Alpine treelines under climate change – How to explain heterogeneous response patterns?
Climatic treelines in the world’s high mountains are altitudinal limits caused by heat deficiency. They will shift to higher elevations in the course of climate change, unless not prevented by non-thermal site factors. Empirical studies from many high mountain ranges have so far shown a treeline advance, but in many cases also a distinct persistence of treeline elevations. These heterogeneous response patterns can be roughly classified according to treeline types and forms, however, physiognomically comparable treeline forms such as diffuse treelines or those with a krummholz belt still show high response variability. In order to explain inconsistent response patterns, many-faceted interactions between global warming as a global/regional input variable and the complexes of abiotic and biotic site factors as well as anthropogenic influences and their interrelationships at the local level have to be analysed.