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Modelling Dissolved Organic Carbon Production in Coniferous Forest Soils
Author(s) -
Ågren Göran I.,
Kleja Dan B.,
Bosatta Ernesto
Publication year - 2018
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj2017.11.0407
Subject(s) - decomposer , dissolved organic carbon , leaching (pedology) , soil water , environmental science , soil carbon , total organic carbon , environmental chemistry , carbon cycle , biomass (ecology) , soil organic matter , chemistry , soil science , ecology , ecosystem , biology
Core Ideas Mechanisms of DOC production affect the quantities and qualities of SOC and DOC. Three models with different physical and microbial processes were analyzed. Comparisons with experimental data provides no strong discrimination between models. The production of dissolved carbon (DOC) in forest soils is still not well understood as a result of difficulties in isolating co‐occurring processes. We have used an extension of the continuous‐quality theory to analyze the consequences of three modes for DOC production in coniferous forest soils: Model A, the production of DOC occurs through physical leaching of soil organic carbon (SOC) and the composition of DOC is proportional to the composition of SOC with respect to carbon (C) qualities; Model B, the production of DOC occurs when the decomposers use SOC and the composition of DOC will be proportional to the composition of SOC that decomposers extract; and Model C, the production of DOC is associated with mortality of decomposers and the composition of DOC reflects the composition of decomposer biomass. The results from Models B and C resemble each other but differ from Model A. Models B and C lead to a larger fraction of C being lost through leaching, a higher quality of the C leached, and a lower 14 C age of the leached C than Model A. Models B and C differ with respect to properties of DOC leached from a horizon. All three models were found capable of describing stores of C in and leaching of DOC from an organic horizon and an underlying mineral soil in three temperate/boreal Norway spruce [ Picea abies (L.) Karst.] forests. Microbial activity should always be an important agent for DOC production. Model B and, in particular, Model C suggest a lager contribution of microbially processed C in DOC than Model A.