SEASONAL PRODUCTION OF HYPOGEAL FUNGAL SPOROCARPS IN A MIXED-SPECIES EUCALYPT FOREST STAND IN SOUTH-EASTERN AUSTRALIA

The seasonal production of hypogeal fungal sporoearps was monitored ov er an 18 month period in a catchment of mixed-species euealypt forest in East Gippsland, Vietoria. During the study, sporocarps of one Ascom ycete and 25 Basidiomycete species were collected from soil quadrats s ampled sequentially around the bases of eucalypt trees- Sporocarps fro m these species varied in their dimensions and morphological character istics. Productivity varied from 21 000 sporocarps ha-1 to 181 000 spo rocarps ha-1 or 1.8 kg ha-1 to 8.3 kg ha-1 per month. The probability of occurrence of sporocarps was, on average, greater in midslope sites on a sheltered aspect than elsewhere within the catchment. The number of sporocarps produced varied over time, with a major peak in product ion occurring during May (late-autumn). This peak occurred mainly with in gully sites, which supported on average a greater number of sporoca rps than ridge or midslope sites, but a lesser weight of sporocarps. T he distribution and productivity (probability of occurrence, number an d weight) of sporocarps appeared to be associated with some environmen tal (soil) variables, but not the physical variables (host tree), that we measured. Sporocarps of some species fruited predominantly in ridg e and slope habitats, some species fruited mainly in gullies, whereas others apparently showed no preference for fruiting in ridges, slopes and gullies. Thus, in forest catchments subject to land-management pra ctices such as logging and fire, it may be important to retain undistu rbed habitat throughout the topographic sequence to conserve a diversi ty of hypogeal species.