Species richness in boreal swamp forests of SE Norway: The role of surface microtopography
Article first published online: 29 JAN 2009
2008 IAVS - the International Association of Vegetation Science
Journal of Vegetation Science
Volume 19, Issue 1, pages 67–74, February 2008
How to Cite
Økland, R. H., Rydgren, K. and Ø kland, T. (2008), Species richness in boreal swamp forests of SE Norway: The role of surface microtopography. Journal of Vegetation Science, 19: 67–74. doi: 10.3170/2007-8-18330
- Issue published online: 29 JAN 2009
- Article first published online: 29 JAN 2009
- Received 23 June 2006; Accepted 24 May 2007
- Picea abies;
Question: What is the relative importance of environmental gradients and surface microtopography (variation in vertical level within sampling units) for fine-scale plant species richness in Picea abies swamp forests?
Location: 11 swamp forests in SE Norway.
Methods: We recorded species richness (number of species of vascular plants, mosses, Sphagnum and hepatics), depth to water table, soil base status and vertical range (microtopographic relief) in 2400 microplots, (each 1/16 m2), in 150 1-m2 plots in the 11 swamp forests. Relationships between species richness and environmental predictors were modelled by GLMM.
Results: Moss and hepatic species richness increased with increasing microtopographic relief, most strongly for wet acid sites, in which similar trends were also found for Sphagnum. Relief was a poor predictor of vascular plant species richness.
Conclusions: Microtopographic relief is a good predictor of local species richness in Picea abies swamp forests, partly because larger vertical variability means higher within-plot habitat diversity with respect to the wet-dry gradient, and partly because qualitatively new microhabitats associated with steep slopes are added in drier sites. The relationship between species richness and microtopographic relief is context dependent, differing in complex ways among species groups and among sites with different environmental conditions.