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Nutrient limitation of terrestrial free‐living nitrogen fixation
Author(s) -
Dynarski Katherine A.,
Houlton Benjamin Z.
Publication year - 2018
Publication title -
new phytologist
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.742
H-Index - 244
eISSN - 1469-8137
pISSN - 0028-646X
DOI - 10.1111/nph.14905
Subject(s) - nutrient , fixation (population genetics) , nitrogen fixation , carbon fixation , biology , ecosystem , biosphere , nutrient cycle , nitrogen , ecology , agronomy , chemistry , carbon dioxide , bacteria , biochemistry , genetics , organic chemistry , gene
Summary Nitrogen (N) fixation by free‐living bacteria is a primary N input pathway in many ecosystems and sustains global plant productivity. Uncertainty exists over the importance of N, phosphorus (P) and molybdenum (Mo) availability in controlling free‐living N fixation rates. Here, we investigate the geographic occurrence and variability of nutrient constraints to free‐living N fixation in the terrestrial biosphere. We compiled data from studies measuring free‐living N fixation in response to N, P and Mo fertilizers. We used meta‐analysis to quantitatively determine the extent to which N, P and Mo stimulate or suppress N fixation, and if environmental variables influence the degree of nutrient limitation of N fixation. Across our compiled dataset, free‐living N fixation is suppressed by N fertilization and stimulated by Mo fertilization. Additionally, free‐living N fixation is stimulated by P additions in tropical forests. These findings suggest that nutrient limitation is an intrinsic property of the biochemical demands of N fixation, constraining free‐living N fixation in the terrestrial biosphere. These findings have implications for understanding the causes and consequences of N limitation in coupled nutrient cycles, as well as modeling and forecasting nutrient controls over carbon–climate feedbacks.