Climatic Resistance and Damage of Trees at Timberline

Abstract

In the ecotone (kampfzone) above the fully stocked forest the occurrence of damage to buds, leaves, and shoots increases rapidly. Towards the upper part of the transition zone injuries become so severe that “cripple” life-forms predominate in trees, ranging from bushes with “flagged” leaders to cushions of krummholz pressed close to the ground (Fig. 50, 51). Tree form is largely dependent on the winter snow-cover, since shoots projecting above the snow are severely damaged with regularity or are completely destroyed. One can confidently state that damage which critically influences the upper limit for trees occurs predominantly during winter.