|ADAPTABILITY Project Description - Innovation aspects|
|In Norway spruce, as well
as in many other forest tree species (for review, see Morgenstern 1996),
variation in ecologically and economically relevant traits have traditionally
been assessed in the context of common garden trials or so-called provenance
tests, where seedlings or young tree collections from different geographical
areas are growing under the same environmental conditions (e.g. Schmidt-Vogt
1978, Ekberg et al. 1991). Based on such tests it could be demonstrated that
traits related to phenology are clinally correlated to latitude and altitude.
These relationships were especially found for traits such as bud set, cessation
of leader growth, duration of growth period and development of frost hardiness
(Dormling 1979, Skrøppa and Magnussen 1993, Eriksson 1995, Dæhlen
et al. 1995). Until recently it was generally agreed that the variation patterns
observed in such provenance tests are based on genetic differences among
the collections evolved by various processes (mostly selection) in the course
of many Generation cycles (Morgenstern 1996).
In contrast to this general doctrine, new results from several tree species indicate another way of adaptation, involving heavy selection pressure or - more likely gene regulation mechanisms during the sexual regeneration processes of trees (for review see Johnsen and Skrøppa 1996, Johnsen et al. 1996, Skrøppa and Johnsen 1999).
|Since these changes in various adaptive traits in dependence on the particular climatic conditions during sexual regeneration occur after only one Generation, this will have important implications for many fields in forestry. In particular, the establishment of new plantations, (including seed orchards), the transfer of seed samples across climatic zones, the introduction of new tree species or races, the breeding strategies and the conservation of gene resources should take into account this new insight into mechanisms of short-term adaptation processes according to the reproductive environment. In the face of global climatic change, forest tree species like Norway spruce are in the position to response in this way to various resultant changes in environmental conditions, so that the disturbance of their ecosystems may become less severe than earlier assumed|
|© 2001 ISOGEN||