PRESENT AND PAST POLLEN RECORDS OF LAPLAND FORESTS

Modern pollen deposition is currently being monitored for each of the major vegetation types of Finnish Lapland. These are (1) treeless oroa rctic vegetation, (2) mountain birch woodland, (3) pine forest, (4) mi xed pine, spruce and birch forest, and (5) spruce-dominated forest. Re sults are presented for 12 sampling sites for the five-year period 198 7-1991; on the basis of these, modem pollen analogues are constructed for each vegetation type. An analogue comprises the total annual polle n influx, the annual arboreal pollen influx, the influx and percentage representation of the major tree species, the AP/NAP ratio, and any c haracteristic indicator species present in only small amounts. Both th e percentage and influx ranges given for each analogue are very wide b ecause of the enormous annual variation inherent in the data. Despite an overlap of characteristics between analogues, it is possible to des ignate specific distinguishing features. The local presence/absence of a species can be seen from its influx value, which is a critical valu e for verifying the northern limits of the major tree species. The ana logues are evaluated in the light of comparable material from northern Fennoscandia. Any discrepancies with earlier published data are attri buted to differences in timing and length of the sampling periods. The analogues are also used to interpret more objectively two pollen diag rams from peat deposits, one from the pine forest region and the other from the mixed pine, spruce and birch forest region. A precise compar ison is hampered by the difficulties involved in calculating pollen in flux for a sediment section to a sufficiently high degree of accuracy.