Loblolly Pines Defy the Progressive Nitrogen Hypothesis

By | June 19, 2014




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As part of one of the most outstanding of such studies ever to be conducted, Finzi and Schlesinger (2003)1 measured and analyzed pool sizes and fluxes of inorganic and organic nitrogen in the forest floor and top 30 cm of mineral soil during the first five years of differential atmospheric CO2 treatment of a stand of initially 13-year-old loblolly pine trees at the Duke Forest FACE facility in the Piedmont region of North Carolina (USA), where half of the experimental plots were maintained at an atmospheric CO2 concentration approximately 200 ppm above ambient. Under these conditions, they found that the extra CO2 significantly increased the input of carbon (C) and nitrogen (N) to the forest floor, as well as to the mineral soil in which the trees were growing.