Opportunistic wetland formation on reconstructed landforms in a sub-humid climate: influence of site and landscape-scale factors

Research output: Contribution to journalArticle

Authors

Colleges, School and Institutes

External organisations

  • Univeristy of Alberta
  • University of Lethbridge

Abstract

Initiation of wetland features is integral to sustaining landscape eco-hydrological function and meeting defined goals in surface mine reclamation. Within the sub humid climate of the Athabasca Oil Sands, Canada, the water generation mechanisms (external water sources, internal feedback mechanisms) that enable wetlands to form opportunistically on recently reconstructed landscapes are currently unknown, restricting the flexibility in mine closure planning. To address this knowledge gap, we interpret site and local physical characteristics of opportunistic wetlands within the Athabasca Oil Sands through a synoptic survey. Wetlands formed in ~ 8% of the random survey transect areas designed and planted for forestlands. Wetlands had vegetation structures characteristic of woody Salix spp. swamps and narrow-leaved Carex spp. marsh wetland types, with minor coverage of open water marshes. Wetlands formed opportunistically over a range of slopes, aspects and topographic positions, across contrasting fine and coarse-textured landforms. However, different wetland establishment and maintenance controls exist on fine and coarse-textured landforms. On coarse-textured landforms with large groundwater transmissivity, wetland formation was influenced by landscape-scale factors; wetlands were restricted to the toes of slopes and areas intersecting groundwater. On fine-textured constructed landforms, small and large wetlands occurred on lower landscape elevations with the potential for the external (cumulative) water sources, and in hydrologically isolated locations with little potential for runoff contribution from adjacent forestlands (saturation and wetland formation through internal feedback mechanisms). Regardless of landscape position, wetlands formed on flat areas and in shallow inward draining endorheic pans with clay rich soils where low water storage potential promotes frequent surface saturation. These findings have important implications in landscape reclamation design, suggesting that passive techniques that support internal feedback mechanisms may offer a more cost effective reclamation approach compared to more active, expensive techniques that aim to develop wetlands with external water sources.

Details

Original languageEnglish
Pages (from-to)587-608
Number of pages22
JournalWetlands Ecology and Management
Volume27
Issue number5-6
Early online date30 Jul 2019
Publication statusE-pub ahead of print - 30 Jul 2019

Keywords

  • Confining layer, Groundwater, Internal feedbacks, Landform texture, Landscape position, Local slope