Saline Grasslands Research Articles

Differential root nutrient‐acquisition strategies underlie biogeochemical niche separation between grasses and forbs across grassland biomes

Abstract Plant nutrient composition is a reliable tool to identify plant ecological strategies and niche differentiation. Here, we aimed to (i) reveal the potential physiological mechanisms governing distinct foliar nutrient compositions among coexisting grassland species and (ii) clarify the role of taxonomy and environmental conditions in these compositions. At the local (grassland) scale, we measured root morphological and physiological traits, photosynthetic parameters and foliar concentrations of six macronutrients (N, P, S, K, Ca and Mg) and four micronutrients (Fe, Mn, Zn and Cu) across 18 coexisting species. At the regional scale, foliar macro‐ and micronutrient concentrations of 76 site‐species combinations of grasses and forbs across temperate meadow, typical, desert and saline grasslands were measured in Inner Mongolia. At the national scale, we collected the data on foliar macronutrient concentrations of 513 site‐species combinations across grasslands in Xinjiang, Qinghai‐Tibet and Inner Mongolia of China. Compared with forbs, grasses had 3.9 times higher root branching intensity, but 58% and 48% lower root carboxylate exudation and leaf transpiration rate. These distinct nutrient acquisition and transport strategies led to lower foliar nutrient (N, P, Ca, Mg and Mn) concentrations in grasses than forbs at the local scale. Most foliar micronutrient concentrations did not differ between grasses and forbs at the regional scale, whereas macronutrient concentrations were higher in forbs than grasses regardless of the grassland type at both the regional and national scales. All macronutrient concentrations exhibited stronger phylogenetic conservatism and less environmental control than micronutrients. The biogeochemical niche segregation (Euclidean distance based on PCA score of foliar macronutrient concentrations) between sympatric grasses and forbs was lower in meadow grassland than in the typical, desert and saline grasslands. Our results suggest that diverse nutrient acquisition and transport strategies can underlie the distinct foliar nutrient compositions between grasses and forbs. The linkage between potential physiological mechanisms and biogeochemical niche differentiation of grasses and forbs will advance our understanding of plant species coexistence and adaptive strategy. Read the free Plain Language Summary for this article on the Journal blog.

Characteristics of anion and cation in rhizosphere soil of saline grassland in North China under different nitrogen addition levels

We investigated the effects and mechanisms of nitrogen additions (0, 1, 2, 4, 8, 16, 24, 32 g N·m-2·a-1) on contents of anion and cation in rhizosphere soil, bulk soil, and mixed rhizosphere and bulk soil in the heavily salinized grassland in the agro-pastoral ecotone of North China. The results showed that pH of rhizosphere, mixed and bulk soils decreased significantly with the increases of nitrogen addition levels. Moreover, pH of three soil types under the 32 g N·m-2·a-1 treatment decreased by 1.2, 0.9, and 0.6, respectively, while pH of rhizosphere soil decreased by 0.44 compared with the bulk soil. Na+ content of rhizosphere, mixed and bulk soils significantly decreased, while the NO3- content significantly increased. The proportion of Na+ content in total soluble salt content in rhizosphere soil decreased by 14% and that in bulk soil decreased by 12% after the 32 g N·m-2·a-1 addition. NO3- content increased by 29% in rhizosphere soil and by 26% in bulk soil. There was significant negative correlation between pH and NO3- content, and significant positive correlation between pH and Na+ content. The total soluble salt content of rhizosphere soil under the 32 g N·m-2·a-1 treatment was significantly reduced by 31.5%. Collectedly, nitrogen deposition could reduce soil pH and total soluble salt content of rhizosphere soil and alleviate saline-alkali stress.

Electrical Conductivity and pH Are Two of the Main Factors Influencing the Composition of Arbuscular Mycorrhizal Fungal Communities in the Vegetation Succession Series of Songnen Saline-Alkali Grassland.

Arbuscular mycorrhizal fungi (AMF) are widely distributed microorganisms in the soil, playing an important role in vegetation succession, plant community diversity, and improving soil physicochemical properties. In this study, morphological identification and high-throughput sequencing technology were used to comprehensively analyze the AMF community composition and diversity at different succession stages of Songnen saline-alkali grassland. To determine the root colonization status of plants collected in the field, a colonization system was established using late-succession plants as host plants to verify the existence of mycorrhizal symbiosis and the matching phenomenon of AMF in Songnen saline-alkali grassland. The results indicated that both morphological methods and high-throughput sequencing technology showed that glomus was the dominant genus of AMF in Songnen saline grassland. Redundancy analysis (RDA) and linear regression analysis showed that electrical conductivity (EC) and pH were the main environmental factors affecting AMF species diversity and community structure in the succession sequence of Songnen saline grassland. In addition, the results of root colonization identification and the colonization system test in the field showed that AMF successfully colonized vegetation at different succession stages and had mycorrhizal symbiosis. The results of this study could help to understand the AMF community of Songnen saline-alkali grassland as well as provide a reference and basis for optimizing the AMF community structure of Songnen saline-alkali grassland through human intervention in the future and using mycorrhizal technology to restore and rebuild the degraded ecosystem of Songnen saline-alkali grassland.

Indirect Prediction of Salt Affected Soil Indicator Properties through Habitat Types of a Natural Saline Grassland Using Unmanned Aerial Vehicle Imagery

Salt meadows, protected within National Parks, cannot be directly surveyed, yet understanding their soil condition is crucial. Our study indirectly estimates soil parameters (Total Salt Content (TSC), Na, and pH) related to salinization/sodification/alkalinization using spectral indices and UAV survey-derived elevation model, focusing on continental lowland salt meadows. A vegetation map was created using 16 spectral indices and a Digital Elevation Model calculated from RGB orthophotos using photogrammetry. Field observations helped define habitat types based on the General National Habitat Classification System (Hungary), and quadrats with complete coverage of specific plant species were identified. Machine learning was employed on 84 training quadrats to develop a prediction algorithm for vegetation patterns. Five saline habitat types, representing variations in soil properties and topography, were identified. Spectral and topomorphometric indices derived from UAV were key to the spatial prediction of soil properties, employing random forest and co-kriging methods. TSC, Na, and pH data served as indicators of salt-affected soils (SAS), and thematic maps were generated for each indicator (57 samples). Overlapping with the vegetation map, the probability range of estimated SAS indicator values was determined. Consequently, a model-based estimation of soil pH, TSC, and Na conditions is provided for habitat types without disturbing protected areas.

Assessment of quality and chemical composition of continental halophytic grasslands in south-east Europe

Continental halophytic grasslands are known for performing of range of ecosystem services especially remarkable in the regions where they are much distributed – in arid and semi-arid areas. Continental halophytic grasslands of the Central and South-East Europe are not considered as favourable for arable farming, however, traditional animal husbandry plays a crucial role in maintaining biodiversity and preserving these natural habitats. The particular interest of this study is the assessment of the chemical composition of biomass and the quality of insufficiently studied halophytic grassland communities of the central Balkans. In addition, the differences in pastoral value were monitored along the geographical gradient, i.e., between grasslands situated in the Pannonian plain (grasslands of Alliance Puccinellion limosae) and those distributed on the south Serbia (Alliance Festucion pseudovinae). The study was carried out at 18 representative sites, focusing on the saline grasslands of the two distinct regions – on the north and on the south of Serbia. The obtained results show that the halophytic grasslands have satisfying quality characteristics (average values: dry matter - 93.67%, crude protein - 8.66%, cellulose - 30.36%, crude fat - 2.27%) compared with other studied grasslands of saline habitats. There were no significant differences in quality and chemical composition of grasslands of the two regions, despite differences in floristic composition, indicating that salinity is the key determinant for pastoral value of the halophytic vegetation. The certain variations were attributed to the specific floristic composition related to ecological conditions and halophytic community characteristics.

Differences in the Seed Germination of Leymus chinensis (Poaceae) Ecotypes Reveal Distinct Strategies for Coping With Salinity Stress: A Common Garden Experiment

Soil salinity is important abiotic stress affecting various ecosystems worldwide such as grassland. Distinct ecotypes often evolve within species by natural selection to facilitate adaptation to different types of environmental stress. Leymus chinensis is a perennial rhizomatous grass that is widely distributed in the eastern Eurasian steppe; it has two main ecotypes, namely, yellow-green (YG) and gray-green (GG), which differ in their strategy for coping with salinity stress. Few studies have examined the seed germination of the two ecotypes under salinity stress. In this study, the seed germination and seedling growth of two ecotypes of L. chinensis in response to different levels of salinity (NaCl) stress [0 (control), 20, 50, 100, and 200 mM] were examined. Then, ungerminated seeds were placed under normal conditions to evaluate seedling growth following exposure to salt stress (i.e., regermination). The germination percentage was significantly higher, and the mean germination time was significantly shorter in the GG ecotype than in the YG ecotype at all NaCl concentrations. As the salinity level increased, the radicle length of the two ecotypes decreased; however, GG had longer radicles and a higher number of radicles, even at 200 mM NaCl when no radicle protruding from the seed coat was detected in YG. The shoot length of GG was significantly longer than that of YG at all NaCl levels. After salinity stress was removed, the seed germination percentage increased as the original concentration of NaCl applied increased, but the total germination percentage did not significantly differ among NaCl concentrations. The total seed germination percentage of GG was approximately 80%, whereas that of the YG was approximately 20%. The seedling length of regerminated seeds for both GG and YG was similar. The thousand-grain weight of GG was significantly higher than that of YG. GG was more salt-tolerant than YG and might be better capable of surviving in harsher environments, suggesting that GG might be particularly useful for saline grassland restoration.

Orthoptera assemblages of the relict meadows of the Szernye marsh area (West Ukraine: Transcarpathia)

Orthoptera assemblages were sampled between 2012 and 2014 on six grasslands in marginal part of the former Szernye Marsh (Bereg Lowland, Transcarpathia, West Ukraine). 24 species in 1306 individuals were observed which is about the half of the Orthoptera species known from the Bereg Lowland. The bulk of the assemblages is formed by generalist chortobiont species (62.5%), while thamnobionts, connected with tall forb and/or shrubby vegetation, also reach a relatively high frequency (29.1%). According to the biogeographical composition, the Euro-Siberian species were predominating (58.3%), combined with only scarce presence of West Palearctic and Mediterranean species. The multivariate analysis did not show any clear subdivision according to the a priori vegetation types with the exception of the xeric habitats. This assemblage type were characterised by a low species number (7–12) and very high frequency of one or at least two dominant species which were common in all types of studied habitats. Although their subdominant species differed from the other two assemlage types but they could not be referred as true character species. Thus the studied xeric habitats are not such true xeric grasslands as the sandy and saline grasslands of the Pannonian lowland. The main natural value of the area is preseved by semi-natural humide and transitional habitat types, which can be conserved by yearly alternating mowing and preserving the mosaic structure with some corridors among them.

Landscape and environmental conditions for the late Holocene in the eastern Pampa-Patagonia transition (Argentina): a phytolith analysis of the El Tigre archaeological site

The El Tigre archaeological site (39°46′49″ S; 62°22′32″ W) is located in the south of Provincia de Buenos Aires, Argentina, on an ancient delta of the Rio Colorado. Its sedimentary sequence shows periods of landscape stability and soil formation processes during the period ca. 1,000–400 years bp. The aim of this paper is to investigate the evolutionary history of the vegetation in order to understand palaeoenvironmental changes during the late Holocene. The study of microremains, mainly phytoliths, from the sedimentary sequence indicates that cold and dry conditions predominated at 2,700–2,200 cal bp, from deposition of non-pedogenetic, aggradational sediments in arid or semi-arid environments and/or sparse vegetation cover. Then the climate became much warmer at ca. 2,200–1,200 cal bp, with greater availability of moisture and the presence of xerophytic shrubs and halophytic grasslands, and also extra-regional trees and shrubs. The records indicate that for ca. 1,500–300 cal bp the climate conditions changed to temperate with periods of greater water availability and the presence of a saline steppe and a greater abundance of Monte-Caldenal scrub vegetation elements. This climatic trend is also in agreement with the soil formation processes defined in the archaeological site sequence. The upper layers of the El Tigre site show lower temperatures in the last 300 years, accompanied by variations in the availability of moisture, with alluvial processes characterized by the presence of saline grasslands with xerophytic shrubs and an increase in Asteraceae and Poaceae, continued by the recent top samples with ruderal communities and sandy grasslands.

Occupancy and diet of the Indian desert fox Vulpes vulpes pusilla in a Prosopis juliflora invaded semi-arid grassland

Encroachment by woody invasive plants has been recognized as a major driver of structural change in grasslands ecosystems. The impact of invasive plant-mediated changes on mammalian species from higher trophic levels is relatively less understood. This study aims to understand the impact of woody encroachment on the ecology of a relatively understudied mesopredator, the Indian desert fox Vulpes v. pusilla in a semi-arid saline grassland ecosystem in Western India. We examined the site occupancy of the Indian desert fox at the landscape level, and den site selection at the micro-habitat scale. We also examined the diet of desert foxes during winter and summer season. We found that at the landscape level the desert fox selects more open Suaeda saline habitats over dense invasive Prosopis juliflora dominated habitats. At the scale of the den, proximity to water and vegetation cover were the main drivers of den site selection. Similar to other arid zone foxes, insects, plant materials and small mammals were the main components of the diet of Indian desert fox. Given its selection of open habitats, invasive shrub encroachment is likely to result in a loss of habitat as well as resources for this species, potentially impacting on the conservation status of this already range-restricted species in India.

True bugs (Heteroptera) of the Pannonic salt steppes and salt marshes in Serbia and their conservation status in the Pannonian countries

Summary Inland saline grasslands and wetlands of the Pannonian Region are areas of great conservation importance since they are the only habitats known for numerous Eurasian steppe species. Characteristic vegetation of halophytes accommodates unique communities of true bugs with several saline habitat specialists. These saline specialists and some rare steppe species are highly threatened and listed in the red lists of several Pannonian countries. Serbian data on true bug fauna from saline habitats are scarce, and the last known work on these insects was done by Géza Horváth more than a century ago. Our study aims to explore the richness of the true bug fauna of saline habitats with the presence of saline specialists in Northern Serbia. We also aim to highlight the species of potential conservation importance. In total, 231 species of true bugs species are recorded from saline habitats of the Pannonian Serbia. For the first time Agramma (Agramma) ruficorne (Germar, 1835), Chlamydatus (Chlamydatus) saltitans (Fallén, 1807), Emblethis brachynotus Horváth, 1897, Lygaeosoma anatolicum Seidenstücker, 1960, Geotomus punctulatus (Costa, 1847) and Phimodera flori Fieber, 1863 are mentioned here from our country. After several decades, seven species are rediscovered – Chartoscirta cocksii (Curtis, 1835), Acalypta gracilis (Fieber, 1844), Aoploscelis bivirgata (Costa, 1853), Compsidolon (Apsinthophylus) pumilum (Jakovlev, 1876), Conostethus hungaricus Wagner, 1941, Criocoris sulcicornis (Kirschbaum, 1856) and Crypsinus angustatus (Baerensprung, 1859) – previously, the most recent records of the latter four species were provided by Horváth in the late nineteenth century. After five years of systematic research of the Pannonic salt steppes and salt marshes, we could say that this unique group of habitats is one of the best-studied for true bugs in our country. However, to give a solid foundation for future red lists of true bugs of Serbia, other parts of the country also need to be explored thoroughly. Besides saline specialists, the red list should consider and prioritize species with rare records in Serbia.

Response of Soil Properties and Microbial Communities to Increasing Salinization in the Meadow Grassland of Northeast China.

Secondary salinization is a serious environmental issue and a major threat to the sustainable use of grasslands. Information about the response of microbial communities and soil properties in already saline soils to increasing salinity is lacking. We investigated soil properties and the structures of soil bacterial and fungal communities across a gradient of salinization in the Horqin Grassland, China. Three sites with relatively lightly (average soluble salt content = 0.11%), relatively moderately (average soluble salt content = 0.44%), and heavily (average soluble salt content = 1.07%) degraded grassland, were selected as experimental sites. We examined variations in the composition and structure of the soil bacterial and fungal communities by using high-throughput sequencing of the 16S and 18S rRNA genes, respectively. We found degrading effects of salinization on soil properties, i.e., decreased soil moisture, organic matter, total N, NH4-N, and NO3-N and increased soil bulk density, pH, and electrical conductivity. The bacterial and fungal community structures changed with increasing salinity. However, dominant microbial taxa (including phylum, genus, and operational taxonomic unit levels) were similar among experimental sites, indicating that increasing salinization slightly affected the basic compositions of microbial communities in already saline grasslands. Furthermore, the relative abundances of most dominant taxa sensitively responded to the soil salt content. Acidobacteria, Actinobacteria, Chloroflexi, RB4, Rubrobacter, Blastocatella, H16, Glomeromycota, and Aspergillus linearly increased with increasing salinization, suggesting that they could be used as bioindicators for salt-tolerant communities. Overall, the changes in the structures of soil bacterial and fungal communities were determined by the relative quantities of dominant taxa rather than community composition. The structures of soil bacterial and fungal communities were linked to soil properties and vegetation. Increasing soil salt content, and thereby varied pH and organic matter, were likely the direct influencing factors of microbial communities in these saline grasslands.

Трансформация галофитной растительности Сердобского солонца (Сердобский район, Пензенская область)

Halophytic vegetation is very rare in the forest-steppe zone. It was studied in the tract Serdobsky solonetsin the vicinity of Serdobsk (Serdobsky district, Penza region). The studies were conducted in the years 2009–2018, using the technique of geobotanical profiling. 80 trial areas were laid (35 in 2009 and 45 in 2008). Ecological and phytocenotic classification of plant communities is performed on the dominant principle. Comparison of two descriptions of vegetation with an interval of 10 years allows us to trace the transformation of halophytic vegetation after intensive anthropogenic impact (grazing and partial plowing) in different environmental conditions. The flora of Serdobsky solonets consists of 179 species of vascular plants, of which 13 species are included in the Red book of the Penza region (2013). The share of halophytic vegetation on the territory of Serdobsky solonetshas changed over 10 years: from 97.0 % to 63.8 %. Moreover, halophyte meadows occupied 67.0 % and halophyte steppes 30.0 % of the area in 2009. Now (2018) halophytic steppes make up 30.8 %, and halophytic meadows 33.0 %.The main stages of demutation of halophytic steppe and meadow vegetation were identified in various environmental conditions (meadows and steppes). The same stages of demutation were identified earlier for the South-Eastern Solonets (Neverskinsky district of the Penza region). However, a special stage of annual saline grasslands has been identified.This place requires protection due to the high level of floral and phytocenotic diversity. We offer to organize here a natural monument called “Serdobsky solonets”.

How steady is the nested pattern in saline grassland true bug communities? Effects of sampling effort and data completeness on nestedness

Nestedness is currently one of the most explored structural patterns of biological communities, especially since its major application in studies on ecological networks. Research on the nested pattern, as a spatial structural descriptor of communities, was mostly focused on theoretical background in the conservation of habitat islands. Here, we explore, to what extent nested true bug communities are present in saline grassland fragments of the Pannonian ecoregion and what are the reasons for their nestedness. In 2015 and 2017, we sampled true bugs from 17 saline pastures in northern Serbia. We applied three different sampling procedures (i.e. gradient in sampling effort) for collecting true bugs: along 20 m long transect, 3 × 30 m long parallel transects and total inventory. Analyses showed significant nestedness of the true bug communities and consistency of the pattern regardless of the data type (binary vs. weighted data) and applied metrics (NODF vs. spectral radius, WNODF vs. spectral radius). However, with the decrease of sampling effort and/or the exclusion of grass feeders, all metrics gradually detect less frequently significant nestedness. The only constant factor which was found to induce nestedness in true bug communities was true bug species richness. Plant cover features showed a weak influence on the nested pattern and landscape features did not take part at all. We believe nestedness of true bugs was the result of differences in habitat complexity among sampling sites, but detailed studies are needed to reveal which abiotic and/or biotic factors are responsible for it. For further studies, priority should be given to investigating the influence of management of saline grasslands on the nestedness in true bug communities.

Regeneration of threatened alkali steppe vegetation after a heavy disturbance by disk tillage

Several methods of tillage are among the practices most destructive to inland saline grasslands, and can result in their complete deterioration. Despite the high frequency of habitat destruction by these means, the recovery of the saline vegetation and regeneration abilities of halophytes are still not sufficiently known. The reaction of inland saline grasslands to disk tillage was studied on the Jatov site located in the Pannonian bioregion of Central Europe. Changes in species composition were tested using ordination methods (DCA, CCA). Although the species composition recovered to a certain extent after the 4 years following the disturbance, the original zonation of halophytic vegetation was disturbed and did not recover. Disturbance primarily suppressed perennial halophytes and promoted the occurrence of species with a ruderal strategy. Testing of halophyte reaction to tillage showed the contracting responses of various halophytic species. The species Atriplex littoralis, Plantago maritima and Matricaria recutita reacted positively to tillage due to the reduced competition. The species Artemisia santonicum subsp. patens and Dichodon viscidum were suppressed by tillage in initial stages, but later recovered their populations. Only A. santonicum subsp. patens was able to return to the abundance seen before the disturbance. The only halophytic species which was unable to recover was a shallow-rooted grass Puccinellia distans. Our study showed that a Pannonian alkali steppe is able to recover quite quickly after tillage, if the soil disturbance is shallow and subsequent management takes place. Some halophytes may even profit for a short time from tillage, but the original species composition cannot be restored in the short term.

Assessing the effect of soil salinization on soil microbial respiration and diversities under incubation conditions

Salinization is a matter of growing concern as it decreases plant productivity in degraded grassland soils; however, its effects on bacterial and fungal communities remain unknown. Therefore, we used the next-generation sequencing technology of soil bacterial 16S rRNA and fungal internal transcribed spacer (ITS) to investigate the diversities and structures of soil bacterial and fungal communities under four different salinity or electrical conductivity (EC) conditions. Our results showed that high salinity increased the relative abundance of Gemmatimonadetes and Bacteroidetes, but, decreased that of Proteobacteria and Firmicutes. In addition, high soil salinity increased the relative abundance of the fungal phylum Ascomycota. The soil pH value significantly increased as the soil salinity increased. Structural equation models (SEMs) showed that soil pH and EC had a total impact on the soil total microbial diversity and basic respiration. Increasing soil pH directly decreased the soil total Shannon diversity and basic respiration according to the SEMs. In contrast, increasing the soil EC directly increased soil total Shannon diversity and decreased soil basic respiration. Soil pH was negatively correlated with both bacterial and fungal diversity compared with soil EC in the SEMs. Our results indicate the opposite effects between soil bacterial and fungal diversity on soil microbial respiration in the highly saline grassland soils.

Soil prokaryotic community structure is determined by a plant-induced soil salinity gradient rather than other environmental parameters associated with plant presence in a saline grassland

Soil microbial communities, which play important roles in biogeochemical cycling, are affected by plants in many ways. To understand how plants affect soil microbes, we compared soils under halophytic shrubs and herbs, whose effects on soil salinity (one of the strongest determining factors for soil microbes in saline grasslands) were different. We measured soil physicochemical properties, as well as prokaryotic abundance, community structure, diversity, and the quantified and predicted abundances of functional genes for nitrogen (N) cycling. As we intended, we found the soil salinity to be the highest in barren areas (BA), intermediate under a tamarisk crown (UC), and the lowest in herbaceous patches (HP), whereas other plant-related properties, e.g. soil organic matter content, differed between vegetated areas (UC and HP) and BA. Prokaryotic community structure and diversity changed along the soil salinity gradient, but not as a function of plant presence or absence. However, N transformation rate and N availability were not affected by the salinity gradient alone. The dominant prokaryotic groups that contributed the most to changes in prokaryotic community structure and diversity were likely not those primarily responsible for N mineralization.

Adatok a kétegyházi két török-halom tájtörténetéhez

Only a few ancient architectural monuments remain standing in the central region of the Hungarian Great Plain. However, the kurgans’ unique 5000-year-old treasures still exist in this area, with many landscape archaeological, archaeological topography, and landscape ecological survey prospects. Mounds can be found on the banks of no-longer exisiting rivers and at some points of higher altitude areas. The oral tradition of the Great Hungarian Plain marked the man-made, artificial, conical rises in the landscape that are associated with ancient, archaeological periods as mounds. According to their origin, kurgans can be classified as burial sites and sacred points of nomad people in prehistory. The two „Török-halom” kurgans are the biggest burial mounds of the kurgan field near Kétegyháza (Békés County, Hungary) in the Körös-Maros National Park (Kígyósi-puszta). Built by people of the Yamnaya Entity in the Late Copper Age (3000–2700 BC), the northern kurgan and its surface is intact without drastic disturbance, and in the vicinity there are natural sites, especially saline grasslands. Our research team worked on landscape archaeological, landscape historical, and GIS informatical investigations. We made a 3D field model of the kurgan, and created the landscape history and local changes of the last 300 years based on boundary charters, handmade and printed maps, archive, air and orto photos. Due to the botanical survey we made a complete list of the vascular plant species found on the surface of the original northern kurgan. The flora of the earth monument is species-rich. Most species have a generalist loess grassland or ruderal character, though there also occur some valuable species of botanical and nature conservation importance (e.g. Ranunculus illyricus, Rosa rubiginosa, Ononis spinosiformis subsp. semihircina, Stachys germanica, Carthamus lanatus). The southern Török-halom kurgan was mined by the local agricultural cooperative in 1967. Before the full mining of the site an archaeological excavation was carried out on the kurgan, during which the central burial site and three other burials were documented. After the mining only a little part of the bottom remained on the north-west side, which conserved original loess vegetation. In a large-scale project the southern kurgan was rebuilt by the Körös-Maros National Park Directorate in 2011, and its surface has reconstructed loess vegetation. Since no settlements of the nomadic Late Copper Age/Early Bronze Age Yamnaya communities have been discovered yet in the Carpathian Basin, the only way to collect more information on these people is through the analysis of their special graves, the burial mounds.

The effect of different genotype cattle grazing on the nutrient content of saline grasslands vegetation

Maintaining saline grasslands in good condition, preserving their yield and diversity is important not only for the purpose of nature conservation, but also for farming. Therefore, the primary purpose of our study is to analyse the effect of pasture use of the smaller weight extensive and the larger weight intensive beef cattle on the grassland vegetation and nutrient content. In this way, we can answer the question whether grazing for nature conservation can be achieved with more profitable, more economical and more intense varieties.
 The tests were carried out in May 2016 and May 2017, in the Hortobágy National Park (Pap-ere and Zám puszta), where a total of 16 sample areas were analysed. These areas are grazed with extensive beef cattle (Hungarian grey) and mixed genotype of intensive cattle. The associations were selected along a moisture gradient, such as wet salt marsh (Bolboschoenetum maritimi) and drier saline meadow (Beckmannion eruciformis). All the vegetative material collected both years in May was analysed for the following parameters: dry matter, crude protein, crude fibre and life-sustaining net energy content. We compared the effects of medium grazing (0.46 livestock/ha) and abandonment on vegetation and nutrient content.
 We examined the effect of (i) grazing, (ii) different grasslands (salt marsh, saline meadow) and (iii) grazing of different cattle breeds (Hungarian grey, intensive beef) on the nutrient content of the vegetation of grasslands Based on our results, it was found that grazing had an impact on crude protein and life-sustaining net energy content. The highest crude protein content (12.75 m/m%) was obtained in the year 2017 in the area where higher density had been grazed for two years. For the lifesustaining net energy, the highest value (5.05 MJ/kg d.m.) was also obtained in 2017 and the lowest in 2016. Furthermore, it was found that there was no significant difference between the effect of the two cattle breeds on the parameters examined. Significant effects were observed only in the case of life-sustaining net energy: in the area of intensive beef cattle we received a higher value (5.15 MJ/kg body weight) than in the area with extensive beef cattle (4.96 MJ/kg body weight).
 Our results have also shown that cattle grazing is of the utmost importance for the maintenance of both wet and mesophilous habitats. Based on our three-year study, we can say that grazing by both extensive and intensive cattle breeds is suitable for the management of saline habitats.

Bryophytesof saline areas in the Pannonian region of Serbia and Croatia

Altogether 40 species (5 liverworts and 35 mosses) were collected in the studied saline grasslands in the Pannonian region of Serbia and Croatia. The following bryophyte species are characteristics both in the Serbian and Croatian sites: Barbula unguiculata, Brachythecium albicans, Bryum algovicum, B. dichotomum, B. ruderale, Didymodon sicculus, Drepanocladus audncus, Microbryum davallianum, M. floerkeanum, Phascum cuspidatum, Protobryum bryoides and Pseudocrossidium hornschuchianum. Most of these are typical elements of the bryophyte assemblages living on the saline-alkaline grasslands of the Danube-Tisza Interfluve in Hungary. Didymodon sicculus is reported for the first time in Croatia here. Microbryum floerkeanum is included in the Red data book of European bryophytes. In addition, in the studied Serbian saline sites another European red- listed species, Entosthodon hungaricus, is also present. Two thalloid liverworts, rare in SE Europe, Oxymitra incrassata and Riccia nigrella, were found in one Serbian site.

Succession of Saline Vegetation in Slovakia after a Large-Scale Disturbance

We studied the vegetation development in the Pannonian salt steppes in SW Slovakia (class Festuco-Puccinellietea) for eight years on permanent plots. The saline grassland was ploughed in 2002 to cultivate wheat and barley, and after two years it was left fallow. An open vegetation structure was typical for the initial stages, dominated by the obligate halophyte Tripolium pannonicum, accompanied by Atriplex littoralis and other annuals. Species richness significantly increased in the subsequent years. From the fifth year of the study, a significant increase of facultative halophytes (e.g. Lotus tenuis, Tetragonolobus maritimus, Agrostis stolonifera) and colonization of some expansive species (Phragmites communis, Calamagrostis epigejos) was observed and accompanied by a decrease in the cover of obligate halophytes (T. pannonicum and Puccinellia distans). Plantago maritima exhibited an opposite trend, and it was the only halophyte that was able to increase its population after the disturbance, due to vegeta...