The puzzle of W eichselian vegetation types poor in trees

Abstract

Palaeobotanical records of many Weichselian deposits indicate stands of vegetation poor in trees and with elements from a range of different environments. The scarcity of trees seems in cases to contradict the prevailing temperature regime as suggested, for example, by records deduced from beetles. Alternative explanations for the recorded combination of plant species are considered. Examples of the influence of periglacial forms and processes on vegetation are given, followed by a more speculative account of the effect of swift climatic changes during the Weichselian. Unstable environmental and climatic conditions are thought to have been particularly effective in controlling the composition of what is today considered to have been a singular combination of plant species. Unstable conditions are also thought to have played a role in hampering the development of continuous palaeobotanical records in NW-Europe. The palaeobotanical data derive from a variety of geographical environments, and as a result it is almost impossible to integrate the scattered findings into a coherent whole so as to elucidate the former ecological conditions. It is suggested that in future investigations one must look for additional possibilities of correlation, such as phases of aeolian activity, deposition of charcoal resulting from natural fires or other discernible events of restricted duration.