Advances in the Conservation of Dry Grasslands: Introduction to Contributions from the Seventh European Dry Grassland Meeting
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Plant Biosystems, Vol. 145, No. 3, September 2011, pp. 507–513 ORIGINAL ARTICLE Advances in the conservation of dry grasslands: Introduction to contributions from the seventh European Dry Grassland Meeting M. JANISˇ OVA´ 1, S. BARTHA2, K. KIEHL3, & J. DENGLER4 1Institute of Botany, Slovak Academy of Sciences, Dumbierska 1, 974 11 Banska´ Bystrica, Slovakia, 2Institute of Ecology and Botany, Hungarian Academy of Sciences, Alkotma´ny u. 2-4, 2163 Va´cra´to´t, Hungary, 3Faculty A & L, Vegetation Ecology and Botany, University of Applied Sciences Osnabru¨ck, Oldenburger Landstr. 24, 49090 Osnabru¨ck, Germany and 4Biodiversity, Evolution and Ecology of Plants, Biocentre Klein Flottbek and Botanical Garden, University of Hamburg, Ohnhorststr 18, 22609 Hamburg, Germany Abstract Dry grasslands in Europe are mostly of zoo-anthropogenic origin, but nevertheless they are among the most diverse plant communities of the world at small spatial scales, and they support a significant proportion of the biodiversity of the continent. Both agricultural intensification and abandonment of former dry grasslands caused dramatic losses in area and quality of this habitat type during recent decades. Here we report from the 7th European Dry Grassland Meeting, organised by the European Dry Grassland Group (EDGG) in Smolenice, Slovakia, in 2010. Under the motto ‘‘Succession, restoration and management of dry grasslands’’ one hundred researchers from throughout Europe discussed conservation issues of this threatened habitat type. We give a brief introduction to those nine articles that are included in this Special Feature. With contributions from many different countries and various dry grassland types, they address issues of conservation value, succession, management as well as regeneration and restoration. We conclude that the diversity of dry grasslands and their conservation problems require further research to develop adequate management techniques under changing frame conditions. However, also the frame conditions, such as the incentives for certain land use practices provided by the Common Agricultural Policy of the European Union need to be addressed if long-term success in conservation of dry grasslands is intended. Keywords: Conference report, European Dry Grassland Group, management, restoration, Special Feature, succession millennia of human land use have created various types Dry grasslands in the Western Palaearctic of grasslands, which cover a significant proportion Grasslands are herbaceous communities dominated by of the surface of the naturally forested regions of Downloaded by [J. Dengler] at 23:59 14 September 2011 grasses (Poaceae)orothergraminoids(Cyperaceae, Europe, for example, approximately 16% in Germany Juncaceae). As the climate in most areas of the Western (BfN 2004) and even 62% in Wales (Stevens et al. Palaearctic is sufficiently moist and warm to support 2010). Accordingly, grasslands constitute a major the growth of forests, we find grasslands as large-scale element of Europe’s cultural landscape. Despite not potential vegetation only in the steppes of Eastern being natural in most places, grasslands make a very Europe and Central Asia (too dry for forests) and in the substantial contribution to the biodiversity of Europe. mountains above the timberline (vegetation period too Hobohm and Bruchmann (2009) found that among short for forests) (units L, M, and B5 in Bohn et al. the more than 6000 vascular plants endemic to Europe, 2004). Small-scale natural stands of grasslands occur grassland species with 18.1% constitute the second where forest cannot grow due to edaphic factors, e.g. largest group after the rock-inhabiting species, but with on salty soils, in coastal dunes, on very shallow soils nearly twice as many endemics as forests (10.7%). surrounding rocky outcrops, or on instable soils on Under ‘‘dry grasslands’’, we summarise several steep slopes (Ellenberg & Leuschner 2010; Klo¨tzlietal. different vegetation classes (see Rodwell et al. 2002). 2010). While nowadays the natural steppes of Eastern From the submediterranean to the hemiboreal zone, Europe and Central Asia have largely been converted the Festuco-Brometea (on base-rich, loamy soils) and into arable land (e.g. Sudnik-Wo´jcikowska et al. 2011), the Koelerio-Corynephoretea (including Festucetea Correspondence: J. Dengler, Biodiversity, Evolution and Ecology of Plants, Biocentre Klein Flottbek and Botanical Garden, University of Hamburg, Ohnhorststr. 18, 22609 Hamburg, Germany. Tel: þ49(0)40-42816-403. Fax: þ49(0)40-42816-539. Email: [email protected] ISSN 1126-3504 print/ISSN 1724-5575 online ª 2011 Societa` Botanica Italiana DOI: 10.1080/11263504.2011.603895 508 M. Janisˇova´etal. vaginatae and Sedo-Scleranthetea; on sandy soils) are grasslands became less and less profitable. In some most widespread both as natural steppe vegetation regions, this led to the afforestation of valuable dry and as semi-natural communities in more oceanic grasslands with pines and other, often non-native regions; the Trifolio-Geranietea sanguinei form their trees with negative consequences for biodiversity spatio-temporal transition to forests. The natural dry (e.g. Ruprecht et al. 2009; Schrautzer et al. 2009). In grasslands above the timberline mostly belong to the many other places, dry grasslands were just aban- classes Elyno-Seslerietea (base-rich soils) and Juncetea doned, and – as semi-natural communities – subse- trifidi (acid soils), while among the Mediterranean dry quently subjected to secondary succession leading to grassland classes, the Helianthemetea guttati (domi- their degradation (Poschlod & Schumacher 1998; nated by annuals) and the Thero-Brachypodietea ramosi Poschlod & WallisDeVries 2002; WallisDeVries (dominated by perennials) are most widespread. While et al. 2002). As a consequence of intensification on mesic and wet grasslands cover much larger areas in the one and abandonment on the other hand, the Europe, dry grasslands are the most diverse group, remaining dry grassland habitats became fragmen- which is mirrored in the much higher number of ted, and populations of many xero- and thermo- syntaxa (see Rodwell et al. 2002). For areas below 100 philous species became threatened by extinction or m2, the world records in plant species richness occur inbreeding depression (Fischer & Sto¨cklin 1997). in nutrient-poor grasslands, not in tropical rainforests The expansion of highly competitive species (both (Wilson, Peet, Dengler & Pa¨rtel, unpublished), in native and non-native ones) into grassland ecosys- particular in mown stands of semi-dry basiphilous tems represents another threat to diverse grassland grasslands (order Brachypodietalia pinnati within the vegetation. It is often enhanced by increased atmo- Festuco-Brometea) (see also Dengler 2005). For exam- spheric nitrogen deposition, which changes the ple, Dengler et al. (2009) reported 102 plant species proportion of available nutrients in soils and pro- on 10 m2 from such a dry grassland in the motes the dominance of tall species and competitive Transylvanian Lowland (Romania), but stands of grasses (Willems et al. 1993; Bobbink et al. 1998), similar extreme richness are known from meadows especially in the absence of management. in the White Carpathians (Czech Republic; e.g. Due to all these negative trends, dry grasslands Klimesˇ et al. 2001) and in Estonia (e.g. Kull & Zobel recently belong to the most endangered European 1991; see also Dengler 2005). In some other taxa, the habitats (Willems et al. 1993, Veen et al. 2009). Since relevance of dry grasslands for biodiversity conserva- they at the same time contain a high proportion of rare tion is even higher than in vascular plants; for example, and endangered species (Wolkinger & Plank 1981; 63% of the butterfly species of Europe are bound to Korneck et al. 1998), the conservation of dry grass- dry calcareous grasslands and steppes (WallisDeVries lands and of high nature value grasslands in general & Van Swaay 2009). became a priority throughout Europe, as reflected, for example, by the fact that most dry grassland types are included in the Habitats Directive of the European Conservation of dry grasslands Union (European Commission 2007). Most European dry grassland communities are semi- Proper management and restoration activities can Downloaded by [J. Dengler] at 23:59 14 September 2011 natural habitats, which developed over centuries or help to maintain and enhance the diversity of dry even millennia of traditional land use, such as grasslands (Groom et al. 2006; Kiehl 2009; Schwabe mowing, grazing, temporary abandonment of arable & Kratochwil 2009; Kiehl et al. 2010). Conservation fields, and/or other disturbance regimes (Pott 1995; management identifies several approaches for biodi- Poschlod & WallisDeVries 2002; Veen et al. 2009; versity maintenance, including conservation of spe- Ellenberg & Leuschner 2010). However, nowadays cies, ecosystems and processes. An effective humans threaten the biological treasure to whose conservation management needs to combine all emergence they contributed much in the past. While available approaches and to take into account in some cases dry grasslands are directly destroyed by requirements of various groups of organisms (Wall- building activities or mining, the more serious threats isDeVries et al. 2002; Bakker & van Diggelen 2006; are those affecting vast areas, namely agricultural Schwabe & Kratochwil 2009; Veen et al. 2009). intensification, land abandonment and atmospheric nitrogen input. 7th