Open AccessSoil carbon CO 2 fertilization factor: The measure of an ecosystem's capacity to increase soil carbon storage in response to elevated CO 2 levels
Author(s) -
Harrison Kevin G.
Publication year - 2004
Publication title -
geochemistry, geophysics, geosystems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.928
H-Index - 136
ISSN - 1525-2027
DOI - 10.1029/2003gc000686
Subject(s) - carbon dioxide , soil carbon , carbon fibers , environmental science , carbon dioxide in earth's atmosphere , ecosystem , carbon cycle , terrestrial ecosystem , environmental chemistry , soil science , carbon respiration , carbon sequestration , atmospheric carbon cycle , soil water , negative carbon dioxide emission , chemistry , ecology , biology , materials science , composite number , composite material
This research introduces the concept of a “CO 2 fertilization factor for soil carbon” (σ CF ). The σ CF is a measure of an ecosystem's capacity to increase soil carbon storage in response to elevated carbon dioxide levels. This paper describes the mathematical derivation of σ CF and illustrates how σ CF can be determined experimentally, using data from a white oak study. I have developed this concept to compare the results of carbon dioxide enrichment experiments having different soil carbon turnover times, different levels of CO 2 enrichment, and different lengths of exposure to elevated carbon dioxide levels. The σ CF can also be used to estimate increases in soil carbon uptake due to observed contemporary increases in atmospheric carbon dioxide levels. Although the approach used here may seem oversimplified, I present it as a simple way of estimating the extent to which elevated levels of CO 2 could increase soil carbon storage. I have determined a σ CF of 1.18 for a white oak ecosystem using soil carbon and radiocarbon measurements. If major terrestrial ecosystems have similar σ CF values, CO 2 fertilization may be transferring enough carbon from the atmosphere to soil to balance the global carbon budget.