Effects of experimental warming on soil respiration and its components in an alpine meadow in the permafrost region of the Qinghai‐Tibet Plateau. (3rd November 2014)

• Record Type: Journal Article
• Authors: Peng, F.; You, Q. G.; Xu, M. H.; Zhou, X. H.; Wang, T.; Guo, J.; Xue, X.
• Is Part Of: European journal of soil science. Volume 66:Number 1(2015:Feb.)
• Page Start: 145
• Page End: 154
• Publication Date: 2014-11-03
• Subjects: Soil science -- Periodicals; 631.4
• DOI: 10.1111/ejss.12187
• Languages: English
• ISSNs: 1351-0754

Abstract

<abstract abstract-type="main" id="ejss12187-abs-0001"> <title>Summary</title> <p id="ejss12187-para-0001">The response of soil respiration (<italic>R<sub>s</sub></italic>) and its components (autotrophic [<italic>R<sub>a</sub></italic>] and heterotrophic respiration [<italic>R<sub>h</sub></italic>]) to climate warming is one of the uncertainties in ecosystem carbon (C) models. Here we conducted a warming experiment in an alpine meadow dominated by <italic>Koresbia</italic> in the permafrost region of the Qinghai‐Tibet Plateau (QTP) to examine effects of warming on <italic>R<sub>s</sub></italic> and its components. Infrared heaters were used to simulate a 2°C warming of the surface soil temperature. Deep collars (50 cm to exclude root growth) were inserted into soil to measure <italic>R<sub>h</sub></italic>: <italic>R<sub>a</sub></italic>, which was calculated by subtracting <italic>R<sub>h</sub></italic> from <italic>R<sub>s</sub></italic>. Average <italic>R<sub>s</sub></italic> and its components (<italic>R<sub>a</sub></italic> and <italic>R<sub>h</sub></italic>) were significantly stimulated by 21.5, 27 and 15.6%, respectively, in warmed plots from January 2011 to October 2013. The contribution of <italic>R<sub>h</sub></italic> to <italic>R<sub>s</sub></italic> decreased in the warmed plots because of the smaller relative increase in <italic>R<sub>h</sub></italic> than in <italic>R<sub>a</sub></italic>. Annual soil C release increased by 263 and 247 g C m<sup>−2</sup> in 2011 and 2012, respectively. Stimulation in <italic>R<sub>a</sub></italic> and <italic>R<sub>h</sub></italic> was related to the significant increase in root biomass (0–50 cm) and in labile soil C in the deeper layer (40–50 cm). The temperature sensitivities (Q<sub>10</sub>) of <italic>R<sub>s</sub></italic> and its components all increased with larger values in <italic>R<sub>a</sub></italic>, followed by <italic>R<sub>s</sub></italic> and <italic>R<sub>h</sub></italic>. Our results suggest a positive feedback between soil C release and climatic warming in the permafrost region of the QTP.</p> </abstract>