Testing the higher-taxon approach to conservation planning in a megadiverse group: the macrofungi

One promising shortcut for the rapid identification of key conservation sites is to carry out surveys only down to the level of genera or families, rather than species. However, few studies have examined how well this method performs when the groups of interest are extremely diverse. We conducted a detailed evaluation of the higher-taxon approach for a highly speciose but neglected group, the macromycete fungi. Using existing UK datasets, we found that at both national and local scales, the species richness of areas could be predicted reasonably closely from their genus-level richness. Family- and order-level data were less informative. However, efficient selection of priority areas for conservation hinges on differences between sites in their biota, as well as their absolute richness. In a simple algorithm designed to explore the consequences of using higher-taxon information for reserve selection: data on genera (but not on families or orders) again performed very well: hypothetical genus-based reserve networks typically captured 98-99% of the macromycete species represented when species-level data were used. Information on genera could successfully identify efficient reserve networks for species because of cross-level congruence in how well different sites complemented one another, as well as congruence in macrofungal richness. Further tests of the higher-taxon approach on highly speciose groups are needed, but the cautious use of genus-level surveys may be the most practical way of identifying priority areas for the conservation of megadiverse taxa. (C) 2000 Elsevier Science Ltd. All rights reserved.