Biomaterial Database

Stimulation of soil respiration by elevated CO2 is enhanced under nitrogen limitation in a decade-long grassland study. 2020

Qun Gao, and Gangsheng Wang, and Kai Xue, and Yunfeng Yang, and Jianping Xie, and Hao Yu, and Shijie Bai, and Feifei Liu, and Zhili He, and Daliang Ning, and Sarah E Hobbie, and Peter B Reich, and Jizhong Zhou

State Key Joint Laboratory of Environment Simulation and Pollution Control, School of Environment, Tsinghua University, 100084 Beijing, China.

Whether and how CO2 and nitrogen (N) availability interact to influence carbon (C) cycling processes such as soil respiration remains a question of considerable uncertainty in projecting future C-climate feedbacks, which are strongly influenced by multiple global change drivers, including elevated atmospheric CO2 concentrations (eCO2) and increased N deposition. However, because decades of research on the responses of ecosystems to eCO2 and N enrichment have been done largely independently, their interactive effects on soil respiratory CO2 efflux remain unresolved. Here, we show that in a multifactor free-air CO2 enrichment experiment, BioCON (Biodiversity, CO2, and N deposition) in Minnesota, the positive response of soil respiration to eCO2 gradually strengthened at ambient (low) N supply but not enriched (high) N supply for the 12-y experimental period from 1998 to 2009. In contrast to earlier years, eCO2 stimulated soil respiration twice as much at low than at high N supply from 2006 to 2009. In parallel, microbial C degradation genes were significantly boosted by eCO2 at low but not high N supply. Incorporating those functional genes into a coupled C-N ecosystem model reduced model parameter uncertainty and improved the projections of the effects of different CO2 and N levels on soil respiration. If our observed results generalize to other ecosystems, they imply widely positive effects of eCO2 on soil respiration even in infertile systems.

UI	MeSH Term	Description	Entries
D009584	Nitrogen	An element with the atomic symbol N, atomic number 7, and atomic weight [14.00643; 14.00728]. Nitrogen exists as a diatomic gas and makes up about 78% of the earth's atmosphere by volume. It is a constituent of proteins and nucleic acids and found in all living cells.
D002245	Carbon Dioxide	A colorless, odorless gas that can be formed by the body and is necessary for the respiration cycle of plants and animals.	Carbonic Anhydride,Anhydride, Carbonic,Dioxide, Carbon
D003198	Computer Simulation	Computer-based representation of physical systems and phenomena such as chemical processes.	Computational Modeling,Computational Modelling,Computer Models,In silico Modeling,In silico Models,In silico Simulation,Models, Computer,Computerized Models,Computer Model,Computer Simulations,Computerized Model,In silico Model,Model, Computer,Model, Computerized,Model, In silico,Modeling, Computational,Modeling, In silico,Modelling, Computational,Simulation, Computer,Simulation, In silico,Simulations, Computer
D000332	Aerobiosis	Life or metabolic reactions occurring in an environment containing oxygen.	Aerobioses
D012987	Soil	The unconsolidated mineral or organic matter on the surface of the earth that serves as a natural medium for the growth of land plants.	Peat,Humus,Soils
D012988	Soil Microbiology	The presence of bacteria, viruses, and fungi in the soil. This term is not restricted to pathogenic organisms.	Microbiology, Soil
D065948	Grassland	An ecosystem dominated by grasses (POACEAE) with few trees or shrubs.	Meadows,Prairie,Savanna,Steppe,Grasslands,Meadow,Prairies,Savannas,Steppes