Responses of peat carbon at different depths to simulated warming and oxidizing

Liangfeng Liu; Huai Chen; Qiuan Zhu; Gang Yang; Erxiong Zhu; Ji Hu; Changhui Peng; Lin Jiang; Wei Zhan; Tianli Ma; Yixin He; Dan Zhu

doi:10.1016/j.scitotenv.2015.11.149

Responses of peat carbon at different depths to simulated warming and oxidizing

Sci Total Environ. 2016 Apr 1:548-549:429-440. doi: 10.1016/j.scitotenv.2015.11.149. Epub 2016 Jan 28.

Authors

Liangfeng Liu¹, Huai Chen², Qiuan Zhu¹, Gang Yang³, Erxiong Zhu¹, Ji Hu¹, Changhui Peng⁴, Lin Jiang¹, Wei Zhan¹, Tianli Ma¹, Yixin He⁵, Dan Zhu⁶

Affiliations

¹ State Key Laboratory of Soil Erosion and Dry land Farming on the Loess Plateau, College of Forestry, Northwest A&F University, Yangling 712100, China; Zoige Peatland and Global Change Research Station, Chinese Academy of Sciences, Hongyuan, 624400, China.
² State Key Laboratory of Soil Erosion and Dry land Farming on the Loess Plateau, College of Forestry, Northwest A&F University, Yangling 712100, China; Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China; Zoige Peatland and Global Change Research Station, Chinese Academy of Sciences, Hongyuan, 624400, China. Electronic address: chenhuai@cib.ac.cn.
³ Zoige Peatland and Global Change Research Station, Chinese Academy of Sciences, Hongyuan, 624400, China; School of Life Science and Engineering, Southwest University of Science and Technology, Mianyang 621010, China.
⁴ State Key Laboratory of Soil Erosion and Dry land Farming on the Loess Plateau, College of Forestry, Northwest A&F University, Yangling 712100, China; Center of CEF/ESCER, Department of Biology Science, University of Quebec at Montreal, Montreal, Canada.
⁵ Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China; Zoige Peatland and Global Change Research Station, Chinese Academy of Sciences, Hongyuan, 624400, China; Key Laboratory of Physical Geography and Environment Process of Qinghai Province, Qinghai, Normal University, Xining 810008, China.
⁶ Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041, China; Zoige Peatland and Global Change Research Station, Chinese Academy of Sciences, Hongyuan, 624400, China.

PMID: 26826851
DOI: 10.1016/j.scitotenv.2015.11.149

Abstract

Warming and water table drawdown greatly reshape peatland carbon cycle, especially when considering the old carbon stored under the peatland subsurface. However, little is known about the effects of warming, oxidizing by drying or their combination on carbon decomposition at different depths (0-100 cm) of peat. In this research, soil of different depths from Zoige Plateau was incubated in four scenarios (8 °C-anaerobic, 8 °C-aerobic, 18 °C-anaerobic and 18 °C-aerobic) to detect the exported carbon. Our result showed that soil respiration (Rs) increased obviously with enhanced temperature and oxygen. The total CO2 fluxes of 2400.22 ± 57.69 mg m(-2) d(-1) under 8 °C-anaerobic condition increased by 73.6%, 40.7% and 176.5% with warming, oxidizing and their combined effect, respectively. The average dissolved organic carbon (DOC) concentration was 74.90 ± 8.09 mg kg(-1) under 8 °C-anaerobic condition, but increased by 53.5%, 44% and 159.4%, respectively under the condition of warming, oxidizing and their combination. Rs and its variation under warming and oxidization differed significantly among different depths, probably caused by the differences of soil substrate, especially the variation in distribution of soil microbes and enzymes among depths of peatlands. By classifying the source of Rs as young soil (YS: 0-20 cm) and old soil (OS: 21-100 cm), this reseaerch found that OS accounted for a huge part of total Rs under 8 °C-anaerobic condition (CO2: 74.2%; DOC: 60.7%). Such relative contribution of OS to total Rs did not change obviously with warming or oxidizing. Though YS and OS responded equally to warming and oxidizing, OS was responsible for a larger proportion of total increase in Rs. Compared with other studies, we concluded that peatlands soil in our field of mid-latitude and high altitude is less sensitive to warming and oxidizing than peatlands of higher latitude, but that OS of this peatlands is more critical in predicting regional carbon cycle.

Keywords: Zoige plateau; aerobic environment; anaerobic environment; incubaiton; peatlands.

Publication types

Research Support, Non-U.S. Gov't