Historical Records and Collections

This chapter introduces the use of historical documents and other forms of information that depend on written explanation, such as natural history collections and historical photographs. After a general explanation of the unique values of these data for establishing historical baselines and trajectories, it gives a brief introduction to the methods used to assess the validity of the sources, including consideration of various biases that are integral to written documents. These include a consideration of scale. The chapter then describes a variety of sources, including historical data, maps, photographs, government documents, and plant and animal collections, with examples of how each has been used to establish some condition or process in the past.

Conclusion

This extensive revision of the first edition of People and the Land Through Time incorporates research over the last two decades to bring the field of historical ecology from an ecological perspective up to date. It emphasizes the use of new sources of data and interdisciplinary data analysis to interpret ecological processes in the past and their impacts on the present. It describes a diversity of past ecosystems and processes, with an emphasis on their effects on affect current ecosystem structure and function. This historical perspective highlights the varied and complex roles of indigenous people in historic ecosystems as well as the importance of past and present climatic fluctuations. The book begins with an introduction to the importance of history for ecological studies. The next three chapters explain methods and approaches to reconstructing the past, using both traditional and novel sources of data and analysis. The following five chapters discuss ways people have influenced natural systems, starting with the most primitive, manipulating fire, and proceeding through altering species ranges, hunting and gathering, agriculture and finally structuring landscapes through land surveys, trade and urbanization. Two chapters then deal with diversity, extinction and sustainability in a changing world. The final chapter specifically focuses on the importance of history in basic ecological studies, in conservation and in understanding the consequences of global change, using a variety of examples. Throughout, the emphasis is on the potential for evidence-based research in historical ecology, and the new frontiers in this exciting field.

Agriculture and Its Residual Effects

This chapter shows how detailed historical ecological research indicates that the impacts of historical agriculture are more widespread than previously thought, and often more subtle. Even apparently obvious connections, such as that between nomadic grazing and erosion, are now being questioned by historical analyses. Agriculture has not resulted universally in decreased biodiversity; in fact, grazing over millennia has in places increased biodiversity. Historical agriculture is also being implicated in millennial scale increases in CO2 and CH4 in the atmosphere, the former from deforestation and fires and the latter from paddy rice agriculture starting five thousand years ago. The discovery of hidden field systems under mature temperate and tropical forests and grasslands in Europe and the Americas are allowing reassessment of the impact of prehistoric agricultural systems on soils, species diversity, landscape patterns, and climate. The concept of "landnam" episodes proposed by Iversen for northern Europe may be applicable much more broadly. This has major consequences for considering human impact on global environments.