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Historically used pesticides poses a threat to biodiversity while their release pathways remain unclear. Trees could be a potential release source due to their long lifespan. This study examined 38 samples to assess pesticide concentrations in pedunculate oak from Belgium. Low concentrations of procymidone were detected in two samples from one stump. Our findings suggest that accumulations of historically used pesticides in pedunculate oaks within forests are improbable. We conclude that leaving dead wood poses no risks for pesticide release to the environment. However, further research involving diverse tree species and regions is needed to refine and validate this conclusion. [ABSTRACT FROM AUTHOR]

Deadwood (DW) is a crucial component of habitats, with both its volume and diversity considered critical for saproxylic organisms. Deadwood position, thickness, snag height, species composition, and decay stage were studied in the context of eight factors characterizing habitats, stands, and management types. A multivariate multiple regression model was used to analyze data from 29,098 sample plots.Deadwood diversity (a 5-dimensional dependent variable) was found to strongly depend on DW volume in a given area and on the species composition of the stand. A less pronounced effect was exerted by site fertility and moisture, the age and DBH structure of the stand, and terrain type. The model also revealed that the location of the stand in managed or unmanaged areas did not have a direct impact on deadwood diversity, with stand features being more important.Analysis of individual qualitative characteristics showed that DW thickness was affected by the same seven factors as DW diversity. DW position and decay stage were influenced by four factors: site fertility and moisture as well as stand age and species composition. In addition to the species composition of stands, DW species composition was positively influenced by more fertile and moist sites and a more varied DBH structure of stands. A significant negative effect was identified for high DW volume, which indicates that the deadwood accumulated in a stand tends to be derived from the tree species that was most vulnerable to mortality at a given time. Snag height variation was influenced by such stand characteristics as age, DBH structure, and species composition; the other significant factors were DW volume and terrain type. The diversity levels of individual DW characteristics were significantly and positively correlated, which means that all of them often revealed high or low diversity at the same time.Our study showed that forests with low DW volume additionally face the problem of DW quality. Thus, efforts to increase DW volume should be focused on those DW characteristics that are lacking (large trees, species diversity, and height variation of snags). DW diversity is lower in younger stands, with little DBH variation, and in forests which are more easily accessible, located mostly in the lowlands, and growing on less fertile and dry or mesic sites.

Aim: European temperate forests have lost dead wood and the associated biodiversity owing to intensive management over centuries. Nowadays, some of these forests are being restored by enrichment with dead wood, but mostly only at stand scales. Here, we investigated effects of a seminal dead‐wood enrichment strategy on saproxylic organisms at the landscape scale. Location: Temperate European beech forest in southern Germany. Methods: In a before–after control–impact design, we compared assemblages and gamma diversities of saproxylic organisms in strictly protected old‐growth forest areas (reserves) and historically moderately and intensively managed forest areas before and a decade after starting a landscape‐wide strategy of dead‐wood enrichment. Results: Before enrichment with dead wood, the gamma diversity of saproxylic organisms in historically intensively managed forest stands was significantly lower than in reserves and historically moderately managed forest stands; this difference disappeared after 10 years of dead‐wood enrichment. The species composition of beetles in forest stands of the three historical management intensities differed before the enrichment strategy, but a decade thereafter, the species compositions of previously intensively logged and forest reserve plots were similar. However, the differences in fungal species composition between historical management categories before and after 10 years of enrichment persisted. Main conclusions: Our results demonstrate that intentional enrichment of dead wood at the landscape scale is a powerful tool for rapidly restoring saproxylic beetle communities and for restoring wood‐inhabiting fungal communities, which need longer than a decade for complete restoration. We propose that a strategy of area‐wide active restoration combined with some permanent strict refuges is a promising means of promoting the biodiversity of age‐long intensively managed Central European beech forests. [ABSTRACT FROM AUTHOR]

Saproxylic species from different taxonomic groups often occur only on certain types of deadwood with specific qualitative characteristics. The various types of deadwood are very dynamic elements of forest ecosystems, associated with many site and stand features, as well as with the type of forest management. Using a pool of 29,098 sample plots spread across Poland, we analyzed 30 different deadwood types defined on the basis of three characteristics: position (standing, lying), degree of decomposition, and size. Statistical hurdle models were used to assess changes in the volume of individual deadwood types based on a broad range of independent variables. Depending on the type of management, terrain, site fertility, stand volume, tree density, and stand age, the models revealed substantial differences in the volume of different deadwood types, ranging from 0 to approx. 4 m3 ha−1. It was found that the volume of most deadwood types (except for a few, mostly with diameters under 15 cm) increases with stand age or stand volume. In managed forests at all stages of stand development there is a deficiency of thick deadwood. Both standing and lying deadwood at different decay stages is available continuously, irrespective of the values of individual independent variables, but considerable differences exist. While most lying deadwood exhibits higher levels of decomposition, in standing deadwood the proportions of different decay stages are strongly associated with tree diameter at breast height. The developed models make it possible to predict the volume of individual deadwood types for a broad range of independent variables. The current work presents several examples, with the results showing extremely complex relationships between deadwood diversity and site and stand features at every stage of forest development, with continuous changes in the volume and proportions of different deadwood types. In general, at the landscape level Polish forests contain both standing and lying deadwood at all decay stages in more or less equal proportions. However, in forest management one should pay special attention to the dimensions of retained deadwood. The absence of thick deadwood is particularly conspicuous in lowland managed forests. • The total deadwood volume consists of many deadwood types with very different characteristics. • Statistical models based on stand features describe the diversity of dead wood with high accuracy. • The diversity of the deadwood changes with the age of the stand, the method of management and habitat conditions. • Some types of deadwood are not found in all forests, especially thick deadwood is completely removed. • Management of deadwood resources should be largely based on its diversity. [ABSTRACT FROM AUTHOR]

The cavities that develop in veteran trees represent a key microhabitat for forest biodiversity and especially for secondary cavity nesters that rely on this resource for shelter. Since the availability of deadwood, veteran and hollow trees is threatened by forest management, we explored the possibility of increasing the presence of these scarce resources. To increase the abundance of dead wood-microhabitats, 113 trees of the hybrid planes (Platanus x acerifolia) were converted into new living structures, the Habitat Trees (HT). To investigate the potential of this resource on the native avian fauna, six types of cavities were designed according to the size requirements of the target bird species. The temporal evolution of the cavities and their use by birds were then studied for eight years. The artificial cavities generally did not compromise growth and stability of the trees, and the majority remained alive. These hollows offered better thermal insulation compared to traditional nest-boxes and natural cavities. Their use increased during the first three years, reaching the 80%. In the following years, the use declined (probably because of the increase of rot and displacement of the lids).This highlights the need of management to maintain their suitability through time. Our results suggest a possible cost-effective alternative use of alien tree species, which should be included in management actions to compensate the shortage of hollow trees in managed forests.

We assessed how environmental drivers influence the occurrences of wood-inhabiting macrofungi in European beech forests, using an extensive dataset of fruit body records collected in 53 reserves across twelve European countries. We found that the 105 species included in this study varied greatly in their responses to covariates related to resource quality, climate and forest connectivity, both in the strength and direction of the observed effects. Climate was the most important driver for some species, while others responded more to connectivity, or simply to the presence of high quality substrates within the reserves. Species occurrences varied also across geographical regions, especially between the UK and the rest of Europe. Our results show that wood-inhabiting fungi in European beech forests respond individualistically to habitat filters and differ in their biogeographical distribution patterns, and they thus provide a detailed perspective of how wood-inhabiting fungal communities are structured across Europe. [ABSTRACT FROM AUTHOR]

Introduced plants are often identified as the major conservation concern worldwide, however, they also may offer conservation benefits, among others, provide habitat and/or food resources to protected animals. Here we aimed to assess the ability of the great Capricorn beetle Cerambyx cerdo, a highly specialised species associated with mature oaks, to use non-native red oak Quercus rubra as a host plant. To test which factors influenced oak colonisation, we surveyed native and non-native oaks in 'Nowosolska Dolina Odry', a site within the 'Natura 2000' network (Western Poland). The beetle was detected in 34 native oaks (10.9% of examined trees), demonstrating clear preferences for trees in a more open environment. Comparison of observed numbers of occupied oaks and values expected from their random colonisation showed that C. cerdo avoided non-native red oaks. Logistic regression revealed that variables with the greatest predictive importance for C. cerdo occurrence were canopy extent around the tree and trunk diameter, followed by an autocovariate (distance-weighted number of occupied trees in the neighbourhood of the target tree). Oak species was a poor predictor of tree occupancy, however, it added considerably to the predictive capability of the models when combined with the remaining variables. We argue that physicochemical properties of the wood and/or phloem and structure of the cortex may also influence colonisation of trees. Our results do not provide arguments for the introduction of non-native oaks to benefit C. cerdo. Instead, we recommend maintaining semi-open conditions around host trees and high density of old oaks in the landscape. [ABSTRACT FROM AUTHOR]

Dead wood is crucial for forest biodiversity. Previous analyses support a positive relationship between dead wood volume and biodiversity, but the strength and direction of the correlation may differ across biomes, forests, dead wood traits, and among taxa and functional groups. Therefore, an up-to-date quantitative synthesis of general patterns and global trends of correlations between dead wood and the biodiversity of common and rare species is needed. Here we present the findings of a global meta-analysis that synthesized 213 correlations from 40 studies using random effects models. The correlations between dead wood volume and all species and rare species were significantly positive and moderate, however, there were noticeable differences between taxa. The summary effects by bioclimatic regions, forest types, stands and management regimes were generally positive and moderate with no statistically significant differences, suggesting a consistent positive effect of dead wood volume on biodiversity. Dead wood types and decay stages have statistically significant differences in correlations regardless of species' rarity status, where the volume of logs and the intermediate decay stage have the strongest correlations with biodiversity. Our results support the idea that dead wood volume can largely be considered an indicator of forest biodiversity, however, dead wood quality attributes are critically important, and hence, should be given priority in forest management and biodiversity conservation interventions. More research is needed in the (sub-)tropics and concerning the relationships between dead wood and rare, threatened, and red-listed species. • Meta-analysis incorporated correlations between dead wood volume and biodiversity from 40 studies conducted in 22 countries. • Effect modifiers included different biomes, forest types, management regimes, dead wood traits, and taxa and functional groups. • The biodiversity of all species combined and rare species had significantly positive correlations with the dead wood amount. • Variations in effects were not apparent among bioclimatic regions, forest types, stands, and management regimes. • Correlations varied among dead wood types and decay stages, implying that dead wood quality attributes are critically important for biodiversity. [ABSTRACT FROM AUTHOR]

Highlights: [•] Most taxa preferred more open and light conditions of the woodland environment. [•] Landscape structures explained more than 10% of the independent variance. [•] Openness in the management of oak woodlands is one solution against biodiversity loss. [ABSTRACT FROM AUTHOR]

Recent interest in using forest residues and small-diameter material for biofuels is generating a renewed focus on harvesting impacts and forest sustainability. The rich legacy of research from whole-tree harvesting studies can be examined in light of this interest. Although this research largely focused on consequences for forest productivity, in particular carbon and nutrient pools, it also has relevance for examining potential consequence for biodiversity and aquatic ecosystems. This review is framed within a context of contrasting ecosystem impacts from whole-tree harvesting because it represents a high level of biomass removal. Although whole-tree harvesting does not fully use the nonmerchantable biomass available, it indicates the likely direction and magnitude of impacts that can occur through energy-wood harvesting compared with less-intensive conventional harvesting and to dynamics associated with various natural disturbances. The intent of this comparison is to gauge the degree of departure of energy-wood harvesting from less intensive conventional harvesting. The review of the literature found a gradient of increasing departure in residual structural conditions that remained in the forest when conventional and whole-tree harvesting was compared with stand-replacing natural disturbance. Important stand- and landscape-level processes were related to these structural conditions. The consequence of this departure may be especially potent because future energy-wood harvests may more completely use a greater range of forest biomass at potentially shortened rotations, creating a great need for research that explores the largely unknown scale of disturbance that may apply to our forest ecosystems. [ABSTRACT FROM AUTHOR]

Many species require or use down wood (fine and coarse woody debris) as habitat. Where forestry has been practiced for several rotations large proportions of these species are considered threatened. Key attributes determining the suitability of down wood as habitat are decay stage, tree species, and size, specifically diameter. Both quantity and distribution of suitable down wood influence species' presence and abundance. We present a simple framework describing use of down wood based on broad natural history features, derive predictions from the framework, then test these by review and summary of literature. Our focus is terrestrial vertebrates, particularly in the Pacific Northwest. Species other than vertebrates are addressed to ensure that metrics derived for vertebrates also are appropriate for other organisms. Basic metrics are the same, but appropriate values span a larger range among nonvertebrates. Current evidence suggests that the 'extinction debt' apparent for nonvertebrates is approaching for vertebrates. Predictions derived from underlying natural history hold when tested. From that basis we derive broad guidelines for forest planning and practice, and suggest how regional target values can be derived. [ABSTRACT FROM AUTHOR]

• Dead black spruce boles were placed in forest stands along a latitudinal gradient. • The boles were colonized by at least 74 springtail species. • Springtail latitudinal diversity gradient was mostly driven by climate. • Dead wood retention in managed forests likely contributes to springtail diversity. Understanding the importance of dead wood-associated biodiversity and related ecological functions has become increasingly important in forest ecosystem management. Yet, studies on dead wood diversity frequently focus on conspicuous organisms such as birds or saproxylic beetles, and are rarely deployed across significant climatic gradients. Here, we investigated the potential role of deadwood as a habitat for springtails, an understudied group of invertebrates generally associated with soils, and tested how these communities were influenced by climate. Black spruce logs were placed in 13 natural forest sites which were distributed among 3 latitudinal zones (southern, central and northern Quebec, Canada). We compared the springtail communities that colonized the logs through different metrics: abundance, richness and species composition. Our results indicated that dead wood was used as a habitat by 74 springtail species. A clear latitudinal diversity gradient was observed, with southern communities being on average two times richer and over 13 times more abundant than the northern ones per log. Moreover, distinct community compositions were observed in the three zones. Overall, our results suggest that (1) dead wood retention could be beneficial for small invertebrates such as springtails and (2) such biodiversity conservation measures would be more efficient if done systematically along large geographic gradients encompassing different biomes, particularly in the context of climate change. [ABSTRACT FROM AUTHOR]

• Coarse woody debris (CWD) was surveyed in urban green spaces. • Dead tree branches were the most prevalent form of CWD. • CWD was the most prevalent in forest remnants, followed by private gardens and parks. • The occurrence of CWD was negatively correlated with property prices. • Sustainable management of CWD should be included in urban planning. Dead wood provides important ecosystem services and has a positive effect on biodiversity. However, urban environments have limited resources of coarse woody debris (CWD). The presence of CWD depends on both progressive tree mortality and the frequency and intensity of CWD removal for safety or aesthetic reasons, which can lead to variations in CWD occurrence. The aim of this study was to assess the variation in the quantity and quality of CWD in urban green spaces and to assess the relationship between CWD resources and management policy, ownership, economic parameters and factors accelerating tree mortality. Fallen logs, dead standing trees and dead tree branches (DTB) were surveyed on 488 sample plots selected at random in the city of Kraków (Poland). Distance to the river, coverage of impervious surfaces, environmental pollution, property prices and types of green space were used to explain the variation in CWD resources. CWD occurred on 46% of the sample plots. DTB were the most frequent form of CWD (44% of plots), while dead standing trees were rare (4%) and fallen logs absent. The prevalence of CWD was the highest in forest remnants, followed by private gardens, urban parks, fallow land and small green patches. DTB were the most abundant in the forest remnants. In both forest remnants and private gardens, the probability of CWD occurrence decreased with increasing property prices. Management policy and economy rather than factors accelerating tree mortality are suggested as shaping CWD resources in urban green spaces. The article highlights the importance of DTB as the most widespread form of CWD and forest remnants as the type of green space having the most abundant resources of CWD. Sustainable management of CWD resources within urban green spaces and environmental education are needed to conserve biodiversity and maintain ecosystem services. [ABSTRACT FROM AUTHOR]