ENVIRONMENTAL CONSEQUENCES in rocky mountain coniferous ...

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June July August September October
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Figure 5.-- Seasonal variation of rnoistxre content in soihood.
HYDROGEN ION CONCENTRATION
Wood pH is controlled primarily by the presence of acetic and formic acids.
Acidity (pH) in sound conifer wood varies between 2.7 to 8.8. Brown-rot fungi
apparently can withstand acid conditions better than white-rot fungi (Henningson
1967). Highley (1976) reported that fungal cellulases and hemicellulases of brown-
rot fungi were more tolerant of lower pH's than white-rot fungi. Furthermore,
brown-rot fungi lower the pH during the decay process through oxalic acid production
(Takao 1965). Also, white-rot fungi utilize acetic acid. Our pH measurements on
brown-rotted wood agree with these observations. Decaying and decayed brown-rotted
wood, in or on soil profiles, is significantly more acidic than other soil components.
The acidity of this substrate appears to have significant implications for forest
management, particularly regeneration.
Microorganisms Associated W i th Residue Decay
s . Analysis of the microbial flora associated with residue decay on the Coram
Experimental Forest, in Montana has provided some insight into occurrence of decay
fungi and a1 so into the associations that exist between decay fungi, yeasts, bacteria,
and non-hymenomycetes, The information assembled to date is provocative in the
sense that it suggests that organism association (and possible interaction) may b,e
important in the brown-rot process producing brown-cubical decayed wood. The
interactions may a1 so provide insight into decay mechanisms +
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