© 1996 Heron Publishing—Victoria, Canada
Evidence that longer needle retention of spruce and pine populations at high elevations and high latitudes is largely a phenotypic
response
Peter B. Reich (1), Jacek Oleksyn (1, 2), Jerzy Modrzynski (3) and Mark G. Tjoelker (1)
1. Department of Forest Resources, University of Minnesota, 1530 N. Cleveland Avenue, St. Paul, MN 55108, USA / 2. Polish Academy of Sciences, Institute of Dendrology, Parkowa 5, PL-62-035, Kórnik, Poland / 3. Akademia Rolnicza w Poznaniu, Wojska Polskiego 69, 60-625 Poznan, Poland / Received October 18, 1995
Summary
There is abundant evidence that evergreen conifers living at high elevations or at high latitudes have longer-lived needles
than trees of the same species living elsewhere. This pattern is likely caused by the influence of low temperature in combination
with related factors such as a short growing season and low nutrient availability. Because it is not known to what degree
such patterns result from phenotypic versus genotypic variation, we evaluated needle longevity for common-garden-grown lowland
populations of European Scots pine (Pinus sylvestris L.) of wide latitudinal origin and Norway spruce (Picea abies L.) of wide elevational origin. Nine-year-old trees of 16 Scots pine populations ranging in origin from 47° to 60° N were
studied in Kórnik, Poland (52° N) and 18-year-old trees of 18 Norway spruce populations ranging in origin from 670 to 1235
m elevation in southwestern Poland were studied near Morawina, Poland (51° N, 180 m elevation). There was no tendency in either
species for populations from northern or high elevation origins to retain needles longer than other populations. All of the
Scots pine populations had between 2.5 to 3.0 needle age cohorts and all of the Norway spruce populations had between 6.4
and 7.2 needle age cohorts. Thus, extended needle retention in Scots pine and Norway spruce populations in low-temperature
habitats at high elevations and high latitudes appears to be largely an environmentally regulated phenotypic acclimation.
Keywords:
genotypic variation, needle longevity, phenotypic variation, Picea abies, Pinus sylvestris, temperature.
