The fate of litter-derived dissolved organic carbon in forest soils: results from an incubation experiment Min Wang . Qiuxiang Tian . Chang Liao . Rudong Zhao . Dongya Wang . Yu Wu . Qianxi Li . Xinggang Wang . Feng Liu Received: 17 October 2018 / Accepted: 30 May 2019 Ó Springer Nature Switzerland AG 2019 Abstract Despite being a crucial component of nutrient cycling and soil carbon (C) dynamics in forest ecosystems, there is too little information from past studies to discern whether dissolved organic carbon (DOC) exchanges with soil organic carbon or passes unaltered through soils. In this study, we added 13 C-labelled litter-derived DOC into different depth soil columns in a 180-day incubation experiment to determine the fate of DOC in soils, and to monitor the changes in DOC composition when it percolates through the soil. The results showed that d 13 C values increased in soil microbes, which indicated that some litter-derived DOC was immobilized by soil microbial communities. Approximately 76% of litter-derived DOC was retained in the soil (60% in topsoil and 16% in midsoil). Meanwhile, 18%, 4%, and 3% of litter- derived DOC were mineralized into CO 2 in topsoil, midsoil and subsoil respectively. Only 0.04% of litter- derived DOC leached from the soil column (0–60 cm). These results indicated that DOC was mainly retained on soil, and a small portion was mineralized by microorganisms, with minimal leaching. The compo- sition of water soluble soil organic carbon (WSOC) and leachate DOC (LDOC) were similar between the control and treatment. This indicated that the compo- sition of WSOC and LDOC was more similar to soil C than the added DOC, which supports the previously hypothesized dynamic exchange model. These find- ings provide new insight by showing that most litter- derived DOC is sequestered in forest soils. Keywords Dissolved organic carbon Á CO 2 emission Á Retention Á Leaching Á Dynamic exchange Introduction Dissolved organic carbon (DOC) is a key component of the terrestrial carbon (C) cycle. Although a small portion of the total soil organic carbon (SOC) pool, DOC is active in various biotic and abiotic processes in the soil C cycle (De Troyer et al. 2011; Kalbitz et al. 2000; Kindler et al. 2011). At the same time, DOC contributes to C sequestration in soils and microbial Responsible Editor: Stephen D. Sebestyen. Electronic supplementary material The online version of this article (https://doi.org/10.1007/s10533-019-00576-3) con- tains supplementary material, which is available to authorized users. M. Wang Á Q. Tian Á C. Liao Á R. Zhao Á D. Wang Á Y. Wu Á Q. Li Á X. Wang Á F. Liu (&) Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan 430074, China e-mail: liufeng@wbgcas.cn M. Wang Á C. Liao Á D. Wang University of the Chinese Academy of Sciences, Beijing 100049, China 123 Biogeochemistry https://doi.org/10.1007/s10533-019-00576-3