Assessing the Bio-geomorphic Effects of Land Management Practices and Climate Change on Rangelands

Activity Rationale

Native prairie rangelands are changing - floral and fauna species are declining due to habitat loss. Exact causes are uncertain, but climatic and land use changes are two probable mechanisms. This activity investigates the role of climate and land management practices as bio-geomorphic drivers of change. We examine the role of grazing, fire and soil disturbance, coupled with climatic parameters (precipitation, temperature and wind), as means of restoring native prairie rangeland habitat under present and future climatic conditions

Leader: Stephen Wolfe

 

The Topic

Model projections of future climate on the prairies indicate that dune activity will likely increase with increasing aridity. However, prairie sand hills have been stabilizing throughout the last century. Dune stabilization occurs when vegetation cover increases, thereby decreasing bare active sand. Dune areas are used for rangelands, parks, recreation areas, wildlife reserves, and hunting areas, and provide habitat for many species of flora and fauna. When dunes stabilize, they can no longer be used by the people, flora, and fauna that rely on them.

An understanding of various drivers of dune activity is important for managing the land and ecosystems resources of rangelands and native prairie habitat. This activity investigates the bio-geomorphic effects of land management practices in sand hills under the current climate, and explores alternative land management options to restore and maintain these areas.

The present focus is on the Middle Sand Hills of the Canadian Forces Base Suffield, which supports a National Wildlife Area, in addition to a Prairie Farm Rehabilitation Administration (PFRA) grazing pasture and ongoing natural gas development. This area is home to several endangered prairie grassland species, and comprises the core habitat of active sand dunes for Ord's kangaroo rats in Alberta. However, dune stabilization rates at Suffield are among the highest on the prairies, even though the area is arguably one of the most arid parts of Alberta. At the present rate, active dunes are projected to disappear by 2014, representing a major loss of habitat for many dune-dependent species.

A three-year program was initiated to restore active dune habitats in CFB Suffield. The goal is to employ and evaluate management approaches coupled with observations of climatic drivers (e.g. wind and aridity) to halt or reverse dune stabilization. A monitoring program measures erosion, and relates it to the intensity of the disturbance treatment and climatic factors. This knowledge will help managers to prescribe appropriate levels of disturbance under present and future climatic regimes to restore and maintain native prairie habitat for dune-dependent species.

 

Results

To date, climate data have been collected since October 2006, recording wind speed, direction, temperature, precipitation and humidity. Preliminary results show that hand-dug erosion sites and fire may be effective in creating active wind erosion on sand dunes that could restore and maintain habitat for dune-dependent species under present and future climatic conditions.

Erosion pits dug in October 2006 are still active and expanding; and Ord's Kangaroo rats have occupied several sites. Burn sites created large tracts of reduced vegetation and caused bare sand and sand mounds (created by pocket gophers) to be mobilized by the wind.

 

Burns conducted during the fall season may permit effective wind erosion to occur throughout the winter and into the spring before vegetation re-grows. Ord's Kangaroo rats have been noted to occupy these burn sites. All sites are presently being monitored to determine which management options, or combinations, may be most effective in restoring habitat for dune-dependent species under present and future climatic conditions.

 

 

Publications

Please note that subscriptions may be required for access to some articles. To request a copy of publications, or for any more information, please contact Stephen Wolfe.

Check for more recent publications in GEOSCAN, the publications database of the Geological Survey of Canada and the Canada Centre for Remote Sensing.

S.A. Wolfe, C.H. Hugenholtz, C. Evans, D. Huntley, and J. Ollerhead. 2007 Potential aboriginal occupation-induced dune activity, Elbow Sand Hills, northern Great Plains, Canada. Journal of Great Plains Research. V.17, no. 2, p. 173-192. Cont. # 20070013.

C.H. Hugenholtz and S.A. Wolfe. 2005 Biogeomorphic model of dune activation and stalbization on the northern Great Plains. Geomorphology, v. 70, p. 53- 70.

C.H. Hugenholtz and S.A. Wolfe.  2005  Recent stabilization of active sand dunes on the Canadian prairies and relation to recent climatic variations. Geomorphology, v. 68, 1-2, p. 131- 147.

Presentations

C.H. Hugenholtz, S.A. Wolfe, D. Bender, D. Gummer, and A. Gillis. 2008 Reactivating Sand Dunes and Restoring Aeolian Processes for Endangered Species in the Middle Sand Hills, Southeastern Alberta. Canadian Geophysical Union – Canadian Geomorphology Research Group Annual Meeting, Banff May 11-14. Oral Presentation. Cont # 20070571.

S.A. Wolfe. 2007 Invited Lecture. Restoration of sand dune habitats in the CFB Suffield

National Wildlife Area: a geomorphic perspective. National Wildlife Research Centre Carleton University. October 24, 2007

D.J. Bender, D.L. Gummer, S.A. Wolfe, and C.H. Hugenholtz. 2007 Disappearing sand dune habitats on the prairies: identification and restoration. 8th Prairie Conservation and Endangered Species Conference, Regina, SK, 1 - 3 March 2007. Poster Presentation. Cont. # 20060387.