SESSION 5

The challenges of paleoenvironmental reconstructions based on bioindicators: signal complementarity, limits and new developments

Audiard Benjamin^1,2 , Arbez Louis³ , Discamps Emmanuel³

 1 – ArScAn, CNRS - UMR 7041, Paris-Sorbonne Université, Nanterre

2 – LGP, CNRS - UMR 8591, Thiais

3 – TRACES, CNRS – UMR 5608, Toulouse

 benjamin.audiard@outlook.fr

The ever-growing development and application of bioarchaeological approaches among paleoenvironmental sciences has contributed to a finer reconstruction of past ecosystems in both ancient and recent history. An increasing number of studies have highlighted that the complexity of past environmental changes can hardly be explained by climatic forcing alone. In fact, the diversity of past ecosystem dynamics can only be traced by the multiproxy analysis of various bioindicators (charcoals, pollens, microfauna, malacofauna, macrofauna, etc.). However, the resulting variety of sampling strategies and methodological approaches involved in the study of bioindicators strongly influences interpretations in various aspects (e.g. spatio-temporal resolution, anthropogenic impact, signal reliability). Additionally, the biological nature of such archives makes them sensitive to various depositional and / or taphonomic processes that can significantly limit the interpretation of site data. Conversely, all bioindicators have different resolutions and often reflect the diversity of landscapes at different scales. Finally, our use of bioindicators heavily relies on present-day data, therefore being impacted by uniformitarianism biases. Some independent analytical techniques (e.g. isotopic studies, microwear analyses) however now provide tools to test assumptions such as niche conservatism.

The present session aims to:

• Discuss the inherent limitations of various biological archives and the associated research methods.
• Promote the value of multi-proxy approaches for this period, particularly those that combine different bioindicators, and/or multi-scalar development (global to local data; long-term changes to high-intensity variations).
• Consider the possible biases in paleoenvironmental reconstructions induced by site formation processes, as well as the pitfalls of uniformitarianism induced by, for example, the recent anthropization of many ecosystems or the high phenotypic plasticity of some taxa.

This session thus proposes to bring together the various communities interested in the diversity of bioindicator records, in terms of nature, rhythms, spatiality and reliability. The underlying aim is to discuss how we can better reconstruct the landscapes and climates faced by prehistoric societies. 

Keywords: Bioindicators, representativeness, actualism, multiproxy, taphonomy.