Bedrock Weathering Controls on Terrestrial Carbon‐Nitrogen‐Climate Interactions

作者：P. Dass, Benjamin Z. Houlton, Ying‐Ping Wang, David Wårlind, Scott L. Morford · 发表于：Global Biogeochemical Cycles · 年份：2021 · DOI：10.1029/2020gb006933 · 被引用次数：14 · 研究领域：Atmospheric and Environmental Gas Dynamics、Geology and Paleoclimatology Research、Methane Hydrates and Related Phenomena

Abstract Anthropogenic nitrogen deposition is widely considered to increase CO 2 sequestration by land plants on a global scale. Here, we demonstrate that bedrock nitrogen weathering contributes significantly more to nitrogen‐carbon interactions than anthropogenic nitrogen deposition. This working hypothesis is based on the introduction of empirical results into a global biogeochemical simulation model over the time period of the mid‐1800s to the end of the 21st century. Our findings suggest that rock nitrogen inputs have contributed roughly 2–11 times more to plant CO 2 capture than nitrogen deposition inputs since pre‐industrial times. Climate change projections based on RCP 8.5 show that rock nitrogen inputs and biological nitrogen fixation contribute 2–5 times more to terrestrial carbon uptake than anthropogenic nitrogen deposition though year 2101. Future responses of rock N inputs on plant CO 2 capture rates are more signficant at higher latitudes and in mountainous environments, where geological and climate factors promote higher rock weathering rates. The enhancement of plant CO 2 uptake via rock nitrogen weathering partially resolves nitrogen‐carbon discrepancies in Earth system models and offers an alternative explanation for lack of progressive nitrogen limitation in the terrestrial biosphere. We conclude that natural N inputs impart major control over terrestrial CO 2 sequestration in Earth’s ecosystems.