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Late Glacial and Holocene vegetation and climate history of an alpine wetland on the Qinghai-Tibetan Plateau

Liu D. L., Chen G., Lai Z., Weis H., Zhou G., Peng M.

Geological Quarterly

2013

Vol. 57, No. 2

261-–268

This study provides a vegetation and climate history of an alpine wetland in the centre of China’s Qinghai–Tibetan Plateau (QTP) over the last 14.8 ka. High resolution climate proxies include vegetation (pollen), geochemical (Ba, Rb, δ13C) and physical (particle size and magnetic susceptibility) data; optically stimulated luminescence (OSL) and AMS radiocarbon dating were used to reconstruct the environmental changes in the wetland ecosystem. Based on physical and geochemical proxies, the sucession divided into five stratigraphic units encompassing time intervals of 14.76–14.31, 14.31–13.17, 13.17–4.47, 4.47–0.51 and 0.51–0 ka. The average sedimentation rate of all these units was 0.098 mm/a. The study showed that this ecosystem was sensitive to climate change.

Winter methane emission from an alpine open fen on Tibetan Plateau

Zhu D., Chen H., Wu N., Wang Y., Luo P.

Polish Journal of Ecology

2011

Vol. 59, nr 1

87-94

Methane (CH4) emission was measured from an open fen on the Zoige Plateau (3500 m a.s.l.) (the eastern edge of the QinghaiTibetan Plateau) during two winters of 2006 and 2007. Three dominant plant stands, including Carex muliensis Hand-Mazz. (CM), Eleocharis valleculosa Ohwif. setosa (Ohwi) Kitagawa.(EV) and Kobresia tibetica Maxim (KT) were chosen to be monitored. Winter CH4 emissions were roughly estimated to be 0.94 mg CH4 m[^-2] h[^-1]. High spatialtemporal variations of the emission were found in this fen (the sequence of CM> EV> KT; 0.63 and 1.24 mg CH4 m[^-2] h[^-1] for 2006 and 2007, respectively). Factors involved in the spatial-temporal variation were: 1) water table in summer determining the winter amount of "old" CH4 stored in peat; 2) ice layer determining the release of CH4; 3) plant growth determining both the quantity of CH4 stored in peat and available substrates for CH4 production in winter. However, due to the homogeneity of freezing in winters, predictive factors such as plant growth and water table in summer could contribute more to winter CH4 emission than in situ freezing conditions. Considering that plant growth and water table are also the key factors controlling the spatial-temporal variation of CH4 emission in summer, we therefore suggested that winter CH4 emission represents the "inertia" of summer CH4 emission.