An investigation into the ecological requirements and niche partitioning of Pterostylidinae (Orchidaceae) species

Abstract

The in situ management of many orchid species is problematic because individual species' ecology and habitat requirements are poorly understood. Here, the requirements of nine Pterostylis species are investigated for the first time. Individual species' abundances were recorded from 35 sites and correlated with known environmental and climatic variables using canonical correspondence analysis to determine which variables may explain species distribution. Altitude, aspect, drainage, precipitation, radiation, temperature and moisture index were identified as important variables that influence distribution patterns. The positioning of several members of the Pterostylis longifolia species complex in ordination space was poorly resolved, as was the relationship between Pterostylis pedoglossa and Pterostylis parviflora. Distinct ecological partitioning was evident among the remaining three species. This study has identified important environmental variables that can be assessed in the field and assist in the detection of suitable habitat for orchid translocations.