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Aims: By analysing cattle‐ and sheep‐grazed sand grasslands, we tested the following hypotheses: (i) livestock type has a stronger effect on the vegetation characteristics than grazing intensity; (ii) sheep grazing results in lower biomass and species and functional diversity than cattle grazing, regardless of intensity; and (iii) increased grazing intensity causes a shift of the trait composition in grasslands. Location: Sand grasslands in the Nyírség region, East Hungary. Methods: We selected 26 sand grassland sites grazed by cattle or sheep and classified them into four intensity levels. Vegetation composition was surveyed in 2 m × 2 m plots. We harvested the above‐ground biomass from 20 cm × 20 cm plots; then dried and sorted it to live biomass, litter, moss, and lichen. We compared Rao dissimilarity index, species richness, Shannon diversity, evenness, and the community‐weighted means of nine vegetative and generative traits along a grazing intensity gradient. We calculated functional richness, evenness, and divergence for comparison. Results: We found that some diversity metrics and community‐weighted means of most studied traits were significantly affected by grazing intensity. Several characteristics were also affected by the interaction of grazing intensity and livestock type, but none of the studied characteristics was affected by livestock type in itself. Increasing Rao dissimilarity index peaking at the fourth grazing intensity level was detected, but for other multitrait indices, no such changes were proven, except for functional divergence, which was the lowest at the first intensity level. Graminoid, forb, and litter biomass were significantly affected by intensity, but none of the biomass fractions was affected by livestock type. Conclusions: We suggest that for the management of sand grasslands, grazing intensity should be carefully adjusted, considering not only livestock units per hectare. For practical recommendations, well‐defined, long‐term experiments studying different livestock and habitat types along an intensity gradient would be essential. [ABSTRACT FROM AUTHOR]

Aim: We evaluated stands of the invasive grass, Sporobolus cryptandrus in its native North American range and its non-native European range, where it is a recent invader. Our aim was to reveal how the species’ increasing abundance affects functional diversity and the ecosystem service-provisioning capacities of plant communities in both ranges. Location: Sand grasslands in the Kiskunság, Hungary and in Montana, USA. Methods: All vascular plant species and their relative abundances were recorded in a stratified random manner in 1 m × 1 m plots in each range, using the following cover categories of Sporobolus as strata: 1%–25%, 26%–50%, 50%–75%, and 75%–100%. The functional characteristics of the plant communities in the two continents were compared. We performed comparisons of the communities both with and without including Sporobolus. Results: Increasing Sporobolus cover resulted in a lower functional diversity and species richness, reduced average specific leaf area and increased the height of whole plant communities in both ranges but these effects were significantly stronger in the non-native stands. Sporobolus also negatively affected the cover of insect-pollinated plant species and the proportion of native perennials, switching the rest of the community from perennial-dominated to annual-dominated. In plant communities without Sporobolus, increasing Sporobolus cover led to a higher specific leaf area and seed mass in both ranges, but average height was decreasing along the Sporobolus abundance gradient in the native range, whereas it was increasing in the non-native range. Conclusions: The spread of Sporobolus, away from its native range, leads to the impoverishment of host communities and compromises the biomass and floral resourceprovisioning capacity of the vegetation to higher trophic levels. Tackling the spread of this new invader should therefore be a priority task. [ABSTRACT FROM AUTHOR]

Sowing grasses supports the rapid development of a closed perennial vegetation, which makes the method universally suitable for fast and effective landscape‐scale restoration of grasslands. However, to increase their diversity and to create a natural‐like species‐rich grassland is a challenging task. Understanding the role of seed bank compositional changes and vegetation dynamics can help to design management regimes that support the establishment of target species and suppress unwanted weeds. Our aim was to reveal the effect of post‐restoration management on the vegetation and seed bank dynamics in grasslands restored in one of the largest European landscape‐scale restoration projects. Eight years after restoration, we sampled the vegetation and the seed bank in 96 quadrats located in 12 restored grasslands in the Great Hungarian Plain. In each grassland stand, we studied and compared a mown (mown from Year 1 to Year 8) and an abandoned plot (mown from Year 1 to Year 3 then abandoned from Year 4 to Year 8). Mown and abandoned plots showed divergent vegetation and seed bank development. Abandonment led to the decline of sown grasses and higher cover of weeds, especially in the alkaline grasslands. Our study underlined that the developing seed bank had a limited contribution to the maintenance of biodiversity in both grassland types. We found that 5 years of abandonment had a larger effect on the seed bank than on the vegetation. We stress that long‐term management is crucial for controlling the emergence of the weeds from their dense seed bank in restored grasslands. [ABSTRACT FROM AUTHOR]

Sowing of grass seed mixtures is a feasible and cost‐effective method for landscape‐scale grassland restoration. However, sowing only grasses usually leads to species‐poor and dense swards, where the establishment of target forbs is hampered by microsite and propagule limitation. To overcome these limitations and increase the diversity of species‐poor sown grasslands, we developed a novel method by creating "establishment gaps.". We used tillage to open gaps of 1‐, 4‐, and 16‐m2 size in the dense grass sward of six species‐poor restored grasslands in the Great Hungarian Plain. We sowed high‐diversity seed mixtures of 35 native species into all gaps. We analyzed vegetation development during the first 5 years after setting up the trial. We also studied the colonization dynamics of the sown species along four 20‐m transects around each gap, resulting in a total of 1440 plots of 1‐m2 size that were studied. Our results indicated that most of the sown species were able to establish permanently in the gaps. The total cover and the cover of perennial sown species increased and the cover of short‐lived sown species decreased independent of gap size. There was only a moderate level of weed abundance in the gaps, and weed cover decreased over the years. The sown target species started to colonize the species‐poor grasslands surrounding the gaps within 5 years. The highest number of species and individuals dispersed from the 4‐m2 gaps, as they had a more stable development than smaller gaps and were exposed to lower grazing pressure than large ones. [ABSTRACT FROM AUTHOR]

Questions: Community assembly in regenerating forests is a key topic in ecology. Most studies examine the assembly process, assessing adult individuals along the forest succession. Although the adult stage is the final outcome of the assembly process, both abiotic and biotic filters can affect community assembly during early ontogenetic stages. Here, we investigate whether the functional composition and trait assembly patterns (trait convergence or divergence) change across ontogenetic stages along regenerating forest stands exposed to precipitation and chronic anthropogenic disturbance (CAD) gradients. Location: Caatinga dry forest, Catimbau National Park, Pernambuco, Brazil. Methods: Seeds (rain and bank), seedlings and adults of woody plant species were recorded across 15 forest regenerating stands (4–70 years since land abandonment) exposed to precipitation and CAD gradients. Seven functional traits related to species dispersal, establishment and resource use were measured for adult individuals and used to calculate the trait values for seeds and seedlings. Twenty old‐growth forest stands were used as a regional flora. Results: Functional composition (community weighted mean, CWM) varied across ontogenetic stages as wood density increased from seeds to seedlings, while seed mass increased from seeds to both seedlings and adults. The CWM also varied along precipitation/disturbance gradients but not along forest regeneration regardless the ontogenetic stage. Among seeds, dispersal distance increased towards wetter forest stands and decreased towards disturbed sites, while adult wood density increased from drier to wetter regenerating forest stands. Traits converged along the precipitation gradient but not in response to time since land abandonment. Conclusions: Caatinga dry forest regeneration is functionally structured across ontogenetic stages mediated mostly by water availability, but not over time since land abandonment. The effect of water availability on forest regeneration across ontogenetic stages highlights the complexity of species assembly in human modified landscapes, imposing important consequences considering the expected increasing aridity in the Caatinga. [ABSTRACT FROM AUTHOR]

Aims: The early phases in the life cycle of a plant are the bottleneck for successful species establishment thereby affecting population dynamics and distribution. In coastal environments, the spatial pattern of plant communities (i.e. vegetation zonation) follows the ecological gradient of abiotic stress changing with the distance from the sea. This pattern has been mainly explained based on the adaptation and tolerance to the abiotic stress of adult plants. However, the adult niche may considerably differ from the germination niche of a plant species. The aim of this work was to investigate to what extent abiotic factors (specifically salinity, temperature, nitrogen and their interactions) constrain seed germination along the sea–inland gradient. Location: Latium coast (Central Italy). Methods: Germination tests were performed on seeds of focal species of three different plant communities which establish at increasing distances from the coastline: Cakile maritima subsp. maritima, Elymus farctus, Crucianella maritima. We tested increasing concentrations of NaCl (one of the main abiotic factors which decrease across the sea–inland gradient), and their interactions with temperature and KNO3, to consider other factors which drive germination processes. Results: The tolerance to salinity significantly decreased in relation to the position of species along the coastal zonation. Crucianella maritima was shown to be the least tolerant species, having a decrease in germination >80% across all conditions. KNO3 significantly (although slightly) increased the germination percentage in Cakile maritima subsp. maritima and Elymus farctus. When combined with NaCl, KNO3 alleviated the negative effects of salinity only in Cakile maritima subsp. maritima. Conclusions: The germination responses to the interaction among the tested factors suggest that the germination niche may explain vegetation zonation filtering species at their early stages. Quantifying environmental niches in different phases of the life cycle of plants may provide important insights into community assembly processes. [ABSTRACT FROM AUTHOR]

Question: Human‐mediated dispersal (HMD) comprises human‐vectored dispersal (HVD; direct movement of organisms by people) and human‐altered dispersal (HAD; indirect change in dispersal patterns through human alteration of ecosystems). In the vegetation dynamics literature, human influence has primarily been studied in terms of perturbations to natural communities. Except for non‐native invasions, the role of HMD in vegetation dynamics has rarely been considered. Given the increasing human population and its pervasive impacts across the world, it is necessary to understand the different ways in which HMD drives changes in vegetation dynamics. Importantly how large are these influences and how do they disrupt natural processes? Method: We reviewed studies examining aspects of HMD in relation to vegetation dynamics and used the broader literature to inform a conceptual synthesis of the impacts of HMD on vegetation dynamics. Results & Conclusions: The propensity to be affected by HMD varies among species, and this is related to seed and plant traits. Together, these effects combine to determine whether HMD disrupts or enhances seed dispersal into a community. The ultimate consequences of changed arrival of seeds into a community are determined by the strength of the environmental and biotic filters, which govern the establishment and persistence of species. The effect of accidental HVD depends whether it follows the same rules as for natural dispersal; indeed humans might replace lost natural dispersers and thus enhance community resilience. Intentional HVD through sowing or planting will generally be highly disruptive especially as it often involves associated management. Traditionally, HAD has been considered to disrupt vegetation dynamics through, e.g., fragmentation or loss of natural dispersers. However, an HMD perspective can inform actions related to HAD that increase resilience, e.g., green infrastructure or vegetation management. Our framework encourages researchers to consider HMD holistically, to understand how the increasing human footprint might affect vegetation dynamics and resilience under future change. [ABSTRACT FROM AUTHOR]