Woody Plants Acting as Carbon and Nitrogen Magnets
Springsteen, A., Loya, W., Liebig, M. and Hendrickson, J. 2010. Soil carbon and nitrogen across a chronosequence of woody plant expansion in North Dakota. Plant and Soil 328: 369-379.
The four researchers report that total soil carbon content rose by 26% across the chronosequence from grassland to woodland within the 0-15 cm soil depth, while total soil nitrogen content rose by 31%. And they add that the rate of woody shrub expansion from 1963 to 1988 (25 years) was ~1,800 m2 per year at their study site, while from 1988 to 2005 (17 years) it was ~3,800 m2 per year, or just a little more than doubled.
As ever more experiments of this type are conducted at ever more sites around the world, it is becoming increasingly evident that soil carbon sequestration driven by woody-plant invasions of grasslands (which are driven to a significant degree by the ongoing rise in the air's CO2 content), as well as the increases in soil nitrogen content required to sustain them, are growing ever greater with the passage of time, as the greening of the earth continues.
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