J Plant Ecol ›› 2019, Vol. 12 ›› Issue (2): 336-345.DOI: 10.1093/jpe/rty031

• Research Articles • Previous Articles     Next Articles

Effects of wildfire on soil respiration and its heterotrophic and autotrophic components in a montane coniferous forest

Jian Song1,†, Zhen Liu2,†, Yuan Zhang2,†, Tao Yan2, Zehao Shen2 and Shilong Piao2,3,4,*   

  1. 1 College of Life Science, Hebei University, Baoding 071000, Hebei, China
    2 Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China
    3 Key Laboratory of Alpine Ecology and Biodiversity, Institute of Tibetan Plateau Research, Chinese Academy of Sciences, Beijing 100085, China
    4 Center for Excellence in Tibetan Earth Science, Chinese Academy of Sciences, Beijing 100085, China
    *Correspondence address. Sino-French Institute for Earth System Science, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China. Tel: +86-10-6275-3298; Fax: +86-10-6275-6560; E-mail: slpiao@pku.edu.cn
    †These authors contributed equally to this work.
  • Received:2018-03-04 Revised:2019-08-10 Accepted:2019-08-23 Online:2018-08-24 Published:2019-04-01

Abstract:

Aims

Episodic wildfires are expected to occur more frequently under future climate change scenarios, with substantial effects on CO2 exchange between terrestrial ecosystems and the atmosphere. This study examined the effects of wildfire on soil respiration (RS) and its heterotrophic (RH) and autotrophic (RA) components, as well as their temperature responses (temperature sensitivity, Q10).

Methods

We began this study in January 2014, 8 months after a wildfire, in a montane coniferous forest in southwestern China. A trenching method was used to exclude plant roots and quantify RHRA was calculated by subtracting RH from RS.

Important findings

From 2014 to 2015, the wildfire significantly reduced RSRH and RA by 61.3%, 42.5% and 84.0%, respectively, leading to increases in the ratio of RH to RS, from 0.63 in the unburned stand to 0.85 in the burned stand. Ignoring diurnal differences, the wildfire did not affect the Q10 of RSor RH, but substantially decreased the Q10 of RA, from 2.62 in the unburned stand to 2.08 in the burned stand. However, the daytime Q10 of RS and RH was suppressed following the wildfire by 25.1% and 28.8%, respectively, primarily due to increased daytime soil temperature. In the montane coniferous forest, monthly precipitation but not soil temperature drove seasonal dynamics of soil CO2 release. Our findings help to clarify the mechanisms underlying carbon cycling responses to natural disturbance, especially under a warmer future climate.

Key words: carbon cycling, climate change, forest management, natural hazards, subtropical forests, temperature sensitivity