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Regional delineation of Sweden in the National Forest Inventory. Regions 1–3 spans from southern boreal to northern boreal zone, region 4 belongs to the hemiboreal zone and region 5 is mainly temperate (nemoral).
Source publication
Dead wood is a critical resource for forest biodiversity and widely used as an indicator for sustainable forest management. Based on data from the Swedish National Forest Inventory we provide baseline information and analyze trends in volume and distribution of dead wood in Swedish managed forests during 15years. The data are based on ≈30,000 sampl...
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... regional delineation of Sweden ( Fig. 1) in the Swedish NFI broadly follows the main biogeographical zones, spanning from temperate (nemoral) forest in the south to mountain forest and the northern boreal zone in the north. Although not strictly adher- ing to the vegetation zones of Ahti et al. (1968), the delineation corresponds well to their description of vegetation ...
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... m in the south to 1800 m in the north. For further details on the NFI see Fridman et al. (2014). A large range of variables are collected in each plot. These includes both general description of the forest stand and detailed information on individual dead wood units. For the present analy- sis we have included; volume of live trees, region (see Fig. 1), clas- sification of Natura 2000 habitats, and stand age (basal area weighted mean tree age). Variables for each dead wood unit (>10 cm in basal diameter and >1.3 m in length) were tree species (see below), size (maximum basal diameter), decay stage (see below) and position (standing or downed). A standing dead tree is defined as ...
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... 150 years in regions 1-4 (>14 m 3 ha À1 ), with a highest recorded value of 22.4 m 3 ha À1 in region 1. In region 5 the volume was highest in forests aged between 125 and 150 years. However, the Table 1 Average volume of dead wood (downed and standing; m 3 ha À1 ) in Swedish managed forests outside formally protected areas. Regions are shown in Fig. 1 lowest recorded volume in forests older than 150 years in region 5 is likely an artefact of few sample plots (only 19 plots) in this cat- egory. By comparison the volume of dead wood in region 5 during the second period (2003)(2004)(2005)(2006)(2007) was 10.2 m 3 ha À1 in forests older than 150 years; more in line with volumes in older ...
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... of dead wood in decay stages 0 and 1 (fresh and hard dead wood) in the two southernmost Table 3 Average volume of dead wood (downed and standing; m 3 ha À1 ) in plots classified as Natura 2000 habitats (for groups see Methods) and plots not classified as Natura 2000 habitats for the time period [2008][2009][2010][2011][2012]. Regions are shown in Fig. 1 Table 2 Average volume of standing dead wood (m 3 ha À1 ) in Swedish managed forests outside formally protected areas. Sample size given in Table 1 and Regions are shown in Fig. 1. Period 1994Period -1998Period 2003Period -2007Period 2008Period -2012 Mean regions during the two last time periods, when compared to the first period. This ...
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... Natura 2000 habitats (for groups see Methods) and plots not classified as Natura 2000 habitats for the time period [2008][2009][2010][2011][2012]. Regions are shown in Fig. 1 Table 2 Average volume of standing dead wood (m 3 ha À1 ) in Swedish managed forests outside formally protected areas. Sample size given in Table 1 and Regions are shown in Fig. 1. Period 1994Period -1998Period 2003Period -2007Period 2008Period -2012 Mean regions during the two last time periods, when compared to the first period. This coincides well with the dramatic storm ''Gudrun", that struck southern Sweden in January 8-9, 2005, severely dam- aging 0.27 million ha forest over a total area of 4.8 million ha. ...
Similar publications
Admixtures of birch in Norway spruce plantations are being promoted as a means to increase habitat and species diversity. The implications of this mixture were analysed with regional survey data from southern Sweden. Permanent sample plots from the Swedish National Forest Inventory (NFI), with Norway spruce and admixture of birch, were used to desc...
Citations
... Our overarching aim was to investigate the diversity of fermentative yeasts found in the northern range limit of oak and identify climatic and environmental drivers of their distribution. For this, we isolated yeasts from oak bark samples collected across southern Sweden, specifically from the nemoral and hemiboreal climate zones (Jonsson et al. 2016). Our sampling area covered 583 km from south to north, along latitudes between 55°52′33″ N and 60°76′78″ N (from southern Sweden to as far north as the Swedish oak tree line allowed) and 379 km from west to east, along longitudes between 12°48′38″ E and 18°63′15″ E (from the North sea to the Baltic sea). ...
Fermentative yeasts play important roles in both ecological and industrial processes, but their distribution and abundance in natural environments are not well understood. We investigated the diversity of yeasts at the northern range limit of their oak tree hosts (Quercus spp.) in Sweden, and identified climatic and ecological conditions governing their distribution. Yeasts were isolated from bark samples from 28 forests and identified to the species level using DNA metabarcoding. Most communities were dominated by species in the Saccharomycetaceae family, especially by species of Saccharomyces, Kluyveromyces and Pichia. Each genus showed a distinct latitudinal and longitudinal distribution, and both temperature and precipitation metrics predicted significant variation in their abundance. Consistent with this, laboratory assays revealed significant effects of temperature on the growth of strains collected from different longitudes and latitudes. We found that older trees harbour more diverse and more balanced fermentative yeast communities with more evenly distributed species abundances. Communities across trees were more similar when sharing a common dominant species. This work provides a baseline for future studies on the impact of climate change on the fermentative yeast biodiversity of temperate forests in northern latitudes and contributes to a growing collection of wild isolates for potential biotechnological applications.
... Current forestry practices are destroying vast habitats through tree clearing and management strategies that leave minimal deadwood. Unmanaged boreal forests can have 50-120 m 3 of deadwood per hectare (Siitonen, 2001), while commercial forests contain only 5-7 m 3 (Jonsson et al., 2016;Korhonen et al., 2021). In Finland, only 13% of forests are protected (Natural Resources Institute Finland, 2022), leaving the rest available for logging. ...
Many species of wood-inhabiting fungi, particularly in the boreal forests of Nordic countries, face significant extinction risks. The historical impact of commercial forestry has led to fragmented old-growth forests, meaning that species lost from these areas may not naturally return to newly protected habitats. This study investigates the potential of inoculation as a management tool to aid the reintroduction of threatened fungal species. Specifically, we tested whether red-listed fungal species associated with dead pine wood could successfully establish in inoculated pine logs and identified factors influencing inoculation success. We cultured mycelium from five target species (Anthoporia albobrunnea, Antrodia crassa, Antrodia infirma, Crustoderma corneum, Dichomitus squalens) and inoculated pine logs in selected forests, monitoring log characteristics and conducting DNA analysis of the fungal community before and after inoculation. Our findings demonstrate that all species successfully established in at least some of the inoculated logs (28–60% success), with variable effects of log characteristics on fungal abundance. Additionally, the presence of certain fungi correlated with the success of the inoculated species. These results suggest that inoculation can be a promising method for aiding the recovery of threatened wood-inhabiting fungi in appropriate forest habitats. Long-term monitoring is necessary to assess fruiting success and population sustainability, while further exploration of alternative techniques could enhance the effectiveness of reintroduction efforts in forest management practices.
... Много автори фокусират вниманието си върху мъртвата биомаса (Pedlar et al., 2002;Larrieu и кол., 2014;Jonsson et al., 2016;Runnel, Lõhmus, 2017;Vítková et al., 2018;Sacher et al., 2022;Tavankar et al., 2022;Lasota et al., 2022 и др.). Тя се разглежда и като съществено депо на биомаса и резервоар на въглерод (Arthur & Fahey, 1992;Bradford et al., 2009;Domke et al., 2011), които е необходимо да се отчитат при инвентаризации и оценяват, съгласно Рамковата Конвенция за промяна на климата на ООН. ...
... However, large-scale estimates on the amount and quality of deadwood are only available in very low resolution. Although these low-resolution datasets offer reliable data, they lack the ability of finding the extremes, i.e., intensively managed forests and deadwood hotspots (Jonsson et al., 2016;Puletti et al., 2019). Hence, determining the ecological quality of the forest remains rather uncertain with the data at hand. ...
Deadwood and decaying wood are the most important components for the biodiversity of boreal forests, and around a quarter of all flora and fauna in Finnish forests depend on them, with third of these species being red-listed. However, there is a severe lack of stand-level deadwood data in Finland, as the operational inventories either focus on the large-scale estimates or omit deadwood altogether. Unoccupied Aerial Vehicles (UAVs) are a cost-effective method for remotely mapping small objects, such as fallen deadwood, over compartment-level areas, as even the most spatially accurate commercial satellites and aerial photography provide 30 cm ground sampling distance, compared to less than 5 cm that is easily achievable with UAVs.
In this study, we utilized YOLOv8 by Ultralytics for detecting and segmenting standing and fallen deadwood instances from RGB UAV imagery. Our study consists of two geographically distinct study areas in Finland, Hiidenportti National Park and Evo. We manually annotated around 13 800 deadwood instances to be used as the training and validation data for the instance segmentation models. These annotations were also compared to field-measured deadwood data from Hiidenportti to assess the extent on how much of the deadwood can even be seen from UAV imagery. We also compared how the models perform on another area than from which its training dataset was from, and whether adding data from another areas to the training dataset improves the performance compared to training only with images from one location.
The best performing model achieved test set mask mAP50 score of 0.682 for Hiidenportti and 0.651 for Sudenpesänkangas datasets. For both areas, including imagery from the another area improved the instance segmentation metrics, whereas using data only from another site to train the models produced significantly worse results. While methods utilizing UAV imagery can not completely replace traditional field work, they should still be considered as an additional tool for field campaigns.
In this study, we utilized YOLOv8 by Ultralytics for detecting and segmenting standing and fallen deadwood instances from RGB UAV imagery. Our study consists of two geographically distinct study areas in Finland, Hiidenportti National Park and Evo. We manually annotated around 13 800 deadwood instances to be used as the training and validation data for the instance segmentation models. These annotations were also compared to field-measured deadwood data from Hiidenportti to assess the extent on how much of the deadwood can even be seen from UAV imagery. We also compared how the models perform on another area than from which its training dataset was from, and whether adding data from another areas to the training dataset improves the performance compared to training only with images from one location.
The best performing model achieved test set mAP50 score of 0.682 for Hiidenportti and 0.651 for Sudenpesänkangas datasets. For both areas, including imagery from the another area improved the instance segmentation metrics, whereas using data only from another site to train the models produced significantly worse results. While methods utilizing UAV imagery can not completely replace traditional field work, they should still be considered as an additional tool for field campaigns.
In this work, we utilized Mask R-CNN to detect individual standing and fallen deadwood instances from RGB UAV imagery. We manually annotated over 14 000 deadwood instances from two separate study sites to be used as the training and validation data, and also compared these data to field-measured deadwood data. Our models achieved test set Average Precision (AP) of 0.341 for the same geographical area the models were trained on, and AP of 0.236 for geographically distinct area used only for testing.
In addition to instance level deadwood maps, we also estimated stand-level deadwood characteristics, such as length and approximate total volume of fallen deadwood based on the annotated polygons. These stand-level features clearly show the borders of the conserved forest, and the volume estimations can distinguish the naturally formed deadwood hotspots from the areas with logging residue. The proposed method enables deadwood mapping for areas consisting of multiple forest compartments, thus complementing the traditional field work.
... New input is halted as living trees have been harvested and smaller dead wood residues are decomposed within a few years. With short rotation times, low volumes of dead wood will be a persistent feature of formerly clear-cut forests (Stokland et al., 2012;Jonsson et al., 2016). In Fennoscandia, dead wood volume in intensively managed forests is about 2-10% of the volume in old-growth forests (Siitonen, 2001;Stokland et al., 2012). ...
Boreal forests are important carbon sinks and host a diverse array of species that provide important ecosystem functions.
Boreal forests have a long history of intensive forestry, in which even-aged management with clear-cutting has been the
dominant harvesting practice for the past 50–80 years. As a second cycle of clear-cutting is emerging, there is an urgent
need to examine the effects of repeated clear-cutting events on biodiversity. Clear-cutting has led to reduced numbers of
old and large trees, decreased volumes of dead wood of varied decay stages and diameters, and altered physical and
chemical compositions of soils. The old-growth boreal forest has been fragmented and considerably reduced. Here,
we review short- and long-term (≥50 years) effects of clear-cutting on boreal forest biodiversity in four key substrates:
living trees, dead wood, ground and soil. We then assess landscape-level changes (habitat fragmentation and edge effects)
on this biodiversity. There is evidence for long-term community changes after clear-cutting for several taxa: epiphytic
lichens; saproxylic fungi, bryophytes and insects; epigeic bryophytes; and soil snails, bacteria, and ectomycorrhizal fungi.
Long-term declines in species richness were found for saproxylic fungi, bryophytes and true flies. However, for the
majority of taxa, long-term effects of clear-cutting are not well understood. On the landscape level, reduced connectivity
to old-growth forests has negative effects on several species of fungi, lichens, bryophytes and insects, notably among
Red-Listed species. Furthermore, altered microclimate near clear-cut edges negatively affects epiphytic lichens and
epigeic arthropods, implying complex effects of habitat fragmentation. Repeated cycles of clear-cutting might pose even
stronger pressures on boreal forest biodiversity due to continued fragmentation of old-growth forests and accumulation
of extinction debts. Examining the broad effects of forestry on biodiversity across the boreal biome is crucial: (i) to
increase our knowledge of long-term and landscape-level effects of former clear-cutting; and (ii) to gain a better
understanding of how forestry will affect biodiversity and, subsequently, ecosystem functioning, with repeated cycles
of clear-cutting.
... In addition to these three, I use the area of forest designated for conservation as a fourth variable. These "conservation forest" areas should, to fulfill their conservation aim, positively influence saproxylic beetles, through e.g. higher amount and diversity of dead wood (Siitonen 2001;Jonsson et al. 2016). ...
Context
Humans have drastically changed many of the world’s forests since the industrial revolution, with northern European forests among the most affected. Research is needed on consequent effects on forest biodiversity. Here I focus on the conservation-relevant wood-living beetles. Whilst previous studies have examined the effect of local stand characteristics on beetle diversity, the influence of the surrounding landscape on alpha diversity may potentially be more important.
Objectives
The aim of this study is to judge the influence and scale of effect of four landscape variables (broadleaf forest volume, area of mature forest, area of conservation forest, area of clear-cut) on alpha diversity of wood-living beetles as a whole, and ecological groups reflecting potentially differing dispersal ecologies (fungivores, wood consumers, predators, red-listed species).
Methods
The landscape variables were analyzed at three scales (within 250, 1250 and 2500 m radius) and related to wood-living beetle diversity sampled using flight interception traps in 73 managed and unmanaged forest stands in the conifer forestry dominated hemiboreal landscape of south-central Sweden.
Results
Wood-living beetle diversity as a whole was positively associated with broadleaf volume at the 2500 m scale, with a weaker association for fungivore diversity at a varying scale. Surprisingly, both predator diversity (varying scale) and red-listed diversity (2500 m scale) was weakly negatively associated with mature forest.
Conclusions
The results highlight the importance of broadleaf trees for the diversity of saproxylic beetles in conifer-dominated forestry landscapes. Further, research and management should more closely consider contrasting responses between species with potentially differing dispersal ecologies, and at different scales.
... Deadwood is a key component of boreal forests, providing habitat for numerous species, including saproxylic (deadwood dependent, (Speight, 1989)) beetles, fungi, bryophytes and lichens (Siitonen, 2001). In many managed boreal forests, the volume of deadwood has been drastically reduced due to intensive human interventions (Jonsson et al., 2016;Linder and Östlund, 1998). To restore this habitat, deadwood enrichment, which involves adding logs and snags with various methods (e.g., sawing, ring-barking, pushing down trees with excavator) is widely employed (Doerfler et al., 2018). ...
... Efforts to restore and enrich forest ecosystems with deadwood are important tools to mitigate the adverse effects of land-use changes on saproxylic beetles. Due to the widespread shortage of deadwood in managed forests (Jonsson et al., 2016;Siitonen, 2001), generating additional deadwood can improve both the availability and diversity of habitats and food sources, leading to greater saproxylic beetle diversity (Grove, 2002;Hjältén et al., 2023;Sandström et al., 2019). Restoration initiatives vary in scale, from small-scale interventions like artificial creation of high-stumps and standing dead trees (Hämäläinen et al., 2021;Schroeder et al., 1999), larger efforts such as stand-level heterogenization and deadwood creation (Gossner et al., 2013;, to approaches that mimic natural disturbances, such as prescribed burns Saint-Germain et al., 2004;Toivanen and Kotiaho, 2010). ...
Restoration of degraded habitat is frequently used in ecological compensation, although it often faces challenges of long delivery times of features important for biodiversity, such as old large dead trees, and difficulties for target species to find and colonize restored areas. Conservation translocation of entire communities of substrates and species is a novel method used in ecological compensation and restoration, to mitigate negative effects of land-use on biodiversity. In a large-scale field experiment in boreal forests of Sweden, I tested a possible way to circumvent the uncertainty of restoration efforts; translocation of deadwood substrates from an impact area to a compensation area. My research focused on the effects of deadwood translocation on several saproxylic organism groups and habitat availability. I assessed how abundance, species richness and assemblages of beetles, bryophytes and lichens were influenced by translocation to a compensation area. By translocating different types of deadwood, the method showed potential in quickly providing habitats important for biodiversity, as well as translocating species to the compensation area. However, the outcomes vary depending on species group. Increased species richness and richer assemblages of saproxylic beetles were noted, especially in areas with high density of translocated deadwood. Sessile species responded differently with unchanged species richness for lichens and increased richness for bryophytes. However, challenges such as differing deadwood composition between impact and compensation sites, and the need for higher efforts to achieve landscape-level compensation, indicate that the method requires further refinement. These findings suggest that deadwood translocation could be a cost-efficient tool in ecological restoration, yet underscore the importance of continued evaluation to optimize methods and fully realize the benefits for biodiversity.
... One of the main structural components of forests is dead wood, serving as a habitat for approximately 7500 species in Fennoscandia (Esseen et al., 1997;Stokland et al., 2012). However, modern managed forests typically possess less than 10 % of the dead wood volume found in natural forests (Jonsson et al., 2016;Siitonen, 2001;Storaunet and Rolstad 2015). This diminished volume, coupled with a less diverse range of dead wood in terms of size and decay classes, represents a significant substrate loss (Jönsson et al., 2007;Stokland et al., 2012). ...
... Our finding that near natural stands have higher volumes of dead wood than previously clear-cut stands are in line with our third hypothesis. This result supports previous studies that managed forests are deprived of dead wood (Jonsson et al., 2016;Siitonen, 2001). The dead wood volume estimates for our previously clear-cut stands (22.1 ± 5.4 m 3 ha − 1 ) are on par with the NFI estimates of 15.5 m 3 ha − 1 from mature managed forests, considering the large variations and that the NFI data includes all site indices and regions (Storaunet and Rolstad 2015). ...
The history of forestry in Fennoscandia spans five centuries, with clear-cutting being the dominant practice since the mid-20th century. This has led to a significant transformation of the forest landscape. In this study we investigated long-term effects of clear-cutting on forest structure and dead wood volumes. We established twelve pairs of spruce forest sites in southeastern Norway, each pair constituting of a mature, previously clear-cut stand and its near-natural counterpart with similar edaphic factors. The near-natural stands had 2.8 times higher volumes of dead wood and a larger proportion of dead wood in late stages of decay. The near-natural stands had on average 36.8 ± 9.1 m 3 ha − 1 of downed dead wood and 24.1 ± 6.2 m 3 ha − 1 of standing dead wood. Corresponding numbers for the previously clear-cut stands were 10.2 ± 2.8 m 3 ha − 1 and 11.9 ± 3.7 m 3 ha − 1. Forests with lower volumes of dead wood often also had lower connectivity of old spruce forests, which potentially have further negative effects on biodiversity. Furthermore, near-natural stands displayed greater tree size heteroge-neity, resulting in a wider variation in light conditions. While no difference was observed in living tree volume, we found only weak evidence for higher basal area in the previously clear-cut stands, which had a higher stem density with more slender stems and shorter crowns. Our findings suggest that managed forests do not develop structures typical of near-natural forests before they become mature for logging. We stress the importance of a thorough site selection for studies of management effects, as forest management history may be confounded with productivity and other edaphic factors. Experimental designs like ours are vital for testing how differences in structure and deadwood volumes, driven by forest management, translate into variations in biodiversity, carbon sequestration and ecosystem functioning in future studies.
... It is possibly surprising that the groups of obligate saproxylic species evaluated showed no association with fire; one of the defining features of a fire is the dead and dying wood created. Presumably, the amounts of deadwood created by fires in today's forests are insignificant (that of a few fires, most of which are small) compared to what can be encountered at the landscape scale [64]. ...
Simple Summary
How far in space and time should conservation burns be conducted to provide most benefit to beetles favoured by forest fires? We systematically sampled forest reserves with different fire history and found that most pyrophilic beetles were found when fires in the vicinity of the reserves were close and quite recent.
Abstract
The number and area of forest fires in northern Europe have been dramatically reduced during the past century, and several fire-favoured species are now threatened. To promote the recovery of these species, prescribed burning is often used as a conservation measure, and to optimise the use of these conservation burns, knowledge is needed on suitable fire frequency, size and placement in the landscape. The aim of this study was to analyse the effect of recent fire history (12 yrs) on beetles sampled using smoke attraction traps at 21 forest sites in a 10,000 km² region. We analysed the odds of finding a fire-favoured beetle species or individual among the beetles in each trap using a new spatiotemporal connectivity measure and compared the results to non-fire-favoured and saproxylic species. For fire-favoured beetles, both the number of species and individuals significantly increased with connectivity to previous fires, while the other two groups did not. The spatiotemporal connectivity that best explained the patterns suggests that fire-favoured beetles mainly respond to fires within a 2 km range up to 2–3 years after the fire. Hence, to preserve fire-favoured insects, prescribed fires must be close in space and time to other fires—whether prescribed or natural.
... Critical factors leading to species endangerment or extinction include changes in forest habitats due to forest management activities, the reduction of old-growth forests, large trees, and the decreasing amounts of dead and decaying wood (Jonsson et al. 2016;Mönkkönen et al. 2022). The challenge of achieving sustainable forest use in Finland arises from the intensive industrial exploitation of boreal forests, primarily through systematic silvicultural practices. ...
Human disturbance compromises the ecological integrity of forests, negatively affecting associated species. Assessing the impact of forest integrity on biodiversity is complex due to the interplay of various human activities, ecological factors, and their interactions. Current large-scale indices assess forest integrity but often lack a direct connection to the biotic environment. We tested the effectiveness of the global Forest Landscape Integrity Index (FLII) in evaluating aspects of anthropogenic forest degradation on the biotic community. We analyzed the relationship between changes in the ecological integrity of Finnish forests and variations in mammal species abundance, using the number of tracks from 17 different species collected during the winter seasons between 2016 and 2020 in south-central Finland. Beyond the FLII, we analyzed forest and canopy cover to enhance the accuracy of habitat preference assessments. We found that the FLII captures the varying degrees of forest integrity, as reflected by the correlation between the abundance of winter tracks and the FLII for most mammals. Species that were positively associated with forest integrity were all native to the boreal forest, while mammals that adapt well to human-disturbed environments including two invasive species were more common in lower FLII forests. Significant differences in habitat preferences were also observed in relation to forest and canopy cover, revealing additional nuances that the FLII alone did not capture. This study demonstrates that the FLII, when combined with a comprehensive dataset and supplemented with region-specific factors, can assess species' adaptability to human-modified forests, aiding in the development of conservation strategies.
