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High invasiveness and well-documented negative impact on biodiversity and ecosystem functioning make Solidago canadensis L. a species of global concern. Despite a good understanding of the driving factors of its invasions, it remains unclear how the surrounding landscape may shape invasion success of this species in human-transformed ecosystems. In our study, we investigated the impacts of different landscape features in the proximity of early successional wastelands on S. canadensis biomass allocation patterns. Further, we examined the relationships between the surrounding landscape, S. canadensis cover, and plant functional diversity, used as a supportive approach for the explanation of mechanisms underlying successful S. canadensis invasion. We found that increasing river net length had positive impacts on S. canadensis rhizome, stem, and total above ground biomass, but negative effects on leaf biomass, indicating that vegetative spread may perform the dominant role in shaping the competitiveness of this invader in riverine landscapes. A higher proportion of arable lands positively influenced S. canadensis above ground and flower biomass; thus promoting S. canadensis invasion in agricultural landscapes with the prominent role of habitat filtering in shaping vegetation structure. Concerning an increasing proportion of settlements, flower biomass was higher and leaf biomass was lower, thereby influencing S. canadensis reproductive potential, maximizing the odds for survival, and indicating high adaptability to exist in an urban landscape. We demonstrated high context-dependency of relationships between functional diversity components and surrounding landscape, strongly influenced by S. canadensis cover, while the effects of surrounding landscape composition per se were of lower importance. Investigating the relationships between the surrounding landscape, invasive species performance, and plant functional diversity, may constitute a powerful tool for the monitoring, controlling, and predicting of invasion progress, as well as the assessment of ecosystem invasibility.

Investigating the direction of changes in functional diversity involving successional pathways and historical disturbances may be a promising tool for predictions of the effectiveness of the seminatural meadows conservation, with great emphasis on formulation of more cost‐effective restoration strategies. The goal of this research was to assess the differences in long‐term shifts in the functional diversity of plant species in seminatural wet meadows unmanaged for the last 40 years, under the influence of different successional pathways and historical disturbances. Using ordination techniques, linear mixed‐effect models, a set of plant functional traits and parameters of functional diversity, we assessed the importance of habitat filtering, competition, and niche partitioning in shaping community assembly changes over time. The most dramatic shifts in functional diversity were found in the Carex acutiformis successional pathway after topsoil removal, where colonization by successional inhibitors was the main driver causing decreases in functional dispersion and divergence. This was expressed as a decrease in the importance of habitat filtering and replacement of specialized species by competitors with heavier seeds and higher specific leaf area. Regarding the C. cespitosa and Salix cinerea pathways, the magnitudes of shifts in functional diversity were milder and differed less between the historical topsoil removal and mowing treatments, thereby maintaining a large role for niche partitioning in shaping the vegetation structure. The results of our study highlight the importance of tussock sedges and shrubs as effective buffers against the functional homogenization of meadows driven by the decreases in functional diversity of plant species, even from a long‐term perspective., The goal of this research was to assess the differences in long‐term shifts in the functional diversity of plant species in seminatural wet meadows unmanaged for the last 40 years, under the influence of different successional pathways and historical disturbances. The most dramatic shifts in functional diversity were found in the Carex acutiformis successional pathway after topsoil removal, where colonization by successional inhibitors was the main driver causing decreases in functional dispersion and divergence. Regarding the C. cespitosa and Salix cinerea pathways, the magnitudes of shifts in functional diversity were milder and differed less between the historical topsoil removal and mowing treatments, thereby maintaining a large role for niche partitioning in shaping the vegetation structure. The results of our study highlight the importance of tussock sedges and shrubs as effective buffers against the biotic homogenization of meadows driven by the simplification of functional composition, even from a long‐term perspective.

Current trends emphasize the importance of the examination of the functional composition of lichens, which may provide information on the species realized niche diversity and community assembly processes, thus enabling one to understand the specific adaptations of lichens and their interaction with the environment. We analyzed the distribution and specialization of diverse morphological, anatomical and chemical (lichen secondary metabolites) traits in lichen communities in a close-to-natural forest of lowland Europe. We considered these traits in relation to three levels of forest ecosystem organization: forest communities, phorophyte species and substrates, in order to recognize the specialization of functional traits to different levels of the forest complexity. Traits related to the sexual reproduction of mycobionts (i.e., ascomata types: lecanoroid apothecia, lecideoid apothecia, arthonioid apothecia, lirellate apothecia, stalked apothecia and perithecia) and asexual reproduction of mycobionts (pycnidia, hyphophores and sporodochia) demonstrated the highest specialization to type of substrate, tree species and forest community. Thallus type (foliose, fruticose, crustose and leprose thalli), ascospore dark pigmentation and asexual reproduction by lichenized diaspores (soredia and isidia) revealed the lowest specialization to tree species and substrate, as well as to forest community. Results indicate that lichen functional trait assemblage distribution should not only be considered at the level of differences in the internal structure of the analyzed forest communities (e.g., higher number of diverse substrates or tree species) but also studied in relation to specific habitat conditions (insolation, moisture, temperature, eutrophication) that are characteristic of a particular forest community. Our work contributes to the understanding of the role of the forest structure in shaping lichen functional trait composition, as well as enhancing our knowledge on community assembly rules of lichen species.

© 2021 The Authors., Aims: Understanding fine-grain diversity patterns across large spatial extents is fundamental for macroecological research and biodiversity conservation. Using the GrassPlot database, we provide benchmarks of fine-grain richness values of Palaearctic open habitats for vascular plants, bryophytes, lichens and complete vegetation (i.e., the sum of the former three groups). Location: Palaearctic biogeographic realm. Methods: We used 126,524 plots of eight standard grain sizes from the GrassPlot database: 0.0001, 0.001, 0.01, 0.1, 1, 10, 100 and 1,000 m and calculated the mean richness and standard deviations, as well as maximum, minimum, median, and first and third quartiles for each combination of grain size, taxonomic group, biome, region, vegetation type and phytosociological class. Results: Patterns of plant diversity in vegetation types and biomes differ across grain sizes and taxonomic groups. Overall, secondary (mostly semi-natural) grasslands and natural grasslands are the richest vegetation type. The open-access file ”GrassPlot Diversity Benchmarks” and the web tool “GrassPlot Diversity Explorer” are now available online (https://edgg.org/databases/GrasslandDiversityExplorer) and provide more insights into species richness patterns in the Palaearctic open habitats. Conclusions: The GrassPlot Diversity Benchmarks provide high-quality data on species richness in open habitat types across the Palaearctic. These benchmark data can be used in vegetation ecology, macroecology, biodiversity conservation and data quality checking. While the amount of data in the underlying GrassPlot database and their spatial coverage are smaller than in other extensive vegetation-plot databases, species recordings in GrassPlot are on average more complete, making it a valuable complementary data source in macroecology., GrassPlot development has been supported by the Bavarian Research Alliance (BayIntAn_UBT_2017_58), the Eurasian Dry Grassland Group (EDGG) and the International Association for Vegetation Science (IAVS); IB, CorM, JAC, IGM, DGM, MHe, DL and MTo were supported by the Basque Government (IT936‐16); CorM, IAx, MCh, JDa, PD, MHá, ZL, ZPr, EŠ and LT were supported by the Czech Science Foundation (19‐28491X); TR was supported by the Estonian Research Council (PUT1173); RJP was funded by the Strategic Research Programme of the Scottish Government’s Rural and Environmental Science and Analytical Services Division”; SBa was supported by the GINOP‐2.3.2‐15‐2016‐00019 project; GFi was partially supported by the MIUR initiative “Department of excellence” (Law 232/2016)"; BJA was funded by the Spanish Research Agency (grant AEI/ 10.13039/501100011033); AK, VB, IM, DS, IV and DV were supported by the National Research Foundation of Ukraine (2020.01/0140); MP and AH were supported by the Estonian Research Council (PRG874, PRG609), and the European Regional Development Fund (Centre of Excellence EcolChange); Data collection of HCP was funded by FORMAS (Swedish Research Council for Environment, Agricultural Science and Spatial Planning) and The Swedish Institute; JR was supported by the Czech Science Foundation (grant No. 20‐09895S) and the long‐term developmental project of the Czech Academy of Sciences (RVO 67985939); ATRA was funded by the Grant of Excellence Departments, MIUR‐Italy (ARTICOLO 1, COMMI 314 – 337 LEGGE 232/2016); JMA was supported by Carl Tryggers stiftelse för vetenskaplig forskning and Qatar Petroleum; AAli was supported by the Jiangsu Science and Technology Special Project (Grant No. BX2019084), and Metasequoia Faculty Research Startup Funding at Nanjing Forestry University (Grant No. 163010230), and he is currently supported by Hebei University through Faculty Research Startup Funding Program; ZB was supported by the NKFI K 124796 grant; The GLORIA‐ Aragón project of JLBA was funded by the Dirección General de Cambio Climático del Gobierno de Aragón (Spain); MCs and LDem were supported by DG Environment through the European Forum on Nature Conservation and Pastoralism and Barbara Knowles Fund, in collaboration with Pogány‐havas Association, Romania; JDa was partially supported by long‐term research development project no. RVO 67985939 of the Czech Academy of Sciences; BD and OV were supported by the NKFI KH 126476, NKFI KH 130338, NKFI FK 124404 and NKFI FK 135329 grants; BD, OV and AKe were supported by the Bolyai János Scholarship of the Hungarian Academy of Sciences; BE was funded by the Environmental Department of the Tyrolean Federal State Government, the MAB Programme of the Austrian Academy of Science, the Mountain Agriculture Research Unit and the Alpine Research Centre Obergurgl of Innsbruck University. The GLORIA projects of BE were funded by the EU project no. EVK2‐CT‐2000‐00056, the Earth System Sciences Program of the Austrian Academy of Sciences (project MEDIALPS), the Amt für Naturparke, Autonome Provinz Bozen‐Südtirol, the Südtiroler Wissenschaftsfonds and the Tiroler Wissenschaftsfonds; RGG was supported by the Spanish Ministry of Research to sample GLORIA sites in central Spain (CGL 2008‐00901/BOS) and present works by the Autonomous Region of Madrid (REMEDINAL TE‐CM, S2018/EMT‐4338); MJ was supporteLatviaed by Latvia Grant No. 194051; NP and SŠ were partly supported by the Slovenian Research Agency, core fundings P1‐0403 and J7‐1822.

Globally accelerating trends in societal development and human environmental impacts since the mid-twentieth century 1–7 are known as the Great Acceleration and have been discussed as a key indicator of the onset of the Anthropocene epoch 6 . While reports on ecological responses (for example, changes in species range or local extinctions) to the Great Acceleration are multiplying 8, 9 , it is unknown whether such biotic responses are undergoing a similar acceleration over time. This knowledge gap stems from the limited availability of time series data on biodiversity changes across large temporal and geographical extents. Here we use a dataset of repeated plant surveys from 302 mountain summits across Europe, spanning 145 years of observation, to assess the temporal trajectory of mountain biodiversity changes as a globally coherent imprint of the Anthropocene. We find a continent-wide acceleration in the rate of increase in plant species richness, with five times as much species enrichment between 2007 and 2016 as fifty years ago, between 1957 and 1966. This acceleration is strikingly synchronized with accelerated global warming and is not linked to alternative global change drivers. The accelerating increases in species richness on mountain summits across this broad spatial extent demonstrate that acceleration in climate-induced biotic change is occurring even in remote places on Earth, with potentially far-ranging consequences not only for biodiversity, but also for ecosystem functioning and services.

Mountain vegetation is often considered highly sensitive to climate and land-use changes due to steep environmental gradients determining local plant species composition. In this study we present plant species compositional shifts in the Tatra Mts over the past 90 years and discuss the potential drivers of the changes observed. Using historical vegetation studies of the region from 1927, we resurveyed 76 vegetation plots, recording the vascular flora of each plot using the same methodology as in the original survey. We used an indirect method to quantify plant species compositional shifts and to indicate which environmental gradients could be responsible for these shifts: by calculating shifts in estimated species optima as reflected in shifts in the ecological indicator values of co-occurring species. To find shifts in species composition, focusing on each vegetation type separately, we used ordination (DCA). The species optimum changed significantly for at least one of the tested environmental gradients for 26 of the 95 plant species tested; most of these species changed in terms of the moisture indicator value. We found that the strongest shifts in species composition were in mylonite grassland, snowbed and hygrophilous tall herb communities. Changes in precipitation and increase in temperature were found to most likely drive compositional shifts in vegetation resurveyed. It is likely that the combined effect of climate change and cessation of sheep grazing has driven a species composition shift in granite grasslands communities.

Mountain vegetation is highly specialized to harsh climatic conditions and therefore is sensitive to any change in environment. The rarest and most vulnerable plants occurring in alpine regions are expected to respond rapidly to environmental changes. An example of such a species is Carex lachenalii subsp. lachenalii Schkuhr, which occurs in Poland on only a few isolated sites in the Tatra Mts. The aim of this study was to assess changes in distribution of C. lachenalii in the Tatra Mts over the past 50-150years and the effects of climate change, tourism and historical grazing on the ecological niche of C. lachenalii. We focused on changes in the importance of functional diversity components in shaping plant species composition. Over the past 50-150years, the elevation of the average distribution of C. lachenalii shifted about 178m upward alongside a significant prolongation of the vegetative season by approximately 20days in the last 50-60years. Species composition of plots without C. lachenalii was characterized by competition between plants, whereas on plots with C. lachenalii habitat filtering was the most important component. Our results suggest that climate change was the main factor driving upward shift of C. lachenalii. Moderate trampling enhanced horizontal spread of this plant, whereas cessation of grazing grazing caused decline of C. lachenalii. The three environmental factors studied that determined shifts in distribution of C. lachenalii may also contribute to changes in distribution of other rare mountain plant species causing changes in ecosystem functioning.

Changes in the local flora of mountains are often explained by climate warming, but changes in grazing regimes may also be important. The aim of this study was to evaluate whether the alpine flora on summits in the Tatra Mts, Poland and Slovakia, has changed over the last 100 years, and if the observed changes are better explained by changes in sheep grazing or climate. We resurveyed the flora of 14 mountain summits initially investigated in the years 1878–1948. We used ordination methods to quantify changes in species composition. We tested whether changes in plant species composition could be explained by cessation of grazing and climate change, and whether these factors have influenced shifts in Ellenberg’s plant ecological indicator values and Raunkiaer’s life forms. Changes in alpine flora were greater on lower elevation summits, and lower on summits less accessible for sheep. More accessible summits were associated with a decrease in mean values of plant species’ light ecological indicator values over time, and a concurrent increase in temperature and nitrogen ecological indicator values. No significant relationships were found between accessibility for sheep and changes in Raunkiaer’s life-forms. Greater accessibility for sheep (meaning high historical grazing pressure) led to greater compositional changes of mountain summits compared with summits with low accessibility. Our results suggest that cessation of sheep grazing was the main factor causing changes in the species composition of resurveyed mountain summits in the Tatra Mts, while climate change played a more minor role.

Polychaetes are one of the most diverse groups of marine organisms, characterized by high species richness, diversity of feeding guilds, life styles, and mobility types. Marine annelids are useful indicators of ecosystem responses to changes in environmental conditions. The aim of our study was to assess the influence of natural and anthropogenic factors on functional diversity of polychaete communities in the Gulf of Guinea, a large marine ecosystem (LME) located in West Africa. This area can be considered as a model marine ecosystem affected by various human influences, such as pollution associated with the oil industry. Material was collected in 2012 across the coast of Ghana. Samples were gathered along four transects, each with six sampling stations (25-1000 m depth range). Analyses of functional richness and evenness, based on generalized linear mixed-effect models and hierarchical partitioning, allowed for complex assessments of the interactions between polychaete communities and environmental factors (e.g., sediments, total organic matter, salinity, fluorescence, oxygen, concentration of toxic metals, total hydrocarbons). Overall species richness of polychaetes was outstandingly high, with 253 species recorded. Functional richness decreased along a depth gradient, while functional evenness increased with depth, and was positively correlated with Ba content, which reached the highest values in the upper bathyal. Gravel content was an important factor in shaping functional composition of shallow water communities. High values of functional richness observed in the shallows may be an expression of high stability of this ecosystem, at the same time indicating its high resilience. Elevated concentrations of lead also influenced community structure at a local scale. Our study demonstrated how a complex set of factors operating along a depth gradient can influence the functional composition of communities. These results are crucial for future management of industrial and environmental protection activities in this region.

Question To what extent does winter supplementary feeding influence vegetation and soil seed banks in forest ecosystems? Location Bialowieza Primaeval Forest, NE Poland. Methods Several dozen feeding stations, each composed of one to several haystacks, are used in Bialowieza Forest for supplementary winter feeding of European bison Bison bonasus. We checked the species composition and availability of seeds in hay in 15 haystacks of the eight oldest feeding stations, which could be a potential source of seeds. Vegetation and soil seed bank were sampled on the overlapping 10 m x 10 m plots distributed along 500 m long transects running south and north of the studied feeding stations. Seed content in the soil samples was studied by the seedling emergence method in an unheated greenhouse. Results We revealed high dissimilarity of species composition of the hayseed, soil seed bank and standing vegetation. The dissimilarity between soil seed banks and standing vegetation increased with the distance from the haystack. The species richness of the standing vegetation was not affected by the distance to the haystack, while seed bank species richness showed significant negative correlation with distance. The mean weighted ecological indicator values of the pH, light and soil fertility were negatively correlated with the distance from the haystack for the seed bank and the standing vegetation. The percentage of damaged bushes and juvenile trees was positively correlated with their density and decreased with the distance from the haystack. Conclusions We revealed distinct but local (25 m -50 m off the haystack) effect of the supplementary feeding on the vegetation and soil seed banks of forest ecosystems. Taking into account the ecosystem approach to nature conservation, the winter feeding in forest ecosystems should be concentrated in few places to avoid the expansion of non-native plant species in forest ecosystems. To prevent potential plant invasions, the origin of the hay used as supplementary winter fodder should be carefully selected, with a preference for local origin and making of hay of native plant species in the forest's meadows or in its surroundings. This article is protected by copyright. All rights reserved.

Bialowieza Forest is one of the closest to pristine forest ecosystems in temperate vegetation zone in European Lowland, which is still being transformed by forest management. We investigated the effects of salvage logging of spruce stands killed by bark beetle on the recovery process and the biodiversity of the herb layer in the early stages of vegetation development after felling, on the habitat of mixed deciduous, oak-lime-hornbeam forest (Tilio-Carpinetum). We tested: (i) to what extent salvage logging modifies the plant species richness and diversity compared to sites left intact; (ii) whether clear-felling leads to an increase in diversity of vascular plants; and (iii) which ecological groups of plants benefit, and which are hindered by disturbance, depending on age and size of the clear-felled site. Salvage harvesting executed between 2012 and 2016 led to an increase in overall plant diversity. However, the winners were the species of open habitats, promoted by soil disturbance, whereas the number and cover of ancient forest indicator species decreased in comparison to unlogged forests. Both trends were significantly related to the increasing size of clear-felled sites, and developed right after logging. A comparison of the species composition of the disturbed (logged and unlogged) sites with undisturbed forest with stands unaffected by infestation, treated as control plots revealed the great potential of the affected sites for spontaneous recovery towards the oak-lime-hornbeam forest community, despite 50–90 years of spruce-dominated stand cover. We conclude that continuous deterioration of the forest habitats via clearcutting of stands affected by insect outbreak, followed by tree planting, substantially reduces the chances of successful, natural regeneration towards deciduous, structurally complex and diverse forests.

Forest habitats change significantly under the influence of global warming. It is important to predict the effects of these changes, especially in primeval forests which currently represent a small percentage of temperate forests. Such changes often manifest themselves in an acceleration of the frequency of mass seeding of trees, which causes cascading effects in various organisms. We evaluated changes in: tree masts (oak Quercus robur and hornbeam Carpinus betulus), rodent abundance (yellow-necked mouse Apodemus flavicollis), folivorous caterpillar abundance (winter moth Operophtera brumata), and the breeding success of a cavity-nesting songbird (collared flycatcher Ficedula albicollis) in over a 30-year period in the Białowieża Forest (E Poland). We also analysed temperature, precipitation and snow cover to determine the effects of weather on each trophic level. Previous studies have exposed the indirect effect of tree masting on songbirds breeding in open nests. Our study uniquely highlights the relationships between trees, rodents, caterpillars, and a cavity-nesting bird. Precipitation was positively correlated with the fructification of trees, abundance of caterpillars, and the breeding losses of flycatchers (in July, August, October in the previous year, in May in the current year, respectively). We found that along with the changing climate, the frequency of mast years of oak increased, which caused an increasing frequency of rodent outbreaks. The abundance of mice was positively correlated with the predation on flycatcher broods (current year) and negatively - with the abundance of caterpillars (following year). We predict that current global trends in climate change will have a negative impact on the flycatcher due to the cascading effects from the above species. Bearing in mind that F. albicollis is one of the most numerous bird species, it can be assumed that more frequent masting will result in substantial changes in the entire bird assemblage, and presumably also other groups of animals.

Functional diversity is considered an important tool for the identification of ecological mechanisms shaping the coexistence patterns of species communities along different environmental gradients. However, there is a huge gap in knowledge regarding the importance of ecological mechanisms in shaping the composition of lichen communities. We analyzed the functional diversity patterns of the lichen species in a European lowland primeval forest ecosystem, taking into consideration levels of forest communities, phorophyte species and substrates. The greatest functional diversity of lichens at the community level (functional richness and functional dispersion) was found in mixed deciduous forests, where Fraxinus excelsior and Carpinus betulus revealed the highest values of functional dispersion. The most functionally diverse lichen communities were found on the bark of trees, the branches of trees, and the bark on trunks or branches of fallen trees. The lowest functional diversity was found in coniferous forests, evidenced by the low functional dispersion of lichen assemblages, indicating lower heterogeneity of possible niches and harsher environmental conditions comparing with deciduous forests. In coniferous forests, lichens produced small ascomata and ascospores, while in deciduous forests, ascomata and spores of lichens were larger. We concluded that two contrasting mechanisms shaped the functional diversity of lichens in the primeval forest ecosystem: (i) niche-partitioning in deciduous forests, and (ii) environmental filtering in coniferous forests. Our study has substantially broadened and enhanced the existing knowledge concerning the assembly rules of lichen communities and can be considered as a model for the distribution of lichen functional traits in the natural lowland forests of Europe. This approach may also be used to model future changes taking place in this type of ecosystem. Our results are particularly important for forest managers responsible for protection, as they highlight the fundamental importance of certain tree species and specific forest substrates for maintaining high lichen functional diversity. Focus on the protection of all features of diverse forest structures and of diverse forests providing high variety of niches is essential for the successful conservation of forest lichen biota.

Amongst the numerous consequences of the rapid development of agriculture and urbanization, biological invasions are highlighted as having the biggest impact on the functioning of ecosystems. One of the alien plant species, considered in Europe and Asia to be highly invasive, is Solidago canadensis L.; and its impact on the functioning of ecosystems has been studied in numerous respects. However, knowledge about how the physico-chemical parameters of soils and biotic interactions between species shape the performance of S. canadensis in a transformed landscape is still insufficient. The aim of this study was to assess how complex soil abiotic conditions and the functional diversity of co-occurring vegetation shape the performance of S. canadensis on the wastelands abandoned by agriculture. Apart from detailed investigations of soil properties and S. canadensis biomass, to achieve our study aims, we used parameters of functional diversity, which allowed us to identify the main ecological processes determining the community assembly processes. Under higher contents of loamy fractions in soil, but lower functional richness in surroundings, S. canadensis achieved larger cover. Alongside increasing functional richness and dispersion in co-occurring vegetation, this species has demonstrated sturdy attributes when competing for water and nutrients, expressed by a higher production of rhizomes and roots. Under elevated zinc and lead levels, as well as higher functional evenness in the surroundings, the flower biomass decreased, while the biomass of stems increased. Thus, S. canadensis exhibits a highly adaptive capacity to grow in soils contaminated by heavy metals, due to the buffer properties and life strategies allowing the use of resources absorbed in loamy soils. Environmental factors seem to be more responsible for the shaping of the performance and for the colonization success of S. canadensis than biotic interactions with plants occurring in the surroundings.

International audience; Aim. Revisits of non‐permanent, relocatable plots first surveyed several decades ago offer a direct way to observe vegetation change and form a unique and increasingly used source of information for global change research. Despite the important insights that can be obtained from resurveying these quasi‐permanent vegetation plots, their use is prone to both observer and relocation errors. Studying the combined effects of both error types is important since they will play out together in practice and it is yet unknown to what extent observed vegetation changes are influenced by these errors. Methods. We designed a study that mimicked all steps in a resurvey study and that allowed determination of the magnitude of observer errors only vs the joint observer and relocation errors. Communities of vascular plants growing in the understorey of temperate forests were selected as study system. Ten regions in Europe were covered to explore generality across contexts and 50 observers were involved, which deliberately differed in their experience in making vegetation records. Results. The mean geographic distance between plots in the observer+relocation error data set was 24 m. The mean relative difference in species richness in the observer error and the observer+relocation data set was 15% and 21%, respectively. The mean “pseudo‐turnover” between the five records at a quasi‐permanent plot location was on average 0.21 and 0.35 for the observer error and observer+relocation error data sets, respectively. More detailed analyses of the compositional variation showed that the nestedness and turnover components were of equal importance in the observer data set, whereas turnover was much more important than nestedness in the observer+relocation data set. Interestingly, the differences between the observer and the observer+relocation data sets largely disappeared when looking at temporal change: both the changes in species richness and species composition over time were very similar in these data sets. Conclusions. Our results demonstrate that observer and relocation errors are non‐negligible when resurveying quasi‐permanent plots. A careful interpretation of the results of resurvey studies is warranted, especially when changes are assessed based on a low number of plots. We conclude by listing measures that should be taken to maximally increase the precision and the strength of the inferences drawn from vegetation resurveys.

Epiphytic lichens are sensitive bioindicators responding to climate change and atmospheric pollutants. Climate warming changes in lichen biota have been reported from Western and Central Europe; therefore, similar trends in the biota of the close-to-natural forests of Eastern Europe were expected. In both examinations (1987-1989 and 2015-2016) of 144 permanent plots the same field method was used. The following functional epiphyte groups were distinguished: climate warming indicators (VDI species and species containing Trentepohlia algae) and Wirth's ecological indicators (T - temperature, N - eutrophication, R - reaction, M - moisture). PCA ordination for exploring species composition changes, species richness and diversity (Shannon-Wiener index) in different forest types was used. When compared with the earlier survey, a higher plot species richness, Shannon-Wiener diversity index, and proportion of more nitrogen-demanding lichens, and lower proportions of warm-demanding and high-acidity tolerant lichens were found. No change in the epiphyte biota composition influenced by the decreasing atmospheric precipitation was detected. The species richness and Shannon-Wiener index of climate warming indicators did not show a significant change. Although the share and frequency of epiphytic lichen species and their functional groups changed over a 25-year period, no relationship was found to be related to climate warming: indicators of global warming showed no significant change in frequency, while those with higher value of T even decreased frequency. The changes suggest a connection with eutrophication (increase in frequency of species with higher value of N) and a decrease in sulphur deposition (increase in frequency of species with higher value of R).

Riparian zones are among the ecosystems with the highest susceptibility to human impacts, and the main drivers influencing their function are river regulation and urbanization. In this study we aimed to assess shifts in species composition of riparian vegetation over three decades and discuss effects of river regulation (expressed as limitation of episodic flooding) on species and functional diversity of the understory of riparian plant communities in an urban landscape before and after dam building. We compared riparian vegetation in 59 pre-dam plots assigned to four types of riparian vegetation, initially investigated in the years 1970–1984 with 50 post-dam plots, sampled by us in 2011-2018. We explored changes in the importance of competition in shaping plant species composition, using a set of ecological indicator values, plant functional traits and components of functional diversity. Results of the study suggest that river regulation drove compositional shifts in plant communities surveyed, probably caused by displacement of species with strategies allowing occurrence under high stress levels by plants with higher competitive abilities, including ornamental alien species. We revealed increasing magnitudes of compositional shifts along an environmental gradient of riparian vegetation with the largest changes observed in pioneer forest communities. Implementing natural flows with consideration for relationships between plant strategies and their key life-history traits, and aspects of the flow regime, may be a proper tool for restoration and maintenance of riparian vegetation as buffer zones in urban landscapes.

Urban parks constitute one of the most important elements of the urban green infrastructure. However, knowledge on how the surrounding landscape influences the functional diversity of plant species is still insufficient. The aim of this study was to assess the impacts of different landscape features in proximity of urban parks on their functional diversity and to recognise the community-level coexistence patterns of the plant species. We demonstrated that an increasing river net density had a positive impact on the functional richness and promoted the occurrence of native xerophytes, non-invasive archaeophytes and invasive kenophytes in urban parks. On the contrary, a higher contribution of settlements drove a decrease in the functional dispersion and had a negative impact on the frequency of deciduous forest species. The conservation of urban parks should be a focus for the maintenance of a high variety of pioneer habitat conditions, which are suitable for rare archaeophytes and xerothermic species. The management of invasive species should be the focus of their removal from open habitats and to prevent them from entering the forest interiors. This may be achieved, for instance, by the maintenance of well-developed edge zones composed of a high number of competitive shrubs and nitrophilous tall herbs of native origin.

Taxonomy and diversity of symptomatic lichenicolous fungi (visible as fruitbodies on lichen thalli, their discoloration, and/or deformation) and their specificity to lichen hosts is becoming more and more studied. However, information on their ecology is still scarce. We assess how large the specialization of these fungi towards their hosts and microhabitat is. Epiphytic, epixylic and epigeic lichens and associated lichenicolous fungi were studied on 144 permanent plots in Bialowieza Forest in relation to forest communities, species of tree phorophyte and substrates. On all these three studied levels lichenicolous fungi were more specialized than their lichen hosts. Our study provides the first estimation of ecological dependences between associations of lichenicolous fungi and their hosts, microhabitats and forest communities in a primeval forest ecosystem representative of lowland Europe.