Mallomonadacean (Chrysophyceae) Scales: Early biotic paleoindicators of lake acidification

17 subfossil mallomonadacean species have been detected in the acidified Kleiner Arbersee. The most abundant one is M. crassisquama. In the top most layers, it is replaced by acid tolerant Synura spp. and several acidophilic and acidobiontic Mallomonas spp. Mallomonadaceae respond to acidification (and alkalinization) of lakes prior to benthic diatoms. Mallomonadaceae live euplanktically and mainly in spring, when most of the annual acid loading enters the lakes.