Monoterpenes and microbial metabolites in the soil.

Volatile microbial metabolites were analysed in the soil beneath 15 H year-old Picea abies which had been fumigated for 5 consecutive years with charcoal-filtered air enriched with ozone and sulphur dioxide. Major compounds which could be attributed to the metabolism of basidiomycete fungi were oct-1-en-3-ol, oct-1-en-3-one and 1,3-octadiene. They were accompanied by other C(8)-compounds. The lower amounts of C(8)-compounds observed in the soil of the sulphur dioxide and ozone treatment chambers indicate a reduced development of basidiomycetes. The higher amounts of geosmin and 2-methylisoborneol found in the soil of the ozone treatment chamber indicate an increase in actinomycete populations. The differences of the monoterpene patterns in the particular soils were not large enough to recognize trends unequivocally.