Plant Diversity In Grasslands Research Articles

Plant diversity maintains multiple soil functions in future environments

Biodiversity increases ecosystem functions underpinning a suite of services valued by society, including services provided by soils. To test whether, and how, future environments alter the relationship between biodiversity and multiple ecosystem functions, we measured grassland plant diversity effects on single soil functions and ecosystem multifunctionality, and compared relationships in four environments: ambient conditions, elevated atmospheric CO2, enriched N supply, and elevated CO2 and N in combination. Our results showed that plant diversity increased three out of four soil functions and, consequently, ecosystem multifunctionality. Remarkably, biodiversity-ecosystem function relationships were similarly significant under current and future environmental conditions, yet weaker with enriched N supply. Structural equation models revealed that plant diversity enhanced ecosystem multifunctionality by increasing plant community functional diversity, and the even provision of multiple functions. Conserving local plant diversity is therefore a robust strategy to maintain multiple valuable ecosystem services in both present and future environmental conditions.

Impacts of grazing exclusion on productivity partitioning along regional plant diversity and climatic gradients in Tibetan alpine grasslands

The biodiversity-productivity relationship is critical for better predicting ecosystem responses to climate change and human disturbance. However, it remains unclear about the effects of climate change, land use shifts, plant diversity, and their interactions on productivity partitioning above- and below-ground components in alpine grasslands on the Tibetan Plateau. To answer this question, we conducted field surveys at 33 grazed vs. fenced paired sites that are distributed across the alpine meadow, steppe, and desert-steppe zones on the northern Tibetan Plateau in early August of 2010–2013. Generalized additive models (GAMs) showed that aboveground net primary productivity (ANPP) linearly increased with growing season precipitation (GSP) while belowground net primary productivity (BNPP) decreased with growing season temperature (GST). Compared to grazed sites, short-term fencing did not alter the patterns of ANPP along climatic gradients but tended to decrease BNPP at moderate precipitation levels of 200 mm < GSP <450 mm. We also found that ANPP and BNPP linearly increased with species richness, ANPP decreased with Shannon diversity index, and BNPP did not correlate with the Shannon diversity index. Fencing did not alter the relationships between productivity components and plant diversity indices. Generalized additive mixed models furtherly confirmed that the interaction of localized plant diversity and climatic condition nonlinearly regulated productivity partitioning of alpine grasslands in this area. Finally, structural equation models (SEMs) revealed the direction and strength of causal links between biotic and abiotic variables within alpine grassland ecosystems. ANPP was controlled directly by GSP (0.53) and indirectly via species richness (0.41) and Shannon index (−0.12). In contrast, BNPP was influenced directly by GST (−0.43) and indirectly by GSP via species richness (0.05) and Shannon index (−0.02). Therefore, we recommend using a joint approach of GAMs and SEMs for better understanding mechanisms behind the relationship between biodiversity and ecosystem function under climate change and human disturbance.

Optimizing management to conserve plant diversity and soil carbon stock of semi-arid grasslands on the Loess Plateau

Grassland recovery from degradation is increasingly occurring worldwide. Diverse managements have been considered as effective ways to restore degraded grassland, but it remains unclear how semi-arid grasslands respond to long-term grazing exclusion and fenced mowing. Here, a study was conducted under open grazing, grazing exclusion and fenced mowing in a semi-arid grassland on the Loess Plateau. We measured plant species composition and diversity, plant production, surface litter and soil water and carbon content. Shifts in grassland management led to significant divergence in plant community composition. Long-term grazing exclusion (35 years) significantly increased plant biomass, surface litter, soil water and carbon storage, but suppressed plant diversity compared to open grazing. Conversely, fenced mowing significantly increased plant diversity accompanying with a weak effect on soil carbon. Moreover, mowing significantly reduced surface litter and soil moisture, which have strong implications for nutrient depletion and soil drying. Our results suggest that introducing disturbances are necessary to safeguard biodiversity, and continuous mowing (5 years) belongs to over exploitation of the long-term protected grassland. Therefore, it is essential to optimize management with dual objectives of biodiversity and soil carbon sequestration in the future.

Response of bryophytes to afforestation, increase of air humidity, and enrichment of soil diaspore bank

The abandonment of agricultural areas is usually accompanied by the stochastic encroachment of shrubs and trees or deliberate afforestation, but this leads as a rule to the decline of grassland plant diversity. Future climate change may increase precipitation and air humidity in temperate and boreal forest zones, and thus change vegetation dynamics.We conducted a five-year experiment on the Free Air Humidity Manipulation experimental facility (FAHM) with planted deciduous trees to examine how both the grassland afforestation with deciduous trees and the increase of air humidity in interaction with forest soil supplementation and cover of herbaceous layer affect the species richness, composition and cover of bryophyte layer. The effects of the same factors on the cover of herbaceous layer were also analysed. The species of bryophytes and cover of herbaceous and bryophyte layer were surveyed in September of 2007–2011.During these early years of forest succession, herbaceous layer cover decreased and bryophyte cover increased, although the direct suppressing effect of tree canopy was observed on both layers. The input of forest soil as diaspore deposit of bryophytes had some positive effect on the cover of bryophytes, while the increased air humidity had quite limited effect. The density of tree canopy (defined in our study through Leaf Area Index) first promoted the species richness of bryophytes, particularly of species with grassland preference. However, together with the herbaceous layer it became suppressing in the last year.The species richness of bryophytes declined during the first years and then stabilised. The decline relied mainly on the disappearance of grassland species. The richness of bryophytes was supported by forest soil supplementation only in the initial year.The bryophyte species composition changed rapidly in first two years mainly due to decline of short-lived grassland species and perennial species started to dominate.Our results show that bryophyte succession during the afforestation is largely driven by natural loss of grassland specialists after tree canopy closure, while diaspore supplementation from forest and improved air moisture level had small effects.

Response of Collembola and Acari communities to summer flooding in a grassland plant diversity experiment.

Flooding frequency is predicted to increase during the next decades in Europe. Therefore, it is important to understand how short-term disturbance events affect soil biota providing essential ecosystem functions and uncover factors modulating their response such as plant community composition. Here we report on the response of soil microarthropod communities (Collembola and Acari) to a severe summer flood in 2013, which affected major parts of central Europe. Collembola and Acari density and Collembola and Oribatida richness were strongly affected by the flood, but they recovered within three months. Effects of plant community composition on soil microarthropods disappeared after the flood, presumably due to homogenization of the field, but the effects of plant community were in a stage of being reasserted three months after the flood. Widespread, surface living and generalistic microarthropod species recolonized the field quickly. Prostigmata and Oribatida were more resilient or recovered to flooding than Astigmata and Gamasida. Long-term impacts, however, remain unknown and deserve further investigation.

GrassPlot – a database of multi-scale plant diversity in Palaearctic grasslands

GrassPlot is a collaborative vegetation-plot database organised by the Eurasian Dry Grassland Group (EDGG) and listed in the Global Index of Vegetation-Plot Databases (GIVD ID EU-00-003). GrassPlot collects plot records (releves) from grasslands and other open habitats of the Palaearctic biogeographic realm. It focuses on precisely delimited plots of eight standard grain sizes (0.0001; 0.001;... 1,000 m(2)) and on nested-plot series with at least four different grain sizes. The usage of GrassPlot is regulated through Bylaws that intend to balance the interests of data contributors and data users. The current version (v. 1.00) contains data for approximately 170,000 plots of different sizes and 2,800 nested-plot series. The key components are richness data and metadata. However, most included datasets also encompass compositional data. About 14,000 plots have near-complete records of terricolous bryophytes and lichens in addition to vascular plants. At present, GrassPlot contains data from 36 countries throughout the Palaearctic, spread across elevational gradients and major grassland types. GrassPlot with its multi-scale and multi-taxon focus complements the larger international vegetationplot databases, such as the European Vegetation Archive (EVA) and the global database sPlot. Its main aim is to facilitate studies on the scale-and taxon-dependency of biodiversity patterns and drivers along macroecological gradients. GrassPlot is a dynamic database and will expand through new data collection coordinated by the elected Governing Board. We invite researchers with suitable data to join GrassPlot. Researchers with project ideas addressable with GrassPlot data are welcome to submit proposals to the Governing Board.

Plant species richness record in Brazilian Pampa grasslands and implications

Species richness remains one of the most valuable type of information for biodiversity conservation. Here, we report a plant richness record in the Brazilian Pampa. We found 56 vascular plant species in a single plot of 1 × 1 m in a privately owned grazed grassland in a region with shallow soils. This number is considerably higher than common species numbers in similar surveys and highlights the high plant diversity in South Brazilian grasslands. We take our record as an opportunity to reflect on some issues of high importance if we wish to reach conservation goals: much of the biodiversity is inside private lands, and these should be more in the focus of conservation efforts; field research, especially quantitative sampling, continues to be essential to improve knowledge on biodiversity and its distribution patterns; training biologists to be able to carry out biodiversity assessments and to interpret the results should be a key issue for universities. We hope that the communication of this record will encourage new scientific discoveries and raise social interest about the conservation of grasslands in South Brazil.

Arbuscular mycorrhizal fungi alter plant community composition along a grazing gradient in Inner Mongolia Steppe

Arbuscular mycorrhizal fungi (AMF) have a significant influence on plant productivity and diversity in non-grazing grassland. However, the interactive effects between grazing intensity and AMF on plant community composition in natural grassland communities are not well known. We conducted a field experiment that manipulated AMF colonization and grazing intensity to study the impact of AMF suppression on plant community composition and nutrient status over 2 years (2015–2016) with contrasting rainfall levels. We found that AMF root colonization was significantly reduced by the application of the fungicide benomyl as a soil drench. Grazing intensity regulated plant community composition and aboveground biomass mainly by reducing the growth of Leymus chinensis over 2 years. AMF suppression increased the growth of Chenopodium glaucum, but it did not alter other plant species across all grazing intensities. The effects of AMF suppression on plant community composition changed along a grazing gradient considerably between years: AMF suppression increased the biomass of C. glaucum across all grazing intensities in 2015, but slightly increased it in 2016. Interactions between AMF suppression and grazing intensity altered the phosphorus concentration of Stipa grandis and Cleistogenes squarrosa in 2015 but not in 2016. AMF suppression decreased the shoot phosphorus content of L. chinensis but increased that of C. glaucum across all grazing intensities. Our results indicate that grazing intensity substantially alters aboveground community biomass and affects growth of dominant species; AMF by itself have limited effects on plant communities along a grazing gradient in typical steppe.

Resource‐mediated effects of grazing and irrigation on insect diversity in a meadow steppe

Abstract Human activities and climate change are key drivers of biodiversity loss in natural ecosystems. In particular, a growing body of evidence shows that grazing and altered precipitation patterns strongly affect grassland plant and insect diversity respectively, but their combined effects and impact on trophic interactions are largely unknown. In this study, a field experiment was conducted with different grazing intensities and irrigation to examine how plant diversity responds to variation in grazing and precipitation, which in turn influences the diversity of herbivores and predators in insect communities in a meadow steppe. Overall, grazing and irrigation increased plant biomass and decreased plant diversity, except for non‐significant effects of irrigation treatments on plant diversity. Higher herbivore diversity in grazing treatments was mediated by plant diversity because path analysis revealed a positive relationship between plant and herbivore species richness. Increased predator diversity caused by grazing was mediated indirectly through changes in herbivore abundance. Our results indicate that plant‐mediated changes in herbivore diversity are consistent with the Resource Diversity Hypothesis, whereas changes in predator diversity correspond with the More Individuals Hypothesis. Our findings highlight the importance of assessing both direct and indirect effects of grazing and irrigation on the diversity of guilds at different trophic levels within an insect community. Furthermore, understanding mechanistic responses to such changes could help us to better account for biodiversity loss in the context of grazing and altered precipitation patterns.

Interspecific trait differences rather than intraspecific trait variation increase the extent and filling of community trait space with increasing plant diversity in experimental grasslands

Niche differentiation among species is supposed to be reflected in the distribution of trait values in communities. Yet, how species-specific trait expression responds to changing plant diversity and how these changes affect community-level trait distributions is less clear. We used monocultures and mixtures of a large biodiversity experiment (Jena Experiment) to evaluate this question. We applied additive partitioning of net biodiversity effects (NE) into complementarity (CE) and selection effects (SE) to community-weighted trait means (CWM). Between 60–100% of NEs on CWMs (i.e. their deviation from the abundance-weighted means of monoculture trait values) were explained by CEs indicating that trait plasticity of different species contributed to shifts in CWMs. Positive CEs for shoot-architectural traits, tissue elemental concentrations and specific leaf area (SLA) indicated on-average higher values of these traits in the mixtures, while negative SEs in these traits suggested that dominant species showed the opposite response to the mixture-environment. Trait plasticity in response to mixture growth conditions increased species-level trait deviation from CWMs in several traits related to structural stability and SLA, while species-level deviation in shoot length from CWMs decreased. Community-wide occupation of trait space (range and variance of trait values) increased with plant diversity. Trait plasticity in response to the mixture-environment reduced the occupied trait space in several size-related traits, while it increased trait space in SLA. Measures of trait-based niche differentiation did not change (kurtosis, i.e. “peakedness” of trait distribution) or decreased (standard deviation of nearest neighbour distances, SDNN) at increased species richness, indicating that plasticity did not reduce niche overlap. Our results suggest that fixed trait differences among species primarily explain the greater extent and denser filling of community trait space at increased plant diversity. Species-specific trait plasticity in response to increased plant diversity does not increase community-wide trait space or decrease niche overlap between species.

Quantifying effects of biodiversity on ecosystem functioning across times and places.

Biodiversity loss decreases ecosystem functioning at the local scales at which species interact, but it remains unclear how biodiversity loss affects ecosystem functioning at the larger scales of space and time that are most relevant to biodiversity conservation and policy. Theory predicts that additional insurance effects of biodiversity on ecosystem functioning could emerge across time and space if species respond asynchronously to environmental variation and if species become increasingly dominant when and where they are most productive. Even if only a few dominant species maintain ecosystem functioning within a particular time and place, ecosystem functioning may be enhanced by many different species across many times and places (β-diversity). Here, we develop and apply a new approach to estimate these previously unquantified insurance effects of biodiversity on ecosystem functioning that arise due to species turnover across times and places. In a long-term (18-year) grassland plant diversity experiment, we find that total insurance effects are positive in sign and substantial in magnitude, amounting to 19% of the net biodiversity effect, mostly due to temporal insurance effects. Species loss can therefore reduce ecosystem functioning both locally and by eliminating species that would otherwise enhance ecosystem functioning across temporally fluctuating and spatially heterogeneous environments.

Hemiparasite-density effects on grassland plant diversity, composition and biomass

Hemiparasitic plants are considered ecosystem engineers because they can modify the interactions between hosts and other organisms. Thereby, they may affect vegetation structure, community dynamics and facilitate coexistence as they are able to reduce interspecific competition by parasitizing selectively on competitive species and promote subordinate ones. In agri-environmental schemes, introducing the hemiparasite Rhinanthus has therefore been suggested as a low-cost method to increase grassland plant diversity, which is still subject to debate.The majority of previous studies simply compared sites with and without hemiparasites. However, as hemiparasite effects are most likely density-dependent, we present a novel approach assessing the effect of Rhinanthus alectorolophus density on grassland plant diversity, yield and community biomass quality. Moreover, we investigated whether functional plant composition and community mean traits are affected by Rhinanthus density, which has been largely neglected in previous studies.The relationship between species richness and relative Rhinanthus biomass followed an optimum curve with highest values at 31% relative Rhinanthus biomass. At this Rhinanthus-biomass level, species richness was increased by 12% and yield decreased by 26% compared with plots without Rhinanthus. At relative Rhinanthus biomass >60%, species richness was even lower than in plots without Rhinanthus. Overall, the biomass of grasses and the cumulative cover of legumes decreased linearly with increasing relative Rhinanthus biomass. Community mean trait analysis revealed that an increasing Rhinanthus density shifts the community composition towards smaller plant species. Biomass quality was not affected by increasing relative Rhinanthus biomass.In summary, our results of increased plant diversity – in line with a slightly lower yield but similar community biomass quality – indicate that Rhinanthus is a suitable biological tool for grassland restoration.

Long-Term Grazing Accelerated Litter Decomposition in Northern Temperate Grasslands

Livestock grazing affects plant community composition, diversity, and carbon (C) and nutrient cycling in grasslands. Grazing leads to plant communities that have higher relative abundance of grazing-tolerant species, which in turn may alter the chemical composition of biomass and subsequent litter decomposition rates. To better understand the effects of long-term grazing and associated vegetation shifts on biogeochemical cycling in northern temperate grasslands of western Canada, we studied litter decomposition over 18 months at 15 locations, stratified across the Mixed-grass Prairie, Central Parkland, and Foothills Fescue natural subregions. At each location, we examined decomposition in an area exposed to grazing and an area where cattle were excluded. We used litterbags containing leaf litter from seven major grass species representing different grazing tolerances and included a local source of community litter from each study site and cellulose paper as standards. Decomposition was affected by litter types, with litter from grazing-tolerant species such as Poa pratensis and Bouteloua gracilis having faster decomposition rates compared to grazing-intolerant species, supporting the hypothesis that changes in vegetation composition due to grazing influences biogeochemical cycling by modifying litter decomposition in grasslands. Litter decomposition was also overall most rapid in the cool–wet Foothills Fescue, followed by the temperate mesic Central Parkland, and slowest in the warmer–drier Mixed-grass Prairie. Combined with known grazing-induced changes in grassland composition, these findings indicate that livestock grazing may accelerate litter decomposition rates in the more mesic Foothills Fescue and parkland regions, but not the more arid Mixed-grass Prairie. Overall, this study elucidates the role of livestock grazing and its associated effects on litter decomposition and ecosystem processes in northern grassland ecosystems.

Overgrazing depresses soil carbon stock through changing plant diversity in temperate grassland of the Loess Plateau

This study mainly estimates the effect of grazing on plant diversity and soil storages on the northern Loess Plateau of China. Four grazing intensities of ungrazed (UG), light (LG), moderate (MG), and heavy (HG) grassland were selected according to the vegetation utilization across the study area, in which plant diversity, heights, above- and belowground biomass, and soil carbon (C) stock were investigated. The results showed that overgrazing negatively affected plant growth and soil C stock. Plant cover, height, litter, above- and belowground productivity, as well as soil C stock significantly decreased with the increasing grazing intensity. Meanwhile, the UG and LG had higher grasses biomass together with lower forbs (P &amp;lt; 0.01) compared with MG and HG. The abundance of dominating grasses species, such as Stipa bungeana and S. grandis were decreased through long-term grazing as grasses species are palatable for herbivores, and the dominating forbs species, such as Artemisia capillaries and Thymus mongolicus were significantly increased with increasing grazing intensities. The results indicated that grazing exclusion or light grazing had positive effects on the sustainable development of grassland ecosystems. Therefore, a balanced use and a long-term efficient management of grasslands were better measures to counteract their local degradations.

Vegetation and soil seed bank in a 23-year grazing exclusion chronosequence in a Mediterranean dry grassland

Long-term grazing shaped plant diversity in dry Mediterranean grasslands. Abandonment of grazing affects plant diversity especially in the northern Mediterranean. Considerable efforts are, therefore, under way for grassland conservation and restoration. Yet, we do not know at which temporal scales impacts of grazing abandonment appear and in particular how soil seed banks evolve after longer grazing abandonment. Here, we provide detailed data from one of the very few long-term experiments available. These experiments provide data for up to 23 years (1982–2005) of grazing exclusion built in 1982, 1989, 2000 and 2001. Grazing exclusion decreased species richness, modified vegetation structure and changed soil parameters. Decline in species richness appears in communities that experienced 16 and 23 years of grazing exclusion. Only four to nine plant species of this Mediterranean grassland built persistent soil seed banks appearing after grazing exclusion, compared to 40–50 species in the established vegetation of grazed plots. Hence, similarity between vegetation and soil seed bank decreased with time of grazing exclusion. Even 23 years after abandonment, no woody plants colonised the experiments. We conclude that vegetation will recover fast from grazing abandonment in the short-term. Nevertheless, longer abandonment will impact diversity due to reduced soil seed banks.

Deconstructing human-shaped treelines: Microsite topography and distance to seed source control Pinus nigra colonization of treeless areas in the Italian Apennines

Human-shaped treelines are a common feature in mountain landscapes across Europe, and particularly in secularly managed Mediterranean high-elevation areas. The abandonment of traditional land use, and especially the reduction in grazing pressure at high elevations, triggered secondary succession in treeless grassland areas, and favored the upward shift of anthropogenic treelines in some cases. We investigated this process in four anthropogenic treeline ecotone sites in the Central Apennines, Italy, populated by European black pine (Pinus nigra Arn.). The upward treeline shift was controlled by microsite topography and the proximity to plantations acting as seed source. We found a 50% probability of producing cones in trees with basal diameters of 15–25 cm, heights of 2–5 m and ages of 20–25 years. The role played by climate on growth and the recruitment processes seems to be secondary, or could be masked by human-shaped processes. The presence of reproductive age trees at the treeline, mainly growing on debris-rich and steep slope sites, could indicate that the recruitment process will increase in future, leading to patchy tree patterns at different elevations. The high growth and encroachment rates observed at these human-shaped treelines would indicate that general growth dynamics are speeding up, including the tree colonization of treeless areas. These succession processes could cause a significant long-term decline in plant diversity in species-rich grasslands. Nonetheless, tree encroachment could increase forest protection against landslides and avalanches in the context of global change.

Changes in Species Diversity Patterns and Spatial Heterogeneity during the Secondary Succession of Grassland Vegetation on the Loess Plateau, China.

Analyzing the dynamic patterns of species diversity and spatial heterogeneity of vegetation in grasslands during secondary succession could help with the maintenance and management of these ecosystems. Here, we evaluated the influence of secondary succession on grassland plant diversity and spatial heterogeneity of abandoned croplands on the Loess Plateau (China) during four phases of recovery: 1–5, 5–10, 10–20, and 20–30 years. The species composition and dominance of the grassland vegetation changed markedly during secondary succession and formed a clear successional series, with the species assemblage dominated by Artemisia capillaris→ Heteropappus altaicus→ A. sacrorum. The diversity pattern was one of low–high–low, with diversity peaking in the 10–20 year phase, thus corresponding to a hump-backed model in which maximum diversity occurring at the intermediate stages. A spatially aggregated pattern prevailed throughout the entire period of grassland recovery; this was likely linked to the dispersal properties of herbaceous plants and to high habitat heterogeneity. We conclude that natural succession was conducive to the successful recovery of native vegetation. From a management perspective, native pioneer tree species should be introduced about 20 years after abandoning croplands to accelerate the natural succession of grassland vegetation.

Negative effects of fertilization on grassland species richness are stronger when tall clonal species are present

Fertilization of grasslands commonly leads to species loss and a dramatic shift in species composition, but the mechanisms underlying this pattern remain unclear. One oft-stated hypothesis is that fertilization increases competition for light and/or reduces spatial heterogeneity of resources, thereby reducing the niche dimensionality for species to coexist. Here, we summarize results from two long-term field experiments showing that the negative effects of fertilization on grassland species richness are greater in the presence of species with a spreading clonal growth form, particularly species that are tall (hereafter ‘tall clonals’). The interactive effect of fertilization and the presence of clonal species on the loss of species richness is associated with: (1) a pronounced increase in the relative abundance of tall clonals following fertilization, and (2) a greater reduction in mean light levels and reduced spatial heterogeneity in light when tall clonal species are present. We hypothesize that tall clonals gain a competitive advantage following fertilization as a result of two important traits related to clonality: (1) the ability to translocate resources between ramets in high to those in low resource patches and (2) the ability to spread vegetatively, especially under conditions where low-light levels limit recruitment from seeds. We suggest that efforts to mitigate the negative effects of nutrient enrichment on grassland diversity may be enhanced by controlling dominance by tall clonal grasses and forbs, and that these results have important implications for management efforts to maintain and enhance plant diversity in grasslands.

Enhancing plant diversity in a novel grassland using seed addition

Abstract Restoration of novel ecosystems to a historical benchmark may not always be possible or advisable. Novel ecosystems may be managed by targeting specific components and accepting the novelty of other ecosystem attributes. The feasibility of this component‐wise management of novel ecosystems has rarely been tested. In a novel grassland, where C3 grasses have replaced C4 grasses, nutrients have been elevated, and diversity has been lost due to a history of agricultural land use, we aimed to return diversity using seed addition, without altering the dominant grass matrix or nutrient status. Using direct seeding, with and without soil disturbance, we assessed the ability of 10 species of native forbs to establish. Eight of the 10 seeded species established in the first year. Soil disturbance increased establishment success by 50%, while high levels of exotic cover decreased it by 24%. Establishment was inversely related to total plant cover at sowing, with a 10% increase in initial plant cover decreasing establishment by 47%. By the third year, six of the eight species persisted and five were flowering. Survival and reproduction in the third year was not associated with the soil disturbance treatment or plant cover. Synthesis and applications. We show that native plant species can be re‐established in grasslands where abiotic and biotic conditions are novel relative to their reference state. This suggests that the conservation value of novel ecosystems can be enhanced using simple restoration tools that target specific ecosystem components.

Changes in grassland management and plant diversity in a marginal region of the Carpathian Mts. in 1999–2015

The political change from socialism to democracy in countries of Central and Eastern Europe at the end of the 20th century induced broad changes in agriculture mostly due to land ownership changes and strong reduction of subsidies to agriculture. This resulted in agricultural decline, including grassland abandonment, which influenced grassland biodiversity and conservation. Between 1999 and 2015 we studied the grasslands in the area depopulated in the early 1980's in the Poloniny National Park (NE Slovakia, Carpathian Mts.). The aim of the study was to examine influence of environmental factors and grassland management driven by the Common Agricultural Policy (CAP) to plant community structure and taxonomical diversity. We identified altitude and soil properties as the main environmental factors: altitude determines climate gradient and probably also management intensity gradient and soil properties express soil fertility via A-horizon depth. We identified remarkable increase of proportion of managed grasslands from only 8% in 1999 to 40% in 2012–2015; other 7% of sampled grasslands were recently restored and prepared for future management. The average species richness in grasslands managed in 2012–2015 increased from 47.5 species per record in 1999 to 54.2 species in 2012–2015, the increase was found statistically significant. In 2012–2015, we observed statistically significant difference in the average species richness between managed (54.2) and abandoned grasslands (46.3). The agricultural subsidies of the CAP drive the grassland management in the study area. Therefore, we conclude that CAP enabled grassland biodiversity maintenance in significant part of the Poloniny National Park following start of its application in 2004 and above provided figures can be considered as indicators of the CAP effectiveness in our study area. However, the conservation of mountain meadows remains a challenge because of their poor accessibility.