ABSTRACT
This chapter proposes to extend Carl Troll's usage of high altitude geoecology to bracket the natural and human sciences within the context of the high mountain systems of the world. There are massive gaps in knowledge in all of the classical disciplines that need to be filled before fully intelligent planning of mountain landscapes can be achieved. The problems of increased population pressures and environmental degradation facing the world's great mountain regions are no more, and indeed no less, than those facing the entire planet. The problem of the Himalaya, and of many of the world's mountain ranges, can be stated very simply. Rates of natural siltation of Himalayan lakes could be obtained from the study of deposits of former lakes, dammed, for instance, by landslides and drained catastrophically several thousand years ago. In terms of any natural hazard reduction policy development it is desireable to better understand the magnitude of the impact and its frequency of occurrence.
