Bill Dunstan

The aim of our experiments was to develop protocols that can be used to contain and eradicate spot infestations of P. cinnamomi that, if untreated, are likely to threaten extensive areas of native vegetation or areas of high conservation value. Treatment regimes were guided by two assumptions: 1) within the selected sites, transmission of the pathogen is by root-to-root contact, and 2) the pathogen is a weakly competitive saprotroph. In Western Australia (WA), treatment and control plots were set-up along an active disease front within scrub-heath vegetation dominated by Banksia spp. Treatments, applied sequentially and in combination, included: 1) destruction of the largest plants within disease free vegetation forward of the disease front; 2) destruction of all plants to create a ‘dead zone’; 3) installation of physical root barriers and subsurface irrigation for the application of fungicide/s; 4) surface applications of fungicides selective against oomycetes (triadiazole and metalaxyl-M), and 5) surface injection and deep (± 1 m) treatments with Metham-sodium. In a separate experiment in Tasmania (TAS), combined treatments including vegetation removal, Ridomil and Metham-sodium and root barriers, or Ridomil and root barriers alone, were applied to experimental plots within active disease centres in Eucalyptus-Banksia woodland. In the WA experiment, P. cinnamomi was not recovered (by soil baiting) from plots after treatment with Ridomil and metham-sodium. In the TAS experiment, similar results were achieved with combined treatments (vegetation removal + Ridomil + metham sodium) but in plots treated with Ridomil alone, recoveries of P. cinnamomi increased after initially showing a significant reduction in recoveries.

In many upland forest regions of SE Asia, sporocarps of fungi, mostly basidiomycetes, have traditionally been collected for local consumption and trade. Many of these fungi, especially members of the Amanitaceae, Boletaceae, Russulaceae, and Tricholomataceae, form ectomycorrhizal associations with trees in the families Dipterocarpaceae, Fagaceae and Pinaceae and are important for maintaining ecosystem function. Species of Termitomyces fruit in association with colonies of soil-dwelling termites. Examples of fungal collecting, marketing and the commercial value of fungi are described for Yunnan in China, northern Thailand, and parts of Indonesia and the Philippines. The highest diversity of edible fungi is collected from mixed forests in China and the lowest diversity from areas of tropical pine and dipterocarps. In general, traded fresh sporocarps are 2 to 20 times more valuable than local seasonal fruits and vegetables. International trade in a small number of species is having a major impact on the quality and sustainability of some collecting sites. With forest destruction, fungal fruiting is increasingly restricted to remnant stands, pockets of secondary forest, small conservation reserves or commercial timber estates. Increasing harvesting pressures on this dwindling resource is likely to result in loss of biodiversity unless management strategies can be identified and implemented in sensitive remnant forest areas. This is particularly urgent for high-value mycorrhizal fungi such as Tricholoma species and hypogeous Ascomycetes. In some regions, there is also a need for the diversity of forest fungi to be documented, fungal herbaria to be established and fungal taxonomists to be trained. Furthermore, the diversity of indigenous edible fungi should be encouraged in suitable industrial timber estates, by silvicultural practices and inoculation strategies if necessary.