Conservation value of low-productive forests measured as the amount and diversity of dead wood and saproxylic beetles

In many managed landscapes, low-productive land comprises most of the remaining relatively untouched areas, and is often over-represented within protected areas. The relationship between the productivity and conservational value of a site is poorly known; however, it has been hypothesized that biodiversity increases with productivity due to higher resource abundance or heterogeneity, and that the species communities of low-productive land are a nested sub-set of communities from more productive land. We tested these hypotheses for dead wood-dependent beetles by comparing their species richness and composition, as well as the amount and diversity of dead wood, between low-productive (potential forest growth < 1 m3 ha-1 year-1) and productive Scots pine-dominated stands in Sweden. We included four stand types: stands situated on (i) thin soils and (ii) mires (both low-productive), (iii) managed stands, and (iv) unmanaged stands set aside for conservation purposes (both productive). Bee...