Identifying critical habitat patches - a case study
Abstract
A quantitative approach is given for evaluating the relative positional importance of landscape elements (habitat patches and ecological corridors) within the landscape graph of an endangered Hungarian Pholidoptera transsylvanica bush-cricket metapopulation. Various graph indices are proposed to reflect positional importance, and a combined measure of importance, based on both pure topology and weighted indices referring to patch and corridor quality, is presented. Since the survival of many natural populations living in fragmented landscapes depends on migration and gene flow between local populations, our methods quantifying the role of spatial elements in maintaining connectivity can be useful in future conservation practice.
References
Beier, P. & Noss, R. F. (1998): Do habitat corridors provide connectivity? - Conservation Biology 12: 1241-1252.
Hanski, I. A. (1998): Metapopulation dynamics. - Nature 396: 41-49.
Jordán, F. (2000): A reliability-theory approach to corridor design. - Ecological Modelling 28: 211- 220.
Jordán, F. (2001): Adding function to structure - comments on Palmarola landscape connectivity. - Community Ecology 2: 133-135.
Jordán, F., Báldi, A., Őrei, K. M., Rácz, I. & Varga, Z. (2003): Characterizing the importance of habitat patches and corridors in maintaining the landscape connectivity of a Pholidoptera transsylvanica (Orthoptera) metapopulation. - Landscape Ecology 18: 83-92.
Orci, K. M. (1997): A comparative study on grasshopper (Orthoptera) communities in the Aggtelek Biosphere Reserve. - In: Tóth, E. & Horváth, R. (eds): Research in Aggtelek National Park and Biosphere Reserve. ANP Directorate, Aggtelek, pp. 109-116.
Pickett, S. T. A. & Cadenasso, M. L. (1995): Landscape ecology: spatial heterogeneity in ecological systems. - Science 269: 331-334.
Tischendorf, L. & Fahrig, L. (2000a): On the usage and measurement of landscape connectivity. - Oikos 90: 7-19.
Tischendorf, L. & Fahrig, L. (20006): How should we measure landscape connectivity? - Landscape Ecology 15: 633-641.
Urban, D. & Keitt, T. (2001): Landscape connectivity: a graph-theoretic perspective. - Ecology 82: 1205-1218.
Varga, Z. (1997): Biogeographical outline of the invertebrate fauna of the Aggtelek Karst and surrounding areas. - In: Tóth, E. & Horváth, R. (eds): Research in Aggtelek National Park and Biosphere Reserve. ANP Directorate, Aggtelek, pp. 87-94.
Varga-Sipos, J. & Varga, Z. (1997): Phytocenology of semi-dry grasslands in the Aggtelek Karst area (N Hungary). - In: Tóth, E. & Horváth, R. (eds): Research in Aggtelek National Park and Biosphere Reserve. ANP Directorate, Aggtelek, pp. 59-78.
