Humped-back shaped response of plant species richness to increasing shrub encroachment in calcareous grasslands
In the present study, we examined the effect of shrub encroachment in temperate semi-natural grasslands on plant species diversity. We tested the hypothesis that an initial shrub encroachment leads to enhanced habitat heterogeneity and thereby to a higher diversity. In a calcareous grassland near Göttingen (Germany) we analysed the effect of shrub encroachment on the species richness in 30, 100 m2 plots each with 10 subplots of 1m2 size. The 30 main plots belonged to six different shrub encroachment classes. A descriptive correlative gradient analysis of shrub invaded grasslands and their species number of flowering plants was performed. Within the 30 plots of different shrub encroachment a total of 203 plant species were recorded. The mean α1-diversity (level of subplots), mean α2-diversity (level of plots) as well as the α3-diversity (level of shrub encroachment classes) have their highest values at medium shrub invaded sites. This finding is in line with our hypothesis of a hump-back relation between shrub encroachment and species richness, and can be explained by the increased habitat heterogeneity. However, Detrended Correspondence Analysis (DCA) emphasized the importance of the present vegetation composition for species richness. The dominance of highly competitive, clonal-growing grass species is accompanied by low diversity swards with a lower facilitation of shrub establishment. Species accumulation curves highlight the benefit of shrub encroachment for γ-(landscape-) diversity. This result emphasises the importance of habitat heterogeneity for biodiversity and, therefore, nature conservation.
Keywordsα-diversity γ-diversity Habitat heterogeneity Semi-natural grassland Shrub cover Shrub invasion Species accumulation curve
Detrended Correspondence Analysis
Generalized Linear Model
Unable to display preview. Download preview PDF.
- Barry, R.G. 2008. Mountain Weather and Climate. 3rd ed. Cambridge University Press, Cambridge, UK.Google Scholar
- Dierschke, H. 2006. Secondary progressive succession of an abandoned calcareous grassland – research on permanent plots 1987–2002. Hercynia N. F. 39: 223–245.Google Scholar
- Duelli, P. 1992. Mosaikkonzept und Inseltheorie in der Kulturlandschaft. Verhandlungen der Gesellschaft für Ökologie 21: 379–383.Google Scholar
- Garve, E. 2007. Verbreitungsatlas der Farn- und Blütenpflanzen in Niedersachsen und Bremen. Nieders. Landesbetrieb für Wasserwirtschaft, Küsten- und Naturschutz, Hannover.Google Scholar
- Grime, J.P. 2001. Plant Strategies, Vegetation Processes, and Ecosystem Properties. 2nd ed. Wiley, Chichester, UK.Google Scholar
- Hondong, H, Langner, S. and Coch, T. 1993. Untersuchungen zum Naturschutz an Waldrändern. Bristol-Schriftenreihe 2: 196S.Google Scholar
- MacArthur, R.H. and Wilson, E.O. 1967. The Theory of Island Biogeography Princeton University Press, Princeton, USA.Google Scholar
- Mitlacher, K., Poschlod, P., Rosen, E. and Bakker, J.P 2002. Restoration of wooded meadows – a comparative analysis along a chronosequence on Oland (Sweden). Appl. Veg. Sci. 5: 63–73.Google Scholar
- Pärtel, M., Bruun, H.H. and Sammul, M. 2005. Biodiversity in temperate European grasslands: origin and conservation. Grassl. Sci. Europe 10: 1–14.Google Scholar
- Prach, K. and Řehounková, K. 2006. Vegetation succession over broad geographical scales: which factors determine the patterns? Preslia 78: 469–480.Google Scholar
- R Development Core Team 2008. R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria.Google Scholar
- Schreiber, K. 1995. Renaturierung von Grünland - Erfahrungen aus langjährigen Untersuchungen und Managementmaßnahmen. Berichte der Reinhold-Tüxen-Gesellschaft 7: 111–140.Google Scholar
- ter Braak, C.J.F. and Šmilauer, P. 2002. CANOCO reference manual and CanoDraw for Windows user’s guide: Software for canonical community ordination (version 4.5). Microcomputer Power, Ithaca NY, USA.Google Scholar
- Whittaker, R.H. 1972. Evolution and measurement of species diversity. Taxon 21: 213–251Google Scholar
- Wisskirchen, R. and Haeupler, H. 1998. Standardliste der Farn-und Blütenpflanzen Deutschlands. Ulmer, Stuttgart, Germany.Google Scholar
This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.