The role of edges in supporting biodiversity in the case of carabids
Abstract
Diversity relationships of carabids in forest edges and neighbouring forest interiors and the surrounding grassland areas were studied. Samples were taken along three replicated forest- grassland transects using pitfall traps in the Aggtelek National Park in Hungary for 2 years. The study revealed significant edge effect on the carabids. The Shannon diversity of carabids was significantly higher in the forest edge and the grassland than in the forest interior. Carabids of the forest interior, forest edge and grassland can be separated from each other by ordinations, both on the species composition and abundance, suggesting that all three habitats have distinct species assemblages. Moreover, indicator species analysis detected significant edge associated species; based on the specificity and fidelity of the carabids we have distinguished five groups of species: habitat generalists, grassland-associated species, forest generalists, forest specialists and edge-associated species. Our result suggests that the increased diversity of the forest edges is due to the edge-associated species and to the occurrence of the species of the neighbouring habitats.
References
Bedford, S. E. & Usher, M. B. (1994): Distribution of arthropod species across the margins of farm woodlands. - Agriculture , Ecosystems and Environment 48: 295-305.
Butterfield, J., Luff, M. L., Baines, M. & Eyre, M. D. (1995): Carabid beetle communities as indicator of conservation potential in upland forests. - Forest Ecology and Management 79: 63-77. den Boer, P. J. (1970): On the significance of dispersal power for populations of carabid-beetles (Coleoptera, Carabidae). - Oecologia 4: 1-28.
den Boer, P. J. (1981): On the survival of populations in a heterogeneous and variable environment. - Oecologia 50: 39-53.
Dufrene, M. & Légendre, P. (1997): Species assemblages and indicator species: the need for a flexible asymmetrical approach. - Ecological Monographs 67: 345-366.
Freude, H., Harde, K. W. & Lohse, G. A. (1976): Die Käfer Mitteleuropas. - Goecke and Evers Verlag, Krefeld, 302 pp.
Lövei, G. & Sunderland, K. D. (1996): Ecology and behavior of ground beetles (Coleoptera: Carabidae). - Ann . Rev. Entomology 41: 231-256.
Magura, T. & Tóthmérész, B. (1997): Testing the edge effect on carabid assemblages in a deciduous forest. - Acta zool. hung. 43: 303-312.
Magura, T. & Tóthmérész, B. (1998): Edge effect on carabids in oak-hornbeam forest at Aggtelek National Park (Hungary). - Acta Phytopat. Entomol. Hung. 33: 379-387.
Magura, T., Tóthmérész, B. & Bordán, Zs. (2002): Carabids in oak hornbeam forest: testing the edge effect hypothesis. - Acta Biol. Debrecina 24: 235-249.
Magura, T., Tóthmérész, B. & Molnár T. (2000): Spatial distribution of carabid species along grass forest transects. - Acta zool. hung. 46: 1-17.
Magura, T., Tóthmérész, B. & Molnár, T. (2001a): Forest edge and diversity: carabids along forest- grass transects. - Biodiversity and Conservation 10: 287-300.
Magura, T., Tóthmérész, B. & Molnár, T. (2001b): Edge effect on carabids along forest-grass transects. - Web Ecology 2: 7-13.
Molnár, T., Magura, T. & Tóthmérész, B. (2001): Ground beetles (Carabidae) and edge effect in oak-hornbeam f rest-grassland transects. - European J. Soil Biol. 37: 297-300.
Murcia, C. (1995): Edge effects in fragmented forests: implications for conservation. - Tree 10: 58-62.
Niemelä, J. K. & Spence, J. R. (1994): Distribution of forest dwelling carabids (Coleoptera): spatial scale and the concept of communities. - Ecography 17: 166-175.
Niemelä, J., Spence, J. R. & Spence, D. H. (1992): Small-scale heterogeneity in the spatial distribution of carabid beetles in the southern Finnish taiga. - J. Biogeogr. 19: 173-181.
Niemelä, J., Haila, Y. & Punttila, P. (1996): The importance of small-scale heterogeneity in boreal forests: variation in diversity in forest-floor invertebrates across the succession gradient. - Ecography 19: 352-368.
Pulliam, H. R. (1988): Sources, sinks, and population regulation. -Amer. Naturalist 132: 652-661.
Saunders, D. A., Hobbs, R. J. & Margules, C. R. (1991): Biological consequences of ecosystem fragmentation: a review. - Conservation Biology 5: 18-32.
Thiele, H. U. (1977): Carabid Beetles in their Environments. - Springer Verlag, Berlin, 369 pp.
Tóthmérész, B. (1993): NuCoSA 1.0: Number cruncher for community studies and other ecological applications. - Abstracta Botanica 17: 283-287.
Tóthmérész, B. (1995): Comparison of different methods for diversity ordering. - J. Veg. Sei. 6: 283-290.
