global perspective on belowground carbon dynamics under nitrogen enrichment

• Published in: Ecology letters Vol. 13; no. 7; pp. 819 - 828
• Main Authors: Liu, Lingli, Greaver, Tara L
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01.07.2010; Blackwell Publishing Ltd; Blackwell
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Biological and medical sciences; Biomass; Carbon; Carbon - chemistry; Carbon - metabolism; Carbon sequestration; climate change; Climatology. Bioclimatology. Climate change; DOC; Earth, ocean, space; Ecology; ecosystem C balance; Exact sciences and technology; External geophysics; fine root; Fundamental and applied biological sciences. Psychology; litter; Meteorology; microbial activity; mineral soil; Nitrogen; Nitrogen - chemistry; Nitrogen - metabolism; organic soil; Soil; Soil Microbiology; Soil microorganisms; soil respiration; Synecology; Terrestrial ecosystems; Microbial activity; Litter; Organic soil; soil respiration; Mineral soils; Nitrogen; Carbon sequestration; Carbon balance; Dynamical climatology; Dissolved organic carbon; mineral soil; Climate change; Dynamics; Ecosystem; Fine root; DOC; Respiration; ecosystem C balance
• ISSN: 1461-023X; 1461-0248
• DOI: 10.1111/j.1461-0248.2010.01482.x

Ecology Letters (2010) 13: 819-828 Nitrogen (N) effects on ecosystem carbon (C) budgets are critical to understand as C sequestration is considered as a mechanism to offset anthropogenic CO₂ emissions. Interactions between aboveground C and N cycling are more clearly characterized than belowground processes. Through synthesizing data from multiple terrestrial ecosystems, we quantified the responses of belowground C cycling under N addition. We found that N addition increased litter input from aboveground (+20%) but not from fine root. N addition inhibited microbial activity as indicated by a reduction in microbial respiration (-8%) and microbial biomass carbon (-20%). Although soil respiration was not altered by N addition, dissolved organic carbon concentration was increased by 18%, suggesting C leaching loss may increase. N addition increased the C content of the organic layer (+17%) but not the mineral soil layer. Overall, our meta-analysis indicates that N addition will increase short term belowground C storage by increasing C content of organic layer. However, it is difficult to predict the response of long term C sequestration since there is no significant change in mineral soil C content.