Soil salinity is a major abiotic stress that reduces the growth, survival and physiological functions of most plants. In the boreal forest, elevated levels of NaCl pose reclamation challenges for habitats disturbed by the oil sand industry. The objectives of this study were to determine how salinity affects the nitrogen fixation capability of the native boreal N-fixing shrub, wolf willow (Elaeagnus commutata), as well as to examine how salinity affects its growth and physiology. Seedlings of E. commutata were exposed to 0, 50 and 100 mM NaCl in a hydroponic system and physiological parameters were measured after 1, 4, 8 and 12 weeks of treatment. All plants survived the salinity treatments. Gas exchange parameters including leaf photosynthesis, stomatal conductance and transpiration were only reduced at 100 mM NaCl. In addition, plants showed signs of photosynthetic recovery after 4 weeks. Increasing salinity also led to moderate declines in plant shoot and root growth. While N and K content in plant leaf and root tissues were not reduced by higher salinity, salinity did reduce Ca content in plant leaf tissues. Root nodule function was largely inhibited at 100 mM NaCl, resulting from the absence of nitrogen-fixing vesicles within these nodules. Our data suggested that E. commutata seedlings can survive and grow under up to 100 mM NaCl while maintaining moderate levels of physiological functions, and reduced ability to fix nitrogen, limiting improvements to soil fertility in restoration applications.

土壤盐分是一种主要的非生物胁迫，会降低大多数植物的生长，存活和生理功能。在北方森林中，NaCl含量升高对受油砂工业干扰的生境提出了开垦挑战。这项研究的目的是确定盐度如何影响天然北方固氮灌木狼柳（Elaeagnus commutata）的固氮能力，并研究盐度如何影响其生长和生理。幼苗E. commutata在水培系统中将其暴露于0、50和100 mM NaCl中，并在治疗1、4、8和12周后测量生理参数。所有植物均在盐处理下存活。气体交换参数（包括叶片的光合作用，气孔导度和蒸腾作用）仅在100 mM NaCl时降低。另外，植物在4周后显示出光合作用恢复的迹象。盐度的增加还导致植物嫩芽和根系生长的适度下降。虽然较高的盐度不会降低植物叶片和根组织中的N和K含量，但盐度确实会降低植物叶片组织中的Ca含量。在100 mM NaCl中，根瘤功能在很大程度上受到抑制，这是由于这些根瘤中不存在固氮囊泡。我们的数据表明，E。commutata 幼苗可以在高达100 mM的NaCl下存活并生长，同时保持适度的生理功能，并降低固氮能力，从而限制了恢复应用中土壤肥力的提高。