CONSIDERATION OF THE TAXONOMY AND BIODIVERSITY OF AUSTRALIAN ECTOMYCORRHIZAL FUNGI

Mycorrhiza management in forestry must be predicated on an understandi ng of fungal biology and ecology. A fundamental building block of the biology and ecology of any organism is accurate identification and an understanding of its relationship to other organisms. The taxonomy of the larger fungi has been largely based on morphological classificatio n of sexual structures but now Taxonomy routinely incorporates mating studies, and biochemical and molecular data. Taxonomy may not revoluti onize theories on mycorrhiza but can clarify some of the inconsistenci es due to misrepresentation or over-generalizations and inappropriate conclusions drawn from studies with inaccurately identified fungi. To illustrate this, we discuss an example where incorrect fungal names we re repeatedly erroneously applied in morphological and physiological r esearch reports on this fungus, e.g. Laccaria laccata. In this case su bsequent taxonomic study revealed the reason for the conflicting resea rch results reported for this fungus. We discuss the status of identif ying the ectomycorrhizal fungi in various forest communities in Austra lia and the relationships of this process to assessing their use in fo restry. Recent intensive efforts to collect, isolate and identify Aust ralian ectomycorrhizal fungi have revealed an enormous and unique spec ies diversity, e.g., for truffle-like fungi, over 2000 collections fro m the last five years alone have yielded 2 new families, 24 new genera , and about 184 new species. Nearly 95% of the described and undescrib ed fungi from Australia are novel, with some 22 genera and 3 families endemic. In most cases the current systematic knowledge of mycorrhizal fungi is inadequate to support clear framework for Australian taxa. T his reflects the traditional Northern Hemisphere view of the world, th e uniqueness of the Australian fungal flora, and how poorly it is know n. For example, the genus Hymenogaster had been widely acknowledged as the most reduced member of the Cortinariaceae. However recent work on Hymenogaster species from the Southern Hemisphere has offered a numbe r of alternative affinities to various species. We also discuss the ro le proper identification of the organisms involved plays in understand ing the ecosystem. Emphasis should be placed on how species diversity equates with physiological and genetic diversity and how a sound taxon omic understanding of species and their systematic position is essenti al to properly manage them. Accurate taxonomic information will contin ue to be required as the basis for assessing the role of ectomycorrhiz al fungi in sustained ecological development. Of particular significan ce is the role of ectomycorrhizal fungi in maintenance of plant divers ity in natural ecosystems and those disturbed by management. In conclu sion, we present some key research areas involving the use of taxonomy that need priority attention.