Designing ecological corridors in a fragmented landscape: a fuzzy approach to circuit connectivity analysis.

2016 - Ecological Indicators, 67, 807-820
Pierik, M.E., Dell'Acqua, M., Confalonieri, R., Bocchi, S., Gomarasca, S.


Landscape connectivity analysis is a major tool in supporting biodiversity conservation. Several methodologies have been developed to tackle it by following two main paths. The first path exploits graph approaches and models focal nodes’ connections on a resistance/conductance matrix depending on focalspecies’ movement potential. The second path considers geometrical pattern analyses based on the calculation of structural landscape metrics. These approaches separately investigate functional and structural features of the landscape, and may come short of a total definition if used separately. Here we proposea new scalable, modular, participative and open-source procedure based on Fuzzy logic to combine thefunctional and structural aspects of connectivity. We applied this method on the highly fragmented landscape of the Po Plain, focusing on its rare and endangered plain springs named fontanili. We identifiedan expert panel and involved it in the assignation of permeability values of land use classes with respectto the capacity of movement of animal species typical of fontanili. We concurrently performed a quantitative evaluation of the landscape fragmentation with a moving window. We found that the functionaland structural evaluations were poorly correlated in the area under study (Pearson’s r = −0.35, p < 0.001). We thus integrated these two non-overlapping analyses of the landscape by Fuzzy logic using thresh-olds and combination weights obtained from questionnaires proposed to the expert panel. The resultingindex, termed Fuzzy Functionality Index (FFI), improved the level of information associated with land-scape classification. By merging functional and structural aspects of the landscape, the FFI allowed usto discriminate different functional values of equally permeable parcels and vice versa. We demonstratethat FFI may act as a conductance measure in a circuit theory approach, highlighting ecological corridorsbetween focal points of species’ distribution. We present FFI as an effective predictive index to inspectcomplex and non-linear landscape dynamics.

Keywords: Biodiversity conservation, landscape analysis, ecological corridors, graph analysis, circuit theory, fragmentation, aggregation Index, Fuzzy analysis, participative process
DOI: 10.1016/j.ecolind.2016.03.032