Conservation of the endangered Small White Lady’s Slipper in Manitoba, Canada – A Hydrogeological Approach

ABSTRACT: The small white lady’s-slipper, Cypripedium candidum is an endangered native terrestrial orchid, found at the northern limit of its range in Manitoba, Canada. Cypripedium candidum has specific site preferences, such that habitat destruction including alteration of hydrology is considered a primary threat to the orchid. Cypripedium candidum populations were examined in the context of their hydrogeological settings. Regionally, locations exhibited a preference for discharge margins of unconfined glacial sand aquifers. Field evidence of groundwater discharge as apparent at candidum sites. Monitoring at three locations found shallow water tables during the active growing period. Water samples exhibited high pH and were rich in calcium. The affected soil chemistry appeared to suppress competing species, allowing Cypripedium candidum to succeed. By understanding characteristic hydrogeological conditions, existing populations may be protected, locations of undiscovered populations may be predicted and habitat may be rehabilitated, thus assisting conservation efforts.