Paleolimnology

by

John P. Smol

• LAST REVIEWED: 14 December 2021
• LAST MODIFIED: 29 November 2017
• DOI: 10.1093/obo/9780199830060-0018

Introduction

The study of inland waters, such as lakes and rivers, is called limnology. However, one of the biggest challenges faced by ecological and environmental sciences is the lack of long-term monitoring data. Fortunately, lake and river sediments archive a diverse library of information that can be used to reconstruct past aquatic and terrestrial communities, and to infer past environmental conditions. Paleolimnology (also spelled palaeolimnology) is the multidisciplinary science that uses the physical, chemical, and biological information (i.e., proxy data or indicators) preserved in sediment profiles to reconstruct past environmental conditions in inland aquatic systems. The overall principles used by paleolimnologists are quite simple, and they are similar to those used by paleoceanographers. Accumulated sediments (if left relatively undisturbed) provide an important stratigraphic archive of past biota and other environmental conditions. The law of superposition states that, for any undisturbed sedimentary sequence, the deepest deposits are the oldest (since these are progressively overlain by younger material). Consequently, a depth-time profile slowly accumulates. Using a variety of dating techniques, researchers can estimate the age of sediment layers, and thus provide a temporal perspective of past environmental change. The job of the paleolimnologist is to interpret the information contained in these profiles in a way that is meaningful to other scientists and the public at large. Paleolimnology has seen tremendous advances over the last twenty-five years or so. Although the field of paleolimnology also includes the study of rivers, in practice most studies have focused on lake ecosystems, because fluvial systems are more difficult to study (i.e., it is more difficult to obtain undisturbed sedimentary sequences in fluvial systems). Each year, however, more papers are being published from diverse aquatic habitats. Paleolimnological approaches are now used to study a wide variety of basic and applied problems. Given the ecological focus of this article, almost all of the citations are primarily biological. However, as described in the sources cited under Textbooks, paleolimnology also encompasses a broad spectrum of physical, chemical, and geological sciences.

Textbooks

The field of paleolimnology is covered, in at least a peripheral way, in a large number of textbooks dealing with limnology, environmental change, paleoecology, and the earth sciences. However, the two textbooks listed in this section deal exclusively with paleolimnology. Cohen 2003 covers a broad spectrum of paleolimnological approaches, with descriptions of many diverse applications. It is an important starting point for students interested in this science. Smol 2008 is the second edition of a textbook originally published as a first edition in 2002 that includes a synthesis of the basic concepts used by paleolimnologists and then focuses on applied aspects of paleolimnology.

• Cohen, Andrew S. 2003. Paleolimnology: The history and evolution of lake systems. Oxford: Oxford Univ. Press.

  A large (500-page) comprehensive textbook on paleolimnology, with fifteen chapters and a glossary. Directed at upper-year undergraduate or graduate students, the book is an introduction to many applications of paleolimnology.

• Smol, John P. 2008. Pollution of lakes and rivers: A paleoenvironmental perspective. 2d ed. Oxford: Wiley-Blackwell.

  This is a much-revised second edition of a textbook by the same name, originally published in 2002. In contrast to Cohen 2003, this book, in seventeen chapters and a glossary, focuses on the long-term impacts of humans on aquatic systems, and shows how paleolimnological approaches can be used to track these issues and assist lake managers and policymakers to make evidence-based decisions. The book, published as a paperback, is written primarily for upper-year undergraduate and graduate students, and in a format that is aimed at being a possible university course textbook.