Transport corridors in Bulgaria

In 2007, the Dutch research institute Alterra   bought together teams from the Netherlands and Bulgaria to look at ways to restore habitat connectivity across transport corridors in Bulgaria.

Bulgaria has a rapidly growing transport network which includes both roads and railways.  It's also a country that's lucky enough to contain several mammal species which roam across large areas of land, such as wolves, brown bears and otters.  As the transport network grows, many of the roads and railways are cutting across areas of habitat and fragmenting them into smaller patches.  This reduces the area of viable habitat for many species and threatens their long term survival.

To counteract this, the Bulgarian and Dutch team used a computer model known as LARCH   to find out which roads and railways were having the greatest impact.  The model evaluated population viability of different species with and without the transport corridors.  This process flagged up which areas of habitat could be made into a viable size for priority species, if the road or railway was removed, or, more realistically, mitigated in some way.

For wolves, for example, network maps were produced that shows viable habitat and habitat patches that are too small, pre and post mitigation of transport corridors.

As Bulgaria is changing fast, this study also considered the effects of new transport corridors, and looked at how negative impacts on habitat connectivity could be reduced.  The study team concluded that Environmental Impact Assessments of new transport projects were an important tool and devised a list of ten guidelines to ensure habitat connectivity was properly considered in these EIAs.

You can read more about this project from the link on the right, and you can find the list of EIA guidelines in the final report.