Dinamica della vegetazione forestale su tempi plurimillenari: problemi e prospettive

Abstract

The pollen records, combining long duration with high resolution and so providing information on different types of processes occurring on different time-scales, stress the importance of the temporal dimension in the study of biological processes. The history of the vegetation of the last tens of thousands of years indicates that the presentday widespread diffusion of forests at the middle latitudes is exceptional rather than normal. An example of processes seemingly similar, but with presumably different causes, is shown: the exponential growth of past plant populations, ascribed in some cases to the reproductive potential of the species concerned, and in other cases to changes of climatic and/or environmental conditions.

Key Words:

• pollen records
• time-scales
• plant populations