Old Growth Forests Still Socking Away Carbon and Nitrogen
Schrumpf, M., Kaiser, K. and Schulze, E.-D. 2014. Soil organic carbon and total nitrogen gains in an old growth deciduous forest in Germany. PLOS ONE 9: e89364.
In an attempt to resolve some of these issues, Schrumpf et al. "analyzed OC, TN and bulk densities of 100 soil cores sampled along a regular grid in an old-growth deciduous forest at the Hainich National Park, Germany, in 2004 and again in 2009." The three German researchers found that "concentrations of OC and TN increased significantly from 2004 to 2009, mostly in the upper 0-20 cm of the mineral soil, with average annual accumulation rates of 65 ± 29 g OC/m2/yr and 7.8 ± 2 g N/m2/yr." And they say the soil OC increases "are estimated to be ~10% of aboveground C gains," and that both the "soil OC and TN gains at the Hainich site seem to be due to increasing litter input, likely because the forest is accumulating biomass."
Schrumpf et al. conclude that their work "supports earlier studies indicating that the old-growth forest at the Hainich National Park is still accumulating OC in soil." And they say "it adds to the growing number of studies showing that soils of temperate forests are currently C sinks."
Ballantyne, A.P., Alden C.B., Miller, J.B., Tans, P.P. and White, J.W.C. 2012. Increase in observed net carbon dioxide uptake by land and oceans during the past 50 years. Nature 488: 70-72.
Levin, I. 2012. The balance of the carbon budget. Nature 288: 35-36.