Author(s): Juggins S, Birks HJB
Abstract: Quantitative reconstructions of past environmental conditions (e.g., lake-water pH) are an important part of palaeolimnology. Such reconstructions involve three steps: (1) the development of a representative modern organism-environment training-set, (2) the development and application of appropriate numerical techniques to model the relationship between modern occurrences and abundances of the organisms in the training-set and their contemporary environment, and (3) the application of this model to stratigraphical palaeolimnological data to infer past environmental conditions, and model selection, testing, and evaluation and assessment of the final reconstruction. These three stages are discussed. Problems of spatial autocorrelation are outlined. The general approach is illustrated by a case-study. The assumptions and limitation of the calibration-function approach are presented, and violations of these assumptions are discussed in relation to different environmental reconstructions. Appropriate computer software is outlined, and future research areas are presented. The chapter challenges palaeolimnologists to be more critical of their environmental-inference models and to be alert to the problems and dangers of confounding variables, and of violating the main assumptions of the approach.
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Dr Steve Juggins
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