Increasing stability by breeding for potential adaptability
may therefore be the only possibility to ‘prepare’
our forest tree populations for an uncertain future (Larsen,
199 1) . The multiple population breeding concept
(Namkoong et al., 1980) might be a promising strategy
to increase genetic variation at the population level.
This should increase the evolutionary adaptive potential,
increasing resilience by promoting the buffer
capacity of the population. However, since only small
losses of plants owing to natural selection can be tolerated,
this strategy has a limited potential in practical
forestry. Breeding for the physiological adaptive potential,
i.e. increasing the homeostatic capacity and
thereby the resistance of the single tree, might in this
context be more promising (Larsen, 1991). However,
adequate methods for testing physiological adaptability
to uncertain environmental changes are still lacking.