Plant diversity and conservation value of continental temporary pools Balázs A. Lukács a,⇑ , Gábor Sramkó b , Attila Molnár V c a Department of Tisza Research, Balaton Limnological Institute, Centre for Ecological Research, Bem tér 18/C, H-4026 Debrecen, Hungary b MTA-ELTE-MTM Ecology Research Group, Pázmány Péter s. 1/C, H-1117 Budapest, Hungary c Department of Botany, University of Debrecen, Egyetem tér 1, H-4032 Debrecen, Hungary article info Article history: Received 9 April 2012 Received in revised form 14 August 2012 Accepted 22 August 2012 Keywords: Agriculture Additive diversity partitioning Elatine Habitat types Isoëto-Nanojuncetea Lindernia procumbens Temporary ponds Vascular plants abstract Temporary pools are unusual habitats because they share features of aquatic and terrestrial ecosystems. They are habitats of community interests according to the Natura 2000 network (Natura code: 3130 and 3170), and can be found in several climatic regions where they harbours various wetland habitats. Whereas Mediterranean temporary pools are well studied, only a few papers deal with their continental counterparts, probably because they are mainly found on arable fields often displaying decades-lasting dormancy. This study aims at filling this gap in our knowledge by evaluating plant species composition, habitat types and diversity of temporary pools in a region of continental climate. We analysed data from 185 phytosociological relevés (79 historical and 106 contemporary data) from different types of water- logged arable fields, including rice paddy fields, from the Pannonian Ecoregion. We found significant dif- ferentiations of rice paddy fields from ‘other’ waterlogged arable fields according to ordination, classification and regression analyses. Diversity partitioning of species abundance data showed that these habitats have a very high alpha (species number, Simpson and Shannon) and beta diversity, which means that all the sites have high importance in habitat conservation. We found many vascular plants listed in IUCN and national red lists among the indicator and characteristic species of continental temporary pools. Our results demonstrate the conservation importance of continental temporary pools in relation to hab- itat and biodiversity management and conservation planning. Ó 2012 Elsevier Ltd. All rights reserved. 1. Introduction Temporary pools (vernal pools) are small and shallow wetlands characterised by mostly annual amphibious plants (Pinto-Cruz et al., 2009). Temporary pools are widespread on a global scale; they can be found in the Mediterranean (Zacharias and Zamparas, 2010; Grillas et al., 2004), in the tropics (Bambaradeniya et al., 2004) and in continental climates as well. In Europe they are con- sidered to be habitats of community interest and harbour many endangered and red list species. Seasonal wetlands in Europe, especially in the Mediterranean, encompass a wide range of vege- tation and community type richness that include annual and perennial vegetation (Deil, 2005; Pinto-Cruz et al., 2009). The gen- eral ecology (Zacharias and Zamparas, 2010; Pinto-Cruz et al., 2011; Bagella and Caria, 2012), threatening factors (Rhazi et al., 2001), conservational aspects (Rhazi et al., 2004; Pinto-Cruz et al., 2009), and diversity of Mediterranean temporary pools are well understood and intensively investigated. It is currently recog- nised as one of the most interesting habitats in the Mediterranean bioclimatic region, which maintain numerous extremely rare and isolated taxa (Médail, 2004). Under continental climatic conditions, temporary wetlands are very shallow water bodies, which appear in the floodplains of riv- ers or any kind of water-saturated or submerged places where as- tatic water conditions (i.e. temporal overdominance of water) can easily arise; such conditions normally occur on arable fields (Deil, 2005). Temporary pools on arable fields have different names in the literature: ‘‘farmland ponds’’ (Giora et al., 2010), ‘‘segetal fields with inland water’’ (Csiky and Oláh, 2006), ‘‘vernal pools on soils with bad water balance’’ (Pál et al., 2006), ‘‘ephemeral mudflat veg- etation’’ (Bissels et al., 2005), and dwarf plant communities (Deil, 2005); or named according to a phytosociological taxon name (Nanocyperion; Isoëto-Nanojuncetea vegetation; Ellenberg, 1988). Mediterranean temporary pools and temporary pools on arable fields have many similar characters: floods, precipitation, 0006-3207/$ - see front matter Ó 2012 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.biocon.2012.08.024 Abbreviations: AIC, Akaike’s Information Criterion; AF, arable fields; CTP, continental temporary pool; GLS, Generalised Least Square model; PCA, Principal Components Analysis; RPF, rice paddy fields; TWINSPAN, two-way indicator species analysis. ⇑ Corresponding author. Tel.: +36 305459845. E-mail address: lukacs.balazs@okologia.mta.hu (B.A. Lukács). Biological Conservation 158 (2013) 393–400 Contents lists available at SciVerse ScienceDirect Biological Conservation journal homepage: www.elsevier.com/locate/biocon