −1 ) (Chang & Yan, ; Tong et al ., ; Wang et al ., ; Ding et al ., ; Zhang & Ding, ). Forested swamps showed very low CH 4 emissions, like swamps in the Xiaoxing'an mountain chain (0.61 ± 1.10 mg CH 4 m −2 h −1 ) (Sun et al ., ) and mangroves (0.06 ± 0.07 mg CH 4 m −2 h −1 ) located in coastal provinces of China (Chang et al ., ; Ye et al ., ; Chen et al ., ,b).…”

Nitrous oxide fluxes from the littoral zone of a lake on the Qinghai-Tibetan Plateau

“…Therefore, in such a grazing region with numerous lakes, the littoral zones of lakes may play an important role as a regional N 2 O source. However, limited researches existed about the N 2 O fluxes from wetlands in such special region, though, there are a few studies about methane emissions from alpine wetlands on the Qinghai-Tibetan Plateau (Chen et al , 2010.…”