Without complex molecular methods, almost all fungi which occur in the UK can only be recorded when they produce fruiting bodies. Whilst in some species, such as some of the larger Ganoderma species, these are large and permanently visible, most species only produce fruiting bodies in response to particular conditions, the fruiting bodies are short-lived, often seasonal and may not be produced every year. A number of surveys have shown that there is a relatively small number of common fungi which fruit every year but in contrast new species are continuously added to site lists after decades of recording, consequently comprehensive documentation of the fungus flora of a site can require decades of recording. So, no matter how desirable, it is not practical to attempt to document the fungus flora of a site for the purposes of environmental impact assessment.
There is also something of a peculiar attitude to fungi in the British Isles compared to other taxa, thus species which are uniquely dependent upon a non-native vascular plant species (such as non-native conifers) and which cannot themselves be native may be considered to be of conservation concern. This, combined with the limited data available on the macro fungi in Britain and Ireland, makes assessment of the conservation value of a site for fungi, at best, very coarse and consequently any attempt to predict impacts on fungi of conservation concern at a site islikely to be somewhat speculative.
Therefore,a pragmatic approach is needed to assess the conservation value of a site for fungi. It is obviously important to strive for the ideal, which involves regular surveys throughout the year for a number of years to establish a good enough list of species to indicate the richness of a site for fungi. However, the minimum must involve a thorough survey of the fungus habitats represented (so including availability of different sizes, ages and species of dead wood, acid substrates, vascular plant species as potential hosts etc.). This, in comparison with national data such as the UK Red List of Fungi and local Red Lists, where available, can then allow for an assessment of the potential of a site to support a fungus flora of conservation value.