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Mycorrhizal Roots In A Temperate Forest Take Up Organic Nitrogen From 13c- And 15n-Labeled Organic Matter, Matthew A. Vadeboncoeur, Andrew P. Ouimette, Erik A. Hobbie

Earth Systems Research Center

Background and Aims

The importance of the uptake of nitrogen in organic form by plants and mycorrhizal fungi has been demonstrated in various ecosystems including temperate forests. However, in previous experiments, isotopically labeled amino acids were often added to soils in concentrations that may be higher than those normally available to roots and mycorrhizal hyphae in situ, and these high concentrations could contribute to exaggerated uptake.

Methods

We used an experimental approach in which we added ¹³C-labeled and ¹⁵N-labeled whole cells to root-ingrowth cores, allowing proteolytic enzymes to release labeled organic nitrogen at a natural rate, as …