The rationale of paleolimnology

Summary

A lake is sensitively responsive to regional changes in climate and to changes in its watershed, whether occurring slowly by natural means or at an accelerated rate through the intervention of man. The sediments that accumulate in a lake basin represent an integration of materials imported from outside the lake and materials elaborated within the lake, all of which are subject to differential transport by currents and turbulence and capable of being modified by biological and chemical activities. Sometimes the sediment accumulates as discrete temporal laminae or strata, whereas more commonly the primary sedimentation is blurred by retransport and secondary deposition.

The information in sediments is extremely diverse and only barely appreciated in its grossest features. All aspects of structure and fine structure, mineralogy, organic and inorganic chemistry, and morphological remains of organisms will eventually enable detailed interpretations of past climates, watershed conditions, water budgets, nutrient budgets, productivity, and the course of eutrophication. Moreover, the remains of organisms provide a rich resource for the study of global distributions and evolution of species, and the development and responses of aquatic communities. Many questions asked by paleolimnologists cannot be answered by our present unterstanding of limnology, which will have the beneficial consequence of stimulating more incisive studies of limnological processes.

This brief review specifies some of the major questions asked by paleolimnologists and gives examples of a few of the studies that have attempted to provide answers. Perhaps even more so than limnology itself, paleolimnology is completely interdisciplinary, drawing on the knowledge and insight of many fields of science and dependent on them for integrated interpretations.