Concentration and biodegradability of dissolved organic carbon derived from soils: A global perspective

Futing Liu; Dong Wang; Beibei Zhang; Jin Huang

doi:10.1016/j.scitotenv.2020.142378

Concentration and biodegradability of dissolved organic carbon derived from soils: A global perspective

Sci Total Environ. 2021 Feb 1:754:142378. doi: 10.1016/j.scitotenv.2020.142378. Epub 2020 Sep 16.

Authors

Futing Liu¹, Dong Wang², Beibei Zhang³, Jin Huang⁴

Affiliations

¹ Research Institute of Natural Protected Area, Chinese Academy of Forestry, Beijing 100091, China; Key Laboratory of Tree Breeding and Cultivation of the State Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China.
² Research Institute of Natural Protected Area, Chinese Academy of Forestry, Beijing 100091, China; Key Laboratory of Tree Breeding and Cultivation of the State Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China. Electronic address: dwang@caf.ac.cn.
³ Key Laboratory of Forest Ecology and Environment of the State Forestry and Grassland Administration, Research Institute of Forest Ecology, Environment and Protection, Chinese Academy of Forestry, Beijing 100091, China.
⁴ Key Laboratory of Tree Breeding and Cultivation of the State Forestry and Grassland Administration, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, China.

PMID: 33254924
DOI: 10.1016/j.scitotenv.2020.142378

Abstract

Dissolved organic carbon (DOC), as active and mobile carbon, plays a critical role in terrestrial and aquatic ecosystems. However, it remains unclear how the concentration and biodegradability of soil-derived DOC (extracted from pore water or soil leachates) vary over a global scale and what determines the variations in DOC concentration and biodegradability. Here we addressed this issue by synthesizing the dataset involved in 121 sites from 39 literatures worldwide, and analyzed the patterns and drivers of DOC concentration and biodegradability. Our results showed that the DOC concentration in either pore water or soil leachates varied considerably, with mean values of 33.2 mg L^-1 in pore water and 213.5 mg kg^-1 in soil leachates, respectively. Mean annual precipitation (MAP) was the dominant control on the variability in soil-derived DOC concentration. Our results also revealed that the biodegradability of DOC in pore water was significantly lower than that in soil leachates, with the means of 16.5% versus 28.7%, respectively. Specific UV absorbance (SUVA₂₅₄, a parameter used for evaluating dissolved aromatic carbon content) was the primary indicator predicting the spatial variation in DOC biodegradability, whereas MAP exerted limited effects on DOC biodegradability. These results demonstrate the high biodegradability of soil-derived DOC, highlighting its crucial role in the global carbon cycle under climate change.

Keywords: Biodegradability; Dissolved organic carbon; Leachate; Meta-analysis; Soil.

MeSH terms

Carbon Cycle
Carbon*
Ecosystem
Soil*
Water

Substances

Soil
Water
Carbon