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Aims: The relative importance of species within an ecosystem shows spatio‐temporal variability related to both the terrain features and numerous rapidly changing factors. Accordingly, functional and species patterns may show some level of persistence, or, due to various disturbances, fluctuations. Communities with high species richness were found to maintain a higher degree of stability than species‐poor or perturbed vegetations; however, diversity and its stability may be spatio‐temporally variable. Based on these considerations, our aim was to assess the responses of a sandy pasture, both species‐wise and at the community level, to the relatively invariant habitat, and to the more rapidly changing environmental conditions. Location: Hungary. Methods: We surveyed the vegetation in an area of about 1 ha by means of high‐resolution spatio‐temporal sampling: we recorded the surface aerial cover (%) of the plant species during 15 campaigns covering spring, summer and autumn aspects for seven years (2013–2019) in 80 × 60 m grids. The biological activity of the ecosystem (above‐ground biomass, soil respiration) was also followed up together with the environmental limiting factors. Results: During the study period, which was characterized by significant warming, the grassland showed a balanced physiological performance with year‐to‐year variability. Fluctuating differentiation of the plant species with different environmental optima along with the terrain attributes was assumed to be responsible for this balanced physiological performance. Although community‐level diversity remained stable, some species favoring cooler, wetter positions disappeared. Conclusions: Terrain features of the study area within 1.5 m or less elevation differences created considerably heterogeneous conditions for a high number (114) of plant species with different ecological needs to co‐occur. The stability of the diversity was found to show terrain relatedness, that is spatial as well as temporal patterns compared to the null model of spatio‐temporal independence, and the ecosystem functions followed these patterns. [ABSTRACT FROM AUTHOR]

The European temperate forest zone has great importance, in terms of maintaining the habitats of not only forests but also anthropogenous grasslands, which were formed as a result of habitat reconstruction. These habitats have great importance, by means of nature conservation, landscape use, economy, and forest and grassland use. The mosaic-like habitat complexes that consist of these grasslands and forest patches help to increase biodiversity and supply the habitat for forest game. In this survey, changes in the vegetation of the temperate forests (Fagetum) of the Mátra Mountains of Hungary were investigated after reconstruction. In 2012, shrub cutting was carried out in the area of Parádóhuta, and then three different management methods (abandoning, mowing, and grazing) were utilized. Our goals were the following: to perform a vegetation survey of the sample areas (i); surveying the natural regeneration of the grassland and analyzing its biodiversity, nature conservation, and economical value (ii); and analyzing the vegetation in terms of nature conservation and valuing its life form spectrum, economy values, and livestock-feeding ability (iii). According to our results, systematic mowing and a less-intensive grazing had a significantly positive effect on biodiversity and the coverage of species, thus increasing the naturalness of the studied grassland habitats, while wild game were able to act as ecological engineers. [ABSTRACT FROM AUTHOR]

Diversity responses to climatic factors in plant communities are well understood from experiments, but less known in natural conditions due to the rarity of appropriate long-term observational data. In this paper, we use long-term transect data sampled annually in three natural grasslands of different species pools, soils, landscape contexts and land use histories. Analyzing these specific belt transect data of contiguous small sampling units enabled us to explore scale dependence and spatial synchrony of diversity patterns within and among sites. The 14-year study period covered several droughts, including one extreme event between 2011 and 2012. We demonstrated that all natural grasslands responded to droughts by considerable fluctuations of diversity, but, overall, they remained stable. The plant functional group of annuals showed high resilience at all sites, while perennials were resistant to droughts. Our results were robust to changing spatial scales of observations, and we also demonstrated that within-site spatial synchrony could be used as a sensitive indicator of external climatic effects. We propose the broad application of high-resolution belt transects for powerful and adaptive vegetation monitoring in the future. [ABSTRACT FROM AUTHOR]

We report an exceptionally fast grassland recovery process from a karst plateau in SW Slovenia. Vegetation of old fields with different ages was sampled using a chronosequence of fields abandoned 1, 3, 6, 9, 13, 15 and 100 years ago. We prepared dendrogram dividing the data set into 9 clusters that were further analyzed: diagnostic species, ecological conditions and life forms were evaluated. The initial stage of succession was characterized by segetal weeds and indicated high levels of soil nutrients. The second stage was dominated by dense patches of perennial forbs (most of them ruderal species) preferring also high levels of soil nutrients. The third stage was dominated by caespitose hemicryptophyte grasses, many of them of sub-Mediterranean origin. The first two stages took 13 years and both could be considered as early successional stages developing on nutrient rich soils. These stages were switched to late successional stage characterized by seminatural grassland species. The quick succession can probably be attributed to the rich species pool of natural grassland flora, the small size and annual mowing of abandoned agricultural fields and the close proximity of seed sources. [ABSTRACT FROM AUTHOR]

Aims: Ecological theories predict that assembly processes shape communities so that co-existing species may either be functionally more dissimilar ("divergence") or more similar ("convergence") than expected by chance. Two important factors that are rarely considered in combination are spatial scale and successional stage. Our aim is to identify different functional patterns during succession across spatial scales and to discuss the likely underlying assembly processes. We expect to find convergence due to environmental filtering at early succession, especially at the largest scales, and a tendency towards divergence driven by competitive interactions as succession unfolds and at smaller spatial scales. Location: Protected Landscape Area “Bohemian Karst”, Czech Republic. Methods: We studied three succession stages (two, eight and 55 years after abandonment). Each field was sampled using 40 1-m² quadrats containing 100 pins in a regular grid. We analysed trait dispersion at several combinations of grain and extent and characterised trait similarity using phylogeny and four traits: specific leaf area, leaf dry matter content, height, and seed mass analysed individually and combined using Gower distance (multi-trait dissimilarity). Results: In the youngest field, three of the traits individually and the multi-trait dissimilarity showed convergence regardless of scale. Phylogeny showed convergence at most spatial scales of the youngest stage. The other two fields showed greater divergence predominantly in the oldest field at the smallest spatial scale. Conclusions: The results are mainly congruent with theoretical expectations and provide a valuable example of directional changes from trait convergence to divergence along succession. The scale-invariant convergence in the early stages of succession seems to be the result of environmental filtering and weaker competitive exclusion. At later stages and particularly at smaller scales, divergence becomes more common, likely because competition limits the trait similarity of species. These results highlight the importance of predictable (non-random) changes in ecological succession. [ABSTRACT FROM AUTHOR]

Spatial patterns of ecosystem processes constitute significant sources of uncertainty in greenhouse gas flux estimations partly because the patterns are temporally dynamic. The aim of this study was to describe temporal variability in the spatial patterns of grassland CO2 and N2O flux under varying environmental conditions and to assess effects of the grassland management (grazing and mowing) on flux patterns. We made spatially explicit measurements of variables including soil respiration, aboveground biomass, N2O flux, soil water content, and soil temperature during a 4-year study in the vegetation periods at grazed and mowed grasslands. Sampling was conducted in 80 × 60 m grids of 10 m resolution with 78 sampling points in both study plots. Soil respiration was monitored nine times, and N2O flux was monitored twice during the study period. Altitude, soil organic carbon, and total soil nitrogen were used as background factors at each sampling position, while aboveground biomass, soil water content, and soil temperature were considered as covariates in the spatial analysis. Data were analyzed using variography and kriging. Altitude was autocorrelated over distances of 40–50 m in both plots and influenced spatial patterns of soil organic carbon, total soil nitrogen, and the covariates. Altitude was inversely related to soil water content and aboveground biomass and positively related to soil temperature. Autocorrelation lengths for soil respiration were similar on both plots (about 30 m), whereas autocorrelation lengths of N2O flux differed between plots (39 m in the grazed plot vs. 18 m in the mowed plot). Grazing appeared to increase heterogeneity and linkage of the spatial patterns, whereas mowing had a homogenizing effect. Spatial patterns of soil water content, soil respiration, and aboveground biomass were temporally variable especially in the first 2 years of the experiment, whereas spatial patterns were more persistent (mostly significant correlation at p < 0.05 between location ranks) in the second 2 years, following a wet year. Increased persistence of spatial patterns after a wet year indicated the recovery potential of grasslands following drought and suggested that adequate water supply could have a homogenizing effect on CO2 and N2O fluxes. [ABSTRACT FROM AUTHOR]

This study investigates how yellow bluestem affects biodiversity in a typical Pannonian grassland. Beta diversity ( i.e. the finescale spatial variability of species compositions), was estimated by the realized number of species combinations sampled at various scales. Sampling was performed by a standard protocol. Presences of plant species were recorded along 52.2 m long belt transect of 1044 units of 0.05x0.05 m contiguous microquadrats. According to the results the massive presence of tested C grass significantly reduced species richness of the grassland. Beta diversity assessment revealed that 90% of species combinations were lost due to yellow bluestem invasion. Fine-scale spatial pattern analyses showed complete local extinctions of other species from microsites dominated by yellow bluestem. This local extinction is enhanced by the specific clonal architecture of this species and by the accumulation of litter. Other dominant grasses had no effect on fine scale diversity, i.e. they could coexist well with other elements of the local flora. This study presents currently developed microhabitat types, forecasts and also draws attention to the danger that climate warming will probably enhance the spread of this detrimental C species. [ABSTRACT FROM AUTHOR]

In this study eight temperate grassland sites were monitored for soil CO 2 efflux (R s ) and the spatial covariate soil water content (SWC) and soil temperature (T s ) at fine scale in over 77 measurement campaigns. The goals of this multisite study were to explore the correlations between environmental gradients and spatial patterns of R s , SWC and T s , which are not site-specific and to quantify the relevance of biotic and abiotic controls over spatial patterns along increasing vegetation structural complexity. These patterns in water-limited ecosystems in East-Central Europe are likely to be influenced by summer droughts caused by the changing climate. A consistent experimental setup was applied at the study sites including 75 sampling locations along 15 m circular transects. Spatial data processing was mainly based on variography. Two proxy variables were introduced to relate the site characteristics in terms of soils, water status and vegetation. Normalised SWC (SWCn) reconciled site-specific soil water regimes while normalised day of year integrated temperature and vegetation phenology. A principal component analysis revealed that the progressing closure of vegetation in combination with large R s and SWCn values, as well as low T s and R s variability support the detectability of spatial patterns found in both the abiotic and biotic variables. Our results showed that apart from SWC the pattern of soil temperature also had an effect on spatial structures. We detected that when the spatially structured variability of T s was low, a strong negative correlation existed between SWCn and the spatial autocorrelation length of R s with r = 0.66 (p < 0.001). However, for high spatially structured variability of T s , occurring presumably at low T s in spring and autumn, the correlation did not exist and it was difficult to quantify the spatial autocorrelation of R s . Our results are indicative of a potential shift from homogeneity and dominance of biotic processes to an increased heterogeneity and abiotic regulation in drought prone ecosystems under conditions of decreasing soil moisture. [ABSTRACT FROM AUTHOR]

Environmental circumstances shaping soil microbial communities have been studied extensively. However, due to disparate study designs, it has been difficult to resolve whether a globally consistent set of predictors exists, or context-dependency prevails. Here, we used a network of 18 grassland sites (11 of those containing regional plant productivity gradients) to examine (i) if similar abiotic or biotic factors predict both large-scale (across sites) and regional-scale (within sites) patterns in bacterial and fungal community composition, and (ii) if microbial community composition differs consistently at two levels of regional plant productivity (low vs. high). Our results revealed that bacteria were associated with particular soil properties (such as base saturation) and both bacteria and fungi were associated with plant community composition across sites and within the majority of sites. Moreover, a discernible microbial community signal emerged, clearly distinguishing high and low-productivity soils across different grasslands independent of their location in the world. Hence, regional productivity differences may be typified by characteristic soil microbial communities across the grassland biome. These results could encourage future research aiming to predict the general effects of global changes on soil microbial community composition in grasslands and to discriminate fertile from infertile systems using generally applicable microbial indicators., (© 2023 John Wiley & Sons Ltd.)

Deeper understanding on natural forest dynamics requires long-term data series from forests that have not been affected by human interventions, which are often scarce especially in the Pannonian Bioregion. Unmanaged, but regularly inventoried forest reserves provide an opportunity to fill this gap. The dataset provides repeated inventory data for 233 permanent plots situated in the core areas of six forest reserves selected from primary forests (Kékes), long abandoned forests (Kecskés-galya, Szalafő, Várhegy) and abandoned ones (Hidegvíz-völgy, Nagy Istrázsa-hegy). The sampled old stands represent the four most widespread hilly forest types in Hungary: Carpathian submountainous beech forest; sessile oak-hornbeam forest; Turkey oak and sessile oak forest; downy oak forest. In each plot, stand level attributes included main mensuration variables (canopy closure, stand height, tree density, basal area, living and dead volume, lying deadwood and admixture of the main tree species). Tree level attributes (diameter at breast height, height measured and estimated, crown position in the canopy, health status, tree history of all trees or shrubs having diameter larger or equal to 5 cm) were also measured in two inventories (after 6-16 years) for a total of 6,986 individual trees sampled in all plots. Fagus sylvatica L., Quercus petraea agg., Q. cerris L., Q. pubescens Willd., Carpinus betulus L., Acer campestre L. and Cornus mas L. were the most abundant. The individual tree history classification refers to regeneration ingrowth, growing phase, mortality, decaying phase and disappearance events, that can be used for calculation of various stand dynamics attributes. The dataset offers valuable opportunities for quantifying changes in stand structures and tree population dynamic attributes after the abandonment of management. Inventory data can be integrated with environmental and climatic information to understand the drivers of forest stand dynamics under a changing climate., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Author(s).)