Ecophysiological adaptations of black spruce (Picea mariana) and tamarack (Larix laricina) seedlings to flooding.

• Author(s) / Creator(s)

  • Macdonald, S. Ellen
  • Islam, M. Anisul

• Black spruce and tamarack are the predominant tree species in boreal peatlands. The effects of flooding on morphological and physiological responses were investigated in greenhouse grown (18 months old) black spruce (Picea mariana) and tamarack (Larix laricina) seedlings for 34 days. Flooding resulted in reduced root hydraulic conductance, net assimilation rate and stomatal conductance and needle electrolyte leakage in both species. Flooded tamarack seedlings maintained a higher net assimilation rate and stomatal conductance compared to flooded black spruce. Flooded tamarack seedlings were also able to maintain higher root hydraulic conductance 8 compared to flooded black spruce seedlings at a comparable time period of flooding. Root respiration declined in both species under flooding. Sugar concentration in shoots increased while decreased in roots in both species under flooding. Needles of flooded black spruce appeared necrotic and electrolyte leakage increased over time with flooding and remained significantly higher than flooded tamarack seedlings. No visible damage symptoms were observed in flooded tamarack seedlings. Flooded tamarack seedlings developed adventitious roots beginning 14 days after the flooding treatment began. To investigate the possible physiological role of adventitious roots, their hydraulic conductivity was measured and compared with similarly sized flooded roots. Adventitious roots exhibited significantly higher root hydraulic conductivity. Flooded black spruce lacked any such morphological adaptation. These results suggest that tamarack seedlings were better able to adjust both morphologically and physiologically to a prolonged soil flooding than black spruce seedlings.

• Date created

  2004

• Subjects / Keywords

  • Gas exchange
  • Root hydraulic conductance
  • Flooding
  • Root respiration
  • Carbohydrate content

• Type of Item

  Article (Published)

• DOI

  https://doi.org/10.7939/R36H4CQ0C

• License

  © 2004 Trees: Structures and Functions. This version of this article is open access and can be downloaded and shared. The original author(s) and source must be cited.