Plant functional group controls litter decomposition rate and its temperature sensitivity: An incubation experiment on litters from a boreal peatland in northeast China

Rong Mao; Xinhou Zhang; Changchun Song; Xianwei Wang; Patrick M Finnegan

doi:10.1016/j.scitotenv.2018.01.162

Plant functional group controls litter decomposition rate and its temperature sensitivity: An incubation experiment on litters from a boreal peatland in northeast China

Sci Total Environ. 2018 Jun 1:626:678-683. doi: 10.1016/j.scitotenv.2018.01.162. Epub 2018 Feb 19.

Authors

Rong Mao¹, Xinhou Zhang², Changchun Song³, Xianwei Wang³, Patrick M Finnegan⁴

Affiliations

¹ Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, 4888 Shengbei Rd, Changchun 130102, China; The Three Gorges Institute of Ecological Environment, Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, 266 Fangzheng Rd, Chongqing 400714, China.
² Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, 4888 Shengbei Rd, Changchun 130102, China. Electronic address: zhangxinhou@hotmail.com.
³ Key Laboratory of Wetland Ecology and Environment, Northeast Institute of Geography and Agroecology, Chinese Academy of Sciences, 4888 Shengbei Rd, Changchun 130102, China.
⁴ School of Biological Sciences, The University of Western Australia, 35 Stirling Highway, Perth, WA 6009, Australia.

PMID: 29898554
DOI: 10.1016/j.scitotenv.2018.01.162

Abstract

In boreal peatlands, litter decomposition plays an important role in modulating ecosystem carbon (C) cycling and nutrient turnover. However, how climate warming and plant functional group interact to affect litter decomposition is still unclear in these ecosystems. Here, we collected fresh litters of six plant functional groups (nitrogen (N)-fixing species, deciduous tree, deciduous shrub, evergreen shrub, graminoid, and Sphagnum moss) from a boreal peatland located in northeast China. A laboratory incubation experiment was used to determine the effect of temperature (10 °C vs. 20 °C) on microbial respiration and mass loss during decomposition. Among the six functional groups, the litters of N-fixing species and deciduous shrub, followed by deciduous tree, generally had the greatest mass losses and microbial respiration rates, whereas the Sphagnum moss decomposed with the slowest rate at both incubation temperatures. Increasing incubation temperature from 10 °C to 20 °C, microbial respiration rate and mass loss increased slightly for Sphagnum moss litters (25% and 19%, respectively), but increased dramatically for vascular plant litters (84-135% and 49-85%, respectively). For litters from vascular plants, both decomposition rate and temperature sensitivity showed a tight linear correlation with the initial C:N and C:phosphorus ratios. Considering that climate warming will cause increased dominance of woody plant species coupled with decreased cover by Sphagnum mosses, this study provides clear evidence that climate warming and the associated changes to vegetation community composition can synergistically accelerate plant litter decomposition in boreal peatlands.

Keywords: Litter decomposition; Peatland; Plant functional group; Sphagnum; Temperature sensitivity.