Significance of pasture landscapes for nature conservation and extensive agriculture

Abstract

Significance of pasture landscapes for nature conservation and extensive agriculture Uwe Riecken, Peter Finck, Eckhard SchrOder German Federal Agency for Nature Conservation (BfN), Germany Abstract Pasture landscapes with free ranging grazers were once typical of large areas in Europe. These ecosystems are important habitats for a great number of endangered plant and animal species. Roaming or transhumant grazers support the dispersal of plant and invertebrate animal species both by transporting diaspores or specimens and by creating open linear structures functioning as connecting lines between patches of open habitats. Changing agro-economic and social conditions have led to a completely different situation. Extensive grasslands have been converted into intensive grasslands or arable land, or they have been abandoned in the case of less productive soils. Also, traditional transhumance systems have been discontinued in large areas of Europe. The re-introduction of large extensive semi-open pastoral landscapes could be an important approach for both the maintenance of extensive grassland farming systems and for nature conservation. This paper provides a brief overview of the ecological significance, historical background and theoretical foundation of pasture landscapes as a tool for nature conservation and for extensive land use. Additionally, problems in implementing largescale pastoral systems caused by current economic and legal circumstances are discussed. 1 Introduction Pasture landscapes with free ranging grazers have been common for large areas in Europe for centuries (e.g. MCCRACKEN and BIGNAL 1995). Most of them have had a semi -open character due to the fact that grazing commenced in former woodlands. Wood pastures may have been a typical form of land use since the Neolithic age as soon as Neolithic men brought domestic livestock to Europe (RACKHAM 1986). The impact of large grazers was responsible for the structure of cultural landscapes in large parts of Europe in the past and even today (BIGNAL and MCCRACKEN 1996). But the impact of these animals was not only important for traditional cultural landscapes. In earlier times, before human influence became dominant, natural grazer communities had a strong influence on the structure and biocoenoses of most land ecosystems (EDWARDS and GILLMAN 1987). Nevertheless the discussion has not yet come to a conclusion on how important this influence has been. In this discussion the points of view range from favouring a savannah-type landscape (GRADMANN 1898) to accepting only small grazed patches within closed dark forests (ELLENBERG 1996) covering almost all of central and northern Europe (BEUTLER 1996; BUNZEL-DRUKE 1997; BUNZELB. Redecker et al. (eds.), Pasture Landscapes and Nature Conservation © Springer-Verlag Berlin Heidelberg 2002 424 Uwe Riecken, Peter Finck, Eckhard Schroder DROKE et al. 1999; SCHOLE 1990, 1992). Our opinion is that such a discussion is more or less academic. Because of the completely changed ecological conditions compared to the past and the impossibility of reconstructing any historical situation, a final result of this discussion will not be of much help in solving nature conservation problems today. Nevertheless it is important to understand that large herbivore communities have had a key function within natural open and woodland ecosystems (VERA 2000) and in the development of historical cultural landscapes (ELLENBERG 1996). Nature conservation has to take this into account and has to analyse what can be learned from this for future nature conservation strategies, policy and management. In this paper an overview of the significance of pastoral landscapes for species and habitats, the problems related to the reestablishment of such pastoral systems under the current economic conditions and an outlook is given, focussing especially on the lectures and the results of the discussion during the workshop in Liineburg as presented in this volume. 2 Significance of pasture landscapes for species and ecosystems Many investigations have shown that the remaining pasture landscapes are of extraordinary importance for biodiversity. The diversity in Spanish "dehesas" for example can be as high as in natural forests or other natural habitats under similar conditions (DIAZ et al. 1997;HERNANDEZ 1998). This is especially true for species inhabiting open and ecotone habitats (ASSMANN and FALKE 1997, FALKE et al. 2000, KRATOCHWIL and SCHWABE 2001, PICKET and WHITE 1985), species using different habitats in their lifetime (KRATOCHWIL and ASSMANN 1996), species living in and on deadwood such as many endangered beetles and fungi (GREEN 2002; GEISER 1983; HARDING and ROSE 1986, Fig. 1) and species depending on natural and semi-natural habitat dynamics. Pastoral systems with free ranging or roaming grazers support the dispersal of plant and invertebrate animal species both by transporting diaspores or specimens and by creating open linear structures functioning as connecting lines between patches of open habitats, e.g. caused by transhumance migrations (BONN and POSCHLOD 1998, FISCHER et al. 1996) which had an important function in traditional economic systems all over Europe (JACOBEIT 1987). Many of these species are endangered and listed in red data books. Most of them are not able to survive in the average modem cultural landscape. Pastoral landscapes are based on a form of land use that is part of a continuum originating in more natural systems. This results from the fact that the animals used for grazing are mostly derived from wild species of the past of a certain area. Therefore the impact they have on ecosystems is not unlike the impact their wild ancestors would have had under more natural conditions, especially in extensive pastures and pastoral woodlands. This might be one of the main reasons for the high biodiversity which can be observed within such extensive land-use systems. Therefore it can be concluded that extensive pastoral land use is the agricultural