The evolutionary species pool concept does not explain occurrence patterns of dead-wood-dependent organisms: implications for logging residue extraction.

Emulation of natural disturbances is often regarded as a key measure to make forestry biodiversity-oriented. Consequently, extraction of logging residues is assumed to have little negative effect in comparison to extraction of dead wood mainly formed at natural disturbances. This is consistent with the evolutionary species pool hypothesis, which suggests that most species are evolutionary adapted to the naturally most abundant habitats. We tested this hypothesis for dead-wood-dependent macrofungi, lichens, and beetles in a boreal forest landscape in central Sweden, assuming that species are adapted to conditions similar to today's unmanaged forest. No occurrence patterns, for the species groups which we investigated, were consistent with the hypothesis. Overall, stumps and snags had the highest habitat quality (measured as average population density with equal weight given to each species) and fine woody debris the lowest, which was unexpected, since stumps were the rarest dead-wood type in unmanaged forest. We conclude that the evolutionary species pool concept did not explain patterns of species' occurrences, and for two reasons, the concept is not reliable as a general rule of thumb: (1) what constitute habitats harbouring different species communities can only be understood from habitat-specific studies and (2) the suitability of habitats is affected by their biophysical characteristics. Thus, emulation of natural disturbances may promote biodiversity, but empirical studies are needed for each habitat to understand how natural disturbances should be emulated. We also conclude that stump extraction for bioenergy is associated with larger risks for biodiversity than fine woody debris extraction.

Species contributions to single biodiversity values under-estimate whole community contribution to a wider range of values to society.

A major task for decision makers is deciding how to consider monetary, cultural and conservation values of biodiversity explicitly when planning sustainable land use. Thus, there is a great need to understand just what "valuing" biodiversity or species really means, e.g. regarding how many and which species are important in providing ecosystem services or other values. Constructing ecosystem-level indices, however, requires weighting the relative contribution of species to the different values. Using farmland birds, we illustrate how species contribute to different biodiversity values, namely utilitarian (pest seed predation potential), cultural (species occurrence in poetry), conservational (declines and rarity) and inherent (all species equal) value. Major contributions to each value are often made by a subset of the community and different species are important for different values, leading to no correlations or, in some cases, negative correlations between species' relative contributions to different values. Our results and methods using relative contributions of species to biodiversity values can aid decisions when weighing different values in policies and strategies for natural resource management. We conclude that acknowledging the importance of the range of biodiversity values that are apparent from different perspectives is critical if the full value of biodiversity to society is to be realised.

Consequences of bioenergy wood extraction for landscape-level availability of habitat for dead wood-dependent organisms.

Stumps and slash resulting from forest clearcutting is used as a source of low-net-carbon energy, but there are concerns about the consequences of biofuel extraction on biodiversity. Logging residues constitute potentially important habitats, since a large part of forest biodiversity is dependent on dead wood. Here we used snapshot field data from a managed forest landscape (25 000 ha) to predict landscape scale population changes of dead wood dependent organisms after extraction of stumps and slash after clearcutting. We did this by estimating habitat availability for all observed dead wood-dependent beetles, macrofungi, and lichens (380 species) in the whole landscape. We found that 53% of species occurred in slash or stumps. For most species, population declines after moderate extraction (≤30%) were small (<10% decline) because they mainly occur on other dead wood types. However, some species were only recorded in slash and stumps. Red listed species were affected by slash and stump extraction (12 species), but less often than other species. Beetles and fungi were more affected by stump extraction, while lichens were more affected by slash extraction. For beetles and lichens, extraction of a combination of spruce, pine and birch resulted in larger negative effects than if only extracting spruce, while for fungi tree species had little effect. We conclude that extensive extraction decreases the amount of habitat to such extent that it may have negative consequences on species persistence at the landscape level. The negative consequences can be limited by extracting only slash, or only logging residues from spruce stands.