© 2005 Heron Publishing—Victoria, Canada
Autumn frost hardiness in Norway spruce plus tree progeny and trees of the local and transferred provenances in central Sweden
Mats Hannerz (1, 2) and Johan Westin (3)
1. Skogforsk, Uppsala Science Park, SE-751 83 Uppsala, Sweden / 2. Corresponding author (mats.hannerz@skogforsk.se) / 3. Skogforsk, P.O. Box 3, SE-918 21 Sävar, Sweden / Received May 13, 2004; accepted October 12, 2004; published online July 4, 2005
Summary
Reforestation with provenances from locations remote from the planting site (transferred provenances) or the progeny of trees
of local provenances selected for superior form and vigor (plus trees) offer alternative means to increase yield over that
obtained by the use of seed from unselected trees of the local provenance. Under Swedish conditions, Norway spruce (Picea abies (L.) Karst.) of certain transferred provenances generally has an advantage in productivity relative to the local provenance
comparable to that of progeny of plus trees. The aim of this study was to explore the extent to which productivity gains achieved
by provenance transfer or the use of plus tree progeny are associated with reductions in autumn frost hardiness, relative
to that of trees of the local provenance. In a field trial with 19-year-old trees in central Sweden, bud hardiness was tested
on four occasions during the autumn of 2002. Trees of the local provenance were compared with trees of a south Swedish provenance
originating 3° of latitude to the south, a Belarusian provenance and the progeny of plus trees of local origin. The Belarusian
provenance was the least hardy and the local provenance the most hardy, with plus tree progeny and the south Swedish provenance
being intermediate in hardiness. Both the Belarusian provenance and the plus tree progeny were significantly taller than trees
of the other populations. Within provenances, tree height was negatively correlated with autumn frost hardiness. Among the
plus tree progeny, however, no such correlation between tree height and autumn frost hardiness was found. It is concluded
that although the gain in productivity achieved by provenance transfer from Belarus was comparable to that achieved by using
the progeny of plus trees of the local provenance, the use of trees of the Belarus provenance involved an increased risk of
autumn frost damage because of later hardening.
Keywords:
Belarus, electrolyte leakage, frost tolerance, Picea abies, tree breeding.
