© 2000 Heron Publishing—Victoria, Canada
Effects of serpentine soil factors on Virginia pine (Pinus virginiana) seedlings
Susan P. Miller (1, 2) and Jonathan R. Cumming (1, 3)
1. Department of Biology, P.O. Box 6057, West Virginia University, Morgantown, WV 26506-6057, USA / 2. Department of Agronomy, N-122 Agricultural Sciences North, University of Kentucky, Lexington, Kentucky 40546-0091, USA / 3. Author to whom correspondence should be addressed (spm@wvu.edu) / Received September 23, 1999
Summary
Effects of simulated serpentine soil conditions (elevated Mg:Ca ratio and Ni concentration) on seedlings from populations
of Virginia pine (Pinus virginiana Mill.) from serpentine and non-serpentine sites were evaluated in sand culture. We determined (1) how seedlings are affected
by elevated Mg:Ca ratio and Ni concentrations, (2) if there are interactive effects between Mg:Ca ratio and Ni concentrations
on seedling growth, needle pigment concentrations, and nutrition, and (3) if Virginia pine populations from serpentine areas
are edaphic ecotypes. A Mg:Ca ratio of 5 and 50 μM Ni both reduced seedling growth compared with control seedlings grown in
the presence of the standard Mg:Ca ratio of 0.5 and no Ni. Interactive effects between Mg:Ca ratio and Ni concentrations were
highly significant for growth, foliar pigments, and needle and root elemental concentrations. Nickel-mediated reductions in
growth and foliar pigment concentrations were less at the serpentine Mg:Ca ratio of 5 than at the standard (non-serpentine)
Mg:Ca ratio of 0.5. Foliar N was reduced by Ni concentrations as low as 10 μM, and foliar and root K, Ca and P concentrations
were significantly reduced by Ni concentrations above 25 μM, with greater reductions at a Mg:Ca ratio of 0.5 than at a Mg:Ca
ratio of 5. There were no population × serpentine soil factor interactions for seedling growth, foliar pigment concentrations,
or nutrition, suggesting that seedlings from trees growing on serpentine soils are not edaphic ecotypes. We conclude that
serpentine conditions present at the site of seed collection have not resulted in the selection of edaphic ecotypes of Virginia
pine with respect to Mg:Ca ratio and Ni concentration.
Keywords:
calcium, edaphic ecotype, magnesium, Mg:Ca ratio, nickel.
