Climatic stress

Abstract

Mountain tops, just like hot deserts are among those environments where life is dominated by climatic stress (Fig. 8.1). Climatic extremes play a key role in selection and evolution of alpine taxa. Whether those species and ecotypes which make their fortune in these “stressful” environments are “stressed” depends on whether stress is defined as a limitation of biomass production or of persistent presence and propagation (see Chap. 1). The two are not necessarily linked. In the first definition, alpine plants would rank as severely stressed, in the second, the answer is uncertain and may be “no” for plants at the alpine distributional center of some highly specialized species. However, independently of which concept one prefers, daily life in the alpine zone requires processes and structures which minimize climatic impact by avoiding or tolerating what is commonly considered stressful in a cold climate.