Following current papers and newly proposed methods is always exciting. Especially when someone proposes a new technique for conservation planning, which
includes the habitat fragmentation caused by roads. The decrease of road-less areas in Europe certainly has an impact on a wide range of species (Selva et al. 2011), especially if they inhabit large home-ranges and frequently move between for instance forest patches. To give an example: Conservation NGOs in Germany are currently celebrating the return of wolves in east German forests. While this is certainly a good thing it requires a lot of future management actions (possible compensation of farmers, education of the public, …) and furthermore the high fragmentation of east German landscapes might also alter wolf behavior and migration. Many other animals are also affected by fast moving traffic (see the picture of the poor frog) and therefore i am certain that roads will become more and more important in future conservation area prioritizations and landscape planing.
In their recent paper Freudenberger et al (2013) shed light on the current fragmentation of an east German state and introduce a new landscape metric called the spatial road disturbance index (SPROADI). The SPROADI is an aggregated index, which integrates the (1) traffic intensity on the habitat intersecting road, (2) density and distribution of roads in a landscape and (3) overall fragmentation caused by roads. Mathematically the new index is just a weighted sum of the three equally weighted subindices, which were previously categorized using available quantitative data. While this is certainly not perfect (data maybe biased and thus has to be normalized beforehand, correlations with subindices) i think that due to its simplicity and easy understanding it might become a handy index for landscape planners and biologists conducting impact assessments for roads. Although i am not entirely convinced by the mathematics behind this new index (next rainy sunday i will put some thoughts behind it) i recommend interested people to give their paper a try.
- Freudenberger et al. “Spatial road disturbance index (SPROADI) for conservation planning: a novel landscape index, demonstrated for the State of Brandenburg, Germany”. Landscape Ecology (2013): 1-17. DOI: http://dx.doi.org/10.1007/s10980-013-9887-8
Selva, Nuria, et al. “Roadless and low-traffic areas as conservation targets in Europe.” Environmental management 48.5 (2011): 865-877.