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Because of their steep gradients in abiotic and biotic factors, mountains offer an ideal setting to illuminate the mechanisms that underlie patterns of species distributions and community assembly. We compared the composition of taxonomically and functionally diverse fungal communities in soils along five elevational gradients in mountains of the Neo- and Palaeotropics (northern Argentina, southern Brazil, Panama, Malaysian Borneo and Papua New Guinea). Both the richness and composition of soil fungal communities reflect environmental factors, particularly temperature and soil pH, with some shared patterns among neotropical and palaeotropical regions. Community dynamics are characterized by replacement of species along elevation gradients, implying a relatively narrow elevation range for most fungi, which appears to be driven by contrasting environmental preferences among both functional and taxonomic groups. For functional groups dependent on symbioses with plants (especially ectomycorrhizal fungi), the distribution of host plants drives richness and community composition, resulting in important differences in elevational patterns between neotropical and palaeotropical montane communities. The pronounced compositional and functional turnover along elevation gradients implies that tropical montane forest fungi will be sensitive to climate change, resulting in shifts in composition and functionality over time.

To secure the ecosystem services forests provide, it is important to understand how different management practices impact various components of these ecosystems. We aimed to uncover how silvicultural treatments affected the ground-dwelling spider communities during the first five years of a forest ecological experiment. In an oak-hornbeam forest stand, five treatments, belonging to clear-cutting, shelterwood and continuous cover forestry systems, were implemented using randomised complete block design. Spiders were sampled by pitfall traps, and detailed vegetation, soil and microclimate data were collected throughout the experiment. In the treatment plots spider abundance and species richness increased marginally. Species composition changes were more pronounced and treatment specific, initially diverging from the control plots, but becoming more similar again by the fifth year. These changes were correlated mostly to treatment-related light intensity and humidity gradients. The patchy implementation of the treatments induced modest increase in both gamma and beta diversity of spiders in the stand. Overall, spiders gave a prompt and species specific response to treatments that was by the fifth year showing signs of relatively quick recovery to pre-treatment state. At the present fine scale of implementation the magnitude of changes was not different among forestry treatments, irrespective of their severity.

Moving from one habitat to another, the dispersal of individuals has consequences for their conditions, population dynamics and gene flow. Our major motivation was to explore the effects of different forestry treatments, such as preparation (partial) cuts and clear cuts, on the selected population of the forest ground beetle, Carabus coriaceus (Coleoptera: Carabidae). We tagged six individuals (three males and three females) with small radio-transmitters and each was released in the treatment habitat core, at the edges and in the core of control forests respectively. The recorded trajectories were divided into two major movement phases: a random walk and a directional movement using hidden Markov models. Our results revealed that in the core zone of preparation cuts, the random walk and the directional movement were equally distributed in the trajectory. A clear directional movement was observed in the clear cuts suggesting the beetles moved directly toward the adjacent (control) forest interior. The trajectories at the edges of both treatments were dominated by the random walk and so for the controls. These results suggest that forest ground beetles can avoid the forestry treatments especially clear cuts, however edge habitats and (the studied) preparation cuts can mitigate the migration constraints due to their more favorable environmental conditions compared to clear cuts.

Erdőökológiai kísérletünkben a vágásos és az örökerdő gazdálkodásban alkalmazott erdészeti beavatkozások aljnövényzetre gyakorolt kezdeti hatásait vizsgáltuk egy korábban vágásos üzemmódban művelt, egykorú gyertyános-kocsánytalan tölgyesben. A kísérletben kisméretű vágásterületeket, hagyásfacsoportokat, bontóvágással kezelt területeket, lékeket és kontrollként idős, záródott állományokat hasonlítottunk össze az aljnövényzet fajszáma, borítása és kompozíciója, valamint négy növényi funkciós csoport összegzett borítása szerint. Kimutattuk, hogy a beavatkozások utáni negyedik évre a fajszám és a borítás leginkább a vágásterületeken és lékekben nőtt meg, míg növekedésük a bontásokban közepes, a hagyásfacsoportokban mérsékelt volt. A kompozíció a vágásterületeken jelentősen átalakult; bennük főleg nem-erdei lágyszárúak, míg a lékekben inkább fény- és nedvességigényes erdei fajok nyertek teret. A növényzet erdei jellegének megőrzése mellett a fás szárú magoncok borításnövekedése is a lékekben és bontásokban volt a legnagyobb. Eredményeink alapján arra következtetünk, hogy a folyamatos erdőborítást fenntartó gazdálkodás természetvédelmi és faanyagtermelési szempontból is kedvező lehet.

We explored the most influential stand-scaled drivers of ectomycorrhizal, terricolous saprotrophic, and wood-inhabiting (main functional groups) macrofungal species richness in mixed forests by applying regression models. We tested 67 potential explanatory variables representing tree species composition, stand structure, soil and litter conditions, microclimate, landscape structure, and management history. Within the main functional groups, we formed and modeled guilds and used their drivers to more objectively interpret the drivers of the main functional groups. Terricolous saprotrophic fungi were supported by air humidity and litter mass. Ectomycorrhizal fungi were suppressed by high soil nitrogen content and high air temperature. Wood saprotrophs were enhanced by litter pH (deciduous habitats), deadwood cover, and beech proportion. Wood saprotrophic guilds were determined often by drivers with hidden effects on all wood saprotrophs: non-parasites: total deadwood cover; parasites: beech proportion; white rotters: litter pH; brown rotters: air temperature (negatively); endophytes: beech proportion; early ruderals: deciduous stands that were formerly meadows; combative invaders: deciduous tree taxa; heart rotters: coarse woody debris; late stage specialists: deciduous deadwood. Terricolous saprotrophic cord formers positively responded to litter mass. Studying the drivers of guilds simultaneously, beech was a keystone species to maintain fungal diversity in the region, and coniferous stands would be more diverse by introducing deciduous tree species. Guilds were determined by drivers different from each other underlining their different functional roles and segregated substrate preferences. Modeling guilds of fungal species with concordant response to the environment would be powerful to explore and understand the functioning of fungal communities.

In Europe, forest management has controlled forest dynamics to sustain commodity production over multiple centuries. Yet over-regulation for growth and yield diminishes resilience to environmental stress as well as threatens biodiversity, leading to increasing forest susceptibility to an array of disturbances. These trends have stimulated interest in alternative management systems, including natural dynamics silviculture (NDS). NDS aims to emulate natural disturbance dynamics at stand and landscape scales through silvicultural manipulations of forest structure and landscape patterns. We adapted a "Comparability Index" (CI) to assess convergence/divergence between natural disturbances and forest management effects. We extended the original CI concept based on disturbance size and frequency by adding the residual structure of canopy trees after a disturbance as a third dimension. We populated the model by compiling data on natural disturbance dynamics and management from 13 countries in Europe, covering four major forest types (i.e., spruce, beech, oak, and pine-dominated forests). We found that natural disturbances are highly variable in size, frequency, and residual structure, but European forest management fails to encompass this complexity. Silviculture in Europe is skewed toward even-aged systems, used predominately (72.9% of management) across the countries assessed. The residual structure proved crucial in the comparison of natural disturbances and silvicultural systems. CI indicated the highest congruence between uneven-aged silvicultural systems and key natural disturbance attributes. Even so, uneven-aged practices emulated only a portion of the complexity associated with natural disturbance effects. The remaining silvicultural systems perform poorly in terms of retention compared to tree survivorship after natural disturbances. We suggest that NDS can enrich Europe's portfolio of management systems, for example where wood production is not the primary objective. NDS is especially relevant to forests managed for habitat quality, risk reduction, and a variety of ecosystem services. We suggest a holistic approach integrating NDS with more conventional practices.

Aim Dead wood-inhabiting bryophyte communities are formed by several important factors. Besides the amount, quality and continuity of the substrate, there are also external factors indirectly influencing their structure. One of the most important is local microclimate. This fact has been recognized by many previous authors, yet studies exploring the direct effect of the microclimate on epixylic bryophytes are still sparse. Based on directly measured values of local temperature, air humidity and canopy openness (CO), we explored the associations between microclimate and epixylic bryophyte communities. Location Old-growth mixedFagus sylvatica-Abies albamontane forest in the Czech Republic (West Carpathians). Methods The associations between microclimate and bryophyte communities were studied on 61 large logs ofAbies albain advanced decay stage. Air temperature and humidity were measured in three periods of the year 2017, CO was measured in leafless and leaf-on periods. Water potential (psi) values were calculated from the data. The importance of the seasons was compared, the effect of microclimate variables on the species composition of logs was explored by canonical correspondence analysis. The effect on total cover and species richness was analyzed by linear models. Results Our analysis revealed a clear relationship between the communities and the microclimatic gradient. The most important factors for bryophyte composition were the spring and summer water potential and CO in the leaf-on period. Total species richness and cover increased with increasing water potential (relatively cool and humid conditions). Also, the appearance of sensitive epixylic specialists (mainly liverworts) was positively correlated with these microclimatic conditions. On the other hand, species more tolerant to desiccation preferred logs with a drier and warmer microclimate. Conclusions Comparing logs with similar physical properties but different microclimates, we confirmed that epixylic bryophyte communities are significantly associated to microclimatic conditions in natural temperate forest.

Forests host most terrestrial biodiversity and their sustainable management is crucial to halt biodiversity loss. Although scientific evidence indicates that sustainable forest management (SFM) should be assessed by monitoring multi-taxon biodiversity, most current SFM criteria and indicators account only for trees or consider indirect biodiversity proxies. Several projects performed multi-taxon sampling to investigate the effects of forest management on biodiversity, but the large variability of their sampling approaches hampers the identification of general trends, and limits broad-scale inference for designing SFM. Here we address the need of common sampling protocols for forest structure and multi-taxon biodiversity to be used at broad spatial scales. We established a network of researchers involved in 41 projects on forest multi-taxon biodiversity across 13 European countries. The network data structure comprised the assessment of at least three taxa, and the measurement of forest stand structure in the same plots or stands. We mapped the sampling approaches to multi-taxon biodiversity, standing trees and deadwood, and used this overview to provide operational answers to two simple, yet crucial, questions: what to sample? How to sample? The most commonly sampled taxonomic groups are vascular plants (83% of datasets), beetles (80%), lichens (66%), birds (66%), fungi (61%), bryophytes (49%). They cover different forest structures and habitats, with a limited focus on soil, litter and forest canopy. Notwithstanding the common goal of assessing forest management effects on biodiversity, sampling approaches differed widely within and among taxonomic groups. Differences derive from sampling units (plots size, use of stand vs. plot scale), and from the focus on different substrates or functional groups of organisms. Sampling methods for standing trees and lying deadwood were relatively homogeneous and focused on volume calculations, but with a great variability in sampling units and diameter thresholds. We developed a handbook of sampling methods (SI 3) aimed at the greatest possible comparability across taxonomic groups and studies as a basis for European-wide biodiversity monitoring programs, robust understanding of biodiversity response to forest structure and management, and the identification of direct indicators of SFM., This review was funded by the EU Framework Programme Horizon 2020 through the COST Association: COST Action CA18207: BOTTOMSUP- Biodiversity Of Temperate forest Taxa Orienting Management Sustainability by Unifying Perspectives.

We studied the response of enchytraeid (Annelida: Oligochaeta) community structure to different forest management treatments via an open-field forestry experiment in a managed sessile oak-hornbeam forest in Hungary. The applied forestry treatments were 1) clear-cutting 2) clear cutting with a small patch of retention tree group, 3) gap-cutting, 4) preparation cutting and 5) control (closed mature stand). Our questions were: how did the selected forestry treatments influence the abundance and species richness of enchytraeids two years after the intervention, and how could the worms compensate the altered environmental conditions by vertical movements in topsoil layers (0–12 cm). The effects of the treatments on the species composition of the assemblages and species-specific responses were also analysed. Two years after the treatments, a strong response of enchytraeids was observed in clear-cutting and even more in retention tree group: in both treatments the abundance and the species richness of enchytraeids were reduced. Species did not show vertical movements into deeper layers and were not able to tolerate the altered soil conditions caused by changed microclimate. Gap-cutting and preparation cutting did not differ significantly from control plots. Our study showed that right after the interventions tree retention at the size of one tree height in diameter had no sheltering effect on this important soil decomposer animal community. These results are in contrast with earlier findings in boreal zones, where soil organic layer is considered a well buffered habitat against environmental changes. Oppositely, enchytraeid assemblages in a temperate deciduous forest are more diverse but seem more vulnerable to management-related alterations in soil conditions (soil temperate increment, reduced soil moisture).

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.

Dry oak forests have one of the richest understory vegetation in Europe, but the environmental drivers of this community have been scarcely revealed. In this study, we assessed whether the amount of light, soil pH or stand heterogeneity affect primarily the species composition of this community. We investigaed 332 sampling plots in 40–165 year old managed and abandoned Quercus cerris and Q. petraea dominated forests in North Hungary. Presence-absence data of herbaceous species and seedlings of woody species were recorded in 28 subplots within each sampling plot. Stand structure, canopy openness and soil pH were also measured in each plot. The relationships between stand characteristics and the species assemblage were explored by redundancy analysis, while the individual responses of species and species groups were studied by generalized linear mixed models. Multivariate methods and individual species response analyses provided similar results, the amount of light and soil pH were equally important variables (both of them explained 2.8% of species variance), while stand heterogeneity had a bit lower, albeit still significant role in determining understory species composition (1.9% of species variance explained). Seedlings of woody species preferred shaded (half-shaded) conditions, while many herbaceous species were positively related to light. The effect of the three explanatory variables was hard to separate, since they influenced each other as well. Sessile oak seedlings and herbs typical of dry forests, forest edges, grasslands and acidic soil habitats preferred light rich habitats with homogeneous stand structure and low soil pH. Mesic forest herbs and seedlings of other woody species were related to relatively high soil pH, heterogeneous stand structure and closed canopy. These two understory types were clearly separated regarding composition. This study emphasizes the importance of heterogenous light conditions and mosaic, diverse forest structure (presence of homogeneous and heterogeneous forest patches) during forest management for the maintenance of understory biodiversity.

Although the functional trait approach can facilitate the understanding of mechanisms that underline community responses to habitat alteration, only a few studies used this way on exploring the structure of insect assemblages compared to taxon-based analyses. We compared the descriptive power of medium-term effects (2014-2018) of forestry treatments in a temperate managed oak-dominated forest on taxon- vs. trait-based descriptors of ground beetle assemblages. The treatments included rotation forestry (partial preparation cutting, clear-cutting, retention-tree group, and mature closed forest as control) and continuous cover forestry (gap cutting) operations. The species composition was only slightly influenced by the treatments; on the ordination biplot, the control, retention tree group, and clear-cutting treatments formed relatively homogeneous groups, well separated from each other, while the others were scattered randomly in the ordination space. Over time, the species richness decreased in all treatments, but it was higher in the retention tree group treatment than in others in 2016 and 2017. The activity density also declined between years, but an immediate mass effect was revealed after the implementation of treatment types especially in the control, gap, and preparation cuts. We found that assemblages in the clear-cutting and retention-tree group had similar characteristics: high functional diversity; more open-habitat, generalist, and omnivore species and fewer carnivore species; while those in the control, gap, and preparation cutting groups had the opposite: lower functional diversity, more forest species, and more carnivorous species. Our findings will demonstrate that the simultaneous use of the two approaches will allow the most articulate understanding of the status of ground beetles assemblages in managed forests.

Harmonization of timber production and forest conservation is a major challenge of modern silviculture. For the establishment of ecologically sustainable forest management, the management-related environmental drivers of multi-taxon biodiversity should be explored. Our study reveals those environmental variables related to tree species diversity and composition, stand structure, litter and soil conditions, microclimate, landscape, and land-use history that determine species richness and composition of 11 forest-dwelling organism groups. Herbs, woody regeneration, ground-floor and epiphytic bryophytes, epiphytic lichens, terricolous saprotrophic, ectomycorrhizal, and wood-inhabiting macrofungi, spiders, carabid beetles, and birds were sampled in West Hungarian mature mixed forests. The correlations among the diversities and compositions of different organism groups were also evaluated. Drivers of organism groups were principally related to stand structure, tree species diversity and composition, and microclimate, while litter, soil, landscape, and land-use historical variables were less influential. The complex roles of the shrub layer, deadwood, and the size of the trees in determining the diversity and composition of various taxa were revealed. Stands with more tree species sustained higher stand-level species richness of several taxa. Besides, stands with different dominant tree species harbored various species communities of organism groups. Therefore, landscape-scale diversity of dominant tree species may enhance the diversity of forest-dwelling communities at landscape level. The effects of the overstory layer on forest biodiversity manifested in many cases via microclimate conditions. Diversity of organism groups showed weaker relationship with the diversity of other taxa than with environmental variables. According to our results, the most influential drivers of forest biodiversity are under the direct control of the actual silvicultural management. Heterogeneous stand structure and tree species composition promote the different organism groups in various ways. Therefore, the long-term maintenance of the structural and compositional heterogeneity both at stand and landscape scale is an important aspect of ecologically sustainable forest management.

Aims: Primary forests are critical for forest biodiversity and provide key ecosystem services. In Europe, these forests are particularly scarce and it is unclear whether they are sufficiently protected. Here we aim to: (a) understand whether extant primary forests are representative of the range of naturally occurring forest types, (b) identify forest types which host enough primary forest under strict protection to meet conservation targets and (c) highlight areas where restoration is needed and feasible. Location: Europe. Methods: We combined a unique geodatabase of primary forests with maps of forest cover, potential natural vegetation, biogeographic regions and protected areas to quantify the proportion of extant primary forest across Europe's forest types and to identify gaps in protection. Using spatial predictions of primary forest locations to account for underreporting of primary forests, we then highlighted areas where restoration could complement protection. Results: We found a substantial bias in primary forest distribution across forest types. Of the 54 forest types we assessed, six had no primary forest at all, and in two-thirds of forest types, less than 1% of forest was primary. Even if generally protected, only ten forest types had more than half of their primary forests strictly protected. Protecting all documented primary forests requires expanding the protected area networks by 1,132km2 (19,194km2 when including also predicted primary forests). Encouragingly, large areas of non-primary forest existed inside protected areas for most types, thus presenting restoration opportunities. Main conclusion: Europe's primary forests are in a perilous state, as also acknowledged by EU's “Biodiversity Strategy for 2030.” Yet, there are considerable opportunities for ensuring better protection and restoring primary forest structure, composition and functioning, at least partially. We advocate integrated policy reforms that explicitly account for the irreplaceable nature of primary forests and ramp up protection and restoration efforts alike.

In recent decades, alternative management techniques integrating conservation concerns into industrial forestry have become increasingly widespread. In order to compare the effects of various management methods on forest site and biodiversity, a systematic forestry experiment was conducted in a managed, mature oak–hornbeam forest. The present work introduces the 2-year responses of environmental variables and understory vegetation to different silvicultural treatments. These belong either to clear-cutting (clear-cutting, retention tree group), to shelterwood (preparation cutting), or to continuous cover forestry systems (gap-cutting). The experiment follows a complete block design with four replicates. Light availability was significantly higher in all the treatments than in the uncut control, with highest values in the clear-cuts. Soil moisture was highest in the gap-cuts and clear-cuts, while in the retention tree group, it did not differ from the control. Species richness, cover, and height of the understory considerably differed from the control in the clear-cuts and gap-cuts, while in the retention tree group, only species richness was higher. The establishment of ruderal, non-forest species altered the species composition in the clear-cuts. Based on these short-term responses, we conclude that as a result of the extreme environmental changes, clear-cutting in oak–hornbeam forests changes the understory vegetation considerably. Retention tree groups can maintain legacies of the understory composition for some years. Despite the experienced high vegetation cover, gap-cutting preserves the forest characteristics of the understory better than clear-cutting. These results confirm that in oak–hornbeam forests, continuous cover forestry may be more sustainable from conservational aspect than clear-cutting system.

Ecological studies may produce presence-absence data sets for different taxonomic groups, with varying spatial resolution and temporal coverage. Comparisons of these data are needed to extract meaningful information on the background ecological factors explaining community patterns, to improve our understanding of how beta diversity and its components vary among communities and biogeographical regions, and to reveal their possible implications for biodiversity conservation. A methodological difficulty is that the number of sampling units may be unequal: no method has been designed as yet to compare data matrices in such cases. The problem is solved by converting presence-absence data matrices to simplex plots based on the decomposition of Jaccard dissimilarity into species replacement and richness difference fractions used together with the complementary similarity function. Pairs of simplex plots representing different data matrices are then compared by quantifying, for each of them, the relative frequency of points in small, pre-defined subregions of the simplex, and then calculating a divergence function between the two frequency distributions. Given more than two data matrices, classification and ordination techniques may be used to obtain a synthetic and informative picture of metacommunity structure. We demonstrate the potential of our data analytical model by applying it to different case studies spanning different spatial scales and taxonomic levels (Mediterranean Island faunas; Finnish stream macroinvertebrate assemblages; Hungarian forest assemblages), and to a study of temporal changes in small islands (insect fauna in Florida). We conclude that, by accounting for various structural aspects simultaneously, the method permits a thorough ecological interpretation of presence-absence data. Furthermore, the examples illustrate succinctly how similarity, beta diversity and two of its additive components, species replacement and richness difference influence presence-absence patterns under different conditions.

One of the main goals of the EU Biodiversity Strategy for 2030 is to avoid further loss of biodiversity and to restore ecosystems. These efforts can be facilitated by compiling the main research topics related to conservation biology to provide new evidence for the most urgent knowledge gaps, and publicise it to researchers, research funders and policy makers. We used the possible future statements from the Hungarian Environmental Foresight Report for 2050 which identified region-specific problems. To highlight likely future environmental and conservation questions, in this study we asked researchers from the fields of ecology and conservation to define research questions addressing these future statements in line with international research trends and challenges. The study resulted in fourteen priority research topics, split into seven clusters relevant to biological conservation that should be targeted by stakeholders, primarily policy makers and funders to focus research capacity to these topics. The main overarching themes identified here include a wide range of approaches and solutions such as innovative technologies, involvement of local stakeholders and citizen scientists, legislation, and issues related to human health. These indicate that solutions to conservation challenges require a multidisciplinary approach in design and a multi-actor approach in implementation. Although the identified research priorities were listed for Hungary, they are in line with European and global biodiversity strategies, and can be tailored to suit other Central and Eastern European countries as well. We believe that our prioritisation can help science–policy discussion, and will eventually contribute to healthy and well-functioning ecosystems.

Correction to: Biologia The original version of the article was published as first online in Biologia on 18 June 2021. Unfortunately, the original version of this article contains a mistake in the Material and Methods section (Page 3, lines 19–22 in the first section) in terms of body/tag mass ratio for insects, please find the corrected statement below

The structure and composition of temperate old-growth oak forests are reviewed based on 108 case studies about 175 stands. The stands were classified as dry, dry-mesic and mesic forest types and the variables (density, basal area, size distribution, dead wood volume) were compared among them. Compared to the global range of this forest type, the United States was overrepresented, while West and Central Asia, Europe and Central America were underrepresented. In mesic oak forests the basal area and density of large trees were higher than in dry stands, while tree density and sapling density were lower. The proportion of oaks in tree and sapling layers were the highest in dry and lowest in mesic forests. The size distribution of trees followed negative exponential or rotated sigmoid types. In dry habitats all size categories are dominated by oaks, while in mesic type, only large ones followed the same trend. The volume of dead wood and the proportion of downed dead wood increased along the humidity gradient. In stands with repeated measurements, basal area and relative density of oaks decreased in the last decades. The understanding of the structure and composition of temperate old-growth oak forests is necessary for their restoration and application of close to nature forestry principles.

The lack of natural references of dry-mesic oak forests creates conceptual obstacles for their conservation and close-to-nature management in Central Europe. Single-tree inventory was used to investigate stand characteristics and old-growth attributes of a Quercus petraea (Matt.) Liebl. and Q. cerris L. dominated, 120-year-old stand in a Hungarian forest reserve, abandoned approximately 40 years ago. All individuals were recorded with diameter ≥ 5 cm on the 3 ha study site. Logs, stumps, saplings and seedlings were also surveyed. 582 woody stem/ha belonging to 14 species were measured with single-tree inventory. Basal area values showed the total dominance of oaks in the canopy layer (99%) as a legacy of the long-term human exploitation. In contrast, young individuals of oak species were almost missing, and Acer campestre L. dominated the lower layers, indicating the transitional nature of the stand. Diameter classes showed a marked bimodal distribution. Both the abandonment of the reserve and the precedent severe oak decline contributed to the relatively high amount of dead wood (46 m3/ha). Four decades of abandonment is rather short time interval to generate a diverse forest composition and structure in a mature dry-mesic oak forest. The dense regeneration and shrub layer and the upsurgence of admixing species indicate the shift towards the uneven-aged and compositionally more diverse old-growth oak forest state. Among the structural forest features the dead wood had similar values as old-growth forests. If the recent trend continues, the studied oak forest develops towards a mixed forest with significantly lower ratio of oak species.

Dead wood (DW) has great importance for many wildlife species and ecological processes. The volume of DW is considered a useful indicator of the sustainability and maintenance of biodiversity in forests. Though dry-mesic oak forests cover large areas in Hungary, little is known about DW quantities or dynamics in these forests. We investigated DW conditions in five age classes of dry-mesic Quercus petraea and Q. cerris dominated forests in the Hungarian Carpathians. Stands of the first four age classes (age class 1: 40–59, age class 2: 60–79, age class 3: 80–99, age class 4: 100–119 years old) were managed and stands at least 120 years old were unmanaged at least for 30 years (age class 5). We measured the volume, density, dominance and size distribution of standing DW and volume of downed DW. We also evaluated the decay stages of DW on an ordinal scale (I-V, intact to well-decayed). The effect of age class on the derived variables such as density, dominance, volume or proportion of DW was analysed with general linear mixed models using age class as a fixed and region as a random effect. Mean total DW volume did not reach 15 m3/ha in age class 1, 2 and 3. A much larger volume of DW was found in age class 4 and 5, where the mean total volume of DW was 36.9 and 45.1 m3/ha, respectively. Volume and proportion of total DW over 30 cm in diameter were markedly lower in age classes 1, 2 and 3 than in age classes 4 and 5, moreover standing and downed DW over 30 cm in diameter were totally absent in stands under 100 years old. The proportion of well-decomposed (decay stage IV and V) DW was much lower (3–18% of the volume) in all five age classes than in old-growth stands of dry-mesic oak forests. After three decades of non-intervention (age class 5), the volume of DW can approach that of old-growth forests. The 40–99-year old stands contained a similarly low percentage of DW as other managed dry-mesic oak forests in Europe. Based on the results, it is likely that stands greater than 100 years old will support much higher biodiversity of saproxylic organisms compared to younger stands.

Direct measurements of aboveground plant biomass are often not feasible, thus various biomass proxies are in use. To obtain biomass estimates, these proxies are calibrated against actual biomass, and the resulting proxy-biomass relationship is often used across multiple years and experimental treatments within a study. We investigated how the proxy-biomass relationship varied across years and considered interannual precipitation variability as a contributing factor. We sampled a perennial grassland for ten consecutive years (2003–2012) in central Hungary and estimated vegetation cover and Normalized Difference Vegetation Index (NDVI); two frequently used biomass proxies representing two contrasting methods. Aboveground live herbaceous plant biomass was harvested from each plot after sampling, and regression models were used to assess the relationship between biomass proxies and actual aboveground biomass. We found that cover and NDVI were equally effective at estimating biomass. However, the relationship between either biomass proxy and actual biomass varied amongst years, and this was related to the amount of precipitation. In wetter years, proxy-biomass relationships were steeper than in drier years. These results indicate that using the same proxy-biomass relationship across different years or precipitation regimes may not be valid and may introduce systematic error into biomass estimations in long-term studies or precipitation manipulation experiments.

Many studies have underlined the fact that once forest continuity is broken, communities of wood-inhabiting organisms may never be restored to their original status. However, only a few studies have actually presented results from sites that have current old-growth structure, and where the history of human interventions is known. In this study we compared the species richness, nestedness, beta diversity, and composition of bryophytes from living trunks and dead logs of beech (Fagus sylvatica) in seven forest stands in the Czech Republic with old-growth structure and various histories of past human impact. Our analysis showed that these communities are nested and that their beta diversity is lower than random. There was a significant proportion of shared species, and rare species were present only in the most heterogeneous and the least man affected habitats. We found that bryophyte communities of forests with more intensive past management were significantly impoverished in terms of both species richness and composition. Beta diversity was not related to management history and reflected current habitat heterogeneity. The effect of decay stage on species richness and beta diversity was stronger than the site effect. Our results demonstrate that the protection of current natural beech-dominated forests and improvements to their connectivity in fragmented landscapes are crucial for the survival and restoration of the diversity of wood-inhabiting bryophytes.

Aboveground plant biomass is one of the most important features of ecosystems, and it is widely used in ecosystem research. Non-destructive biomass estimation methods provide an important toolkit, because the destructive harvesting method is in many cases not feasible. However, only few studies have compared the accuracy of these methods in grassland communities to date. We studied the accuracy of three widely used methods for estimation of aboveground biomass: the visual cover estimation method, the point intercept method, and field spectroscopy. We applied them in three independent series of field samplings in semi-arid sand grasslands in Central Hungary. For each sampling method, we applied linear regression to assess the strength of the relationship between biomass proxies and actual aboveground biomass, and used coefficient of determination to evaluate accuracy. We found no evidence that the visual cover estimation, which is generally considered as a subjective method, was less accurate than point intercept method or field spectroscopy in estimating biomass. Based on our three datasets, we found that accuracy was lower for the point intercept method compared to the other two methods, while field spectroscopy and visual cover estimation were similar to each other in the semi-arid sand grassland community. We conclude that visual cover estimation can be as accurate for estimating aboveground biomass as other approaches, thus the choice amongst the methods should be based on additional pros and cons associated with each of the method and related to the specific research objective.

The complex interactions between stand characteristics and forest site variables result in specific understory microclimate conditions, which are essential for many forest-dwelling organism groups. The main aim of our study was to evaluate the relative importance of stand structure variables and landscape elements that account for the microclimate in closed, managed, mature forest stands. The relationships between different microclimatic variables were also analyzed. 35, 70–100 year-old deciduous-coniferous mixed forest stands were selected in Western Hungary. Air temperature, relative humidity, and relative diffuse light were measured at eight sampling periods between 2009 and 2011. Below-canopy air temperature and humidity showed a strong negative correlation, but diffuse light was independent. The mean values of air temperature and humidity depended on stand structure elements, chiefly on the subcanopy and shrub layer, while their variance was lowered by litter cover. The amount of diffuse light was negatively affected by tree diameter, basal area and tree size diversity. Our results suggest that structural elements have a stronger influence on microclimate conditions than tree species composition of the overstory. The midstory and the shrub layer play key roles in maintaining the special microclimate of forests with continuous canopy-cover. Our results can provide adoptable aspects for forest management and nature conservation for the maintenance of the specific conditions favorable to sensitive forest specialist taxa (e.g. forest herbs, forest-dwelling ground beetles, epiphytic bryophytes, and lichens).

Light is one of the most important drivers of understory vegetation in forests, influencing the patterns of total cover as well as the abundance of individual species. Based on a multi-scale approach, the relationships between the amount and pattern of relative diffuse light and forest understory were studied in an old-growth, temperate mixed forest (Hungary). The recorded vegetation variables were the cover of the vascular understory (herbs, woody seedlings), the bryophyte layer, and some selected vascular understory species. The pattern of light showed aggregations at two scales: 10 × 10 and 25 × 25 m. Both vascular understory and bryophyte cover had significant positive correlations with light availability, and their spatial pattern was related to it. The pattern of seedlings displayed the strongest relationships with that of light at a coarser scale (25 × 25 m) than herbs and bryophytes (10 × 10 m). At the species level, Festuca heterophylla , Fragaria vesca and Poa nemoralis were characterized as light-demanding herbaceous species (their spatial pattern was congruent with light), Brachypodium sylvaticum and Carex pallescens were transitional, while some species proved to be shade-tolerant (e.g. Ajuga reptans , Dryopteris carthusiana , Viola reichenbachiana ). Regarding seedlings, the patterns of Betula pendula , Carpinus betulus , Pinus sylvestris and Quercus petraea were related to the pattern of light. According to our observations, diversity and composition of vascular forest understory and bryophytes were related to heterogeneous light conditions. Forest management should maintain continuous shelter on the stand level; however, smaller gaps are necessary for the survival of light-demanding forest herbs and bryophytes, and larger gaps for tree seedlings.

A stable below‐canopy microclimate of forests is essential for their biodiversity and ecosystem functionality. Forest management necessarily modifies the buffering capacity of woodlands. However, the specific effects of different forestry treatments on site conditions, the temporal recovery after the harvests, and the reason for the contrasts between treatments are still poorly understood. The effects of four different forestry treatments (clear‐cutting, retention tree group, preparation cutting, and gap‐cutting) on microclimatic variables were studied within a field experiment in a managed oak‐dominated stand in Hungary, before (2014) and after (2015–2017) the interventions by complete block design with six replicates. From the first post‐treatment year, clear‐cuts differed the most from the uncut control due to the increased irradiance and heat load. Means and variability of air and soil temperature increased, air became dryer along with higher soil moisture levels. Retention tree groups could effectively ameliorate the extreme temperatures but not the mean values. Preparation cutting induced slight changes from the original buffered and humid forest microclimate. Despite the substantially more incoming light, gap‐cutting could retain the cool and humid air conditions and showed the highest increase in soil moisture after the interventions. For most microclimate variables, we could not observe any obvious trend within 3 yr. However, soil temperature variability decreased with time in clear‐cuts, while soil moisture difference continuously increased in gap‐ and clear‐cuts. Based on multivariate analyses, the treatments separated significantly based mainly on the temperature maxima and variability. We found that (1) the effect sizes among treatment levels were consistent throughout the years, (2) the climatic recovery time for variables appears to be far more than 3 yr, and (3) the applied silvicultural methods diverged mainly among the temperature maxima. Based on our study, the spatially heterogeneous and fine‐scaled treatments of continuous cover forestry (gap‐cutting, selection systems) are recommended. By applying these practices, the essential structural elements creating buffered microclimate could be more successfully maintained. Thus, forestry interventions could induce less pronounced alterations in environmental conditions for forest‐dwelling organism groups.

Policies to mitigate climate change and biodiversity loss often assume that protecting carbon-rich forests provides co-benefits in terms of biodiversity, due to the spatial congruence of carbon stocks and biodiversity at biogeographic scales. However, it remains unclear whether this holds at the scales relevant for management, with particularly large knowledge gaps for temperate forests and for taxa other than trees. We built a comprehensive dataset of Central European temperate forest structure and multi-taxonomic diversity (beetles, birds, bryophytes, fungi, lichens, and plants) across 352 plots. We used Boosted Regression Trees to assess the relationship between above-ground live carbon stocks and (a) taxon-specific richness, (b) a unified multidiversity index. We used Threshold Indicator Taxa ANalysis to explore individual species' responses to changing above-ground carbon stocks and to detect change-points in species composition along the carbon-stock gradient. Our results reveal an overall weak and highly variable relationship between richness and carbon stock at the stand scale, both for individual taxonomic groups and for multidiversity. Similarly, the proportion of win-win and trade-off species (i.e. species favored or disadvantaged by increasing carbon stock, respectively) varied substantially across taxa. Win-win species gradually replaced trade-off species with increasing carbon, without clear thresholds along the above-ground carbon gradient, suggesting that community-level surrogates (e.g. richness) might fail to detect critical changes in biodiversity. Collectively, our analyses highlight that leveraging co-benefits between carbon and biodiversity in temperate forest may require stand-scale management that prioritizes either biodiversity or carbon-in order to maximize co-benefits at broader scales. Importantly, this contrasts with tropical forests, where climate [...], Pre-review Version 2018, 07\23 + Supplementary information 43 Pages, 5 figures + 9 supplementary Figures

Herbaceous understory vegetation is an important part of temperate forested ecosystems, the diversity and composition of which are strongly dependent on the conditions of the forest stand and the landscape. The aim of this study was to find the most important environmental drivers influencing understory herb layer species composition (explored with multivariate analysis), and richness and cover (analysed by linear modelling) in managed mixed forests in West Hungary. Our detailed inventory showed that the most important factors increasing the diversity and cover of the understory are light, tree species richness, and landscape diversity. Composition is also mainly influenced by light conditions and tree species richness, with minor effects of tree species composition, soil texture, and moss cover. As the strongest influencing factors are closely linked to stand structure and tree species composition, they can either directly or indirectly be altered by forest management. In the studied region, heterogeneous light conditions and canopy structure, the maintenance of tree species richness and forest continuity are key elements for the conservation of forest herbs. Forestry that maintains continuous forest cover and the tree selection management system can better provide these conditions than the presently widely used shelterwood management system.

Species richness, composition and abundance of the bryophyte diaspore bank of Central European temperate mixed forests were compared with the forest-floor bryophyte assemblage. The impact of environmental variables and anthropogenic disturbances, including tree species composition, stand structure, microclimate, light conditions, soil and litter properties, management history, and landscape properties, potentially influencing bryophyte diaspore bank assemblages were explored. Thirty-four, 70–100 years old mixed stands with differing tree species composition were examined in the Őrseg National Park, Western Hungary. The diaspore bank was studied by soil collection and cultivation, and data were analysed by multivariate methods. Contrary to the forest-floor bryophyte assemblage, where substrate availability, tree species composition and stand structure were the most influential environmental variables, the composition and abundance of the diaspore bank was mainly affected by site conditions (microclimate, l...

In September 2011, an international team of cryptogam experts visited seven national nature reserves in five mountain areas of Slovakia: Havesova and Stužica in the Poloniny Mts., Vihorlat in the Vihorlatske vrchyMts., Oblik in the Slanske vrchyMts., Dobrocský prales and Klenovský Vepor in the Veporske vrchy Mts. and Badinsky prales in the Kremnicke vrchy Mts. The reserves were selected to represent examples of the best protected old-growth beech forests in the country. The aim was to study the diversity of wood-inhabiting fungi on fallen beech logs and epiphytic lichens on standing beech trees. In total, 215 fungal species and 128 lichens were recorded on beech wood and bark, and 27 fungi and 26 lichens on additional substrates. The site of the highest conservation value is Stužica with 126 fungi and 79 lichens recorded on beech, of which 12 fungi and 19 lichens are indicators of high nature conservation value. Combined with historical records, a total of 19 non-lichenised fungal indicators are now reported from the site, making it the highest ranked natural beech forest in Europe. The second most important reserve for fungal diversity is Havesova with 121 species, including 14 indicator species recorded on beech wood. For lichens, the second most important reserve is Klenovský Vepor with 69 species including 18 lichen indicators recorded on beech. Nine fungus species are here reported as new to Slovakia: Asterostroma medium, Entoloma hispidulum, E. pseudoparasiticum, Gloeohypochnicium analogum, Hohenbuehelia valesiaca, Hymenochaete ulmicola, Hypocrea parmastoi, Melanomma spiniferum and Scutellinia colensoi. Lichen species Alyxoria ochrocheila is reported as new to Slovakia and Lecanographa amylacea, which was considered extinct in the Slovak Red list, was also recorded. This is the first list of wood-inhabiting fungi and epiphytic lichens of old-growth beech forests in Slovakia, and hence an important contribution to the exploration of biodiversity in Slovakia.

Lowland rivers and their floodplains have changed markedly over the last centuries. River dikes have become among the most extensive secondary habitats of former floodplains. Our main question was, what role do secondary habitats on river dikes play in harbouring plant species and maintaining plant diversity of lowland landscapes dominated by agricultural areas? We compared historical maps and current habitat maps to understand the effects of landscape changes on the vegetation pattern of the study region, in southern Hungary. Dikes and primary vegetation of the landscape were selected for intensive vegetation sampling. We compared the floristic similarity and the Shannon diversity of the vegetation types. We used ordinations to visualize relationships among the vegetation types and among dike vegetation and environmental variables. Our results indicated that profound changes have been brought about in the vegetation during the last 150 years, resulting in a transition from marshland to agricultural land. The species composition and pattern of dike vegetation strongly depended on their relative position to the river and their aspect. We conclude that dikes can harbour many vascular plants that are absent or rare in the surrounding habitats and therefore play a decisive role in maintaining plant diversity in agricultural landscapes.

The effects of stand structure, tree species composition, proportion of habitat types and land use history on breeding bird assemblages in temperate mixed forests in Western Hungary were studied. The species richness, the abundance and the composition of the whole breeding bird assemblage and of some groups formed on the basis of nesting site and rarity were examined. Stand structural variables had the highest impact on the breeding bird assemblage, while tree species composition, the varying proportion of vegetation types and land use history had no significant effect. In the case of the species richness, the abundance and the composition of the whole assemblage, the most important variables were the mean diameter of trees, the vegetation cover of the forest floor and the dead wood volume. The explained variance in the linear models of different groups varied between 20% and 60%, and the relative importance of these three variables also differed considerably. These results indicate that forest management may considerably influence the diversity and the composition of birds, as all the structural elements affecting birds deeply depend on it. Within the shelterwood management system, the elongation of the rotation and regeneration periods, and the relatively high proportion of retention tree groups after harvest could contribute to the conservation of forest birds. Our results also showed that for the forest bird communities, both the prevalence of big trees and the presence of a dense understory layer are important. Management regimes which apply continuous forest cover might be more appropriate for providing these structural elements simultaneously on small spatial scales, and for the maintenance of a more diverse bird community, thus healthier forest ecosystems.

Ecological, economic, and social demands triggered a shift in the management of temperate deciduous forests from rotation forestry system towards more nature-based forest management techniques such as continuous cover forestry. However, there is insufficient knowledge on the regeneration success of different tree species—especially oaks—within this management system. Through a systematic experiment, we compared the regeneration processes of a sessile oak-hornbeam forest after gap-cutting (as an element of continuous cover forestry system) to regeneration after clear-cutting, preparation cutting, and in retention tree groups (treatments of rotation forestry system). A managed, closed, mature forest was used as control. Several different aspects of the regeneration were studied: (1) seed supply of sessile oak—Quercus petraea (Matt.) Liebl., (2) species number and abundance of the natural regeneration, (3) survival and growth of individual saplings of five tree species (sessile and Turkey oak—Quercus cerris L., hornbeam—Carpinus betulus L., beech—Fagus sylvatica L., and common ash—Fraxinus excelsior L.). The number of acorns was high in closed forest, intermediate in preparation cutting and retention tree group, low in gaps, and zero in clear-cutting. Four years after the interventions, there was no detectable treatment effect on the species number of regeneration. Survival increased in every treatment compared to control, but there was no significant difference in this measure between the differently treated sites. Height growth was highest in the gaps and clear-cuts, intermediate in preparation cuts, and lowest in retention tree groups and controls. Species with different seed dispersal mechanisms responded differently to treatments: oaks were dispersal-limited in the gaps and clear-cuts, while anemochorous species (e.g., hornbeam and manna ash) were present in every treatment. The survival and growth pattern of the particular species proved to be similar, but the intensity of the response differed: shade-tolerants (hornbeam, beech, and ash) showed better survival than oaks in most treatments, and their height growth was larger. According to our results, oak regeneration establishes successfully in oak-hornbeam forests not only in the case of rotation forestry, but also during continuous cover forestry (gap-cutting). The survival and growth of the saplings are similar in cutting areas and gaps, but keeping in mind other considerations (such as preserving forest continuity, balanced site conditions, and forest biodiversity), continuous cover forestry should be preferred.

There are only few studies that explore the ecological consequences of forest management on several organism groups. We studied the short-term effects of four forestry treatments including preparation cutting, clear-cutting, retention tree group and gap-cutting in a temperate managed forest on the assemblage structure of understory plants, enchytraeid worms, spiders and ground beetles. Here we show, that the effect of treatments on the different facets of assemblage structure was taxon-specific. Clear-cutting and retention tree group strongly impoverished enchytraeids assemblages. Even if the species richness and cover of plants increased in clear-cutting and gap-cutting, their species composition moderately changed after treatments. For spiders only their species composition was influenced by the treatments, while the response of ground beetles was slightly affected. Short-term effect of forest management interventions on biodiversity might be compensated by the dispersal (spiders, ground beetles) and resilience (plants) of organism groups, however sedentary soil organism showed high sensitivity.