Review Article Declining sand dune activity in the southern Canadian prairies: Historical context, controls and ecosystem implications Chris H. Hugenholtz a, * , Darren Bender b , Stephen A. Wolfe c a Department of Geography, University of Lethbridge, 4401 University Drive, Lethbridge, Alta., Canada T1K 3M4 b Department of Geography, University of Calgary, 2500 University Drive NW, Calgary, Alta., Canada T2N 1N4 c Natural Resources Canada, 601 Booth Street, Ottawa, Ont., Canada K1A 0E8 article info Article history: Received 13 November 2009 Revised 27 May 2010 Accepted 27 May 2010 Keywords: Canadian prairies Sandhills Sand dune stabilization Habitat decline Biodiversity abstract Sandhills are islands of biodiversity in the southern Canadian prairies that sustain habitat for many rare and endangered species. These unique areas consist of large expanses of dune fields now mostly stabi- lized by grassland vegetation. Historically, the number of active dunes has decreased significantly due to vegetation stabilization, resulting in a dramatic decline of open-sand habitat for a variety of dune- dependent species. Without a certain level of wind erosion, opportunities for establishment of early- stage, species-rich vegetation types are diminished and open-sand habitat decreases by encroachment of the surrounding grassland vegetation. The current trend of dune stabilization, however, implies that wind erosion is decreasing, thereby threatening the continued existence of a variety of dune-dependent plants, arthropods and vertebrates, as well as other less-specialized species that benefit indirectly from these habitats. By reviewing factors contributing to the historical decline of active dunes, as well as the ecological implications of dune stabilization, the aim of this paper is to establish the biophysical con- text for new land management strategies that conserve valued landscape components, such as active dunes, and the processes therein. As dune stabilization continues management interventions will be required to sustain or re-establish open sand and the species that rely on these habitats. Ó 2010 Elsevier B.V. All rights reserved. Contents 1. Introduction .......................................................................................................... 72 2. Regional setting and climate ............................................................................................. 72 3. Geomorphology of sandhills ............................................................................................. 74 3.1. Post-glacial development and evolution .............................................................................. 74 3.2. Aeolian landforms ................................................................................................ 74 4. Sandhill ecology ....................................................................................................... 74 4.1. Vegetation processes .............................................................................................. 74 4.2. Wildlife habitat .................................................................................................. 76 5. Past and present land use activities ....................................................................................... 77 6. Early explorer accounts ................................................................................................. 77 7. Historical sand dune stabilization ......................................................................................... 77 8. Factors contributing to the historical decline of dune activity .................................................................. 78 8.1. Long-term regional factors ......................................................................................... 78 8.2. Short-term local factors ........................................................................................... 79 9. Ecological implications of declining dune activity ............................................................................ 79 10. Conclusions .......................................................................................................... 80 Acknowledgements .................................................................................................... 80 References ........................................................................................................... 80 1875-9637/$ - see front matter Ó 2010 Elsevier B.V. All rights reserved. doi:10.1016/j.aeolia.2010.05.002 * Corresponding author. E-mail address: chris.hugenholtz@uleth.ca (C.H. Hugenholtz). Aeolian Research 2 (2010) 71–82 Contents lists available at ScienceDirect Aeolian Research journal homepage: www.elsevier.com/locate/aeolia