Ecological studies of hypogeous fungi. 2: Sporocarp phenology in a western Oregon Douglas-fir stand

Sporocarp phenology of hypogeous or subterranean fruiting fleshy fungi was studied betweenMarch 1972 and March 1975 in a 40- to 65-year-old Douglas fir stand in western Oregon.Estimates of yearly productivity ranged from 11 052 to 16 753 sporocarps ha- ' and 2.3 to 5.4 kgdry weight ha- . The productivity curve was bimodal as a result of temperature and moistureeffects, with peaks in May-June and October. Eleven hypogeous ascomycete species and 13hypogeous basidiomycete species were collected during the study. Major species that eachaccounted for 5% or more of the total weight were Tuber murinum, Hymenogaster parksii,Hysterangium crassum, H. separabile, and Truncocolumella citrina var. citrina. Sporocarpmoisture content as determined for several species presumably varied with sporocarp age and soilmoisture content and ranged from 17.4 to 88.6%. Hypogeous sporocarps had substantially highermacronutrient contents of N, P, and K plus the micronutrients Fe and Al than did epigeoussporocarps of Fomes pinicola. Sporocarp numbers increased exponentially with distance fromnearest live Douglas fir stem to a peak at 160 to 200 cm, beyond which numbers dropped sharply.The optimum sporocarp zone was slightly less than the average midpoint between tree stems (205cm).