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Lolium perenne Grasslands May Function as a Sink for Atmospheric Carbon Dioxide
Author(s) -
Ginkel J. H.,
Whitmore A. P.,
Gorissen A.
Publication year - 1999
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq1999.00472425002800050023x
Subject(s) - lolium perenne , grassland , sink (geography) , carbon dioxide , lolium , environmental science , atmosphere (unit) , agronomy , carbon dioxide in earth's atmosphere , chemistry , carbon sink , decomposition , atmospheric sciences , soil science , environmental chemistry , poaceae , ecology , biology , climate change , meteorology , physics , cartography , organic chemistry , geography
Model calculations and scenario studies suggest the existence of a considerable positive feedback between temperature and CO 2 levels in the atmosphere. Rising temperatures are supposed to increase decomposition of soil organic C leading to increased production of CO 2 and this extra CO 2 induces a positive feedback by raising the temperature still further. Evidence was found that negative feedback mechanisms also exist: more primary production is allocated to roots as atmospheric CO 2 rises and these roots decompose more slowly than roots grown at ambient CO 2 levels. Experimental data partly obtained with 14 C‐techniques were applied in a grassland C model. The model results show that at an atmospheric CO 2 concentration of 700 µL L −1 increased belowground C storage will be more than sufficient to balance the increased decomposition of soil organic C in a ryegrass ( Lolium perenne L.) grassland soil. Once a doubling of the present atmospheric CO 2 concentration has been reached, C equivalent to 55% of the annual CO 2 increase above 1 ha ryegrass can be withdrawn from the atmosphere. This indicates that grassland soils represent a significant sink for rising atmospheric CO 2 .