The impact of tourism and reindeer herding on forest vegetation at Saariselkae, Finnish Lapland: a pollen analytical study of a high-resolution peat profile

摘要

A high-resolution peat profile from the vicinity of Saariselkae (68°25.24′N, 27°25.19′E), a large tourist centre in northern Finnish Lapland, was sampled continuously at near annual resolution to a depth of 22 cm in order to interpret the changes in pollen assemblages and vegetation resulting from human interference and reindeer herding. Fifteen AMS dates were wiggle-matched with the atmospheric ~(14)C calibration curve. The resulting age-depth model allows the calculation of pollen accumulation rates (PAR grains/cm~2 per yr), which, in turn, enables the fine-scale human impact to be interpreted on much better grounds than would be possible with the classical pollen percentages approach. Results indicate that increasing tourist numbers since the building of the Saariselkae resort in 1950 are not seen in the pollen diagrams. Only a slight, although clear, increase in the pollen taxa of disturbed sites (mainly Gramineae with some herb pollen taxa) can be detected from the PAR diagram after the 1950s, along with a decrease of Pinus pollen following the clearance of the ski slopes in the 1970s. Principal components analysis (PCA) of fossil pollen spectra and modern pollen analogues obtained from both natural and human-disturbed sites confirms that human interference that has affected the vegetation around Saariselkae is not visible in the pollen record to the degree that might have been expected. This is interpreted as resulting from the considerably different nature of human impact at Saariselkae, where the infrastructure is fully developed and weed species are efficiently removed. The remarkable growth of reindeer population in the area during the 1980s, however, can be observed in the peat profile through an increase in the number of coprophilous fungal spores (Podospora, Sporormiella). This increase in fungal spores occurs simultaneously with a decrease in Betula pollen, which is interpreted to be a consequence of reindeer foraging the young Betula trees and seedlings.