Abstract Detail

Ecophysiology

Lauer, Nathan [1], Zwiazek, Janusz J. [2].

Effects of pH on Salt Tolerance in White Spruce and Trembling Aspen.

Revegetation of land disturbed by oil sands surface mining in northeastern Alberta can be hindered by elevated soil pH and salt levels found at reclamation sites. In this study, the tolerance of white spruce (Picea glauca) and trembling aspen (Populus tremuloides) to elevated pH and salinity was investigated. Both species are commonly used in land reclamation following oil sands surface mining. Seedlings were maintained in liquid culture for 50 days while being exposed to three pH levels (5, 7, and 9) with three separate NaCl concentrations (0, 30, and 60 mM NaCl) in a factorial design for a total of 9 treatments. For white spruce, elevated pH caused decreases in leaf phosphorus, calcium, and iron. Elevated NaCl induced decreases in leaf iron, potassium, total chlorophyll content, net photosynthesis, and net transpiration. However, elevated pH and NaCl did not induce mortality or changes in biomass. For trembling aspen, elevated pH and NaCl induced mortality as well as decreases in leaf nitrogen, phosphorus, calcium, iron, total chlorophyll content, net photosynthesis, net transpiration, and total biomass. Interestingly, aspen exposed to elevated pH and NaCl exhibited an increased root:shoot ratio, suggesting that both stresses caused enhanced root growth. Furthermore, aspen exhibited a great ability to exclude sodium ions from entering the leaves by storing the ions within the root tissue. In conclusion, white spruce was exceptionally tolerant to elevated pH and NaCl levels with no changes in biomass or mortality occurring; however, physiological indicators of stress (decreases in chlorophyll content, net photosynthesis, and transpiration) occurred with elevated NaCl. Trembling aspen was able to tolerate moderate increases in pH and NaCl, but appeared to be more sensitive with mortality occurring, especially at harsher treatments (pH 5 & 7; 60 mM NaCl, pH 9; 0-60 mM NaCl). Ultimately, this information could be used for reclamation efforts of lands disturbed by oil sands surface mining in northeastern Alberta, especially lands affected by elevated pH and salt levels.

1 - Univeristy Of Alberta, Renewable Resources, 116st & 85th Ave, Edmonton, AB, T6G 2E3, Canada
2 - Univeristy Of Alberta, Renewable Resources, 116st & 85th Ave, Renewable Resources, Edmonton, AB, T6G 2E3, Canada

Keywords:
spruce
trembling aspen
Land reclamation
stress tolerance
salt stress.

Presentation Type: Oral Paper:Papers for Topics
Session: 41
Location: Salon 16/The Shaw Conference Centre
Date: Tuesday, July 28th, 2015
Time: 11:15 AM
Number: 41005
Abstract ID:1098
Candidate for Awards:Physiological Section Physiological Section Li-COR Prize