Assessing habitat connectivity for land-use planning: a method integrating landscape graphs and Delphi survey

Abstract

Increasing fragmentation is occurring in most valley floors in Alpine regions, where urbanization and infrastructure development are reducing connectivity among remnant natural areas. This undermines the conservation of alpine biodiversity. Using a landscape graph-based approach, we visualized and assessed the dispersal opportunities for three target species (Rana synk. esculenta, Erinaceus europaeus, Moscardinus avellanarius) on a municipal scale. We considered the barrier effect caused by landscape objects, such as linear infrastructures and artificial land covers. Species-specific barrier effects were estimated through a Delphi survey involving 25 experts. The information collected was then used to draw a landscape graph of local connections and to estimate the functioning of the networks of habitat patches in terms of their capability of sustaining local populations of target species. The methodology was applied in an alpine valley floor in Trentino, northern Italy, and resulted in the mapping of all possible and remnant linkages between habitat patches in its current state. The approach may provide a better qualitative understanding of the impacts of proposed land-use changes, and was found to be particularly helpful in contexts where availability of data is limited.

Keywords:

• habitat connectivity
• Delphi survey
• landscape planning
• landscape graph
• Alpine valley
• fragmentation
• landscape barrier

View correction statement:

Assessing habitat connectivity for landuse planning: a method integrating landscape graphs and Delphi survey

Acknowledgements

The authors gratefully thank all the experts (from University of Milano-Bicocca, University of Insubria, University of Torino, University of Pavia, Forest and Fauna Service of Autonomous Province of Trento, Wildlife Office of Adamello Brenta Nature Park, Biodiversity Office of WWF Italia, Tridentine Museum of Natural Sciences) who voluntarily contributed to the Delphi survey. They also wish to thank two anonymous reviewers for valuable comments on an earlier version of the manuscript. In particular, Scolozzi acknowledges the Autonomous Province of Trento (PAT) for providing financial support for the research project (OPENLOC 2008–2011; www.openloc.eu). This work was partially conducted while Davide Geneletti was a Giorgio Ruffolo Fellow in the Sustainability Science Program at Harvard University's Center for International Development. Support of CID and the Italian Ministry for Environment, Land and Sea is gratefully acknowledged.