TY - JOUR
T1 - Nutrient Limitations Lead to a Reduced Magnitude of Disequilibrium in the Global Terrestrial Carbon Cycle
AU - Wei, Ning
AU - Xia, Jianyang
AU - Wang, Ying Ping
AU - Zhang, Xuanze
AU - Zhou, Jian
AU - Bian, Chenyu
AU - Luo, Yiqi
N1 - Funding Information:
This work was financially supported by the National Key R&D Program of China (2017YFA0604600) and National Natural Science Foundation of China (31722009 and 41630528).
Publisher Copyright:
© 2022. American Geophysical Union. All Rights Reserved.
PY - 2022/5
Y1 - 2022/5
N2 - The terrestrial carbon (C) cycle is shifting to a state of dynamic disequilibrium under a rapid global climate change. However, the magnitude of such disequilibrium is inherently hard to measure directly. Abundant studies have revealed that the availability of nutrients, particularly nitrogen (N) and phosphorus (P), constrains ecosystem productivity and carbon stocks across the globe. However, whether and how nutrient limitation affects the disequilibrium magnitude of the terrestrial C cycle (Xp) has never been evaluated. Here, we developed an approach by combining a process-based numerical model and an analytical framework to evaluate the role of nutrient limitation on Xp. We found that nutrient limitation did have significant impacts on the Xp. Over the modeled period of 1901–2013, absolute change in Xp was 497.6 PgC under the C-only run, while it decreased to 155.6 and 124.3 PgC under N and NP limitations, respectively. To understand the underlying reasons, we further disaggregated the changes of Xp into changes in steady-state C storage and transit C storage with the former being decomposed into a productivity-driven change, an ecosystem-C-residence-time-driven (τE-driven) change, and a change induced by productivity-τE interactions. We found that nutrient constrained the increase in Xp primarily by dampening the productivity-driven changes in the steady-state C storage. Reductions in the productivity-driven term under N and NP limitations accounted for 94.7% and 94.9%, respectively, of the reductions in the steady-state C storage. These results indicate that nutrient limitations have profound impacts on future climate-biosphere feedback by reducing the disequilibrium magnitude of the terrestrial C cycle.
AB - The terrestrial carbon (C) cycle is shifting to a state of dynamic disequilibrium under a rapid global climate change. However, the magnitude of such disequilibrium is inherently hard to measure directly. Abundant studies have revealed that the availability of nutrients, particularly nitrogen (N) and phosphorus (P), constrains ecosystem productivity and carbon stocks across the globe. However, whether and how nutrient limitation affects the disequilibrium magnitude of the terrestrial C cycle (Xp) has never been evaluated. Here, we developed an approach by combining a process-based numerical model and an analytical framework to evaluate the role of nutrient limitation on Xp. We found that nutrient limitation did have significant impacts on the Xp. Over the modeled period of 1901–2013, absolute change in Xp was 497.6 PgC under the C-only run, while it decreased to 155.6 and 124.3 PgC under N and NP limitations, respectively. To understand the underlying reasons, we further disaggregated the changes of Xp into changes in steady-state C storage and transit C storage with the former being decomposed into a productivity-driven change, an ecosystem-C-residence-time-driven (τE-driven) change, and a change induced by productivity-τE interactions. We found that nutrient constrained the increase in Xp primarily by dampening the productivity-driven changes in the steady-state C storage. Reductions in the productivity-driven term under N and NP limitations accounted for 94.7% and 94.9%, respectively, of the reductions in the steady-state C storage. These results indicate that nutrient limitations have profound impacts on future climate-biosphere feedback by reducing the disequilibrium magnitude of the terrestrial C cycle.
KW - biogeochemistry
KW - carbon cycle model
KW - carbon storage potential
KW - dynamic disequilibrium
KW - nutrient limitation
KW - terrestrial carbon sequestration
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U2 - 10.1029/2021JG006764
DO - 10.1029/2021JG006764
M3 - Article
AN - SCOPUS:85130804884
SN - 2169-8953
VL - 127
JO - Journal of Geophysical Research: Biogeosciences
JF - Journal of Geophysical Research: Biogeosciences
IS - 5
M1 - e2021JG006764
ER -