Ecological studies of hypogeous fungi. II. Sporocarp phenology in a western Oregon Douglas Fir stand

Abstract

Sporocarp phenology of hypogeous or subterranean fruiting fleshy fungi was studied between March 1972-March 1975 in a 40 to 65 yr old Douglas fir stand in W Oregon [USA]. Estimates of yearly productivity ranged from 11,052-16,753 sporocarps ha-1 and 2.3-5.4 kg dry weight ha-1. The productivity curve was bimodal as a result of temperature and moisture effects, with peaks in May-June and Oct. Eleven hypogeous ascomycete spp. and 13 hypogeous basidiomycete spp. were collected during the study. Major species that each accounted for 5% or more of the total weight were Tuber murinum, Hymenogaster parksii, Hysterangium crassum, H. separabile and Truncocolumella citrina var. citrina. Sporocarp moisture content as determined for several species presumably varied with sporocarp age and soil moisture content and ranged from 17.4-88.6%. Hypogeous sporocarps had substantially higher macronutrient contents of N, P and K plus the micronutrients Fe and Al than did epigeous sporocarps of Fomes pinicola. Sporocarp numbers increased exponentially with distance from the nearest live Douglas fir stem to a peak at 160-200 cm beyond which numbers dropped sharply. The optimum sporocarp zone was slightly less than the average midpoint between tree stems (205 cm).