To what extent does surrounding landscape explain stand-level occurrence of conservation-relevant species in fragmented boreal and hemi-boreal forest? - a systematic review.

BACKGROUND: Forestry and land-use change are leading causes of habitat loss, degradation, and fragmentation worldwide. The boreal forest biome is no exception, and only a small proportion of this forest type remains intact. Since forestry will remain a major land-use in this region, measures must be taken to ensure forest dependent biodiversity. Stand level features and structures promoting conservation relevant species have received much attention, but the landscape level perspective is often missing. Hence, we review the literature that has related fragmentation in the surrounding landscape to occurrence of threatened, declining, red-listed, rare, or deadwood dependent species as well as those considered to be indicator, flagship, umbrella, and/or keystone species in a given boreal forest stand. METHODS: A comprehensive search string was developed, benchmarked, and adapted for four bibliographic databases, two search engines, and 37 specialist websites. The online evidence synthesis tool Cadima was used for screening of both abstracts and full texts. All articles meeting the inclusion criteria were subject to study validity assessment and included in a narrative table. Studies reporting means and variance were included in quantitative meta-analysis when more than 3 comparable studies were available. RESULTS: The searches resulted in 20 890 unique articles that were reduced to 172 studies from 153 articles. These studies related stand level presence, abundance, species richness, and/or composition of conservation relevant species to landscape factors such as: categorical fragmentation intensity (higher vs. lower), amount of habitat or non-habitat, distance to habitat, and/or habitat configuration, on scales ranging from tens to tens of thousands of ha. Forty-three studies were suitable for meta-analysis. These showed a significant negative effect of fragmentation on both presence and abundance of conservation relevant species, as well as a near significant trend for species richness. This was particularly clear when fragmentation was measured as distance to surrounding habitat for presence, and as habitat amount for abundance. The organism groups with the strongest support for a negative effect of fragmentation were wood fungi and birds. CONCLUSION: As hypothesised, there is strong support for negative effects of fragmentation in boreal forest. These results emphasize the negative consequences of the intensive forestry and associated landscape transformation that has been the norm for the last century. We argue that this should have direct implications for policy makers to shift towards including a landscape perspective in all planning of harvesting, preserving, and restoring forest. In addition, we found that research effort has been very uneven between organism groups, that studies on landscape change over time were rare, and that many studies have not quantified the difference in fragmentation intensity among landscapes making it difficult to quantify the extent of the negative effect. One way forward would be to revisit the studies included here in to incorporate change over time, as well as a true quantification of landscape fragmentation. By doing so, the scale of the negative effects would be much better analysed, which would greatly assist conservation practitioners all throughout the boreal forest biome.

Unlocking the biodegradative potential of native white-rot fungi: a comparative study of fiberbank organic pollutant mycoremediation.

Fiberbanks refer to a type of fibrous sediment originated by the forestry and wood pulping industry in Sweden. These anthropogenic sediments are significantly contaminated with potentially toxic elements, and a diverse array of organic pollutants. Additionally, these sediments are of environmental concern due to their potential role in greenhouse gas emissions. Given the environmental risks posed by these sediments, the development of effective remediation strategies is of critical importance. However, no specialized methods have been established yet for the cleanup of this specific type of contaminated sediments. To identify effective fungal species for the mycoremediation of the fiberbank substrate, we performed a detailed screening experiment. In this research, we primarily aimed at assessing both the growth capacity and the proficiency in degrading organic pollutants of 26 native white-rot fungi (WRF) species. These species were sourced from natural forest environments in northern Sweden. The experimental setup involved evaluating the WRF on plates containing fiberbank material with a central Hagem-agar disc to closely monitor the interaction of these species with fiberbank substrates. Among the fungi tested, Laetiporus sulphureus exhibited the highest growth area percentage at 72%, followed by Hymenochaete tabacina at 68% and Diplomitoporus crustulinus at 67%. For the removal of 2-3 ring polycyclic aromatic hydrocarbons (PAHs), Phellinus punctatus led with 68%, with Cystostereum muraii at 57% and Diplomitoporus crustulinus at 49%. Regarding the removal percentage of 4-6 ring PAHs, Diplomitoporus crustulinus showed the highest efficiency at 44%, followed by Phlebia tremellosa at 40% and Phlebiopsis gigantea at 28%.

To what extent does surrounding landscape explain stand-level occurrence of conservation-relevant species in fragmented boreal and hemi-boreal forest?-a systematic review protocol.

BACKGROUND: Silviculture and land-use change has reduced the amount of natural forest worldwide and left what remains confined to isolated fragments or stands. To understand processes governing species occurrence in such stands, much attention has been given to stand-level factors such as size, structure, and deadwood amount. However, the surrounding matrix will directly impact species dispersal and persistence, and the link between the surrounding landscape configuration, composition and history, and stand-level species occurrence has received insufficient attention. Thus, to facilitate optimisation of forest management and species conservation, we propose a review addressing 'To what extent does surrounding landscape explain stand-level occurrence of conservation-relevant species in fragmented boreal and hemi-boreal forest?'. METHODS: The proposed systematic review will identify and synthesise relevant articles following the CEE guidelines for evidence synthesis and the ROSES standards. A search for peer-reviewed and grey literature will be conducted using four databases, two online search engines, and 36 specialist websites. Identified articles will be screened for eligibility in a two-step process; first on title and abstract, and second on the full text. Screening will be based on predefined eligibility criteria related to a PECO-model; population being boreal and hemi-boreal forest, exposure being fragmentation, comparator being landscapes with alternative composition, configuration, or history, and outcome being occurrence (i.e., presence and/or abundance) of conservation-relevant species. All articles that pass the full-text screening will go through study validity assessment and data extraction, and be part of a narrative review. If enough studies prove comparable, quantitative meta-analyses will also be performed. The objective of the narrative review and the meta-analyses will be to address the primary question as well as six secondary questions, and to identify important knowledge gaps.

Escherichia coli Bacteria Develop Adaptive Resistance to Antibacterial ZnO Nanoparticles.

Antibacterial agents based on nanoparticles (NPs) have many important applications, e.g., for the textile industry, surface disinfection, wound dressing, water treatment, and food preservation. Because of their prevalent use it is important to understand whether bacteria could develop resistance to such antibacterial NPs similarly to the resistance that bacteria are known to develop to antibiotics. Here, it is reported that Escherichia coli (E. coli) develops adaptive resistance to antibacterial ZnO NPs after several days' exposure to the NPs. But, in contrast to antibiotics-resistance, the observed resistance to ZnO NPs is not stable-after several days without exposure to the NPs, the bacteria regain their sensitivity to the NPs' antibacterial properties. Based on the analyses it is suggested that the observed resistance is caused by changes in the shape of the bacteria and the expressions of membrane proteins. The findings provide insights into the response of bacteria to antibacterial NPs, which is important to elucidate for designing and evaluating the risk of applications based on antibacterial NPs.

Assemblage composition of fungal wood-decay species has a major influence on how climate and wood quality modify decomposition.

The interactions among saprotrophic fungal species, as well as their interactions with environmental factors, may have a major influence on wood decay and carbon release in ecosystems. We studied the effect that decomposer diversity (species richness and assemblage composition) has on wood decomposition when the climatic variables and substrate quality vary simultaneously. We used two temperatures (16 and 21°C) and two humidity levels (70% and 90%) with two wood qualities (wood from managed and old-growth forests) of Pinus sylvestris. In a 9-month experiment, the effects of fungal diversity were tested using four wood-decaying fungi (Antrodia xantha, Dichomitus squalens, Fomitopsis pinicola and Gloeophyllum protractum) at assemblage levels of one, two and four species. Wood quality and assemblage composition affected the influence of climatic factors on decomposition rates. Fungal assemblage composition was found to be more important than fungal species richness, indicating that species-specific fungal traits are of paramount importance in driving decomposition. We conclude that models containing fungal wood-decay species (and wood-based carbon) need to take into account species-specific and assemblage composition-specific properties to improve predictive capacity in regard to decomposition-related carbon dynamics.

Competitive outcomes between wood-decaying fungi are altered in burnt wood.

Fire is an important disturbance agent in boreal forests where it creates a wide variety of charred and other types of heat-modified dead wood substrates, yet how these substrates affect fungal community structure and development within wood is poorly understood. We allowed six species of wood-decaying basidiomycetes to compete in pairs in wood-discs that were experimentally burnt before fungal inoculation. The outcomes of interactions in burnt wood differed from those in unburnt control wood for two species:Antrodia sinuosanever lost on burnt wood and won over its competitor in 67% of the trials compared to 40% losses and 20% wins on unburnt wood. In contrast, Ischnoderma benzoinumwon all interactions on unburnt wood compared to 33% on burnt wood. However, the responses differed depending on the identity of the competing species, suggesting an interaction between competitor and substrate type. The observed shift in competitive balance between fungal species probably results from chemical changes in burnt wood, but the underlying mechanism needs further investigation. Nevertheless, the results indicate that forest fires indirectly structure fungal communities by modifying dead wood, and highlight the importance of fire-affected dead wood substrates in boreal forests.

Diverse ecological roles within fungal communities in decomposing logs of Picea abies.

Fungal communities in Norway spruce (Picea abies) logs in two forests in Sweden were investigated by 454-sequence analyses and by examining the ecological roles of the detected taxa. We also investigated the relationship between fruit bodies and mycelia in wood and whether community assembly was affected by how the dead wood was formed. Fungal communities were highly variable in terms of phylogenetic composition and ecological roles: 1910 fungal operational taxonomic units (OTUs) were detected; 21% were identified to species level. In total, 58% of the OTUs were ascomycetes and 31% basidiomycetes. Of the 231 337 reads, 38% were ascomycetes and 60% basidiomycetes. Ecological roles were assigned to 35% of the OTUs, accounting for 62% of the reads. Wood-decaying fungi were the most common group; however, other saprotrophic, mycorrhizal, lichenized, parasitic and endophytic fungi were also common. Fungal communities in logs formed by stem breakage were different to those in logs originating from butt breakage or uprooting. DNA of specific species was detected in logs many years after the last recorded fungal fruiting. Combining taxonomic identification with knowledge of ecological roles may provide valuable insights into properties of fungal communities; however, precise ecological information about many fungal species is still lacking.

Effect of debarking water from Norway spruce (Picea abies) on the growth of five species of wood-decaying fungi.

Norway spruce (Picea abies) debarking water is an aqueous extract obtained as waste from the debarking of logs at paper mills. The debarking water contains a mixture of natural compounds that can exhibit diverse biological activities, potentially including fungicidal activity on some species of wood-decaying fungi. Thus, we investigated the growth rates of such fungi on agar plates to which debarking water extracts had been added. The experiment included five wood-decaying fungi, viz. Gloeophyllum sepiarium, Oligoporus lateritius, Ischnoderma benzoinum, Junghuhnia luteoalba, and Phlebia sp. Growth reduction was observed for all species at the highest tested concentrations of freeze-dried and ethanol-extracted debarking water, the ethyl acetate-soluble fraction and the diethyl ether-soluble fraction. However, the magnitude of the effect varied between different species and strains of individual species. The brown-rot fungi G. sepiarium and O. lateritius were generally the most sensitive species, with the growth of all tested strains being completely inhibited by the ethyl acetate-soluble fraction. These results indicate that development of antifungal wood-protecting agents from debarking water could potentially be a way to make use of a low-value industrial waste.

Increased heat resistance in mycelia from wood fungi prevalent in forests characterized by fire: a possible adaptation to forest fire.

Forest fires have been the major stand-replacing/modifying disturbance in boreal forests. To adapt to fire disturbance, different strategies have evolved. This study focuses on wood fungi, and a specific adaptation to forest fire: increased heat resistance in their mycelia. Fifteen species of wood fungi were selected and a priori sorted in two groups according to their prevalence in fire-affected environments. The fungi were cultivated on fresh wood and exposed to 100, 140, 180, 220 °C for 5, 10, 15, 20 and 25 min. under laboratory conditions. A clear difference was found among the two groups. Species prevalent in fire-affected habitats had a much higher survival rate over all combinations of time and temperature compared to species associated with other environments. Thus, the results indicate that fire adaptation in terms of increased heat resistance in mycelia occurs in some species of wood fungi. Such adaptation will influence the ecology and population dynamics of wood fungi, as well as having implications for best practices during restoration fires.

Fungi and wind strongly influence the temporal availability of logs in an old-growth spruce forest.

Coarse woody debris (CWD) is a key habitat for many species in forest ecosystems. To ensure the long-term survival of such species, forest management regimes must include measures that promote dead wood dynamics similar to those of natural forests. Thus, information on CWD dynamics under natural conditions is required, including data pertaining to the underlying agents of disturbance. This study examines modes of mortality, decay rates, and temporal patterns in the availability of Picea abies logs in a Swedish old-growth forest affected by internal, small-scale disturbance. All 684 logs in a 6.6-ha plot were mapped and classified into one of six decay classes. Logs in the early stages of decay were examined for the presence of heart-rot fungi. Six years later all logs were re-inventoried, including newly formed logs. Matrix models based on the transition rates between decay classes showed that it took about 60 years for 90% of the logs to decay beyond class 6 (a deformed trunk with soft wood). Large logs (> 26 cm) decayed 40% more slowly than small logs (< 25 cm). The initial volume of logs was 37.6 m3/ha but increased to 44.8 m3/ha after six years. In addition, there was a large shift in the decay-class distribution. The volume of logs in early and late decay classes increased by 71% and 45%, respectively, while the volume of logs in the intermediate decay classes decreased by 32%. The fluctuations appear to result from pulses in mortality, driven by a combination of strong winds and the heart-rot fungus, Phellinus chrysoloma, which was present in more than 30% of all logs at an early stage of decay. These results show that large temporal fluctuations in dead wood also occur in the absence of large-scale disturbance, and that heart-rot fungi are important factors driving the overall dynamics of dead wood. Since many wood-inhabiting species are naturally rare and have very specific substrate demands, such temporal variability in dead wood availability may have effects on biodiversity and should be taken into account when designing small, protected forest areas.

Wood-disk traps provide a robust method for studying spore dispersal of wood-decaying basidiomycetes.

Spore traps consisting of disks containing monokaryotic mycelia as bait were tested to find a robust, long-time sampling method for studying dispersal of wood-decaying basidiomycetes. In total, 288 disks, 48 for each of six fungal species, were exposed 2 wk at 12 sites in northern Sweden. Both common and rare fungi were used, and the longest distance to a potential dispersal source exceeded 3 km. After 3-16 wk of incubation in the laboratory, the disks were investigated for spore hits. These were detectable both microscopically, by the presence of hyphal clamps, and macroscopically, by mycelial incompatibility zones. Spore traps resisted rain and freezing temperatures well, and spore hits from all species were found at all 12 sites. We argue that lengthy sampling makes it possible to detect low rates of spore deposition, aiding in the study of long-distance dispersal and dispersal of rare species. In addition, because several spore hits can be recognized in the same trap, spore deposition of wood-decaying fungi can be characterized with quantitative data.