THE SOIL PROPAGULE BANK IN A BOREAL OLD-GROWTH SPRUCE FOREST - CHANGES WITH DEPTH AND RELATIONSHIP TO ABOVEGROUND VEGETATION

The species composition and the depth distribution of the soil propagu le banks of bryophytes and vascular plants from three different soil l ayers in a boreal old-growth spruce forest in SE Norway were studied u sing the emergence method. A total of 34 taxa germinated with a predom inance of ferns and mosses. The frequency of the different species exh ibits a common community pattern with a few common and a large number of low frequency species. The tree Betula pubescens, the ferns Athyriu m filix-femina, Gymnocarpium dryopteris, and Phegopteris connectilis, and the mosses Plagiothecium laetum agg. and Polytrichum spp. were the most frequent. There is only a moderate correspondence, decreasing wi th soil depth, between the propagule bank and the aboveground vegetati on in the sampled plots. In the soil profile, the litter layer on aver age had more taxa than the peaty mor and bleached layer (7.7, 6.0, and 5.5 taxa, respectively). Five of the 17 taxa occurring in more than 1 0% of the soil samples from the different soil layers were significant ly more frequent in the upper soil layer, while two taxa were more fre quent in either peaty mor and (or) the bleached layer than in the uppe rmost layer. The propagule bank in the different soil layers represent s an in situ potential for regeneration of the vegetation after differ ent degrees of disturbance in the forest floor.