Relationships Between Plant Assemblages and Water Flow Across a Boreal Forest Landscape: A Comparison of Liverworts, Mosses, and Vascular Plants
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The distribution of water across landscapes affects the diversity and composition of ecological communities, as demonstrated by studies on variation in vascular plant communities along river networks and in relation to groundwater. However, non-vascular plants have been neglected in this regard. Bryophytes are dominant components of boreal flora, performing many ecosystem functions and affecting ecosystem processes, but how their diversity and species composition vary across catchments is poorly known. We asked how terrestrial assemblages of mosses and liverworts respond to variation in (i) catchment size, going from upland-forest to riparian settings along increasingly large streams and (ii) groundwater discharge conditions. We compared the patterns found for liverworts and mosses to vascular plants in the same set of study plots. Species richness of vascular plants and mosses increased with catchment size, whereas liverworts peaked along streams of intermediate size. All three taxonomic groups responded to groundwater discharge in riparian zones by maintaining high species richness further from the stream channel. Groundwater discharge thus provided riparian-like habitat further away from the streams and also in upland-forest sites compared to the non-discharge counterparts. In addition, soil chemistry (C:N ratio, pH) and light availability were important predictors of vascular plant species richness. Mosses and liverworts responded to the availability of specific substrates (stones and topographic hollows), but were also affected by soil C:N. Overall, assemblages of mosses and vascular plants exhibited many similarities in how they responded to hydrological gradients, whereas the patterns of liverworts differed from the other two groups.
Keywordscatchment size groundwater discharge liverworts mosses riparian river network species richness vascular plants
We thank Henrik Weibull for inventorying and identifying all bryophytes in the study plots, Johan Lingegård, Julia Jansson, and Isak Lindmark for helping with the fieldwork, and three anonymous reviewers for valuable comments on the manuscript. Funding was provided by the Swedish Research Council Formas (to R. Jansson), SITES, Mistra Future Forests, and Formas Forwater (to H. Laudon), and SJCKMS Kempe foundation and Gunnar and Ruth Björkmans Fund for Botanical Research in Norrland (to L. Kuglerová).
- Anderson MJ. 2001. A new method for non-parametric multivariate analysis of variance. Austral Ecol 26:32–46.Google Scholar
- Bates DM, Maechler M. 2009. lmer4: linear mixed-effects models using S4 classes. R package version 0.999375-32.Google Scholar
- Chevan A, Sutherland M. 1991. Hierarchical partitioning. Am Stat 45:90–6.Google Scholar
- Glime, JM. 2007. Bryophyte ecology. Volume 1. Physiological ecology. Ebook sponsored by Michigan Technological University and the International Association of Bryologists. http://www.bryoecol.mtu.edu/. Accessed 14 Jan 2015.
- Hallingbäck T, Hedenas L, Weibull H. 2006. New checklist of Swedish bryophytes. Svensk Botanisk Tidskrift 100:96–148.Google Scholar
- Krok TOBN, Almquist S. 1994. Svensk flora. Fanerogamer och ormbunksväxter. Stockholm: Liber Utbildning.Google Scholar
- Oksanen J, Blanchet FG, Kindt R, Legendre P, Minchin PR, O’Hara RB, Simpson GL, Solymos P, Stevens MHH, Wagner H. 2013. Vegan: R Community ecology packge.Google Scholar
- Pabst RJ, Spies TA. 1998. Distribution of herbs and shrubs in relation to landform and canopy cover in riparian forests of coastal Oregon. Can J Bot 76:298–315.Google Scholar
- Pollock MM, Naiman RJ, Hanley TA. 1998. Plant species richness in riparian wetlands—a test of biodiversity theory. Ecology 79:94–105.Google Scholar
- R Developmental Core Team. 2013. R: a language and environment to statistical computing. Vienna: R Foundation for Statistical Computing.Google Scholar
- Walsh C, Mac Nally R. 2013. hier.part: hierarchical partitioning. R package version 1.0-4. https://cran.r-project.org/web/packages/hier.part/.
- Wastenson L, Fredén C, Eds. 2002. Sveriges Nationalatlas. Berg och Jord. Vällingby: Sveriges Nationalatlas.Google Scholar