Abstract
Landscape connectivity is a key issue of nature conservation and
distance parameters are essential for the calculation of patch level
metrics. For such calculations the so-called Euclidean and the least
cost distance are the most widespread models. In the present work we
tested both distance models for landscape connectivity, using
connectivity metrics in the case of a grassland mosaic, and the ground
beetle Pterostichus melas as a focal species. Our goal was to
explore the dissimilarity between the two distance models and the
consequent divergence from the calculated values of patch relevance in
connectivity. We found that the two distance models calculated the
distances similarly, but their estimations were more reliable over short
distances (circa 500 m), than long distances (circa 3000 m). The
variability in the importance of habitat patches (i.e. patch
connectivity indices) was estimated by the difference between the two
distance models (Euclidean vs. least cost) according to the patch size.
The location of the habitat patches in the matrix seemed to be a more
important factor than the habitat size in the estimation of
connectivity. The uncertainty of three patch connectivity indices
(Integral Index of Connectivity, Probability of Connectance and Flux)
became high above a habitat size of 5 ha. Relevance of patches in
maintaining connectivity varied even within small ranges depending on
the estimator of distance, revealing the careful consideration of these
methods in conservation planning.
Keywords
Distance models; Matrix effect; NDVI; Patch connectivity; Pterostichus melas
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