© 1990 Heron Publishing—Victoria, Canada
Solution aluminum and transpiration in Picea rubens and Gleditsia triacanthos seedlings
Z. Ren and E. I. Sucoff
Department of Forest Resources, University of Minnesota, 1530 North Cleveland Avenue, St. Paul, MN 55108, USA / Received July 24, 1989
Summary
Soil solution Al may contribute to red spruce (Picea rubens Sarg.) decline by inhibiting transpiration (Klein 1985). This study examines how Al affects transpiration in red spruce and
honeylocust (Gleditsia triacanthos L.) seedlings and explores mechanisms for the observed responses. Red spruce seedlings were grown in dilute nutrient solutions
containing 0 to 925 μM Al at pH 4.5 or 3.8. Solution Al had no effect on the transpiration, root hydraulic conductivity (Kr) or shoot water potential (Ψ) of red spruce.
Transpiration of honeylocust was higher in the presence of 100 to 350 μM Al than 0, 500, or 600 μM Al. The Al-induced increases
in transpiration of honeylocust were unrelated to shoot Ψ or root Kr, but were closely correlated with the greater root lengths produced by intermediate levels of Al. In neither species was
transpiration correlated with tissue concentrations of Al, P, K, Ca or Mg.
