1 / 9

Nitrogen Controls on Carbon Sequestration

Nitrogen Controls on Carbon Sequestration. J. Melillo 1 , D. Kicklighter 1 , H. Tian 1 , A. McGuire 2 , J. Clein 2 , B. Moore III 3 [jmelillo@mbl.edu] 1 Marine Biological Laboratory 2 University of Alaska 3 University of New Hampshire.

dava
Download Presentation

Nitrogen Controls on Carbon Sequestration

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Nitrogen Controls on Carbon Sequestration J. Melillo1, D. Kicklighter1, H. Tian1, A. McGuire2, J. Clein2, B. Moore III3 [jmelillo@mbl.edu] 1 Marine Biological Laboratory 2 University of Alaska 3 University of New Hampshire

  2. The Global Nitrogen (N) Cycle and Carbon Sequestration Fact: • Humans have more than doubled the rate at which reactive N is added to the biosphere annually. Fact: • Through fertilizer production, the planting of legumes, and high temperature combustion, humans transform about 150 TgN annually from unreactive N to reactive N. Fact: • A fraction of this reactive N enters ecosystems in which carbon sequestration is N limited. Question: • Is N-stimulated carbon sequestration currently a significant component of the global carbon budget?

  3. Approach • We used a process-based biogeochemistry model running with an open N cycle to estimate the annual N-stimulated carbon sequestration rate in North America. • The current spatially explicit N-deposition pattern for the region was estimated using the results of Dentner and Crutzen.

  4. Nitrogen Deposition in North America (>150N)

  5. Annual N-deposition RatesTg N/yr All land Forest only North America 7.3 3.2 USA 4.8 1.9 Canada 1.8 1.1 Other 0.7 0.2

  6. N-Stimulated Carbon Storage g C /m2 /yr

  7. Carbon Sequestration in North America (PgC) N- Other All stimulated Mechanisms USA +0.051 +0.259 +0.310 Canada +0.023 -0.019 +0.004 Other +0.010+0.038+0.048 North America +0.084 +0.278 +0.362

  8. Conclusions • We estimate that N-stimulate carbon sequestration accounts for about ¼ of the current C sink in North America. • Other important mechanisms include land cover and land use changes and CO2 fertilization. • Biogeochemistry models used in carbon-cycle studies must include coupled C-N cycles.

More Related