IPS2012 marks the 30th anniversary of Renberg & Hellberg’s paper (1982) in which the authors presented a methodology for quantitatively reconstructing past pH changes using diatoms preserved in lake sediments.  Over the last 30 years methods have been refined and so-called transfer functions have been developed for a number of organism groups and wide range of hydrochemical and other environmental parameters, including measures of water acidity, nutrients, ionic concentration, organic carbon, heavy metals, temperature, water depth, duration of ice and snow cover, and flooding period.  

While it is true that quantitative reconstructions have revolutionised aspects of palaeolimnology a number of recent studies have demonstrated that many transfer functions lack statistical validity and violate the basic assumptions of the approach. This session will explore these issues and challenge palaeolimnologists to address both fundamental questions such as which environmental variables can we reconstruct, and more practical issues around testing the significance of reconstructions.