Chin J Plant Ecol ›› 2022, Vol. 46 ›› Issue (7): 797-810.DOI: 10.17521/cjpe.2021.0288

• Research Articles • Previous Articles     Next Articles

Effects of dissolved organic matter derived from different plant and tissues in a subtropical forest on soil priming effect and the underlying mechanisms

GAN Zi-Ying1, WANG Hao1, DING Chi1, LEI Mei1, YANG Xiao-Gang2, CAI Jing-Yan1, QIU Qing-Yan1,*(), HU Ya-Lin1   

  1. 1Forest Ecological Stable Isotope Research Center, Forestry College, Fujian Agricultural and Forestry University, Fuzhou 350002, China
    2Forestry and Grassland Bureau of Keshiketeng Banner, Chifengshi, Inner Mongolia, Chifeng, Nei Mongol 024005, China
  • Received:2021-08-11 Accepted:2021-11-05 Online:2022-07-20 Published:2022-07-15
  • Contact: QIU Qing-Yan
  • Supported by:
    National Natural Science Foundation of China for Promoting Cross Strait Scientific and Technological Cooperation(U1805243);National Natural Science Foundation of China(42077094);National Natural Science Foundation of China(41703066)


Aims The input of exogenous organic matter can affect the mineralization of soil organic carbon (SOC) through positive or negative priming effects. However, few studies have considered the effect of dissolved organic matter (DOM) derived from different plant and tissues on soil priming effect and revealed the underlying mechanisms.

Methods In this study, we investigated the different priming effects of 13C-labeled DOM derived from roots and leaves of different plants (i.e., Cyclobalanopsis glauca, Cunninghamia lanceolata, Manglietia fordiana and Acacia confusa) on SOC mineralization and clarifying the underlying mechanisms via an incubation experiment of soils sampled from Wuyi Mountain.

Important findings Inputs of DOM derived from different plant and tissues all accelerated the mineralization of SOC, exhibiting a positive priming effect at the initial stage after DOM input, and then showed a negative priming effect. For the cumulative priming effect during the whole incubation period (90 d), the input of DOM inhibited the mineralization of SOC, with the reduction magnitude ranging from 22% to 49%. Among them, the input of DOM derived from roots of Cyclobalanopsis glauca had the most pronounced effect on the reduction of SOC mineralization, while the input of DOM derived from leaves of M. glauca had the least effect on reduction of SOC mineralization. The intensity of soil priming effect induced by DOM was significantly affected by different plant tissues. DOM derived from plant roots showed more pronounced negative priming effect than DOM derived from plant leaves. In general, DOM input increased soil microbial biomass carbon (MBC) and soil β-glucosidase activities and cellobiohydrolase activities and soil available nitrogen content, but had no significant effect on the composition of soil microbial community. The structural equation model showed that soil priming effect induced by DOM was mainly affected by soil 13C-MBC, cellobiohydrolase activity and soil available nitrogen content. Changes in these factors could explain 68% and 86% of the variation of priming effect induced by plant leaf-derived DOM and root-derived DOM, respectively. The results suggested that if the soil is rich in available nitrogen, DOM input can accelerate the decomposition of exogenous organic matter through increasing microbial biomass and soil enzyme activity, and thus reducing the decomposition of SOC. Therefore, “substrate preferential utilization” is the main mechanism of soil priming effect in this study.

Key words: dissolved organic matter, priming effect, enzyme activity, soil organic carbon mineralization, subtropical plants