High Mountain Environment as Indicator of Global Change

Abstract

The recent debate on global change effects on the living world is still characterized by lack of confidency as depending on rather hypothetical assumptions and predictions. This is a consequence of missing global ecological observation networks comparable to those which have been established for climate, glacier movements, atmospheric composition etc. Alpine biota such as grasslands, dwarf shrub heaths, alpine steppes, the tropical paramo, vegetation fragments at the high elevational limits of plant life, snow beds offer a broad spectrum for permanent long term ecological monitoring as it could be demonstrated by the few already available examples such as biodiversity changes in the Central Alps during this century. Most of these biota are simply structured, show clear habitat dependences, thus indicating change of one dominating environmental factor, and are in many high mountain regions still in a natural or at least seminatural state which means that direct anthropogenic effects could be excluded, or clearly described. As indicators for short term effects ({\textless} 10 years) we recommend 1. flowering phenology of vascular plants, 2. composition and abundance of moss species; for medium term effects ({\textless} 50 years) 1. structural parameters of plant communities such as rank/frequency relations, or horizontal individual distribution pattern, 2. species composition of plant communities, appearance of exotics and pathogens, 3. abundance, appearance and disappearance of selected animals (soil and above ground). A simple functional classification based on {CO2-} requirement, thermal and water relations, mobility and trophic characters is provided for selecting such species. For long term observations ({\textgreater} 50 years) also landscape patterning might be useful especially close to tree line. Efforts for developing a global network of alpine monitoring sites should be started immediately. The next generations will that gratefully acknowledge.