%0 Research article
%T Sub-montane Norway spruce as alternative seed source for a changing climate? A genetic and growth analysis at the fringe of its natural range in Austria
%A Schiessl, Eduard
%A Grabner, Michael
%A Golesch, Gerald
%A Geburek, Thomas
%A Schueler, Silvio
%D 2010
%J Silva Fennica
%V 44
%N 4
%R doi:10.14214/sf.453
%U https://silvafennica.fi/article/453
%X Insights into the intraspecific variation in climate response of forest  trees and the utilization of suitable seed sources are required to  maintain forest ecoystems under expected climate change. Individuals of  Norway spruce with an anomalous spherical-shaped crown were  characterized by genetic (using a mtDNA marker) and dendroclimatic  analysis. Such trees occur frequently at the fringe of the spruce  distribution in east/south-east Austria. We employed pair-wise  comparisons between trees with spherical and “regular” conical crowns on  47 sites. No evidence was found for a different phylogeographic history  of spherical and conical spruces, but the high allelic diversity at the  nad1 locus highlighted the importance of east/south-east Austria as  refugium and migration corridor for Norway spruce. Analysis of mean  annual increment revealed a larger amount of earlywood within the  sapwood area and fewer negative pointer years for spherical spruces than  for conical ones, pointing at a higher vitality and smaller  interactions between climate and growth for spherical spruces. Although  the results cannot explain the anomalous crown form, they suggest  spherical trees to have a higher ability to cope the warm and dry  climate of the region than “regular” conical spruces. We discuss the  origin of spherical crowns in terms of population history and phenotypic  plasticity and speculate on possible effects of crown architecture on  canopy-atmosphere exchange.