Pioneer vegetation on glacier forelands in southern Norway: emerging communities?

• Published in: Journal of Vegetation Science
• Main Authors: Robbins, Jane A., Matthews, John A.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2009
• Subjects: Plant Science; Ecology; Deschampsia alpina; glacier; Poa alpina; Saxifraga cespitosa
• Online Access: http://dx.doi.org/10.1111/j.1654-1103.2009.01090.x; https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fj.1654-1103.2009.01090.x; https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1654-1103.2009.01090.x

Abstract Question: How variable is the pioneer plant community on glacier forelands in southern Norway, both in terms of species composition and geographical distribution? Location: The Jotunheim and Jostedalsbreen regions of southern Norway (61°‐62°N, 6°‐9°E). Methods: The relative frequencies of vascular plant species were recorded in the pioneer zones of 43 glacier forelands, with an altitudinal range of 80‐1860 m (boreal to high alpine) and an east‐west range of 100 km. Classification and ordination techniques were used to search for evidence of consistently recurring communities, variability along a continuum or stochasticity. Results: Mean variability in species composition between all glacier forelands sampled was 65% (Sørensen dissimilarity). Poa alpina , Oxyria digyna , Deschampsia alpina and Festuca ovina had the highest frequency, occurring on over 80% of forelands. Non‐metric multidimensional scaling did not reveal clear divisions between groups of sites, but cluster analysis, multi‐response permutation procedures and indicator species analysis suggested two sub‐communities: the Saxifraga cespitosa‐Trisetum spicatum sub‐community is restricted to forelands above 1100 m in the Jotunheim region; whereas the D. alpina‐O. digyna sub‐community has a wider altitudinal range of 80‐1780 m. Variance partitioning indicated that altitude alone accounts for 24%, distance east for 18%, and the component shared by altitude and distance east for 17% of the variance in species composition. Conclusions: At the broadest scale, pioneer vegetation on the glacier forelands can be viewed as a single P. alpina‐O. digyna community of predominantly wind‐ and water‐dispersed perennials. However, this community shows a high degree of variability, with dominant species missing from a number of sites, and is poorly structured, suggesting a degree of stochasticity. Furthermore, the pioneer vegetation can be dissected within a continuum of variation to produce two emerging sub‐communities, reflecting the influence of environmental ...