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Urban forests are threatened by land cover change and invasive species but little is known about how they are changing over time. Furthermore, although management is sometimes used to maintain native communities, we have little information about the long-term outcomes of forest management actions. In this study, we examined current status and long-term changes in 35 urban forest plots in DuPage County, Illinois (USA). From 1979 to 2014, in five-year intervals, presence/absence of all woody species was recorded in the plots. Environmental conditions in and surrounding the plots were measured in the field or with GIS. With these data, we analyzed trends and changes in the community, looked for evidence of biotic homogenization, and examined drivers of non-native species. We found a significant change in community composition over time but no evidence of biotic homogenization in either managed or unmanaged plots. There was a significant increase in non-native species richness over time but no change in richness of other species groups. Vegetation management such as fire prescription and clearing seemed to somewhat decrease the number of non-native species, but did not increase the number of more desirable species. Distance to agriculture and deer control frequency determined the variation in both non-native species abundance and richness. Overall, we conclude that the management activities were able to slow down the spread of some undesirable species but did not prevent their increase over time. More consistent management, as well as collaboration with stakeholders outside the forest preserves, is likely needed to maintain native communities.

One long-standing, unresolved issue in forest management is how to achieve high levels of biodiversity conservation and commercial forestry for timber production. Retaining fallen logs on the forest floor is effective in preserving the habitats essential for many wood-dwelling organisms. However, the contributions of fallen logs toward the plant species diversity of forest understories are less clear, even though the importance of fallen logs on the emergence and survival of coniferous seedlings and saplings is well known, especially in boreal forests. This study aimed to clarify the roles of fallen logs in the maintenance of species diversity of understory vascular plants in forests. We investigated species richness and the composition of vascular plants on 319 fallen logs and in 128 forest-floor quadrats (2 × 2 m) in a 4-ha plot in a mixed coniferous and broad-leaved forest in Hokkaido, northern Japan. We also measured canopy openness in summer, surface area, wood resistance, and moss cover of fallen logs, and soil thickness in forest-floor quadrats. Additive partitioning and permutational multivariate analysis of variance (PERMANOVA) were used to examine differences in composition between quadrats and fallen logs. Generalized linear model (GLM) and canonical correspondence analysis (CCA) were also applied to test the determinants of species richness and composition in quadrats and fallen logs. In total, 83 vascular plant species were identified. For woody and herbaceous plants, several species occurred predominantly on fallen logs in comparison with quadrats. Species richness of woody plants on fallen logs was positively affected by surface area and moss cover, and negatively by wood resistance; although in quadrats it was not significantly associated with any environmental factors. Herbaceous species richness on fallen logs was also negatively influenced by wood resistance. In contrast, herbaceous species richness in quadrats was positively associated with canopy openness. These results suggest that fallen logs promote plant species diversity, including herbaceous plants, by creating habitat conditions favored in forest understory environments. This study implies that leaving fallen logs on the forest floor at logging sites contributes toward plant diversity conservation.

Wind is a natural disturbance factor in boreal and temperate forests having large ecological and economic consequences. We investigated recovery processes in forests severely damaged by windthrow, by conducting a systematic quantitative literature review of 34 case studies. We addressed three questions on forest ecosystem recovery: (1) Which forest regeneration processes dominate forest recovery after windthrow? (2) Which structures and processes enhance or impede forest recovery after windthrow? (3) Does salvage logging after windthrow influence forest recovery? Our analyses showed that the main focus of the reviewed studies was on post storm seedling regeneration and survival. Advanced regeneration from suppressed seedlings or saplings also played an important role in the studies, especially for shade tolerant species and in the boreal biome. Pits and mounds and coarse woody debris played an important role for the establishment of Picea sp., especially in the studies from the boreal biome, whereas in the temperate biome game interference and competition from ground vegetation seemed to be the most important influencing processes. Salvage logging mostly acted as a subsequent disturbance after the windthrow, pushing the forest ecosystem towards an earlier successional stage, hereby impeding recovery. In none of the studies however, did the windthrow nor the consequent salvaging halt recovery completely, confirming the resilience of forests as the dominant vegetation type in these biomes. Based on our results forest management implications are discussed.

Wildlife conservation in multi-use landscapes requires identifying and conserving critical resources that may otherwise be destroyed or degraded by human activity. Summer day-roost sites are critical resources for bats, so conserving roost sites is thus a focus of many bat conservation plans. Studies quantifying day-roost characteristics typically focus on female bats due to their relative importance for reproduction, but large areas of species’ ranges can be occupied predominantly by male bats due to sexual segregation. We used VHF telemetry to identify and characterize summer day-roost selection by male northern long-eared bats (Myotis septentrionalis) in a ponderosa pine (Pinus ponderosa) forest in South Dakota, USA. We tracked 18 bats to 43 tree roosts and used an information theoretic approach to determine the relative importance of tree- and plot-level characteristics on roost site selection. Bats selected roost trees that were larger in diameter, more decayed, and under denser canopy than other trees available on the landscape. Much like studies of female northern long-eared bats have shown, protecting large-diameter snags within intact forest is important for the conservation of male northern longeared bats. Unlike female-specific studies, however, many roosts in our study (39.5%) were located in short (≤ 3 m) snags. Protecting short snags may be a low-risk, high-reward strategy for conservation of resources important to male northern long-eared bats. Other tree-roosting bat species in fire-prone forests are likely to benefit from forest management practices that promote these tree characteristics, particularly in high-elevation areas where populations largely consist of males.

Prescribed burning has become more common for the management of eastern forests in North America, so understanding if and how foraging bats respond to structural changes generated by fire is of increasing importance. Our objective was to investigate the effects of post-fire landscape conditions on the occurrence of foraging bats in mixed forests of the Cumberland Plateau physiographic region. We deployed Anabat II bat detectors in 164 paired burned and unburned forest sites for ≥2 nights from mid-May through August 2014 and 2015 to monitor bat foraging and commuting habitat use. We conducted vegetation surveys to quantify site-specific structural characteristics, which indicated that measures of structure were significantly lower in burned sites than unburned sites. We used Program Presence to test a priori hypotheses of species-specific probability of detection and site occupancy related to weather, burn history (i.e., site burned within the past 10 years or unburned), and site and landscape characteristics. Bats were detected at 94% of burned sites and 83% of unburned sites. Probability of detection was affected by weather conditions, vegetative structure, and burn history for most species. Occupancy for all species/species groups examined was positively associated with burning and generally associated with lower vegetative structure. Although burn severity did not affect most species groups, occupancy of Myotis species and tri-colored bats (Perimyotis subflavus) was lower in sites that received moderate severity burns than in sites that received low severity burns. Therefore, while prescribed fire may provide vegetative structure conducive to efficient foraging for all bats of the Cumberland Plateau, our results demonstrate that retaining some unburned forests while creating mosaics of lower and higher severity burns across the landscape will result in favorable foraging conditions for all resident bat species.

Many tree species worldwide are suffering from slow or failed natural regeneration with dramatic consequences for biodiversity and ecosystem services. However, it is difficult to disentangle the complex effects of factors influencing regeneration processes on long-lived tree species at large scales. In this study, we use long-term data from the Swedish National Forest Inventory (1953–2015) combined with deer hunting data (1960–2015) to reveal experimentally-intractable processes impeding oak (Quercus spp.) regeneration in southern Sweden. Oak-dominated ecosystems are widespread in northern temperate regions, where oaks are foundation species with disproportionate importance for biodiversity and ecosystem functions. Our study reveals that during the last six decades, oak tree numbers and standing volume have continuously increased, while natural regeneration of oak declined steeply after the early 1980s. We connect this decline to denser and darker forests, combined with increased abundance of deer. Land use changes during the six decades, such as abandonment of traditional practices and large-scale introduction of forest management oriented towards high volume production, led to continuously denser forests and thereby reduced the oak regeneration niche. In addition, the impact of changed game management was evident. This was particularly clear from a natural experiment on Gotland, a large island free of deer until roe deer were introduced in the late 20th century, at which point oak regeneration began a steep decline. At the stand level, natural oak regeneration could be expected to mainly occur in pulses after disturbance events, followed by a period of low regeneration success as the cohort ages. However, at a landscape scale one would expect a mix of successional stages that would even out such demographic patterns. A prolonged period of low regeneration at a landscape scale will eventually lead to a large gap in the oak size distribution as was observed in this study. This could eventually hurt the many species dependent on old and large oak trees. Active management to restore the oak regeneration niche, i.e. forest habitats with more light and less browsing pressure, therefore seems essential. The latter includes developing strategies that manage both deer populations and their available food across landscapes. Our study is the first to link oak regeneration failure to long-term changes in land use and increased deer populations at a landscape scale in this region. Furthermore, our study show how historical data can clarify confounded processes impacting long-lived forest species.

From a forest management stand point, it is crucial to know which ecological processes are most likely to drive changes in tree species distributions and abundance under warming climate conditions. In this study, we simulated forest dynamics in a 703,580 km2 territory that straddles the boreal and temperate broadleaved forest biomes in the province of Quebec (Canada), under a RCP 8.5 climate change scenario. The objective was to evaluate how future forest composition is sensitive to variation in four potential drivers: fire regimes, harvesting regimes, the capacity of tree species to persist under warmer climate conditions, and species capabilities for long-distance colonization. The results indicate that forest composition in 2100 is most sensitive to variation in the parameters controlling species persistence when conditions become warmer or dryer than the conditions found in their current range. Concretely, this points to avenues of research to improve the accuracy of our predictions regarding the impacts of climate change on forest composition. For instance, we should further investigate the underlying ecological (competition) or physiological (drought stresses) processes that influence tree species persistence at the receding edge of their current distributions.

To better understand natural regeneration of trees and forest dynamics it is important to gain insight into the drivers of invertebrate herbivory. In mature forests, associational resistance of trees resulting from a high diversity of neighbouring trees is common, and can have cascading effects on tree growth through resource concentration effects or through changes in top-down control. While the underlying biological processes are known to be influenced by the forest’s spatial properties, we lack insights on how resource concentration, top-down control and fragmentation jointly affect sapling performance in fragmented landscapes. We therefore experimentally quantified effects of the proportion of conspecific trees in the overstorey (resource concentration), avian top-down control (natural enemies) and distance to the forest edge on invertebrate herbivory levels and sapling growth. The assessments were made on planted saplings of Fagus sylvatica, Quercus robur and Quercus rubra in 53 experimental plots and birds were excluded by means of exclosures from a subset of these saplings. Excluding avian top-down control increased herbivory on each tree species. Increased herbivory led to decreased sapling growth in F. sylvatica and Q. rubra. On Q. robur saplings, top-down control was stronger closer to the forest edge. Furthermore, in this species, herbivory inside the exclosures increased with an increasing proportion of conspecific trees in the overstorey, while such a resource concentration effect was not observed outside the exclosures. Our results show the importance for forest management of conserving insectivorous birds and promoting a mixed overstorey, which can decrease sapling herbivory when bird abundance is low. More generally, our study provides insight into the complex, multitrophic interactions that drive sapling growth in forest stands located within fragmented landscapes.

Central European temperate oak woodlands are highly valued for their rich biodiversity. They are also of great economic importance and forest management aims to produce high quality timber, which demands high investments. The aim of this literature review is to identify management options for forestry and nature conservation that sustain both the ecological value of oak forests and the economic viability of oak silviculture. We addressed three main questions: (a) Oaks and close-to-nature forestry – what are the key silvicultural challenges and options?, (b) What is the particular significance of ecological continuity and which structural features are of importance for biodiversity conservation in oak forests?, (c) What are the key elements and possible strategies of forest management that sustain the ecological values in oak forests in combination with viable forestry? Light availability appeared to be a conspicuous link connecting the conservation and the silvicultural aspects of multifunctional oak forest management: Both young oak trees and multiple oak woodland specialist species are characterized by their need for increased sunlight exposure. This common denominator provides a sound basis for integrative management practices for forestry and nature conservation. The concept of retention forestry offers purposeful approaches. So the harvest of valuable timber oaks or the creation of canopy gaps for oak regeneration can be used to release the crowns and trunks of habitat oaks from shading and competition. When looking at the management of oak woodland biodiversity hotspots, the re-establishment of (modified) historical forest management techniques, which increase stand openness and create transitional habitats that provide suitable oak regeneration niches, seems to be necessary. Not only the continuity of oak woodland cover and natural site conditions, but also the uninterrupted temporal continuity and availability of wood-related structural features turned out to be of particular importance for oak woodland specialist species. We identified an urgent need for systematic forest planning approaches that secure the long-term availability of these structural features within areas or “sustainability units” that are large enough to maintain viable populations of oak woodland specialist species. In particular, conservation-oriented forestry measures should mainly be implemented in those areas, where the greatest effectiveness is to be expected. In the sustainability units, oak regeneration measures ought to take place either in close vicinity to old oak stands or directly in these stands. The choice of one of these options should be based on a careful consideration of the needs and possibilities of both silvicultural and nature conservation management.

Connecting forest management with the conservation of forest-associated animals requires an understanding of habitat quality, as well as identifying long-term silvicultural strategies that align with high quality habitat. It is, therefore, essential to characterize the spatio-temporal dimensions of habitat quality. Here, we leveraged multiple datasets to assess high quality habitat for female Canada lynx (Lynx canadensis), a federally threatened forest carnivore in the contiguous U.S. Our datasets included a spatially extensive sample of snowshoe hares (Lepus americanus) collected in 2013 (n = 1340 plots), an expansive time-series (i.e., 1972–2013) of forest structural classes derived from remote sensing, and a longitudinal dataset where we monitored habitat use and the reproductive success (i.e., litter of kittens present or absent) of female Canada lynx during 1999–2013 (n = 32 female lynx over 92 lynx years). Our results indicated that the probability of a female producing kittens was most associated with the connectivity of mature, multistoried forests (composed of mostly spruce-fir). However, the variation among female lynx accounted for ≈62% of the total variation explained in litter production, suggesting substantial individual-level variation. Thus, managers can contribute to increased reproductive success of female Canada lynx by facilitating the development of mature forests, but measuring that success will be difficult given the individual variation. In core areas of high quality females (i.e., produced kittens frequently), mature forest was 17% more abundant (i.e., ≈60% of the total core area), more connected, less clumpy, and exhibited 2.25-times larger patch sizes than the core areas of low quality females. At the home-range extent, patterns were less pronounced while the abundance of mature forests remained high (≈50%) for high quality females. Additionally, we demonstrated that the relative density of snowshoe hares was ≥2.8 times higher in advanced regenerating forests compared to all other structural classes, including mature forest. Advanced regenerating forests accounted for ≈18–19% of the core area and home range of high quality female lynx. Combined, our results suggest that a high quality mosaic for female Canada lynx contains ≈50–60% mature forest and ≈18–19% advanced regenerating forest. Furthermore, we used Forest Inventory and Analysis data to characterize the approximate age distribution of advanced regeneration and mature forest, which was relevant for rotation schedules of forest silviculture. Results indicated that advanced regeneration was ≈20 to 80 years old while mature forest was ≈50 to ≥200 years old. Our results provide novel insight into how forest management could increase habitat quality for female Canada lynx, and suggest that multiple silvicultural methods (e.g., intermediate treatments, regeneration harvests) could be employed to maintain a forest mosaic that enhances the ability of females to produce kittens. We concluded by providing a framework that integrates our new insights into a management context with the aim of conserving Canada lynx on multiple-use lands.

Land-use intensification has been shown to negatively affect biodiversity and ecosystem functioning. Because higher trophic levels are expected to suffer most strongly from intensification, negative consequences for ecosystem services, such as biological pest control by natural enemies, are likely. In European beech forests ambrosia beetles are common secondary pests of freshly cut wood and stored timber, but they may also infest living trees that are highly stressed. We examined whether forest management intensity, ranging from unmanaged beech forests to non-natural conifer plantations, affects the abundance, attack rate, and breeding success of ambrosia beetles across three regions of Germany. We applied pheromone trapping to estimate the abundance of ambrosia beetles and exposed experimental beech logs to measure infestation rates and breeding success. In general, we found decreasing abundance and attack probability by ambrosia beetles with increasing management intensity, which is most likely related to the availability of suitable breeding substrate. However, the abundance of the invasive species Xylosandrus germanus increased with increasing management intensity in one region, where high management intensity was represented by pine forests; the drier and warmer conditions in this forest type most likely increased population densities. Breeding success of Trypodendron domesticum increased with increasing management intensity, suggesting less effective pest control by natural antagonists, in particular by specialised parasitoids, at high management intensities. We conclude that the availability of breeding substrate, in combination with microclimate and antagonist effectiveness, shape ambrosia beetle populations in Central European forests. Forest management strategies should thus reduce the availability of breeding substrate in production forests, in particular where microclimatic conditions are favourable for beetle reproduction (i.e. warm, moist). Moreover, unmanaged forest patches should be maintained to promote parasitoid abundance and thus to mitigate negative effects of climate change, such as increasing drought stress of trees.

Insights into the underlying ecological mechanisms for diversity-biomass relationships across forest strata (i.e., overstorey and understorey) are crucial to understand the importance of vertical stratification on ecosystem function in natural forests. Yet, it remains unclear how multiple abiotic (i.e., soil nutrients) and biotic (i.e., biodiversity, functional identity and stand structural complexity) factors simultaneously determine aboveground biomass in each individual forest stratum and whole-community. To address this knowledge gap, we disentangled the relative effects of soil nutrients (soil fertility hypothesis), taxonomic, functional trait and evolutionary diversity (niche complementarity hypothesis), stand structural complexity (niche differentiation hypothesis based on tree sizes), and community-weighted mean trait values (mass ratio hypothesis) on aboveground biomass across forest strata and whole-community. We used forest inventory, functional traits and environmental factors datasets from 125 subtropical forest plots in Eastern China. Multiple linear regression models were performed for the selection of best predictors within each biotic group, and structural equation modelling was used to evaluating how multiple abiotic and biotic drivers determine aboveground biomass. In the overstorey, aboveground biomass was positively related to the community-weighted mean of tree height (i.e., functional dominance) and stand density but was negatively related to functional evenness on nutrient-rich soils. In the understorey, aboveground biomass was positively related to phylogenetic species richness and stand-level tree mean diameter (i.e., a proxy for forest growth) but was negatively related to Shannon’s species diversity on nutrient-poor soils. Understorey aboveground biomass was also determined by overstorey stand structure and functional dominance through direct and indirect effects via understorey biotic drivers. These results suggest that functional dominance and stand structural complexity are the main biotic drivers of overstorey aboveground biomass. Whereas, functional dominance and stand structural complexity of overstorey, soil nutrients, and niche complementarity among understorey species with the conservative strategy determine understorey aboveground biomass. Whole-community aboveground biomass might be resulting from the superior role of overstorey functional dominance. This study highlights that the niche complementarity, mass ratio and soil nutrients effects are important for driving aboveground biomass, but in different ways across overstorey and understorey strata in natural subtropical forests. We argue that the relative effect of biodiversity loss on aboveground biomass depends critically on the functional and evolutionary identity of the lost species in the specific forest stratum. Better insights can be gained into forest management and biodiversity conservation by considering overstorey and understorey strata separately in complex natural forests.

Species rarity is often an important driver of conservation priorities in lieu of greater knowledge of extinction risk. Land management agencies often prioritize management based in part on the commonness of a species, yet identifying what constitutes where a species lies on the commonness-rarity continuum is difficult. Given limited resources, incorrect classification may have detrimental effects on species conservation. In a large area of the Northwest Forest Plan, which guides management of 9.1 million ha of federal forests in the Pacific Northwest, USA, forest management is closely tied to mitigation for the red tree vole (Arborimus longicaudus), a species considered uncommon due in part to its association with older forests. I explore the ability to provide insight into where a species lies along the commonness-rarity continuum by a multi-species comparison. I compared the relative distribution, abundance, and extrinsic conservation threats of red tree voles to western red-backed voles (Myodes californicus), a similar species considered common. Both species occur in younger forests with legacy components of older forests, but reach their greatest densities within older forests. Densities of the two vole species were qualitatively similar. If assignment of a species along a commonness-rarity continuum is a goal of species surveys, their value may be enhanced by including in the survey a set of similar species whose level of rarity is better understood. Although management of the red-tree vole was intended to be guided by adaptive management, challenging policy and legal issues have made that difficult; rarity as a criterion for prioritizing management is partly responsible.

European forest management practices create broad-scale mosaics of tree-species composition and developmental stages, inducing gradients in environmental conditions at landscape scales. However, consistent effects of specific forest-management types on general characteristics of soil microarthropod assemblages could not always be determined. This study aimed to reveal generalizable effects of similar forest-conversion measures using collembolan data extracted from the German soil-zoological data warehouse “Edaphobase”. Data of collembolan assemblages and environmental variables from forest-conversion studies were analyzed from three forest types – deciduous, coniferous and mixed forests – in two German regions (a northern and a southern) with various sites in two areas each. We hypothesized that forest management has a strong effect on soil Collembola and the different forest types induce consistently dissimilar assemblages independent of region. Abundance, diversity and species richness of collembolan assemblages were compared between forest types. Community composition was analysed with cluster analysis and canonical ordinations to reveal similarity patterns and the driving environmental variables. Contrary to our hypothesis, forest conversion caused only small differences in quantitative community variables, most likely due to site-specific influences and high variability. More than a third of the considered species showed preferences for stands with either deciduous or coniferous trees. The collembolan assemblages of the two regions differed from each other, indicating separate species pools. Nonetheless, as opposed to the quantitative metrics, different species compositions did consistently occur between forest types across regions, revealing a gradient from deciduous over mixed to coniferous stands. Collembolan assemblages were primarily associated with dominant tree species (forest stands) and humus forms, while quantitative environmental parameters had low explanatory power. Therefore, forestry measures induce qualitative differences in the soil-habitat, leading to habitat-specific environmental filtering of the regional collembolan species pools and a mosaic of soil microarthropod communities at the landscape level.

Recently, many studies have found positive biodiversity–productivity relationships in forests. In contrast, different types of correlations have been identified in the analyses of tree diversity–structure–productivity relationships. We suspect that these conflicting conclusions might result from the different developmental stages of the investigated forest stands. We therefore analyzed the development of tree diversity–structure–productivity relationships at the stand level and individual tree level in 192 long-term experimental plots in Central Europe. As a measure of stand productivity, we analyzed stand volume growth (m3 ha−1 year−1). Tree species diversity was quantified by the Shannon index and structural heterogeneity was represented by the Gini coefficient of basal area. For a more detailed analysis at the tree level using a smaller portion of the dataset, the tree position–dependent indices, diameter differentiation index, and aggregation index were used. Whether the effect of structural heterogeneity on stand productivity was positive or negative depended on the stand development stage. In early developmental stages, high structural heterogeneity lowered productivity. In later developmental stages, however, stand structural heterogeneity had a positive effect on productivity. Our study might provide insights regarding the mechanisms underlying the contradictory findings obtained in recent studies dealing with tree diversity–structure–productivity relationships. This knowledge is vital for the adaptation of forest management to meet future demands on forest ecosystems.

The relative contribution of private and public forest to the conservation of species in mixed-ownership landscapes has often been contentious because management goals vary among owners. This tension can be exacerbated by a lack of understanding about how wildlife use habitats managed by different landowners and the relative value of habitats in having different structures, configurations, and management histories. To address this knowledge gap and enhance science-based conservation planning among different ownerships, we analyzed habitat selection by 53 GPS-tagged California spotted owls across multiple temporal scales within mixed-ownership landscapes in the Sierra Nevada. At a fine temporal scale, step-selection function analysis of hourly locations collected by GPS tags suggested that foraging spotted owls selected closed-canopy, larger-tree forest (Quadratic Mean Diameter [QMD] ≥ 33 cm, canopy cover ≥ 60%). Point selection function (PSF) analysis based on single nightly locations suggested that spotted owls selected a broader range of forest conditions including selection of forests having intermediate sized trees and intermediate canopy cover (QMD 28–33 cm, canopy cover ≥ 50%), and the strength of selection for these forest conditions increased in the less frequently used areas of home ranges. The PSF also suggested that spotted owls selected areas with relatively high cover type heterogeneity that included a mix of seral stages, except in the core of their home range where they selected relatively spatially homogenous forests characterized by large trees and closed canopy. Spotted owl home ranges increased in size with increasing elevation and cover type heterogeneity, and decreased in size with forest characterized by intermediate-sized trees. Collectively, these results indicate that landscapes having forest patches characterized by either intermediate or large-sized trees, both with high canopy cover, likely constitute the important foraging habitat for California spotted owls in Sierra Nevada mixed conifer forests. However, selection for any one particular cover type was not sufficiently strong for us to infer selection of individual landownership types, in spite of differences in forest conditions among ownerships. Collectively, our findings suggest that privately-owned lands used in our study may harbor more suitable spotted owl foraging habitat than previously recognized. Finally, given the importance of understanding the relationship between landowner management priorities and the resultant pattern of vegetation on lands with different ownerships, the development of forest management strategies relevant for broad-scale conservation of the Sierra Nevada forest will benefit from effective collaboration between forest managers, landowners, and research organizations.

As modern silviculture in natural forests is based on natural regeneration, finding the most important drivers of regeneration is crucial for forestry as well as conservation. We explored the relationship between numerous environmental and land use history variables and the species richness, cover and composition of the regeneration layer, and also the cover of the dominant species of the regeneration (sessile oak, hornbeam and beech) in coniferous-deciduous mixed forests. We identified the key factors which forest management can influence to support the regeneration of mixedwoods. Thirty-four stands were sampled, representing different tree species combinations and stand structures. We used redundancy analysis to explore the effects of the explanatory variables on the regeneration’s species composition, and general linear modelling to examine their effects on its species richness and cover. The most important drivers of species composition were tree species richness, the amount of relative diffuse light, the proportion of beech in the overstory, and the heterogeneity of the diameter of trees. The cover of the regeneration layer was positively related to the density of large trees and to the amount of relative diffuse light. Its species richness was most strongly influenced by light and tree species richness. For the cover of a particular species in the regeneration, the proportion of the conspecific species in the overstory was determinant for every species, but other, various drivers also played a role in the case of the different species. According to our results, the community variables of the regeneration are mainly driven by the characteristics of the current forest stands, thus they are strongly influenced by management. Compositional heterogeneity of the overstory, various tree size distribution and the presence of large trees play key roles in the maintenance of a heterogeneous regeneration layer. The shelterwood forestry system is partially capable of providing these conditions, but continuous cover forestry is much more suitable to achieve them. Besides the stand structural variables, among the drivers of the individual species, various variables of forest site, landscape and land use history also occurred. Therefore, we conclude that maintaining the landscape-scale heterogeneity of forest types and management systems may promote the coexistence of various species in the region.

Prescribed fire is commonly used as a tool to meet a range of forest management goals. Owing to their limited movement abilities, terrestrial turtles are likely to be at high risk of injury and mortality, and to experience other fitness consequences with population-level implications from fire. Using radiotelemetry, we studied the responses of Eastern Box Turtles, Terrapene carolina carolina, to prescribed fire management in a sandhills Longleaf Pine forest system over a five-year period and compared our results to a nearby population in an unburned coastal plain location. Individual variation in turtle survival was strongly dependent on how frequently and extensively the areas were burned, with annual survival rates of 94.5% in unburned areas decreasing to 45.9% in the most extensively burned areas. Turtles at the fire-maintained sandhills site had annual survival rates 4.9% less than at the unburned coastal plain site, and females had annual survival rates 6.8% less than males. Survival varied seasonally, with greatest mortality rates in winter and spring, especially among females. Growth rates and body condition did not differ between sites, nor did they vary according to fire extent and frequency at the fire-maintained site. Although mortality was greater and spatially variable at the fire- maintained site, annual survival rates across the site (86–90% for females and males, respectively) were comparable to other stable populations of T. carolina. The lesser than expected mortality rate at the fire-maintained site was likely the result of turtles’ strong selection of mesic hardwood forests near bottomlands and streams – habitats that may serve as refugia from fire. In areas where T. carolina conservation is a priority, land managers should integrate maintenance of fire refuge habitats into burn planning to minimize unintended negative impacts to this imperiled species.

Our current understanding of the relationship between imperiled species and forest management can benefit from global positioning system (GPS) technologies. Fauna of lateseral stage forests have historically been difficult to detect and track in rugged terrain, leading to challenges in movement characterization and conservation. We investigated movement of California Spotted Owls (Strix occidentalis occidentalis) using automated GPS loggers affixed to 15 owls in the northern Sierra Nevada, California. We used >17,000 locations from individual owls to characterize homerange size, movement distances, and roosting and foraging habitat selection at four spatio-temporal scales (landscape, home range, foray, nightly) during the breeding season (April–August). Additionally, we assessed owl use of Protected Activity Centers (PACs), which are designated by the U.S.D.A. Forest Service to protect nesting and roosting habitat. Our results corroborated some previous findings about habitat requirements of California Spotted Owls, while also revealing new nuances in space use and habitat selection. Roosting and foraging owls selected stands with high canopy cover and large trees at multiple spatio-temporal scales, with foraging owls showing strongest selection at the largest (landscape) scale investigated. Although owls selected for PACs while foraging and roosting, PACs protected less than one quarter of foraging space use (volume of use) and fewer than half of observed roosts during the breeding season. Female owl home ranges were double the size of male home ranges, and distances travelled from the nest by females were 1.3 times greater than distances travelled by males, with non-breeding females travelling farthest and visiting up to six PACs during a single breeding season. Foraying behavior of this sort has not been documented previously in California Spotted Owls. Our findings support protection of later seral stage forest attributes for roosting and foraging California Spotted Owls. Given their selection for later seral forest attributes, strongest evidence of foraging habitat selection at the landscape scale, long distances travelled by owls and limited habitat protection afforded by PACs, habitat connectivity across the landscape is likely an important component for owl conservation, and distribution of current protected areas may be inadequate for this wide-ranging species.

Dead wood availability and the variability in dead wood quality, i.e. tree species and decay stages, are often low in managed forests, which negatively affects biodiversity of invertebrate species. Leaving more (coarse) dead wood can increase invertebrate richness, but it remains unclear how many and which combinations of tree taxa and decay stages are required to optimize niche heterogeneity in managed forests. We investigated the diversity of the main arthropod groups associated with dead wood, i.e. millipedes, centipedes, isopods and beetles, through the first four years of decomposition of logs of twenty common temperate tree species placed in the “common garden” experiment LOGLIFE. We hypothesized that (1) invertebrate richness for combinations of a given number of tree species would be promoted by mixing both tree species and decay period and that (2) invertebrate richness increases up to a saturation point with more tree species at different decay stages added. We also hypothesized that (3) an increase in phylogenetic distance among the tree species in combinations would promote their overall invertebrate diversity. We found that the better combinations, in terms of invertebrate richness, after one and two years of decay, but not after four years, consisted of a mix of gymnosperms and angiosperms, indicating that variation in tree species is especially important during the initial decomposition period. The best combinations in terms of invertebrate richness consisted of at least one tree species from each decay period, indicating that also variation in the decay stage of the tree is important to promote invertebrate diversity. We observed that at least four wood types were required to approach the 95% saturation point for species richness. The third hypothesis, that dissimilarity in phylogenetic position could be a predictive tool for increasing invertebrate richness in combinations of tree species, was not supported by our results. Thus, in order to maintain diversity of dead wood invertebrates in forests we recommend not only to provide richness in tree species, but also to plant particular combinations of trees (preferably angiosperm-gymnosperm combinations) that differ in the invertebrate communities they typically host and to temporally spread the logging of trees. This way the logging residues cover different resources and habitats at each moment in time, which is likely to result in a large diversity of dead wood invertebrates.

Forest management can be used to increase the local abundance of species of conservation concern. To achieve this goal, managers must be sure that the relationships between the targeted forest attributes and the focal species abundance are based on robust data and inference. This is a critical issue as the same forest attributes could have opposing effects on species abundance and the detectability of individuals, impairing our ability to detect useful habitat quality surrogates and to provide correct forest management recommendations. Using spatially stratified capture-recapture models (a.k.a. multinomial N-mixture models), we evaluated the effects of stand-level forest attributes on detection probability and local abundance for the endangered Southern Darwin’s frog (Rhinoderma darwinii), a forest-specialist and fully terrestrial amphibian endemic to the South American temperate forest. Our results show that an increase of stand basal area and a decrease of daily microclimatic fluctuation (i.e. an increase in structural complexity) were positively associated with the local abundance of R. darwinii. These stand-level forest attributes also explained the among-population variation in detection probability, although the relationships were opposite to those for abundance. Consequently, an analysis of raw frog counts (i.e. not adjusted for imperfect detection) did not reveal all the factors associated with local abundance. Our results provide further support to previous claims that raw counts of individuals should not be used, generally, as a proxy of abundance in species inhabiting forest ecosystems and elsewhere. More importantly, the opposite effect of forest attributes on abundance and detectability observed in our study highlights the need to use methods that quantify species-habitat relationships in a robust way and which take habitat-specific imperfect detection into account.

The western spruce budworm (Choristoneura occidentalis Freeman = C. freemani (Razowski), Lepidoptera: Tortricidae) (WSB) is a recurrent defoliator of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and other conifers in western North America. Repeated defoliation causes timber depletions, which often require control using pest management programs involving combinations of aerial sprays with biological controllers (Bacillus thuringiensis) and other tactics. Anticipating the recurrence cycle of this periodic defoliator is important for forest management planning, which needs to consider budworm-caused depletions in timber supply analyses, and for risk management and control. We studied the historical periodicity of outbreaks at the western edge of the insect’s distribution, on southern Vancouver Island, British Columbia, using the methods of dendrochronology applied to a living Douglas-fir chronology spanning 734 years (1281–2014 CE) and a floating chronology dating from 1863 to 1528 before the Common Era (BCE). To separate the growth fluctuations due to budworm defoliation from climatic fluctuations in the living chronology, we compared the temporal growth patterns of Douglas-fir with those of the non-budworm host western red cedar (Thuja plicata Donn ex D. Don), which is sympatric with Douglas-fir in this area. We concluded that before the 1930s, outbreaks were frequent, severe, and often spatially synchronized. Following the 1930s, periods of growth reductions indicative of outbreaks were present at the same frequency, but were less severe and not as synchronized as before. We provide evidence to suggest that periodic budworm disturbances on southern Vancouver Island have persisted through the centuries but that this regime has gradually shifted outside its historic range at about 1930. We concluded that although WSB is still present in this setting, population levels have not reached detectable outbreak levels for the last 90 years. We hypothesized that the absence of budworm outbreaks in the last 90 years is a response to the drastic ecosystem changes in this region caused by exploitation and fragmentation of the virgin forests, to possible changes in climate and to the accidental introduction of novel budworm predators into the ecosystem.

Operational-scale forest management experiments are long-term investments because harvest treatment effects may be dynamic throughout one or more rotation lengths. We examined deermouse (Peromyscus spp.) abundance over the first 20 years of the Missouri Ozark Forest Ecosystem Project (MOFEP), which assesses ecological responses to even-aged, uneven-aged, and no-harvest forest management systems applied at landscape scales in the Missouri Ozarks. In the spring of each of 11 sampling years, we sampled Peromyscus populations on two permanent trap grids on each of nine study sites (n = 3 sites per management system). Management entries occurred in 1996 and 2011, with small mammal sampling conducted during two pre-treatment years (1994–1995), and Years 2–5 (1998–2001), Years 13–14 (2009–2010), and Years 16–18 (2012–2014) after the first entry. We estimated abundance for each grid in each sampling year with Bayesian closed-population mark-recapture models, and modeled variation in abundance with negative binomial log-linear mixed effects models. Uneven- and even-aged management systems caused similar increases in Peromyscus abundance that were detectable shortly after the first management entry [proportional effect of even-aged management on Peromyscus abundance vs. no-harvest management: posterior median = 1.8, 95% credible interval 1.0–3.2; proportional effect of uneven-aged vs. no harvest management = 1.7 (1.0, 2.8)]. These effects were not surprising given positive effects of harvest treatments on understory cover and food resources. However, the consistency of this increase was less expected, as we observed no conclusive dissipation of harvest effects even in Years 13–14 after the first entry or amplification of harvest effects after the second entry. Observing extremely high system-wide yearly variation in Peromyscus abundance, we did not detect evidence of increasing divergence in effects of these three management systems or of any area-wide trends in abundance during 1994–2014. However, over subsequent decades, we expect higher potential for divergence in Peromyscus abundance as the three management systems differentially shape forest structure and tree species composition. Thus, the MOFEP study offers a unique framework for building and testing hypotheses about patterns and mechanisms of long-term changes in Ozark forests and effects on vertebrate communities.

Windthrows are natural disturbances that influence the functioning and structure of forest ecosystems and the belowground components of an ecosystem. Soil processes such as the recycling of organic matter, energy and nutrients are controlled by soil fauna. However, little is still known about the post-disturbance recovery of soil microarthropod communities in forest stands exposed to windthrow of various severity and post-windthrow forest management over time. This study assessed soil Collembola community recovery in pine forest stands over the long-term (between 9 and 14 years after the disturbance event). We predicted that (1) different severity of windthrow disturbance in a pine forest has different effects on the recovery of Collembola community composition and functional structure, even after 10 years; (2) The recovery of Collembola communities is similar during regeneration of a forest disturbed by windthrow and in a pine plantation planted after clearing of a windthrown forest and subsequent soil preparation; (3) The changes in the Collembola community during forest regeneration after windthrow disturbance can be explained by selected environmental variables, especially the leaf area index LAI. As expected, regeneration processes within forest stands shifted the species composition of collembolan communities and changed their functional structure. The surface dwelling collembolan species (epigeic and atmobiotic life form) responded to regeneration processes mainly in pine stands, especially in a pine plantation established after a clearing of broken pines and subsequent soil preparation. Our results suggest different sensitivity of collembolan communities to environmental changes induced by various degrees of opening of the tree canopy by windthrow and to those caused by the post disturbance treatment. These findings confirm that collembolan community composition recovery is slow and divergent during natural regeneration of pine stands and regeneration by planting but does not differ between moderately and severely successional trajectories. Our results also confirm the importance of canopy closure for the possibility of Collembola community regeneration. If canopies were more closed (higher leaf area index, LAI index), the possibility of regeneration increased, especially in the young pine plantations, as seen in the final years of our study.

The influence of management practices on forest ecosystems is usually analyzed by a comparison of species composition and richness. Different types of management practices increase plant species richness, mainly due to an increase in the number of ruderal and open habitat species. So far, most of the studies have been performed in the forest types that were most common in the studied regions. In this study we focused on broadleaved ravine forests that are spatially limited to specific habitat conditions, including steep rocky slopes with skeletal soil and unstable ground. These forests are local biodiversity hotspots, and, due to limited accessibility, have been subject to only limited management practices, mainly removal of single trees. We collected a dataset of 215 plots sampled between 1991 and 2015 in both managed forests and protected areas. We used multivariate techniques to compare the differences in the overall species composition. In addition, we compared differences in diversity, structural and habitat indices to find any possible differences. There were no differences in both the plot level and accumulative species richness and diversity indices between protected and managed forests. In addition, a comparison of habitat conditions and different ecological groups, including ruderal and open habitat species, alien species and ancient forest indicator species also revealed no differences. The only significant differences between the protected and managed forests related to the evenness and shrub cover. We concluded that low intensity forest management in ravine forests resembles natural disturbances, which are characteristic of natural ravine forests. The species composing these communities are adapted to frequent natural disturbances and thus forest management did not influence significant habitat conditions. However, to fully understand the effect of these practices on biodiversity, a comparison of structural characteristics is needed.

International audience; Tree-related microhabitats (TreMs) are important features for the conservation of biodiversity in forest ecosystems. Although other structural indicators of forest biodiversity have been extensively studied in recent decades, TreMs have often been overlooked, either due to the absence of a consensual definition or a lack of knowledge. Despite the increased number of TreM studies in the last decade, the role of drivers of TreM profile in primary forests and across different geographical regions is still unknown. To evaluate the main drivers of TreM density and diversity, we conducted the first large-scale study of TreMs across European primary forests. We established 146 plots in eight primary forests dominated by European beech (Fagus sylvatica L.) in the Carpathian and Dinaric mountain ranges. Generalized linear mixed effect models were used to test the effect of local plot characteristics and spatial variability on the density and diversity (alpha, beta, and gamma) of TreMs. Total TreM density and diversity were significantly positively related with tree species richness and the proportion of snags. Root mean square tree diameters were significantly related to alpha and gamma diversity of TreMs. Both regions reached similarly high values of total TreM densities and total TreM densities and diversity were not significantly different between the two regions; however, we observed between the two regions significant differences in the densities of two TreM groups, conks of fungi and epiphytes. The density and diversity of TreMs were very high in beech-dominated mountain primary forests, but their occurrence and diversity was highly variable within the landscapes over relatively short spatial gradients (plot and stand levels). Understanding these profile provides a benchmark for further comparisons, such as with young forest reserves, or for improving forest management practices that promote biodiversity.

Mesophication refers to the positive feedback cycle that occurs when fire suppression causes compositional shifts from oak (Quercus spp.) to other, primarily mesophytic, species. Because mesophytic species tend to be associated with relatively high-moisture sites, we sought to understand the extent to which physiographic and edaphic factors influence this process by examining forest successional dynamics over a period of 22 years. In 2016, we resampled a network of permanent plots first sampled in 1994 that were stratified across different landscape positions (e.g., north-facing slopes vs. south-facing slopes) in the Athens Unit of the Wayne National Forest in southeastern Ohio. By studying the changes in forest structure and composition relative to ecological land type, our results suggest little, if any, resistance to mesophication on sites with low moisture availability. For example, the relative density of red maple (Acer rubrum) large saplings on dry ridges increased 25%, while zero oaks were recorded in the large sapling layer on dry ridges in 2016. However, we did observe that American beech (Fagus grandifolia) is becoming substantially more abundant in the understory and may be more influential than red maple in determining the future species composition of these forests. American beech is expected to respond differently than red maple to future scenarios under predicted climate change, and is subject to a suite of novel pathogens that have broad implications for forest management in the region.

Logging has been operated throughout Bornean tropical forests that harbor diverse fauna species. We examined the responses of ground-dwelling wildlife to logging intensity in two certified forest management units under the same climate and vegetation in East Kalimantan, Indonesia, in 2012–2016. A total of ten and 13 circular plots with a diameter of 1 km were established respectively, and 10–18 camera points were distributed randomly in each plot to record wildlife for two years. A total of 41 species of medium to large-sized terrestrial wildlife were recorded in the two management units. Canonical Correspondence Analysis (CCA) was performed to examine the response of wildlife community to the logging influences with the following three variables: forest intactness (as a surrogate of tree-species composition), above-ground carbon (as a surrogate of forest structure), and distance to the nearest village to represent hunting pressure. Forest intactness was the strongest factor affecting the assemblage of wildlife species in both management units, suggesting that changes in tree-species composition due to logging were a decisive factor influencing animal assemblage. Poisson Generalized Linear Model (GLM) was employed to examine the response of each species to forest intactness in each management unit. We found that eight out of the 32 tested wildlife species responded to forest intactness consistently between the two units, while the other species responded more individualistically. We suggest that consistent responses of several species, as well as individualistic responses of the other species to the changes of tree-species composition, determine the animal assemblage in logged-over Bornean rainforests. Sustainably managed logged-over forests in Borneo are a habitat for diverse wildlife community and therefore also require attention for biodiversity conservation.

In many parts of the boreal biome intensive forest management has resulted in profound changes in forest structure, tree species composition and dead wood availability, and by so negatively effecting forest biodiversity. Restoration of degraded forest habitats is therefore of high priority, both internationally and nationally. Consequently, it is of uttermost importance to develop cost-efficient restoration methods. We have therefore initiated a cost neutral ecological restoration experiment aimed at increasing the variety and volume of dead wood in voluntary set-asides (as part of the FSC certification requirements) by mimicking the two natural disturbances, forest fire and small scale gap dynamics. We studied how tree species and substrate type, i.e. the way in which a tree was killed (cut, girdled, tipped over or cut to produce a high stump), affect species composition, abundance and species richness of saproxylic beetles. We found that species composition differed between tree species in burned as well as gap-cut stands, and that tree posture, i.e. standing or downed trees, also affected species composition in gap-cut stands. In addition, abundance and species richness differed between tree species in gap-cut stands, generally being higher in spruce than in pine and birch. Based on our results we recommend a wider practice of dead wood creation involving a multitude of tree species and tree postures, through mimicking natural disturbances in the management of boreal forests. Furthermore, we suggest that voluntary set-asides provide an excellent opportunity for restoration as they are wide spread and already available in the forest landscape. Restoration cost can therefore be kept at a minimum or totally avoided as in this study.

Management of forest regrowth is a key issue globally, particularly where it occurs as high densities of small-sized stems and where there is little to no self-thinning. Thinning can reduce stem density to accelerate tree growth and potentially restore forest-structural complexity. Yet, in some forest types, it remains unclear how biodiversity responds to thinning, especially over longer periods. White cypress pine Callitris glaucophylla is geographically widespread in Australia and has history of silvicultural thinning in parts of its distribution. We used a chronosequence approach to assess the short- and longer-term responses of multiple taxa (bats, birds, invertebrates, reptiles, non-volant mammals, and plants) to thinning of C. glaucophylla in the dry Pilliga forests of New South Wales. We recorded data from a total of 227 taxa. The short ( 20 years) responses to thinning of C. glaucophylla regrowth were mostly positive or neutral for the taxa considered. Bat activity and diversity were comparable to levels in long-undisturbed reference forest, though this was influenced by time since thinning. Reptile diversity and abundance was positively associated with thinning at an intermediate time since thinning (8–20 years), with both metrics greater than unthinned regrowth and long-undisturbed reference forest. Bird diversity was greater in recent and old thinning treatments when compared to unthinned forest regrowth, although species composition was not affected by thinning. Though thinning did not affect volant invertebrate biomass, it was associated with a relatively more even distribution among size classes >8 years post-thinning, and a greater representation of beetles to overall insect biomass. The activity, diversity and composition of non-volant mammals did not differ among treatments, nor did understorey plant diversity or composition. Combining these multiple taxa into a composite ‘biodiversity’ index demonstrated a 16–22% increase with thinning relative to index values in long-undisturbed reference forests. Overall these results indicate that thinning has neutral to positive effects on biodiversity, but responses are species-specific and likely to be dependent on forest-type and the broader landscape of a site. Given unthinned forest represented habitat of similar value to thinned forest for some taxa, we recommend that that regrowth patches of varying size are retained across the landscape to provide a mosaic forest structure suitable for a diverse suite of flora and fauna.

Moths are a vital ecosystem component and key food source for many species, but have shown widespread and often severe declines. Multiple factors have been implicated in these declines, although the most important large-scale factors in the temperate zone are considered to be land use change and climate change. The majority of forest cover in the U.K. and elsewhere in Europe is dominated by intensively managed plantation woodlands, and studies have shown reduced broadleaved woodland cover can negatively affect moth diversity and biomass. However, few studies have examined how open habitats within the plantation forest matrix, which often represent a large proportion of the total forest area, are utilised by moth species. Here, we aimed to determine: (1) how moth biomass in open habitats within plantation forests varies seasonally and in response to management; and (2) how species diversity and Welsh conservation priority (“Section 7”) species respond to management at multiple spatial scales. We sampled moth communities in open habitats within five coniferous plantation forests across Wales, using light traps deployed in areas that ranged from 20 years post-felling. We found a significant non-linear relationship between space, time and moth biomass, with a significant peak in biomass in the summer months (∼29th June) suggesting important phenological effects with associated implications for dependent species. Biomass was also strongly affected by time since felling, with older habitats in general supporting a higher moth biomass, although this was dependent on the seasonal variation in habitat ‘greenness’ and productivity, as measured by NDVI. We also found that the abundances of Welsh priority species responded positively to increased extents of open habitats of ages 1–10 years post felling, but the amount of recent clear felling (0 years post felling) in the surrounding landscape had a negative correlation with both abundance and diversity. We conclude that habitat, seasonality/ productivity and short-term weather variations play a key role in determining moth biomass, species diversity and the presence of Welsh priority moth species within managed coniferous plantation woodland. This means there is an opportunity for forest management practices to adopt measures that can not only enhance moth biomass productivity, in turn supporting insectivorous species such as European nightjar Caprimulgus europaeus, but also deliver wider ecosystem services through the provision of habitat matrices that support invertebrate species of conservation concern.

Producción Científica, Wildfire is a recurrent factor that shapes and influences Mediterranean ecosystems where mixed oak (Quercus) forests with a rockrose (Cistus) understory are broadly represented. These ecosystems are also associated with large and diverse fungal communities. These fungal communities play essential ecological roles for the survival of vascular plant, such as the mineral and water uptaking or resistance against pathogens carried out by mycorrhizal fungi, as the saprotrophic fungi are a key factor for the recycling of the dead matter. In addition, edible fungi, such as Boletus edulis, provide a source of income for the nearby rural population. Fuel reduction treatments are applied to reduce the risk of wildfire; however, their potential impact on fungal communities is unclear. Thus, the aim of this work was to investigate the effect of different fuel reduction treatments on fungi associated with Quercus and Cistus. This aim is accompanied by the management-driven objective to obtain data from fuel reduction treatments that will enable managers to find solutions with a balanced approach to maintaining productive areas of edible mushroom production while reducing fire risks across the landscape. Sporocarps were sampled over a five-year period in stands dominated by mature or coppiced Quercus pyrenaica and accompanied by Cistus ladanifer understory. These stands had been subjected to different fuel reduction treatment levels involving moderate- or high-intensity thinning, for Q. pyrenaica, or clearing, for C. ladanifer. The goal was to determine sporocarp production, species richness, and taxonomic composition. Sporocarp production and fungal richness were drastically affected by the fuel reduction treatments but only when C. ladanifer is included in the treatment. Taxa composition was strongly correlated with the treatments applied to the rockrose understory. This was probably due to the large range of associated ectomycorrhizal fungi of C. ladanifer and their high capacity to recolonize an area after disturbances. Based on our results, we conclude that the implementation of moderate-/high-intensity fuel reduction treatments is compatible with the conservation of the fungal community present in these systems. In addition, the creation of a multi-stage mosaic of stands through mechanical management could enable fire prevention to be managed in an effective way while maintaining fungal diversity and sporocarp production, favoring the use of non-wood resources in rural areas and conserving a healthier forest ecosystem., Ministerio de Ciencia, Innovación y Universidades (project PID2019-105188RB-I00)

Understanding the driving factors for individual tree growth is of great significance to devise effective forest management strategies. Such information can be used to select appropriate tree harvesting times, and to provide valuable guidance for creating suitable local environmental conditions during the period of tree growth. However, currently it remains unclear how biotic and abiotic factors affect individual tree growth on large geographical scales. In the present study, based on a dataset from 457 field plots and the growth records of 7,560 individual trees in natural forests in northeastern China, the effects of tree size, local environmental conditions, and regional climate characteristics on the 5-year basal area increment (BAI) of the three dominant species (Quercus mongolica, Betula platyphylla, and Larix gmelinii) were investigated using nonlinear mixed-effects models. Although the magnitude and direction of the drivers’ effects on the BAI differed among the three species, the following variables explained major proportions of the variation (conditional R2 ranging from 0.57 to 0.66) in the BAI: 1) Diameter at breast height; 2) Mean temperature and precipitation during the growing seasons; and 3) Species mingling and the basal areas of larger trees. In addition, an interactive effect between temperature and precipitation was significant for Q. mongolica. On the basis of our results, we identified the most important variables among multiple drivers affecting the growth of individual trees, and developed individual tree growth models for the three species. Our results provide an initial basis for the future scientific management of some of the most important natural forest regions in the world.

Since the industrial revolution, atmospheric nitrogen deposition has increased strongly and has been shown to alter nitrogen cycles, species composition and diversity in many ecosystems, including forests. At the same time, nitrogen removal from forests through biomass extraction via historical management techniques has decreased considerably. A proven tool to analyze the effects of long-term environmental changes are vegetation resurveys. In this study, we tested whether environmental changes resulting from atmospheric nitrogen deposition and altered forest management are reflected in the vegetation composition of temperate forest understories in six acidophilic and oligo-mesophilic forest types in south-western Germany. We compared historical surveys from 1950 to 1976 with surveys from 2017/18 and examined changes in the vegetation using NMDS ordinations and Ellenberg indicator values. While an increase in the number of nitrophilic species was detected in all forest types, only the acidophytic and oligotrophic Vaccinio-Abietetum and Luzulo-Quercetum forests (dominated by Abies alba (Mill.) and Quercus spec., respectively) exhibited a replacement of oligotrophic species by nitrophilic species, amounting to an overall trend of eutrophication. Despite the uncertainties resulting from different plot locations and the slow dynamics of forests, we demonstrate a significant trend in the understory vegetation composition, which is likely caused by atmospheric N deposition. Differences in the sensitivity of different forest types indicate an influence of geological and climatic site characteristics and historical land use on the effects of environmental changes.

Bat populations face numerous threats, including the loss of forests in which they roost and forage. Present-day forests are commonly managed for timber harvesting, recreation, and wildlife. Understanding bat responses to forest management is crucial for balancing the conservation of endangered bats and forest restoration. We used radio telemetry to study nocturnal movements and habitat selection patterns of female and juvenile bats of two forest-dependent, federally listed bat species in an oak-dominated managed forest. We estimated foraging space use and assessed habitat selection for 33 northern long-eared bats (Myotis septentrionalis) and 25 Indiana bats (Myotis sodalis) from May to August 2014–2017 in south-central Indiana, USA. Myotis septentrionalis space use averaged 176 ha and bats selected water, historic thinning, and patch cuts (≤4 ha) over other habitats, with all but one bat avoiding larger openings (≥4-ha clearcuts). Myotis sodalis space use averaged 343 ha and bats selected 4-ha patch cuts, historic openings, and historic thinning over other habitats. In contrast to M. septentrionalis, one-third of the M. sodalis foraged over larger clearcuts, while two-thirds foraged over smaller openings and thinnings. We showed that bats were attracted to small regeneration harvests of varying structural ages. Forests maintained for a mix of mature stands, thinned stands, shelterwoods, small regenerative cuts (

Lianas are important and yet understudied components of tropical forests. Recent studies have shown that lianas are increasing in abundance and biomass in neotropical forests. However, aboveground biomass estimates of lianas are highly uncertain when calculated from allometric relations. This is mainly because of the limited sample size, especially for large lianas, used to construct the allometric models. Furthermore, the allometry of lianas can be weakly constrained mechanically throughout its development from sapling to mature form. In this study, we propose to extract liana stem biomass from terrestrial laser scanning (TLS) data of tropical forests. We show good agreement with a concordance correlation coefficient (CCC) of 0.94 between the TLS-derived volume to reference volume from eleven synthetic lianas. We also compare the TLS-derived biomass for ten real lianas in Nouragues, French Guiana, with the biomass derived from all existing allometric equations for lianas. Our results show relatively low CCC values for all the allometric models with the most commonly used pantropical model overestimating the total biomass by up to 133% compared to the TLS-derived biomass. Our study not only facilitates the testing of allometric equations but also enables non-destructive estimation of liana stem biomass. Since lianas are disturbance-adapted plants, liana abundance is likely to increase with increased forest disturbance. Our method will facilitate the long-term monitoring of liana biomass change in regenerating forests after disturbance, which is critical for developing effective forest management strategies. publishedVersion

Amphibians are declining worldwide and one of the major causes of such decline is habitat loss. Forestry practices have a primary role in causing habitat loss and fragmentation, detrimental to amphibians. We studied the ecological requirements of a fully terrestrial and threatened amphibian, the Golden Alpine Salamander Salamandra atra aurorae, which is endemic to a small portion of the Italian Alps. This rare and elusive salamander lives exclusively in forest environments and forestry practices are considered among its major threats. We employed both a capture-mark-recapture (CMR) and an occupancy approach in fifty 400 m2 plots, within a managed mixed forest dominated by Norway spruce and to a lesser extent beech, and silver fir. Modelling salamander occupancy as a function of site-specific habitat features allowed us to understand the ecological requirements of this salamander and provide precise guidelines for forest management. The application of hierarchical models (occupancy) for evaluating forest management plans is highly effective, requires less effort and is a less impacting methodology than CMR performed by searching for salamanders under shelters also in non-optimal weather conditions. Distance from open pasture edges significantly affects the distribution of salamanders while, at a smaller scale, brushwood piles, classified as fine woody debris (FWD, diameter from 1 to 10 cm), play a key role in providing suitable habitat for this endangered amphibian. The importance of FWD in the conservation of small vertebrates is generally poorly studied and probably underestimated. However, our results show that FWD should be considered as an additional element that has to be managed to enhance habitat suitability for this and, intuitively, for other small forest vertebrates.

Understanding the implications of shifts in disturbance regimes for plants and pollinators is essential for successful land management. Wildfires are essential natural disturbances that are important drivers of forest biodiversity, and there is often pressure to respond to wildfire with management like post-wildfire logging (i.e., removal of dead trees for economic value immediately following wildfire). We investigated how local floral and bee density, species richness, and community composition and dispersion were influenced by post-wildfire logging, and how these effects differed between an older (24 years-since-fire) and a more recent (8 years-since-fire) wildfire in the Gallatin National Forest, Montana USA. We also tested how these local patterns scaled up to influence landscape patterns in floral and bee diversity. After recent wildfire, local floral and bee density and species richness were higher in logged than in unlogged sites, and these effects were variable over the course of the growing season. There were no differences in community dispersion except that of bees in logged areas of the recent wildfire, which were less heterogeneous compared to unlogged areas. Despite this reduction in bee community heterogeneity, overall bee diversity was highest across logged areas of the recent fire. While the positive effects of post-wildfire logging on local density and richness did not persist in the older fire, compositional differences in flowers and bees between logged and unlogged areas were observed in both the recent and older wildfire. Together, these results suggest that the local benefits of post-wildfire logging for floral and bee richness are evident within a decade of these disturbances, but have diminished within a quarter century of fire. Nevertheless, compositional effects persist, resulting in higher overall landscape floral and bee diversity when both logged and unlogged areas of each wildfire were present. This study provides evidence for near-term benefits of post-wildfire logging for local and landscape floral and bee communities. Post-wildfire logging may be considered as a forest management option when balanced with the maintenance of unlogged areas to encourage biodiversity conservation at the landscape scale.

This study compared 141 ecologically relevant climate metrics to field assessments of sugar maple (Acer saccharum Marsh.) canopy condition across Vermont, USA from 1988 to 2012. After removing the influence of disturbance events during this time period to isolate the impact of climate, we identified five climate metrics that were significantly related to sugar maple crown condition. While three of these are monthly summary metrics commonly used in climate analyses (minimum April, August and October temperatures), two are novel metrics designed to capture extreme climate events (periods of unusual warmth in January and August). The proportion of climate-driven variability in canopy condition is comparable to the proportion accounted for by defoliating pests and other disturbance events. This indicates that climate conditions, though rarely included in sugar maple decline studies, may be of equal importance as more traditionally studied stress agents. Modeled across the state, results indicate that changes in historical climatic conditions have negatively impacted sugar maple health over the 25 year study period, and are likely to degrade further over time. Climate projections under a low emissions scenario indicated that by 2071 55% of sugar maple across the state would likely experience moderate to severe climate-driven stress relative to historic baselines, increasing to 84% under a high emissions scenario. However, geographic variability in projected climate impacts indicates that while conditions for sugar maple will likely deteriorate across the state, climate refugia should also be available to maintain sugar maple in spite of changing climatic conditions. Considering the predominant role of sugar maple in Vermont’s economy and culture, managing this resource into the future could pose a considerable challenge.

Declines in the diversity of herbaceous and woody plant species in the understory of eastern North American hardwood forests are increasingly common. Forest managers are tasked with maintaining and/or promoting species diversity and resilience; however, the success of these efforts depends on a robust understanding of past and future system dynamics and identification and application of appropriate silvicultural interventions. We review how historical timber harvesting and land use, increases in deer population sizes, invasive species, and contemporary forest management practices interact to erode ecological memory and increase resilience debt of hardwood forests of eastern North America. The erosion of ecological memory and growing resilience debt in these forests pose significant challenges for forest managers because they alter the response of forests to management from the understory to overstory. Differences in how much ecological memory these systems retain, as well as the mosaic of interacting factors influencing contemporary dynamics, preclude a one size fits all management approach. That being said, our review has identified a host of common factors and pathways that can be manipulated. The approach we propose requires a more thoughtful understanding of the forest understory as the foundation upon which resilient systems are built. Which silvicultural levers will have the greatest utility clearly depend on the ecological context of the forest, and a willingness to experiment and adapt. We offer a conceptual model and recommendations for managers confronting novel plant communities and uncertain system dynamics.

Taxonomic and functional diversity of animals respond to habitat heterogeneity. However, how structural heterogeneity at the stand level of differently managed forests drives species richness across taxa is not clear. Here we analyze how birds and bats, sharing the ability to fly, respond to the structural composition of the vegetation layers in differently managed forests. We combined datasets of birds and bats and compared their response as taxonomic vs. functional richness towards forest structure. Overall our results revealed that bird and bat species richness were positively correlated and species richness of both taxa peaked within the same forest stands. In contrast to our prediction that richness of mobile vertebrates with similar ecological traits (the ability to fly) should respond alike to forest stand characteristics, our results showed almost no congruence. Using Generalized Linear Mixed Effects Modeling (GLMM) with model selection based on AICc and model averaging, we found that taxonomic richness of birds and bats as well as functional richness (based on main diet and foraging mode) responded to forest structure in very different ways. While the taxonomic richness of birds was mainly associated with the structural parameters contrast and forest height, representing tall trees and a relatively closed canopy, richness of bat species increased with vertical and horizontal heterogeneity within forest stands. Our findings indicate that functional richness is more useful to understand responses of bird and bats species richness to land use, forest structure and forest management, rather than focusing solely on taxonomic groups.

Shelterwood (SW) cutting is a silvicultural method for establishing natural tree regeneration. It is considered to be less destructive for forest biodiversity than intensive harvest methods. In boreal forests, bryophytes are an important taxonomic group, but are vulnerable to changes caused by intensive forest management. To date, the effect of SW cutting on bryophytes has been insufficiently tested, particularly if the entire cutting cycle and different forest-type groups are included. Bryophyte assemblages and forest structural features were surveyed at the stand scale in 30 dry and fresh boreal study sites to test which factors influence bryophyte species richness and composition in SW cuttings as compared to mature managed forests. Total species richness of bryophytes was generally higher in mature forests (123 species) compared to SW cuttings after the first (96 species) and final (90 species) stages of the cutting rotation, but the mean stand scale richness was similar among SW cuttings and mature stands. Independent of the management, a higher number of deciduous trees favoured richness of mosses and liverworts, the latter also positively influenced by the volume of well-decayed logs. Bryophyte assemblages of the first and completed SW cut sites were similar, but distinct from those of mature forests. This pattern also held if mosses and liverworts were analysed separately or if assemblages of the same substrate type (i.e. live trees, stumps, dead wood) were compared between management treatments. The general impact of SW cutting on bryophytes was mild in dry boreal sites, but destructive for species of conservation concern in fresh boreal sites. Retaining a higher density of coniferous and deciduous trees during the SW rotation, as well as careful retention of dead wood legacies (snags and logs), is critical to support bryophyte assemblages in SW post-cut sites.

Forest disturbance regimes are beginning to show evidence of climate-mediated changes, such as increasing severity of droughts and insect outbreaks. We review the major insects and pathogens affecting the disturbance regime for coastal Douglas-fir forests in western Oregon and Washington State, USA, and ask how future climate changes may influence their role in disturbance ecology. Although the physiological constraints of light, temperature, and moisture largely control tree growth, episodic and chronic disturbances interacting with biological factors have substantial impacts on the structure and functioning of forest ecosystems in this region. Understanding insect and disease interactions is critical to predicting forest response to climate change and the consequences for ecosystem services, such as timber, clean water, fish and wildlife. We focused on future predictions for warmer wetter winters, hotter drier summers, and elevated atmospheric CO2 to hypothesize the response of Douglas-fir forests to the major insects and diseases influencing this forest type: Douglas-fir beetle, Swiss needle cast, black stain root disease, and laminated root rot. We hypothesize that (1) Douglas-fir beetle and black stain root disease could become more prevalent with increasing, fire, temperature stress, and moisture stress, (2) future impacts of Swiss needle cast are difficult to predict due to uncertainties in May-July leaf wetness, but warmer winters could contribute to intensification at higher elevations, and (3) laminated root rot will be influenced primarily by forest management, rather than climatic change. Furthermore, these biotic disturbance agents interact in complex ways that are poorly understood. Consequently, to inform management decisions, insect and disease influences on disturbance regimes must be characterized specifically by forest type and region in order to accurately capture these interactions in light of future climate-mediated changes.

Even though temperate forests have lower non-native plant species richness and cover in comparison to some other habitats, such as anthropogenically influenced habitats or some grassland habitats, several recent studies from Central Europe suggest that there has been an increase in the numbers and proportions of non-native species in forests. Previous studies on the level of invasion in forest habitats were usually conducted on a relatively coarse scale, often excluding plantations of non-native trees or analyzing them together as a group regardless of the different biological properties of different species. Therefore, a more detailed analysis would be helpful to obtain better insight into the processes taking place in forests, focusing not only on the analysis of the invasion level of different forest types at a finer scale (e.g., in various types of floodplain, beech or coniferous) but also on the character of the non-native plants found there (invasive status, frequencies and habitat preferences). In this study, we aimed to (i) compare the invasion level of various forest habitats (including forests dominated by non-native trees) in Slovakia with regard to different residence times and invasive status of non-native species, (ii) analyze whether forest habitats possess specific non-native species combinations, and (iii) determine the preferences of non-native plants with respect to specific forest habitats and the co-occurrence of other plant species with the most frequent non-native species. Our study confirmed that almost all forest habitats contained at least one non-native species. Native forests at lower elevations and closer to rivers were more invaded, while broadleaved, mixed and especially coniferous forests at higher elevations and ecologically strictly limited forests were less (or un-) invaded. Significant differences between various types of riparian and coniferous forests, emphasized the importance of the more detailed discrimination of the forest habitats in comparison with previous studies. Non-native tree plantations, which are among the most invaded forests, also deserve special attention. Some non-native trees form stable communities with typical native and non-native species, where non-native dominants can act as drivers of further changes in the vegetation composition, facilitating spread of other co-occurring non-native shrubs and herbs. Taking into consideration the potential negative impacts of some non-native plants on species composition, forest microclimate and soil chemistry, it would be advisable for foresters to factor this into forest management because their choice of planted species may both positively and negatively influence the level of invasion in managed forests.

The intentional movement of tree genotypes, or assisted migration, is an operational approach proposed to adapt forest management to climate change. Assisted migration assumes that tree populations are locally adapted to environmental conditions, but this fact should be tested specifically. In this study, both a reciprocal transplant and a common garden experiment were carried out to test local adaptation to variable environmental conditions of seedling emergence and survival of the tree species Pinus nigra. Reciprocal sowing experiments involved the cross-sowing of four seed origins among four destination habitats, located in high- and low-altitude sites within central and peripheral populations of Pinus nigra. Evidence of local adaptation was taken to be a significant destination x origin interaction. Then, the possibility of local adaptation was further evaluated under the ‘‘local versus foreign’’ and the ‘‘home versus away’’ criteria. Results showed negative evidence of local adaptation to the emergence and survival environment faced by Pinus nigra seedlings, which would reduce the utility of assisted migration as an effective tool to adapt forests to ongoing climate change.

Understanding how changes to habitat characteristics affect behaviors is necessary to integrate biodiversity goals with land management. Managed forests are a significant landscape component in the southern United States and provide opportunities for conservation alongside production of wood products. We investigated behavioral responses of rodents to differences in understory habitat characteristics from intercropping switchgrass (Panicum virgatum), a native biofuel feedstock, in intensively managed loblolly pine (Pinus taeda) stands. Previous research indicated that planting switchgrass increased rodent population abundance but reduced recruitment and community diversity. To understand potential mechanisms underlying our previous results, we measured behaviors of individual cotton rats (Sigmodon hispidus), a grassland specialist, to planted switchgrass. We hypothesized that female territory size, foraging activity, overlap with other adult females, and reproduction indices would differ among treatments (switchgrass monocrop, intercropped switchgrass, and control plots) due to variation in grass abundance and vertical vegetation cover. We conducted live-trapping, radio telemetry, and foraging activity surveys on cotton rats during summers of 2013–2015. We found no treatment effect on territory size, but foraging activity was 2 times higher in monocrop than control plots. We also found a positive relationship between female spatial overlap and percentage of grass in control plots and evidence for higher reproductive indices in control than monocrop plots. Our results suggest that cotton rats in monocrop plots exhibited unexpected behaviors, and monocrop plots may serve as population sinks with low rodent diversity. Overall, results from this replicated experiment suggested that intercropping provides adequate food and cover to maintain rodent populations and produce forest products.

Growing-season burns are increasingly used in upland hardwood forest for multiple forest management goals. Many species of reptiles and amphibians are ground-dwelling, potentially increasing their vulnerability to prescribed fire, especially during the growing-season when they are most active. We used drift fences with pitfall traps to experimentally assess how herpetofaunal species and communities responded to early, growing-season burns, dormant-season burns, and unburned controls. We documented no adverse effects of either growing-season burns or dormant-season burns on any common herpetofaunal taxa, but capture rates of total, adult, and juvenile five-lined skinks (Plestiodon fasciatus) were greater following growing-season burns. Most measurements reflected little or transient change in forest structure. However, canopy cover decreased by an average of 16% in growing-season burns within four growing-seasons of burning, with some tree mortality in patches where fire temperature likely was hotter. Our study suggests that even modest reductions in canopy cover may positively affect relative abundance and reproductive success of P. fasciatus. We cautiously suggest that a higher mean ground-level fire temperature and the physiologically active condition of vegetation in growing-season burns interacted to damage a greater proportion of trees, resulting in more canopy thinning than in dormant-season burns. However, weather, fuel types and condition, vegetation structure, and topography interact to affect fire intensity and the level of mortality or damage to canopy trees within and among stands, regardless of season conducted. We suggest that herpetofaunal response, for the species we studied, is more closely linked to change in canopy cover than to season of burn per se.

Forests provide fundamental ecosystem services. Environmental changes are predicted to affect forest growth directly through increased environmental stressors, and indirectly by amplifying disturbance. To increase our understanding of effects of environmental changes and disturbance on Afromontane forest growth, we used tree-ring data collected from Juniperus procera trees from church forests in the northwest highlands of Ethiopia. We used structural change models to detect structural shift in growth trends. We applied Linear Mixed Effect Models (LMM) to compare growth rate differences between successive tree generations. The running mean method and radial growth pattern analysis were used to detect disturbance events. Three groups of generations were identified based on Basal Area Increment (BAI) rates. There are significant differences (χ2 = 204.64, P

To harvest more biofuel from forests, tree stumps are sometimes extracted after clearcutting. Species in different organism groups rely on deadwood, and biofuel extraction reduces their substrate. Our aim was to investigate the potential landscape effects of stump extraction, and compare the effects among trophic levels of deadwood-dependent (saproxylic) beetles. We sampled saproxylic beetle species in clearcut stumps using bark sieving. We did the study in 2013 in 49 clearcuts (1–4 years old) in three regions in central Sweden where stump extraction had been performed for six years prior to sampling. We selected landscape buffers with 500 m, 1000 m, and 2000 m radius with different intensities of stump extraction (0–100%). We show for the first time, based on empirical data, that increasing stump extraction can affect deadwood-dependent species at the landscape level. On average, obligate predators were more negatively affected than cambivores and facultative predators. The 34 studied saproxylic beetle species showed varied responses to stump extraction in the surrounding landscape, including stable (no response), negative, or positive responses. Positive responses could be due to a crowding effect, indicating a time-lagged response to habitat loss. Since stump extraction in the study area started just six years prior to sampling, time-lags in population-level responses could be expected. The age of the sampled clearcuts influenced the abundance of eleven species, but other local factors had little effect on abundance. Our results suggest that if stump extraction is widely introduced, deadwood retention—planned for both spatial and temporal continuity—should be an integrated part of intensified forest management. We suggest monitoring the long-term effects of stump extraction.