The relationship between vegetation composition, vegetation zones and modern pollen assemblages in Setesdal, southern Norway

Abstract

Reconstructing and interpreting past vegetation composition can be enhanced by studying modern pollen samples and contemporary vegetation. Here, we compare pollen in surface sediments from 52 medium-sized lakes with the surrounding vegetation along an elevational gradient covering six major vegetation zones in south-central Norway. The aims are to detect how well the vegetational composition and terrestrial pollen assemblages distinguish the major vegetation zones, whether the pollen composition in surface-sediment samples reflects the composition of the surrounding vegetation and whether aquatic pollen and spores reflect the major vegetation zones. We use multivariate classification trees, ordination and co-correspondence analysis to address these questions. We show that it is possible to separate the major zones using terrestrial pollen assemblages and using plant species in the vegetation reasonably well, whereas aquatic pollen and spores poorly reflect the zones. Surprisingly, the terrestrial pollen assemblages separate the zones better than vegetational composition does. The compositional match between the pollen assemblages and surrounding vegetation is consistent for sites along the elevational gradient within the forested zones, but deteriorates in increasingly open vegetation zones. Our results are consistent with other investigations of modern pollen–vegetation relationships. Careful interpretation of past vegetation from pollen assemblages is needed when the vegetation is treeless because of a larger potential pollen-source area and hence a higher proportion of long-distance dispersed pollen in open areas.

Are diversity trends in western Scandinavia influenced by post‐glacial dispersal limitation?

“…Composition of pollen assemblages and vegetation in southern Norway corresponds well within and between different vegetation zones, except for sites near the tree line and in the low‐alpine zone (Felde et al. , ; Birks et al. ).…”

“…Despite these biases and problems, several studies show that there are positive correlations between modern pollen and plant diversity and modern pollen and landscape mosaic Felde et al, 2016;Matthias, Semmler, & Giesecke, 2015;Meltsov, Poska, Reitalu, Sammul, & Kull, 2013). Composition of pollen assemblages and vegetation in southern Norway corresponds well within and between different vegetation zones, except for sites near the tree line and in the low-alpine zone Felde, Peglar, Bjune, Grytnes, & Birks, 2014;Felde et al, 2016).…”

Does pollen-assemblage richness reflect floristic richness? A review of recent developments and future challenges

“…Translation table -a table that lists all the known plant taxa for a region and their equivalent pollen or spore types and permits the translation or transformation of a plant taxon to its appropriate pollen or spore type (pollen equivalents) (Bennett, 1995(Bennett, -2007Felde et al, 2012Felde et al, , 2014aFelde 2015).…”

“…Punt et al, 1976Punt et al, -2009Faegri et al, 1989;Beug, 2004), the pollen and spore taxonomic level (e.g. Peglar, 1993;Odgaard, 1994;van der Knaap and van Leeuwen, 1994;Felde et al, 2012Felde et al, , 2014a) is steadily improving. Many data sets are not, however, of such high standards, having been analysed 20-30 years ago or to a lower taxonomic resolution.…”

John Birks: Pioneer in quantitative palaeoecology

“…They included: (1) KILO (Kiruna to LOfoten) with lake Bjørnfjelltjørn near Narvik as one of the main sites (Bjune et al, 2010); (2) the southern Norway Setesdal-project where modern pollen as well as modern and fossil sediment samples were analysed in great detail (e.g. Eide et al, 2006;Felde et al, 2014); (3) the Oslo To Trondheim transect or, as it was also called, the 'over-the-top' (OTT) project; (4) environmental reconstructions on Svalbard during the last two millennia (with colleagues at UCL; Birks et al, 2004b); (5) reconstructions of past climate and environments in NORPAST-1 and -2 (Past Climates of the Norwegian Region; Nesje et al, 2006;Bjune and Birks, 2008); (6) the large Strategic University Programme NORPEC (Norwegian palaeoenvironments and climates as reconstructed from lake sediments; e.g. Velle et al, 2005;Bjune et al, 2005;Heggen et al, 2012); and (7) the NoAClim (No-analogue climates and ecological responses in the past and future) project.…”