Estimation of microfungal diversity in tropical rainforest leaf litter using particle filtration: the effects of leaf storage and surface treatment

Fungal species richness and abundance were assessed in leaf litter of the Australian rainforest tree Neolitsea dealbata (Lauraceae) using particle filtration. Results were comparable to the species richness and abundance reported in previous studies of tropical leaf litter microfungi. Eight leaf samples yielded 1365 strains. In an assessment of the effect of surface treatments, 736 strains in 112 morphotaxa were isolated, while 639 strains in 141 morphotaxa were recovered to assess the effect of surface treatment. Isolation rates in airdried leaves stored at room temperature for four weeks declined linearly, while the number of morphotaxa remained essentially constant for the first three weeks. Isolates of common morphotaxa were lost preferentially over those of rarer taxa. Such losses of isolates may be acceptable if only presence/absence data are collected. If frequency data are vital for community analysis, only fresh material should be utilised. Two surface sterilisation treatments were applied to N. dealbata leaves. An ethanol/sodium hypochlorite treatment was considered unsuitable because it significantly reduced the number of morphotaxa derived from the leaf lamina. A sodium hypochlorite treatment reduced the number of detectable propagules in the wash water without changing the number of morphotaxa derived from leaf particles in comparison with those of the control group.