A comparison of reconstructions based on aquatic and terrestrial beetle assemblages: Late glacial–Early Holocene temperature reconstructions for the British Isles

Abstract

This paper presents the results of a study of MCR estimates of mean July temperature (TMAX) during the late glacial interval from four British sites, comparing estimates based on terrestrial and aquatic species. We have generated precise age models for three of these datasets, and have found that in most cases the terrestrial-based estimates agree with the aquatic-based estimates. The temperatures across the late glacial are consistent and warm in the early interstadial. However, differences exist in the later interstadial where Llanilid seems to be slightly warmer than either St Bees or Gransmoor. The small-scale discrepancies between aquatic and terrestrial beetle MCR temperature estimates that were found from these sites appear to occur during the transition into the late glacial interstadial, during the transition into the Younger Dryas cooling, and during the Younger Dryas interval. We tentatively attribute these discrepancies to the presence of meltwater from snowbanks surrounding the study sites during the stated intervals, and suggest that MCR studies of late glacial beetle assemblages from northwest Europe should adopt the protocol of generating separate aquatic and terrestrial estimates, for comparative purposes.