Limited effects of simulated acidic deposition on seedling survivorship and root morphology of endemic plant taxa of the Athabasca Sand Dunes in well-watered greenhouse trials

作者：Guy Amanda L; Mischkolz Jenalee M; Lamb Eric G^*

来源：Botany, 2013, 91(3): 176-181.

DOI：10.1139/cjb-2012-0162

• Athabasca Sand Dunes
• acid deposition
• endemic vascular plants
• species at risk

The Athabasca Sand Dunes of northern Saskatchewan support 10 endemic vascular plant taxa listed under the Species at Risk Act (SARA). The Athabasca Sand Dunes are subject to acidic deposition; the potential impacts of which are a significant knowledge gap to a comprehensive reassessment of the conservation status of these taxa. We used a greenhouse experiment to assess the potential effects of acidic deposition on the root system morphology of the following three endemic species: Armeria maritima (P. Mill) Willd. ssp. interior (Raup) Porsild, Deschampsia mackenzieana Raup, and Stellaria arenicola Raup. We found limited effects of three pH treatments on root diameter, root length, surface area, and branching. Although acidic deposition is likely not a short-term threat, current and future deposition still may be a significant long-term threat. The Athabasca Sand Dune soils are considered highly sensitive, and acidification and nutrient leaching can take several decades to manifest. This should be considered when assessing the conservation status of these endemic taxa, particularly A. maritima, as this species may be more sensitive than the other species to acidic deposition owing to a small population size and limited habitat breadth.

• 出版日期2013-3