N2 fixation associated with wood decayed by some common fungi in western Montana

Abstract

Decay caused by some common wood-destroying fungi in several associated tree hosts of the Intermountain forests of western Montana [USA] was evaluated as a potential environment for the fixation of N2. Differences in the rates of fixation were demonstrated between various decay stages, tree species, decay fungi, and brown and white rots. Advanced brown-rotted wood was a more favorable system for N fixation than wood partially brown rotted. Also, brown-rotted substrates were more favorable than were white rotted, particularly Pseudotsuga menziesii (Mirb.) Franco wood decayed by Fomitopsis pinicola (Swartz ex Fr.) Karst. A nitrogenase function coexists naturally with decay fungi in woody substrates; appreciable and significant amounts of N are fixed in these substrates.