Indici di valutazione dei cambiamenti di biomassa vegetale nel passato

Indexes for the evaluation of past plant biomass changes. The application of new indexes for the evaluation of past plant biomass is presented. The significanse of pollen concentration of arboreal pollen as a tool for reconstructing variations in the past forest density is discussed and compared with the information obtained from pollen percentages and changes of forest composition. The arboreal pollen concentrations are also compared with the quotinet Arboreal Pollen /Non Arboreal Pollen, wich is independent from sedimentary processe and provides a reliable indication of the extent and timing of the changes of past plant biomass.