Showing papers by "Anders Dahlberg published in 2011"

Modelled impact of Norway spruce logging residue extraction on biodiversity in Sweden

Abstract: Logging residues are increasingly being extracted for bioenergy purposes. This study estimates how extraction of fine woody debris (FWD) may affect the overall habitat availability for 577 species of wood-and bark-inhabiting basidiomycetes, beetles, and lichens in Sweden using Norway spruce (Picea abies (L.) Karst.) as their primary substrate. We combined modeling of (i) the amount of various types of woody debris available throughout a forest rotation in managed forests with (ii) a classification of each species' associations with different types of wood. In three different regions, we compared a scenario with no logging residue extraction with three different levels of extraction. Our results suggest that the extraction may cause a 35%-45% reduction in aboveground FWD and a more than 20% decline in the potential amount of substrate for about 50% of the species (affecting basidiomycetes and beetles more than lichens). The intensified forestry during the last century has, however, steadily increased the production of FWD. Furthermore, no red-listed species is primarily associated with logging residues of Norway spruce. Therefore, the current situation in Sweden with extraction of 70% of Norway spruce FWD on 50% of the clearcuts probably constitutes a minor contribution to the regional extinction risks.

Introducing Intensively Managed Spruce Plantations in Swedish Forest Landscapes will Impair Biodiversity Decline

Abstract: Due to pressure to raise forest productivity in Sweden, there are proposals to apply more intensive forestry methods, but they could have potentially large effects on biodiversity. Here we report a compilation and evaluation of the extent and significance of such effects. We evaluated potential effects on biodiversity by introducing intensively fertilized Norway spruce plantations as a management option in Swedish forests with low conservation values on insects, vascular plants, lichens, bryophytes, and red-listed species. Due to a lack of specific studies addressing this question, we based the evaluation on a combination of available and appropriate empiric and anecdotic knowledge; literature data, and expert judgments largely available in species data bases. Our evaluations suggest that such forests will only harbor species that are common and widespread in conventionally managed stands and that species of conservation interest will be lacking, due to the low heterogeneity and light intensity of even-aged monocultures with dense canopies, short rotation times and low availability of coarse woody debris. Effects at the landscape scale are more difficult to evaluate, but will be dependent on the area utilized and the conservation value of sites used. We conclude that negative effects on biodiversity can be reduced if: (1) only land with the lowest conservational value is utilized; (2) plantations are spatially arranged to minimize fragmentation of the landscape; (3) the quality and quantity of key structural elements (e.g., coarse woody debris, old living trees and snags) are maintained at the landscape level; and (4) management intensity is relaxed on other land. For effective implementation of these measures, legislative frameworks and policy instruments need to be adjusted and new models for planning and monitoring need to be developed.

Corrigendum: Modelled impact of Norway spruce logging residue extraction on biodiversity in Sweden

Abstract: The following corrections are made to the article. p. 1220: The fifth sentence in the Abstract should read “Our results suggest that the extraction may cause a 35%–45% reduction in FWD and a more than 20% decline in the potential amount of substrate for about 50% of the species (affecting basidiomycetes and beetles more than lichens).”. The fifth sentence in the Resume should read “Nos resultats indiquent que la recuperation peut eliminer 35 % – 45 % des DLF et reduire de plus de 20 % la quantite potentielle de substrat pour environ 50 % des especes (ce qui affecte les basidiomycetes et les insectes plus que les lichens).”. p. 1221, Table 1: A correcting and clarifying note to the table 1 is added: “In scenarios 2–4; we assumed that logging residue extraction caused a 70% decrease in the volume of 0–5 cm and a 30% decrease in the volume of 5–10 cm of all fine woody debris (including what present before final harvest).”. p. 1225, right column, “Modelled effects of logging residue extraction on the amount of dead wood” section: The first sentence should read “Extraction of logging residues left after final felling (scenario 2) caused a 35% reduction in the average availability of FWD, a 24% reduction of the inflow of aboveground FWD, and a 14% reduction in the total inflow of FWD within a stand during a forest rotation compared with scenario 1 (Figs. 2 and 4).”. The third sentence should read “Removal of aboveground FWD also after all thinnings (scenario 3) caused a reduction by 45% in the average availability of FWD, a 32% reduction of the inflow of aboveground FWD, and a 19% reduction in the total inflow of FWD within a stand during a forest rotation compared with scenario 1 (Figs. 2 and 4).”. p. 1226, caption to Fig. 4: The first sentence of the caption should read “Simulated average amount of various types of dead wood at the landscape level or during a forest generation measured as (a) volume and (b) surface area at different levels of logging residue extraction in Kronoberg.”.