Since the present climate in Switzerland includes abundant rainfall, the climatic changes should not present any serious danger of the ground drying out. In fact, higher precipitation levels are predicted. So it would seem that climate is likely to become more luxuriant rather than more dry. These conditions – together with the entry of nutrients with the rainfall – favour the growth of ash and maple but not of oak. Even with an increase in stressful dry summer periods, a consideration of the broad areas of distribution of indigenous species shows they possess a sufficiently great adaptability. Research into the effects of physiological stress on fir trees from different provenances shows in particular that those with local origins are better adapted to the habitat than those from elsewhere. The danger of an increase in storms should be countered by strategies aimed at increased resistance – through mixed plantation regulation and thinning out – rather than avoidance strategies. Ecoforestry is basically well armed for this task. It should be even more orientated towards the adaptability and resilience of forests.
Tree physiology and bark beetles
