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Questions: Changed land use, nitrogen deposition, climate change, and the spread of non‐native species have repeatedly been reported as the main drivers of recent floristic changes in northern Europe. However, the relevance of the geographical scale at which floristic changes are observed is less well understood and it has only rarely been possible to quantify biodiversity loss. Therefore, we assessed changes in species richness, species composition and mean ecological indicator values (EIVs) at three nested geographic scales during two different time periods, each ca 30 years, since the mid‐1900s. Location: Two parishes in central Scania, southernmost Sweden. Methods: We analyzed species presence/absence data from three inventories at ca 30‐year intervals over 1957–2021 and three geographic scales (157 m2, ca 7 km2 and ca 45 km2) to document temporal trends and differences between geographic scales in terms of species richness, species composition and mean EIVs. Results: We found shifts in species composition across all geographical scales. However, the magnitude of biodiversity loss and the main drivers of these changes were scale‐dependent. At the smallest spatial scale, we saw a dramatic loss of plant biodiversity with local species richness in 2021 being only 48% of that of 1960. In contrast, at the larger geographic scales no significant changes in species richness were observed because species losses were compensated for by gains of predominantly non‐native species, which made up at least 78% of the new species richness. At the smallest spatial scale, changed land use (ceased grazing/mowing and intensified forestry) appeared as the main driver, while an increasing proportion of non‐native species, as well as climatic changes and increasing nitrogen loads appeared relatively more important at larger geographic scales. Conclusion: Our results highlight the precarious situation for biodiversity in the region and at the same time the fundamental importance of geographic scale in studies of biodiversity change. Both the magnitude and drivers of changes may differ depending on the geographic scale and must be considered also when previously published studies are interpreted. [ABSTRACT FROM AUTHOR]

Aims: Shallow soils on acidic bedrock in dry areas of Central Europe support dry grasslands and heathlands that were formerly used as extensive pastures. These habitats are of high conservation value, but their abandonment in the 20th century triggered slow natural succession that poses a threat to specialized plant species. We asked how this vegetation and its plant diversity have changed over the past three decades and whether protected areas have positively affected habitat quality. Location: Southwestern and central Moravia, Czech Republic. Methods: In 2018–2019, we resurveyed 94 vegetation plots first sampled in 1986–1991 at 47 acidic dry grassland and heathland sites. We compared the number of all vascular plant species, Red List species and alien species per plot using parametric and non‐parametric tests, life‐form spectra using the chi‐square test, species composition using detrended correspondence analysis, and indicator values using a permutation test. We also compared these changes between sites within and outside protected areas. Results: Vegetation changes over the past three decades have been relatively small. However, we detected a decrease in total species richness, the number of Red List species and the number of characteristic species of dry grasslands. Neophytes were infrequent, while archaeophytes increased slightly. The competitive tall grass Arrhenatherum elatius, annual species and young woody plants increased in abundance or newly established at many sites. Indicator values did not change except for a slight increase in nutrient values. These negative trends occurred both within and outside protected areas but were more pronounced outside. Conclusions: Formerly grazed acidic dry grasslands and heathlands in Moravia are slowly losing habitat specialists, including threatened plant species, and are increasingly dominated by Arrhenatherum elatius. Conservation management, especially cutting in protected areas, slows down the negative trends of decline in plant diversity and habitat quality but is insufficient to halt these processes completely. [ABSTRACT FROM AUTHOR]

Aims: The summit grasslands of many European mountain ranges were historically used for summer grazing, which ceased in the 20th century. These grasslands are changing, partly through succession after abandonment and partly owing to environmental changes. Subalpine vegetation is also affected by artificially reduced avalanche frequency. Recent conservation efforts have attempted to reverse the negative trends of change. We ask: (1) How has subalpine vegetation changed following the abandonment and avalanche control? (2) Was conservation management able to reverse the post‐abandonment trend of vegetation change? (3) Did avalanche disturbance have a positive effect on plant species diversity? Location: Summit area of the Hrubý Jeseník Mountains (1,491 m a.s.l.), Eastern Sudetes, Czech Republic. Methods: Vegetation plots sampled in the 1970s were resurveyed in the 2000s and again in 2021. Subalpine vegetation was classified into six types, and transitions between these types over time were quantified. Vascular plant species richness and the proportion of threatened species were compared between periods, between areas with and without conservation management, and between areas affected vs unaffected by a large avalanche from 2019. Species composition was analysed using principal coordinate analysis and distance‐based redundancy analysis. Results: Vegetation types remained relatively stable except for species‐rich grasslands, some of which changed to heathlands or tall‐forb vegetation. Some competitive species have increased, and species specialized to threatened habitats declined. Conservation management systematically implemented after 2010 slowed the decline of habitat‐specialized species but did not reverse it. Disturbance by an avalanche positively affected species richness but not the number of threatened species. Conclusions: Subalpine vegetation is slowly losing its plant diversity owing to grazing cessation and possibly acidification from past atmospheric deposition. Recently implemented conservation management and restoration of avalanche activity are essential to stop this trend, but future monitoring is needed to evaluate the success of management actions.Subalpine plant communities in the Hrubý Jeseník Mountains (Czech Republic) were repeatedly sampled in the 1970s, 2000s and 2021. Although vegetation changes were not large, species‐rich grasslands lost some of their habitat‐specialized species. Conservation management partly slowed this process but did not reverse it. Disturbance by an avalanche positively affected species richness but not the number of threatened species. [ABSTRACT FROM AUTHOR]

Questions: Mountain grasslands can be strongly affected by extreme droughts such as those related to climate change. What are the impacts of extreme droughts on community composition, diversity, Ellenberg indicator scores and species groups in oligotrophic montane Nardus grasslands, and what are the associated mechanisms of vegetation change? Location: Rhön Mountains, Germany. Methods: Over three consecutive years, we investigated the effects of yearly droughts (April–August) in an experimental setup with rainout shelters. Owing to the coincidence of ambient extreme dry conditions in those years and our artificial rainfall reduction, we evaluated the contribution to community change of ambient drought conditions and the treatments. We analysed changes in community composition by applying redundancy analysis to species differences in comparison with the pretreatment year, and used mixed‐effects models to test for changes in community‐weighted means of Ellenberg indicator scores, sociological and functional groups. Results: We found significant changes in species abundance and community structures in response to drought. Evenness increased, but species richness remained rather stable over time. Ellenberg indicator scores for temperature and nitrogen increased, whereas the score for moisture decreased. Simultaneously, dominant species declined and subdominants increased. Changes occurred with a time lag and were driven largely by the high ambient drought level and less by the artificial treatments. Conclusions: Our results show that drought‐related changes in community composition in Nardus grasslands occur across community structures, characteristic species, and species groups. The post‐drought recovery of the community is shaped by community filters, which in particular allow subdominants to take advantage of newly available niches in the matrix, even if they lack strong drought tolerance. Our findings indicate a certain resilience of the community to droughts related to climate change, which suggests that the observed changes should not lead to an accelerated short‐term decline in these grasslands, but that this cannot be excluded in the long term. [ABSTRACT FROM AUTHOR]

Aim: To assess vegetation changes in mountain hay meadows of high conservation value over 15 years. Location: Jura Mountains and Vosges Mountains (France). Methods: In 2019, we resampled old phytosociological relevés (made from 2005 to 2009) in extensive mountain hay meadows. To detect shifts in composition from old to recent relevés, we performed a permutational multivariate analysis of variance, and visualized observed patterns using non-metric multidimensional scaling on the Bray-Curtis dissimilarity matrix of the vegetation data. We tested for differences in taxonomic, functional and phylogenetic diversity metrics, CSR strategies and ecological indicator values using paired Wilcoxon-Mann-Whitney tests. Results: Non-metric multidimensional scaling paired with a permutational multivariate analysis of variance showed that, overall, old and recent plant communities were not different in the Vosges Mountains, contrary to the situation in the Jura Mountains. Wilcoxon-Mann-Whitney paired tests revealed that, in the Jura Mountains, plant communities underwent a significant decrease in taxonomic, functional and phylogenetic diversity, associated with an increase of ruderal and competitive strategies. Ecological indicator values for nutrient availability and defoliation tolerance both increased, suggesting an intensification of agricultural practices. In the Vosges Mountains, only species richness increased while the inverse Simpson index and Pielou evenness decreased. Conclusions: Our results show that plant diversity is not currently threatened in the studied grasslands in the Vosges Mountains. By contrast, in the studied grasslands in the Jura Mountains, plant diversity is declining. The situation in the Vosges shows that agricultural activities and biodiversity conservation can be reconciled. This situation should be further investigated to help resolve conflicts between agriculture and biodiversity conservation in semi-natural grasslands. [ABSTRACT FROM AUTHOR]

Questions: The hydrophilous tall herb community is an important refuge for grazing‐sensitive broad‐leaved flowering plants. It is distributed throughout upland Europe but overgrazing has contributed to an unfavourable conservation status. To guide tall herb restoration, we asked: (a) Does using grazing exclusion where the tall herb habitat is confined to cliff ledge patches promote an expansion into the grassland below? (b) Does this management negatively affect vascular plant diversity? Location: Ben Lawers NNR, Scotland. Methods: Large herbivores have been excluded from a 180‐ha area containing patches of outcrops rich in tall herb habitat. Using 1999 and 2017 surveys of permanent plot transects located in the grassland below (Before–After design), we quantify impacts on community composition and tall herb abundance. Results: Species diversity remained constant although total species richness declined slightly and tall herb species richness increased significantly. There was a large expansion in tall herb cover (+29.67%) and a corresponding decrease in grass cover (−26.16%), as well as smaller increases in bryophytes and small herbs and a reduction in bare ground. Community composition shifted significantly from species typical of upland calcareous grassland towards those found in tall herb habitats. Seven tall herb species were amongst those showing the greatest increase in cover, along with taller grasses and understory herbs. Grazing tolerant grasses and low‐growing, prostrate and annual herbs decreased. Competition for light, rather than resilience to herbivory, now has a major influence on the vegetation. Conclusions: Using grazing exclusion where the tall herb habitat is largely confined to patches on cliff ledges facilitates an expansion into the upland grassland below. Although this management favours species tolerant of shadier conditions, there is no evidence of a negative impact on vascular plant community composition. It is therefore an effective strategy for promoting the restoration and favourable condition of this grazing‐sensitive habitat. [ABSTRACT FROM AUTHOR]

Questions: West African savanna ecosystems are affected by increasing land use intensity (e.g., agriculture and livestock herds) due to a growing human population. To understand the impact of land use intensification on savanna vegetation, we aim to answer the following questions: How do savanna species composition, diversity and structure change with increasing land use pressure? Are the impacts of land use change different in the woody and the herbaceous layers? Do the effects of land use change differ between vegetation types? Location: Southeastern Burkina Faso, West Africa. Methods: Vegetation plots from the early 1990s representing vegetation types occurring in fallows of different age and in uncultivated pasturing zones were resurveyed. We distinguished between woody (tree and shrub layer) and herbaceous vegetation types. Species composition changes were analyzed using ordination techniques (detrended correspondence analysis, DCA) and indicator species analysis (IndVal). Species turnover and plant diversity as represented by species richness and evenness were compared between the baseline survey and the resurvey. Results: In most woody vegetation types, we found no change in species composition and richness over the past two decades. However, some highly valued woody species decreased in abundance. In contrast, in most herbaceous vegetation types, species composition changed considerably and species richness increased. The proportion of wide‐ranging, ruderal herbaceous species increased, indicating a homogenization of herbaceous vegetation types, while preferred fodder herbaceous species decreased. We assume that the increased grazing intensity over the past two decades is the driver of these changes in the herbaceous layer. Conclusions: Our results show different reactions of vegetation types and layers to land use intensification and reinforce the need for studies on the basis of vegetation type that incorporate both the herbaceous and the woody layers. [ABSTRACT FROM AUTHOR]

Question: Alpine plant communities are often distributed as a mosaic reflecting micro‐scale heterogeneity of environmental conditions, indicating the importance of diverse habitats in maintaining species diversity in alpine ecosystems. Because snow‐meadow vegetation is particularly sensitive to climate change, species composition and community structure may have changed over the last few decades in response to global warming. The aim of the present study is to quantify changes in species diversity and snow‐meadow community composition over the last 40 years. Location: Taisetsu Mountains, Hokkaido, Japan. Methods: The presence and ground cover of plant species were surveyed in two snow‐meadow sites in 1971–1972 (44 and 113 plots) and 2012 (85 and 115 plots). In addition, soil moisture and snowmelt time were measured in every plot in 2012. Changes in species richness, functional types and species composition between the survey periods were analysed. Results: Community structure of snow‐meadow vegetation has changed significantly. Although the total number of species at each site was the same between the survey periods, Shannon's diversity index and species richness per plot have increased. Moreover, similarity in species composition among community types has been enhanced, indicating the mosaic structure of alpine vegetation has become obscure. The relative dominance of forbs (particularly tall herbaceous species) decreased, while that of shrubs increased. The distribution of community types reflected the snowmelt and soil moisture conditions. Conclusions: Significant changes have occurred in vegetation structure in the alpine snow‐meadows, possibly due to accelerated snow melt and drier soil conditions linked to global warming. To predict the dynamics of alpine vegetation, we need to clarify how micro‐scale heterogeneity of environmental conditions is modified by global change. Alpine plant communities are often distributed as a mosaic reflecting micro‐scale heterogeneity of environmental conditions. By comparing the vegetation records of alpine snow‐meadows between present and 40 years ago, we detected that mosaic structure has been obscured, where tall herbs decreased and shrubs increased the dominance. Accelerated snowmelt and drier soil conditions might change the spatial pattern of alpine vegetation. [ABSTRACT FROM AUTHOR]

Question What are the main drivers of vegetation change within coastal dune and machair habitats and are these amenable to action to protect biodiversity at a local and national scale? Location Coastal areas of Scotland. Methods A national-scale, quadrat-based re-visitation survey was used to assess where changes were occurring in terms of species richness and composition. Regression trees and linear mixed modelling were used to identify the main drivers of change between 1976 and 2010. Results There were losses of habitat to erosion (4.7% of previously visited quadrats) and development (2.3%). Species richness changes were largely positive where sand dune and machair habitats remain part of an agricultural management system in the Inner and southern part of the Outer Hebrides. Richness losses were driven by acidic deposition and reduced grazing. Compositional changes were less related to agricultural changes, climate change and pollutant deposition than species richness changes. Conclusions Reintroduction of grazing to coastal areas appears to be a policy that would have positive effects on biodiversity, as would continued efforts to reduce atmospheric deposition and coastal planning that allowed for realignment as sediment supply decreases and sea level rise continues. [ABSTRACT FROM AUTHOR]

Questions How do various grassland restoration methods (hay transfer from local or distant donors, seed sowing or natural regeneration) perform in restoration of species-rich, semi-natural grasslands? Are any of the donors particularly well suited as reference vegetation? Do bare soil treatments give better results than treatments where the soil is covered? What are the probabilities of steering vegetation development towards donor vegetation under the various restoration treatments? Location Sunnfjord open-air museum in rural, Western Norway. Methods In a replicated field trial we tested four restoration methods: transferring fresh hay from a local or a distant donor (hay transfer), seeding with a regional species mix, and allowing natural regeneration. We evaluated outcomes by comparing species richness, transfer rates and vegetation dynamics in donor and trial vegetation over four successive years. Results Our study revealed considerable changes in species composition under all restoration treatments, which decreased over time, indicating decelerating succession rates. Many non-trial grassland species became established, especially after seeding and natural regeneration (bare soil treatments). All trajectories became synchronized from the second year, and by trial end, the restoration treatments converged with respect to species richness and species composition. Conclusion All restoration treatments gave high resemblance to a specific donor: the local one. Distant hay transfer resulted in larger temporal changes and exemplified a climatic donor-receiver mismatch, while the failure of several seeded species to germinate indicated an ecological mismatch under the seeding treatment. Vigorous germination of non-trial seeds in the two bare soil treatments evened out the initial treatment-related differences. Dispersal from the surrounding area and between treatments may be utilized for restoration purposes, but also limits the potential for restoring a specific species composition. Although we apparently failed to tailor donor species composition to the recipient, we note that the slow dynamics of long-lived grassland species may lead to a different long-term restoration outcome. [ABSTRACT FROM AUTHOR]

Questions How do recent patterns of drought-induced woody plant mortality in Texas semi-arid savanna compare to the extended drought of the 1950s? Does the relative composition of the woody plant community shift ubiquitously across the landscape following woody plant mortality and dieback or are shifts dependent on differences among species, soils, land use and plant demography? Location Texas Agrilife Research Station, Sonora, Texas, USA (30.1° N 100.3° W). Methods Following an exceptional drought from 1951 to 1957, a study was conducted to quantify rates of mortality for various woody plant species. In 2011, we repeated this study within three long-term grazing treatments that were established in 1948. Ten transects were established in each treatment to quantify the frequency and cover of live and dead woody individuals for all woody species. Rates of woody plant dieback were determined for each species and tested for differences among height classes, soil categories, total woody densities and pastoral treatments. Results Flash droughts (defined as rapidly intensifying droughts characterized by moisture deficits and high temperatures) from 2000 to 2011 were the second most severe since 1919 (low PDSI = −4) and were only surpassed by the prolonged drought from 1951 to 1957 (low PDSI = −5.17). Drought-induced shifts from one woody plant community to another did not occur uniformly across the landscape. Instead, high mortality rates of mature Juniperus ashei trees in deep soils (67.3%, 33 of 49 trees), combined with the recruitment of Quercus species where grazing had been excluded for the last 60 yr, were the only patch types to shift from a Juniperus- Quercus woodland to an alternate state. Conclusions Flash droughts since 2000 resulted in significant mortality and dieback, but dieback in cover was 28% higher following the more severe drought of the 1950s. Legacies from long-term land management practices interacted with localized differences in topoedaphic factors to drive patch-level shifts in woody vegetation following drought. [ABSTRACT FROM AUTHOR]

Abstract. Due to economic pressures and policy changes Lolium perenne‐Trifolium repens sown swards in upland UK sheep systems are likely to become less intensively managed. We present results from the first 5 yr of a long‐term experiment studying vegetation change under more extensive grazing management at three sites. One treatment was representative of current, intensive management and 5 were unfertilized with different intensities of seasonal grazing. The species composition of unfertilized, ungrazed swards changed dramatically within 2 yr and the sown species had virtually disappeared by year 5. Ranunculus repens, Poa trivialis, Agrostis gigantea, Juncus spp. and Carex spp. became dominant at the wettest site. Grasses were dominant at the other sites. In contrast, the sown species were retained in the unfertilized, grazed treatments; there were small shifts in abundance of the species present initially and few additions or losses of species. Some colonizing species were present in the seed bank whereas others with a transient seed bank appeared to have invaded from neighbouring vegetation. Implications of these results for compensation schemes to reduce animal output and increase biodiversity are discussed. [ABSTRACT FROM AUTHOR]