The distribution, abundance, and environmental affinities of the endemic vascular plant taxa of the Athabasca Sand Dunes of northern Saskatchewan

Abstract

The Athabasca Sand Dunes in northern Saskatchewan are a unique landscape characterized by large areas of active sand dunes. The dunes are of high conservation value as they support 10 endemic vascular plant taxa, including 9 sand dune specialists: Achillea millefolium var. megacephala, Armeria maritima ssp. interior, Deschampsia mackenzieana, Salix brachycarpa var. psammophila, Salix silicicola, Salix turnorii, Salix tyrrellii, Stellaria arenicola, and Tanacetum huronense var. floccosum. This paper describes the patterns of distribution, abundance, and environmental affinity of the Athabasca endemic flora and assesses the implications of these patterns for the conservation status of the species. Extensive field surveys found large populations of Deschampsia mackenzieana, Salix brachycarpa, Salix silicicola, Salix turnorii, Salix tyrrellii, Stellaria arenicola, and Tanacetum huronense. With the exception of S. brachycarpa the abundant species were widely distributed across the dune landscape. Two species, Achillea millefolium and Armeria maritima, had relatively small populations that were concentrated in limited environments within the dune landscape (wet dune slack and gravel pavements respectively). Few immediate external threats were observed, and flowering, seed set, and seedling establishment were observed for all taxa. The small populations and limited environmental breadth of Achillea millefolium and Armeria maritima indicate that the conservation status of these species should be re-examined.