Selecting herb-rich forest networks to protect different measures of biodiversity

Data on vascular plants of herb-rich forests in Finland were used to compar e the efficiency of reserve selection methods in representing three measure s of biodiversity: species richness, phylogenetic diversity, and restricted -range diversity. Comparisons of reserve selection methods were carried out both with and without consideration of the existing reserve system. Our re sults showed that the success of a reserve network of forests in representi ng different measures of biodiversity depends on the selection procedure, s election criteria, and data set used. Ad hoc selection was the worst option . A scoring procedure was generally more efficient than maximum random sele ction. Heuristic methods also appeared to be efficient. Each biodiversity m easure can be used as a criterion for a selection algorithm and as a measur e of efficiency of protection at the network level. The results indicate th at different measures of biodiversity should be taken into account. For ins tance, phylogenetic diversity of a network was maximized by a heuristic met hod using phylogenetic diversity as the selection criterion. However, a heu ristic method based on restricted-range diversity was more efficient than t hat based on species richness in representing high species richness in a fo rest network. Our results showed also that complementing the existing reser ves is less efficient than selection starting with a blank slate. That is, the total number of sites required to protect a given level of biodiversity is higher when complementing the existing network, because some previously protected sites contribute relatively little diversity to the network. Dat a on species of a historic network should be available when new sites are s elected for complementing the historic network.