Agriculture, Ecosystems and Environment 145 (2011) 29–37 Contents lists available at ScienceDirect Agriculture, Ecosystems and Environment jo ur n al homepage: www.elsevier.com/lo cate/agee Adaptation of plant functional group composition to management changes in calcareous grassland Juliane Drobnik a,∗ , Christine Römermann b , Markus Bernhardt-Römermann c , Peter Poschlod a a Institute of Botany, University of Regensburg, Universitätsstraße 31, D-93040 Regensburg, Germany b Institute of Physical Geography, University of Frankfurt, Altenhöferallee 1, D-60438 Frankfurt am Main, Germany c Institute of Ecology, Evolution & Diversity, University of Frankfurt, Max-von-Laue-Straße 13, D-60438 Frankfurt am Main, Germany a r t i c l e i n f o Article history: Received 30 April 2010 Received in revised form 13 December 2010 Accepted 22 December 2010 Available online 22 January 2011 Keywords: Semi-natural grasslands Management treatments Functional traits Assembly rules Vegetation response a b s t r a c t It is the aim of plant functional research to generate general rules of species assembly and species reactions based on plant functional traits. Here we determined plant functional groups that are important with regard to land use types (grazing, mowing, mulching, burning, abandonment) and looked for mechanisms leading to changes in species composition after management changes in calcareous grasslands. To filter out the set of traits which best described the variation in plant composition along the studied land use gradient and to identify functional groups we chose an iterative three-table ordination method. We included traits related to persistence as well as traits describing the germination niche of a plant. To gain insight into underlying mechanisms which led to differing importance of these plant functional groups at different management regimes we investigated shifts in dominance of the identified functional groups at eight management regimes using long-term vegetation data of a site which was grazed before the onset of different management regimes in 1974. Ongoing unidirectional changes in cover of the four determined functional groups at most of the treatments indicated that even after almost 30 years new equilibria of functional group composition were still not reached. The study showed that other management treatments but grazing and mowing led to changes in func- tional group composition, which were mainly driven by increasing dominance of a highly competitive species group. © 2011 Elsevier B.V. All rights reserved. 1. Introduction Semi-natural grasslands in Northwestern Europe evolved mainly under grazing management. Their high diversity in flora and fauna makes them extremely valuable for nature conservation (Willems, 1983; WallisDeVries et al., 2002). Due to loss of agricul- tural usefulness calcareous grasslands suffered strong decreases during the 20th century and were put in the focus of conserva- tion efforts (Poschlod and WallisDeVries, 2002; Poschlod et al., 2005). In the course of this development the fallow experiments Baden-Württemberg were initiated in 1974 to test the capability of cost-effective management treatments like mulching and burn- ing regimes to maintain this vegetation which also includes a great number of rare and endangered species. This project encouraged a range of studies on management induced vegetation changes ∗ Corresponding author. Tel.: +49 0 941 943 3124; fax: +49 0 941 943 3106. E-mail addresses: Juliane.Drobnik@biologie.uni-regensburg.de (J. Drobnik), Roemermann@em.uni-frankfurt.de (C. Römermann), Bernhardt-m@bio.uni-frankfurt.de (M. Bernhardt-Römermann), Peter.Poschlod@biologie.uni-regensburg.de (P. Poschlod). analysing species reactions based on their phytosociological affili- ation as well as studies focusing on plant functional traits (Schiefer, 1981, 1983; Kahmen et al., 2002; Moog et al., 2002; Kahmen and Poschlod, 2004; Moog et al., 2005; Schreiber, 2005, 2006; Kahmen and Poschlod, 2008; Römermann et al., 2009). Those func- tional approaches help to reveal underlying mechanisms leading to changes in plant species composition that could hardly be detected by taxonomic approaches. In case of the fallow experiments clear results were found for the functional trait development under suc- cession. Over all 14 study sites included in the fallow-experiments tall species were promoted, as well as species with regular leaf dis- tribution, high vegetative lateral spread, late flowering and high seedmass (Kahmen and Poschlod, 2004). Abandonment and burn- ing treatments favoured spring germination (Kahmen et al., 2002). Enhancement of certain germination strategies after management change was also found for other study sites (Olff et al., 1994). Poschlod et al. (1998) pointed out that dispersal and seedbank features are also crucial for maintenance and re-establishment of calcareous grasslands. Predicting vegetation development to a changing environment based on plant traits is a helpful tool in nature conservation prac- tice. It provides the opportunity to adjust management treatment 0167-8809/$ – see front matter © 2011 Elsevier B.V. All rights reserved. doi:10.1016/j.agee.2010.12.021