Asymbiotic nitrogen fixation on woody roots of Norway spruce and Silver birch

High rates of asymbiotic nitrogen fixation have been measured in woody roots in temperate forests, but this rate has not been quantified in boreal forests. We studied the asymbiotic N2 fixation associated with living and decomposing woody roots of Norway spruce in three sites in Finland. In addition, tree species effect was studied in one site that included Norway spruce and Silver birch monocultures and mixed stands. The rate of N2 fixation measured as nitrogenase activity was affected by host tree species, spruce roots being the most active (in spruce monocultures 0.67 C2H4.dThe accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author