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Rhizosphere processes are quantitatively important components of terrestrial carbon and nutrient cycles
Author(s) -
Finzi Adrien C.,
Abramoff Rose Z.,
Spiller Kimberly S.,
Brzostek Edward R.,
Darby Bridget A.,
Kramer Mark A.,
Phillips Richard P.
Publication year - 2015
Publication title -
global change biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.146
H-Index - 255
eISSN - 1365-2486
pISSN - 1354-1013
DOI - 10.1111/gcb.12816
Subject(s) - rhizosphere , mineralization (soil science) , nutrient cycle , ecosystem , environmental science , nitrogen cycle , primary production , nutrient , cycling , terrestrial ecosystem , bulk soil , soil carbon , decomposition , carbon cycle , soil organic matter , temperate climate , organic matter , soil water , soil science , ecology , nitrogen , biology , chemistry , forestry , genetics , organic chemistry , bacteria , geography
While there is an emerging view that roots and their associated microbes actively alter resource availability and soil organic matter ( SOM ) decomposition, the ecosystem consequences of such rhizosphere effects have rarely been quantified. Using a meta‐analysis, we show that multiple indices of microbially mediated C and nitrogen (N) cycling, including SOM decomposition, are significantly enhanced in the rhizospheres of diverse vegetation types. Then, using a numerical model that combines rhizosphere effect sizes with fine root morphology and depth distributions, we show that root‐accelerated mineralization and priming can account for up to one‐third of the total C and N mineralized in temperate forest soils. Finally, using a stoichiometrically constrained microbial decomposition model, we show that these effects can be induced by relatively modest fluxes of root‐derived C, on the order of 4% and 6% of gross and net primary production, respectively. Collectively, our results indicate that rhizosphere processes are a widespread, quantitatively important driver of SOM decomposition and nutrient release at the ecosystem scale, with potential consequences for global C stocks and vegetation feedbacks to climate.