General connectivity improvement and clearly localised connectivity improvement can be efficient compensation measures for area loss

Trading connectivity improvement for area loss in patch-based biodiversity reserve networks

Thomas Dalang and Anna M. Hersperger

Biological Conservation Volume 148, Issue 1, Pages 116-125

Here is a good paper on connectivity.

In densely populated countries it often becomes imperative to compensate for biotope loss by improving connectivity. Creation of new biotopes takes too long.

Here the researchers analysed four compensation scenarios. The scenarios vary in how strong loss and compensation is locally fixed. The reserve network was modelled as a graph.  Biotope patches are represented by nodes and connectivity corresponds to edges along which animals migrate from patch to patch. Connectivity improvement was modelled as a reduction of edge lengths. Ecological equivalence was measured by metapopulation capacity as defined by Hanski and Ovaskainen (2000). Localised modifications were analysed with eigenanalysis. Modifications spread over the whole component were analyzed with a linear regression model. This uses the total biotope area and the length of the minimal spanning tree as input. The results clearly showed that both general connectivity improvement and clearly localised connectivity improvement can be efficient compensation measures for area loss.

The researchers sign off saying that their results clearly show that connectivity improvement is a valuable compensation alternative to creation of new patches.