Open Access

Stephen Clark, Claire deLacey, Steven Chamberlain

• An improved approach to predicting preferred habitat and targetting survey effort for threatened plant species is needed to aid discovery and conservation of new populations. This study employs several approaches to aid in the delineation of preferred habitat for the Leafless Tongue Orchid, Cryptostylis hunteriana Nicholls. BIOCLIM, a bioclimatic analysis and prediction system, is used initially to generate a bioclimatic habitat envelope within which the species can be expected to occur, based on all known sites in the Shoalhaven Local Government Area. Within the BIOCLIM envelope it is possible to further investigate the extent to which the species exhibits preferences for other habitat factors such as geology, soil landscapes and forest ecosystems. Multivariate techniques are used to compare floristic data from sites where Cryptostylis hunteriana is present, and sites from forest ecosystems where it has not been recorded historically. These techniques are also used to identify species which are diagnostic of each of these sets of sites. All 25 sites with Cryptostylis hunteriana populations are restricted to six forest ecosystems having a total area of 15% of the Shoalhaven Local Government Area and 47% of the BIOCLIM envelope. Within these forest ecosystems, ten plant species deemed indicative of the possible presence of the Cryptostylis hunteriana are identified.