Open AccessStoichiometrical regulation of soil organic matter decomposition and its temperature sensitivity
Author(s) -
He Nianpeng,
Yu Guirui
Publication year - 2016
Publication title -
ecology and evolution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.17
H-Index - 63
ISSN - 2045-7758
DOI - 10.1002/ece3.1927
Subject(s) - decomposition , organic matter , soil water , substrate (aquarium) , grassland , environmental chemistry , soil organic matter , chemistry , kinetic energy , incubation , kinetics , thermal decomposition , analytical chemistry (journal) , soil science , environmental science , ecology , biology , organic chemistry , physics , biochemistry , quantum mechanics
The decomposition of soil organic matter (SOM) can be described by a set of kinetic principles, environmental constraints, and substrate supply. Here, we hypothesized that SOM decomposition rates ( R ) and its temperature sensitivity ( Q 10 ) would increase steadily with the N:C ratios of added substrates by alleviating N limitation on microbial growth. We tested this hypothesis by investigating SOM decomposition in both grassland and forest soils after addition of substrates with a range of N:C ratios. The results showed that Michaelis–Menten equations well fit the response of R to the N:C ratio variations of added substrates, and their coefficients of determination ( R 2 ) ranged from 0.65 to 0.89 ( P < 0.01). Moreover, the maximal R , Q 10 , and cumulative C emission of SOM decomposition increased exponentially with the N:C ratios of added substrates, and were controlled interactively by incubation temperature and the N:C ratios of the added substrates. We demonstrated that SOM decomposition rate and temperature sensitivity were exponentially correlated to substrate stoichiometry (N:C ratio) in both grassland and forest soils. Therefore, these correlations should be incorporated into the models for the prediction of SOM decomposition rate under warmer climatic scenarios.