Mineral weathering is linked to microbial priming in the critical zone
Qian Fang, Anhuai Lu, Hanlie Hong, Yakov Kuzyakov, Thomas J. Algeo, Lulu Zhao, Yaniv Olshansky, Bryan Moravec, Danielle M. Barrientes, Jon Chorover
Abstract
Decomposition of soil organic matter (SOM) can be stimulated by fresh
organic matter input, a phenomenon known as the ‘priming effect’. Despite its
global importance, the relationship of the priming effect to mineral weathering and nutrient release remains unclear. Here we show close linkages between mineral weathering in the critical zone and primed decomposition of SOM. Intensified mineral weathering and rock-derived nutrient release are generally coupled with primed SOM decomposition resulting from “triggered” microbial activity. Fluxes of organic matter products decomposed via priming are linearly correlated with weathering congruency. Weathering congruency influences the formation of organo-mineral associations, thereby modulating the accessibility of organic matter to microbial decomposers and, thus, the priming effect. Our study links weathering with primed SOM decomposition,
which plays a key role in controlling soil C dynamics in space and time. These
connections represent fundamental links between long-term lithogenic element cycling (= weathering) and rapid turnover of carbon and nutrients (= priming) in soil.
Mineral weathering is linked to microbial priming in the critical zone