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Bedrock nitrogen weathering stimulates biological nitrogen fixation
Author(s) -
Dynarski Katherine A.,
Morford Scott L.,
Mitchell Scott A.,
Houlton Benjamin Z.
Publication year - 2019
Publication title -
ecology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.144
H-Index - 294
eISSN - 1939-9170
pISSN - 0012-9658
DOI - 10.1002/ecy.2741
Subject(s) - biogeochemical cycle , bedrock , weathering , ecosystem , biogeochemistry , biome , ecology , earth science , biosphere , environmental science , temperate climate , terrestrial ecosystem , nutrient cycle , nitrogen cycle , temperate rainforest , temperate forest , geology , nitrogen , biology , chemistry , geomorphology , organic chemistry
Global ecosystem models suggest that bedrock nitrogen (N) weathering contributes 10–20% of total N inputs to the natural terrestrial biosphere and >38% of ecosystem N supplies in temperate forests specifically. Yet, the role of rock N weathering in shaping ecological processes and biogeochemical fluxes is largely unknown. Here, we show that temperate forest ecosystems underlain by N‐rich bedrock exhibit higher free‐living N fixation rates than similar forests residing on N‐poor parent materials, across sites experiencing a range of climate and tectonic regimes. This seemingly counterintuitive result can be explained by increased accumulation of soil C and P in high bedrock N sites, resulting in increased energy inputs and nutrient supplies to N fixing microorganisms. Our findings advance a novel ecosystem biogeochemical framework that recognizes long‐term plant–soil–microbe feedbacks in shaping biogeochemical processes, with potentially widespread implications given the global distribution of bedrock N across Earth's terrestrial biomes.