From micromammals to paleoenvironments

Abstract

Micromammal assemblages are often used in paleoecological reconstructions. However, in studies to date, the environmental variables reconstructed were not shown to drive micromammal community structure before the reconstruction was attempted. Furthermore, the relative abundance data is too often dismissed despite its potential paleoecological value. Here we chose to reconstruct the botanical succession stage known to impact micromammal communities in the Mediterranean zone of Israel. We used weighted averaging partial least squares (WAPLS) regression to model the connection between botanical succession phase and the micromammal faunas as reflected in Tyto alba pellets. In addition to cross-validation, we validated our model using historical T. alba pellet data and contemporary maps. Moreover, we tested the repercussions of misidentifying the owl species in archaeological micromammal assemblages by applying our model to Recent assemblages collected by other owl species. Our WAPLS model differentiated forested environments from garrigue or grassland dominated ones in both the cross-validation and in the reconstructed historical environments. However, urban environments were not well distinguished from grasslands and garrigues, and misidentifying the owl species severely compromised model performance. Our results stress the potential insight deducible from micromammal relative abundance data, given its reliance on empirically tested relationships between fauna, environment, and taphonomic agent (predator).