Showing papers by "Anders Dahlberg published in 2019"
TL;DR: Forestry with short stand generations and simplified forest structures has markedly affected forest biodiversity, and conservation of more infrequent species requires higher levels of tree retention, and results suggest that around 75% of the ECM species are lost with the forest certification standard of 5% retention trees left at logging.
Abstract: Forestry with short stand generations and simplified forest structures has markedly affected forest biodiversity. One group of organisms adversely affected by clear‐cutting is ectomycorrhizal (ECM) fungi, as they are associated with the roots of living trees. Retention forestry is a way of reducing logging impacts and enhancing biodiversity conservation. Increasing the proportion of trees retained at harvest may improve ECM fungal diversity. We investigated the potential for lifeboating of ECM fungi through the harvesting phase in an experimental field study in a 190‐year‐old Scots pine forest in northern Sweden. The experiment comprised four levels of tree retention—unlogged forest, plots with 60% or 30% of evenly distributed trees retained and clear‐cuts without retained trees. We sampled soils and determined identities, frequencies and relative abundances of ECM fungal species during 3 years following logging through the use of high‐throughput sequencing of amplified ITS2 markers. We identified 149 ECM fungal species, with the five most abundant species accounting for 50% of the total ECM fungal amplicons. Three years after harvesting, the proportion of ECM sequences in the total amplicon pool had decreased proportionally to the extent of tree removal. In clear‐cuts, ECM fungal relative abundance had decreased by 95%, while ECM fungal species richness had declined by 75%, compared to unlogged plots. Tree retention enabled the maintenance of the most frequent ECM species, while more lowly abundant species were progressively lost at random with increasing level of tree removal. Five of the most frequent ECM fungal species remained present after clear‐cutting, probably associated with pine seedlings. Synthesis and applications. Tree retention can moderate short‐term and potentially also long‐term logging impacts on ECM fungi. Local ECM fungal diversity is preserved in proportion to the amount of retained trees. Abundant species may be largely maintained, even by low levels of tree retention and on naturally established seedlings. However, conservation of more infrequent species requires higher levels of tree retention, and our results suggest that around 75% of the ECM species are lost with the forest certification standard of 5% retention trees left at logging.
32 citations
TL;DR: Fungi constitute one of the major lineages of life (with organisms treated as 'fungi' also scattered in other lineages).
Abstract: Fungi constitute one of the major lineages of life (with organisms treated as 'fungi' also scattered in other lineages).
17 citations
TL;DR: The evolutionary species pool concept did not explain patterns of species’ occurrences, and the concept is not reliable as a general rule of thumb, so empirical studies are needed for each habitat to understand how natural disturbances should be emulated.
Abstract: 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.
3 citations