Alluvial Meadows Research Articles

Varying patterns of taxonomic and functional plant composition and diversity across different types of urban and rural grasslands

AbstractSemi‐natural grasslands are found predominantly in agricultural landscapes; however, their counterparts are also found in cities, referred to as urban grasslands. We sampled the most extensive patches of urban grasslands in Wrocław (Poland, Europe) in urban parks and along a river valley. We compared urban grasslands to broadly defined rural grasslands in terms of compositional gradients and both taxonomic and functional diversity. We also tested for relationships between rare species and different facets of diversity. Urban grasslands corresponded to three rural grassland habitat types: mesic pastures, mesic meadows, and alluvial meadows. We conducted analogous analyses, including and excluding habitat‐level assignment, to determine if emerging patterns between rural and urban grasslands are habitat‐dependent. Rural pastures and their urban counterparts showed high taxonomic and functional similarity, implying that short‐ and frequent‐cutting, applied in cities, mimics grazing management on agricultural sites. Rural mesic hay grasslands and alluvial meadows showed high taxonomic and functional dissimilarities from their urban counterparts. We found that rare species contribute to taxonomic diversity while only affecting functional diversity in a few cases. Varying patterns of taxonomic and functional similarity were observed across different habitats. Comparisons of grasslands without regard for habitat types mask diverging patterns in taxonomic and functional diversity. Despite high environmental and management pressures in urban areas (higher nutrient levels and temperatures, decreased moisture, and intensified management and soil disturbances), we showed that urban grasslands hold a considerable portion of the plant diversity found in rural grasslands.

The utility of airborne hyperspectral and satellite multispectral images in identifying Natura 2000 non-forest habitats for conservation purposes

Aerial hyperspectral and multispectral satellite data are the two most commonly used datasets to identify natural and semi-natural vegetation. However, there is no documented analysis based on data from several areas concerning the difference in the classification accuracy of non-forest Natura 2000 habitat with the use of aerial hyperspectral and satellite multispectral data. Also, there is no recommendation, on which habitat can be classified with sufficient accuracy using free multispectral images. This study aimed to analyse the difference in classification accuracy of Natura 2000 habitats representing: meadows, grasslands, heaths and mires between data with different spectral resolutions and the results utility for nature conservation compared to conventional maps. The analysis was conducted in five study areas in Poland. The classification was performed on multispectral Sentinel-2 (S2) and hyperspectral HySpex (HS) images using the Random Forest algorithm. Based on the results, it can be stated that the use of HS data resulted in higher classification accuracy, on average 0.14, than using S2 images, regardless of the area of the habitat. However, the difference in accuracy was not constant, varying by area and habitat characterisation. Greater differences in accuracy were observed for areas where habitats were characterised by high α-diversity or β-diversity. The HS and S2 data make it possible to create maps that provide a great deal of new knowledge about the distribution of Natura 2000 habitats, which is necessary for the management of protected areas. The obtained results indicate that by using S2 images it is possible to identify, at a satisfactory level, alluvial meadows and grassland. For heaths and mires, using HS data improved the results, but it is also possible to acquire general distribution of these classes, whereas HS images are obligatory for mapping salt, Molinia and lowland hay meadows.

Life in a Contaminated Environment: How Soil Nematodes Can Indicate Long-Term Heavy-Metal Pollution.

We investigated the genera, trophic groups, and functional guilds of soil nematodes at five alluvial meadows along the Litavka River in the Czech Republic to assess their usefulness as indicators of heavy metal pollution in soils. The Litavka River flows around the waste-sedimentation pond of a smelter in the city of Příbram in the Central Bohemian Region. Lead, zinc, and arsenic are the main pollutants in the soils in the vicinity of the smelter. The alluvial meadows closest to the pond and mine waste were the most heavily polluted sites, and contamination decreased downstream along the river with increasing distance from the sources of pollution. The nematode communities were sensitive to pollution, with the most contaminated sites having considerably fewer nematode individuals, fewer genera, and a less diverse and more degraded food web with less nematode biomass. Arsenic, lead, and zinc contents were significantly negatively correlated with the numbers of bacterivores, predators, omnivores, plant parasites, and fungivores, which were significantly less abundant at highly polluted sites. This correlation suggests that nematode groups with higher c-p values, and those with c-p 1 and 2 designations, can be useful indicators of high heavy-metal contamination in areas polluted for a long time. In contrast, the abundance of c-p 3 plant parasitic nematodes was positively correlated with copper, nickel, and zinc contents and with soil-moisture content in the alluvial meadows. Maturity index (MI) and MI2-5 were the most sensitive indices of the degree of disturbance of the soil ecosystem, with enrichment index, structure index, and basal index indicating the altered decomposition channels and diminished structure of the food web.

The Dessau Grassland Experiment—Impact of Fertilization on Forage Quality and Species Assembly in a Species-Rich Alluvial Meadow

Since alluvial meadows of river valleys of the Cnidion dubii are protected by the EU Habitats Directive, reconciling farmers’ demands for forage quality with the objective of maintaining them in good conservation status is an important issue in grassland research. In a long-term experiment from 2010 to 2018, we investigated the impact of fertilizing on forage quality and species assembly on a species-rich and twice-mown alluvial grassland in the Dessau Elbe floodplain (Germany). The experiment was composed of an unfertilized control, PK, N60, N60PK and N120PK applications. A significant improvement in forage quality was achieved by nitrogen fertilization only for crude protein, with higher feeding requirements for sheep met only in individual years. The legume cycle was inhibited by the application of nitrogen and high grass cover was maintained, but not increased, at the highest nitrogen application after an exceptional summer flood. The target forbs persisted in numbers over the study period in all treatments. For cover, the low-competitive target forbs responded neutrally to nitrogen fertilization, whereas detrimental effects were demonstrated for the competitive ones. Thus, we recommend not applying more than 60 kg year−1 of nitrogen and only in combination with phosphorus and potassium.

Holocene regression of the critically endangered species Cladium mariscus (L.) Pohl on Žitný ostrov Island (site Mad, Danubian plain Lowland)

This study presents the palaeo-botanical record from the central part of Žitný Ostrov Island on the Danubian Lowland in Slovakia. The record spans almost the entire Holocene period and provides evidence that the wetland species Cladium mariscus (Cyperaceae) was present in this region as late as the Greenlandian period. In addition, the combination of C. mariscus and Carex elata beds were most likely an important part of the littoral zone vegetation during that period. Our investigations are based on plant macro-remain analysis, radiocarbon dating and physical sedimentary analysis of the former Danube side channel. The palaeo-channel infill active in the Late Pleistocene reflects complete hydroseral succession of a terrestrialised palaeo-lake. The earlier of two possible hiatuses in the fossil record was likely associated with a disturbance which caused Cladium mariscus to disappear from the local plant spectra. The most likely drivers of C. mariscus’ decline are a climate change of 8.6 cal ka BP associated with water fluctuations and the local habitat alteration to an eutrophic environment. These are discussed herein together with the isolated scattered populations surviving in the surrounding micro-region throughout the Meghalayan period. Finally, there are only two known remaining C. mariscus sites in the Žitný Ostrov Island area, and the key modern driving factor was the dramatic water regime changes in 19–20th Century caused by anthropogenic impact. These were caused by the construction of drainage canal systems and the transition from alluvial meadows to agricultural land.

Recursive Feature Elimination and Random Forest Classification of Natura 2000 Grasslands in Lowland River Valleys of Poland Based on Airborne Hyperspectral and LiDAR Data Fusion

The use of hyperspectral (HS) and LiDAR acquisitions has a great potential to enhance mapping and monitoring practices of endangered grasslands habitats, beyond conventional botanical field surveys. In this study we assess the potentiality of recursive feature elimination (RFE) in combination with random forest (RF) classification in extracting the main HS and LiDAR features needed to map selected Natura 2000 grasslands along Polish lowland river valleys, in particular alluvial meadows 6440, lowland hay meadows 6510, and xeric and calcareous grasslands 6120. We developed an automated RFE-RF system capable to combine the potentials of both techniques and applied it to multiple acquisitions. Several LiDAR-based products and different spectral indices (SI) were computed and used as input in the system, with the aim of shedding light on the best-to-use features. Results showed a remarkable increase in classification accuracy when LiDAR and SI products are added to the HS dataset, strengthening in particular the importance of employing LiDAR in combination with HS. Using only the 24 optimal features selection generalized over the three study areas, strongly linked to the highly heterogeneous characteristics of the habitats and landscapes investigated, it was possible to achieve rather high classification results (K around 0.7–0.77 and habitats F1 accuracy around 0.8–0.85), indicating that the selected Natura 2000 meadows and dry grasslands habitats can be automatically mapped by airborne HS and LiDAR data. Similar approaches might be considered for future monitoring activities in the context of habitats protection and conservation.

Multiple Flights or Single Flight Instrument Fusion of Hyperspectral and ALS Data? A Comparison of their Performance for Vegetation Mapping

Fusion of remote sensing data often improves vegetation mapping, compared to using data from only a single source. The effectiveness of this fusion is subject to many factors, including the type of data, collection method, and purpose of the analysis. In this study, we compare the usefulness of hyperspectral (HS) and Airborne Laser System (ALS) data fusion acquired in separate flights, Multiple Flights Data Fusion (MFDF), and during a single flight through Instrument Fusion (IF) for the classification of non-forest vegetation. An area of 6.75 km2 was selected, where hyperspectral and ALS data was collected during two flights in 2015 and one flight in 2017. This data was used to classify three non-forest Natura 2000 habitats i.e., Xeric sand calcareous grasslands (code 6120), alluvial meadows of river valleys of the Cnidion dubii (code 6440), species-rich Nardus grasslands (code 6230) using a Random Forest classifier. Our findings show that it is not possible to determine which sensor, HS, or ALS used independently leads to a higher classification accuracy for investigated Natura 2000 habitats. Concurrently, increased stability and consistency of classification results was confirmed, regardless of the type of fusion used; IF, MFDF and varied information relevance of single sensor data. The research shows that the manner of data collection, using MFDF or IF, does not determine the level of relevance of ALS or HS data. The analysis of fusion effectiveness, gauged as the accuracy of the classification result and time consumed for data collection, has shown a superiority of IF over MFDF. IF delivered classification results that are more accurate compared to MFDF. IF is always cheaper than MFDF and the difference in effectiveness of both methods becomes more pronounced when the area of aerial data collection becomes larger.

Financing of grassland habitats in the Slovak Republic in 2010–2016

Abstract The grasslands in the Slovak Republic are divided into 7 categories that have different way and conditions of management to protect and maintain them. From the area of 1,239,777 hectares of habitats in SR and payments per hectare, we calculated the amount of financial support that represents 130,265,701 € for the A-G habitats in 2010-2016. Based on the data about potential use of grassland habitats in livestock feeding (mountain meadows and alluvial meadows), the production potential of C 3.12 t.ha-1biotope E 4.25 t.ha-1of dry matter was calculated, as a result of 5-years long experiment of the Department of Grassland Ecosystems and Forage Crops of SUA in Nitra. We calculated the direct costs for the production of hay dry matter, which reached 116.78 €.ha-1in the meadows, and 71.11 €.ha-1in valleys. Direct costs per 1 hectare of hay dry production are with a support covered on 111.0% of mountain meadows and 74% of meadows. The annual value of ecosystem services of grassland habitats reached 579,789,008 €. Subsidies for permanent grassland habitats stimulate the economy of agricultural subjects and protect the biodiversity of permanent grasslands.

Restoration of floodplain meadows: Effects on the re-establishment of mosses.

Vascular plants serve as target species for the evaluation of restoration success as they account for most of the plant species diversity and vegetation cover. Although bryophytes contribute considerably to the species diversity of meadows, they are rarely addressed in restoration projects. This project is a first step toward making recommendations for including mosses in alluvial floodplain restoration projects. The opportunity to assess the diversity and ecological requirements of mosses on floodplain meadows presented itself within the framework of a vegetation monitoring that took place in 2014 on meadows located along the northern Upper Rhine. In this area, large-scale meadow restoration projects have taken place since 1997 in both the functional and fossil floodplains. Other studies have shown that bryophytes are generally present in green hay used in restoration, providing inadvertent bryophyte introduction. We compared bryophyte communities in donor and restored communities and correlated these communities with environmental variables—taking into account that the mosses on the restoration sites possibly developed from green hay. This analysis provided insights as to which species of bryophytes should be included in future restoration projects, what diaspores should be used, and how they should be transferred. Data on bryophyte occurrence were gathered from old meadows, and from restoration sites. We found distinct differences in bryophyte composition (based on frequency) in restored communities in functional flood plains compared to donor communities. Generally, restoration sites are still characterized by a lower species-richness, with a significantly lower occurrence of rare and red listed species and a lower species-heterogeneity. In conclusion, our research establishes what mosses predominate in donor and restored alluvial meadows along the northern Upper River, and what microsite conditions favour particular species. This points the way to deliberate introduction of moss diaspores for more complete alluvial meadow restoration.

Relative importance of management and natural flooding on spider, carabid and plant assemblages in extensively used grasslands along the Loire

In Europe, agri-environment schemes (AES) have been implemented to counteract the effects of agricultural intensification. Studies investigating the role of management improvement induced by AES are quite numerous, but rarely take into account the effect of natural perturbations such as flooding, although severe disturbances are well known to shape community structure. Here we investigated the relative importance of management improvement and flooding to explain community parameters of two dominant arthropod groups and vegetation in alluvial meadows.Sampling took place in 2013, using suction samplers for arthropods and phytosociological relevés for vegetation, in 83 meadows distributed along 200km of the Loire Valley (France). Pair-matched approach (by R-ANOVA) was used to assess overall effects of AES whereas a gradient analysis (GLM) was carried out to assess the impact of AES prescriptions (fertilisation and cutting-date) together with indirect (long-term) and direct (short-term) effects of flooding.No significant effect of AES was found on arthropod and plant assemblages, abundance/productivity or diversity (both α and β), but the number of rare plant species was higher in sites under AES. Prescriptions had little impact on most response variables considered; the only significant impact being the positive effect of high-amounts of fertilisers on spider α- and β-diversities. Conversely, systematic long-term effects of flooding were found on all response variables of spiders, carabids and plants, underlining the key role of this factor in alluvial meadows. Our study demonstrates that maintaining or enhancing hydrological functioning of ecosystems is even more important than regulating both the cutting-dates and the low input of fertilisers for conservation purposes in flooded, already naturally nutrient rich, meadows.

Diversity and composition of ground-dwelling beetle assemblages (Insecta: Coleoptera) in Rawdhat Khorim National Park, Kingdom of Saudi Arabia

Rawdhats are unique alluvial meadows that provide a major opportunity for conservation of biodiversity in the Arabian hyper-arid regions. This study investigated the diversity and composition of the ground-dwelling beetle assemblages in two locations within Rawdhat Khorim National Park, Saudi Arabia. Beetles were collected during 24-periods from November 2011 to October 2012 using pitfall traps. A total of 114 species, 96 genera and 22 families were identified. Four Tenebrionidae dominated the catch, Mesostena puncticollis Solier, Oxycara saudarabica Kaszab, Gonocephalum prolixum (Erichson) and Apentanodes arabicus (Kirchsberg). Although richness and abundance did not differ significantly between the locations, diversity and evenness were different. The beetle family abundance showed variations between the locations. Non-metric multidimensional scaling (NMDS) and the analysis of similarity (ANOSIM) showed a high dissimilarity degree in species composition. Scavengers occurred in higher abundance and richness in one location. Predators and herbivores occurred in higher abundances in the other location. This study suggests that scavengers can be used for monitoring the ecology integrity in xeric-lands. It revealed the difficulty of interpreting richness and diversity measures without a high species identification level and knowledge about feeding guilds. Our findings will assist in monitoring approaches for conservation of natural habitats in arid lands.

The Conservation Status of Grassland Habitats Belonging to Protected Areas from Oltenia ‘Natura 2000’ Site, Romania

In the present paper, are rendered the results of the research referring to the conservation status of the grasslands from two sites ‘Natura 2000’ located in Oltenia region, in South-Western part of Romania: ROSCI0202 Oltenia Forest Steppe and ROSCI0039 Ciuperceni - Desa. Within these sites, there are five habitats: 62C0* Ponto-Sarmatic steppes, 6260* Pannonic sand steppes, 6440 Alluvial meadows of river valleys of the Cnidion dubii, 6510 Lowland hay meadows (Alopecurus pratensis, Sanguisorba officinalis) and 1530* Pannonic salt steppes and salt marshes. The investigation of the conservation status of these habitats was carried out by assessing their conservation status at EU level, namely by assigning them to one of the four categories – “favourable”, “unfavourable-inadequate”, “unfavourable-bad”, and “unknown” – according to the stated attributes for each habitat, to the threats of destruction and to the dangers that may lead to their destruction or disappearance. By applying the evaluation matrix of the conservation state of the five habitats from the two sites Natura 2000, only three of the five studied habitats have a good conservation status: 62C0* Ponto-Sarmatic steppes, 6260* Pannonic sand steppes, 6440 alluvial meadows of river valleys of the Cnidion dubii. The habitat 1530* Pannonic salt steppes and salt marshes have a good-moderate status while 6510 Lowland hay meadows (Alopecurus pratensis, Sanguisorba officinalis) has amoderate-poor status. Referring to the characteristic structure and functions to the type of habitat, the research revealed that in numerous areas occupied by the five habitats good conservation conditions are not good.

The Conservation Status of Grassland Habitats Belonging to Protected Areas from Oltenia ‘Natura 2000’ Site, Romania

In the present paper, are rendered the results of the research referring to the conservation status of the grasslands from two sites ‘Natura 2000’ located in Oltenia region, in South-Western part of Romania: ROSCI0202 Oltenia Forest Steppe and ROSCI0039 Ciuperceni - Desa. Within these sites, there are five habitats: 62C0* Ponto-Sarmatic steppes, 6260* Pannonic sand steppes, 6440 Alluvial meadows of river valleys of the Cnidion dubii, 6510 Lowland hay meadows (Alopecurus pratensis, Sanguisorba officinalis) and 1530* Pannonic salt steppes and salt marshes. The investigation of the conservation status of these habitats was carried out by assessing their conservation status at EU level, namely by assigning them to one of the four categories – “favourable”, “unfavourable-inadequate”, “unfavourable-bad”, and “unknown” – according to the stated attributes for each habitat, to the threats of destruction and to the dangers that may lead to their destruction or disappearance. By applying the evaluation matrix of the conservation state of the five habitats from the two sites Natura 2000, only three of the five studied habitats have a good conservation status: 62C0* Ponto-Sarmatic steppes, 6260* Pannonic sand steppes, 6440 alluvial meadows of river valleys of the Cnidion dubii. The habitat 1530* Pannonic salt steppes and salt marshes have a good-moderate status while 6510 Lowland hay meadows (Alopecurus pratensis, Sanguisorba officinalis) has amoderate-poor status. Referring to the characteristic structure and functions to the type of habitat, the research revealed that in numerous areas occupied by the five habitats good conservation conditions are not good.

Local topography affects seed bank successional patterns in alluvial meadows

Seed banks may play a crucial role in the maintenance of community diversity, but their role on semi-natural grasslands, one of the most species rich habitats in Europe, is usually unexplored in population and community studies. We aim to clarify how local factors and topography influence seed bank successional patterns on semi-natural alluvial meadows. All 35 meadows were situated in the Eagle (Orlické) Mountains in the Czech Republic and were divided according to fallow time. Paired plots, represented low and high topography, were established on each meadow. We recorded plant species occurrence in vegetation and in the seed bank to ascertain how seed abundance, diversity and the similarity between seed bank and vegetation were influenced by topography and management. Seed abundance significantly changed, whereas seed diversity remained stable after meadow abandonment. Seed abundance was high in the low topography plots probably due to higher aboveground biomass which promoted seed accumulation. In the high topography plots, seed abundance was low in managed meadows, but seeds were accumulated after abandonment. Similarity between the seed bank and vegetation was low, but over half of the typical meadow species survived in the seed bank for long periods of time, even when they had disappeared from the aboveground vegetation. In conclusion, the local topography of alluvial meadows influenced seed bank successional patterns, mainly seed abundance, similarity between the seed bank and vegetation and responses of individual species in the seed bank. Seed bank successional patterns are dependent on specific habitat conditions and communities with high seed bank accumulation are more stable and better restored than communities where the seed bank has become severely depleted.

The Location and Extent of Systematic Drainage in Relation to Land Use in the Past and at Present and in Relation to Soil Vulnerability to Accelerater Infiltration in the Protected Landscape Area Železné Hory

This study searched for associations between the extent of hydromelioration systems and the land use (in the past and at present), degree of nature conservation, and infiltration of water through soil profile in the Protected Landscape Area (PLA) Železné hory. According to the available evidence, 34.6% of arable land and 32.1% of permanent grasslands in this area are drained by the drainage systems. Analysis of the original design documentations of drainage structures indicate, that the extent of drained areas can actually be even higher. The hydromelioration systems were built namely in the second half of the 20th century. The drainage also affected alluvial meadows, wetlands, and ecologically valuable stations. After establishment of PLA Železné hory in 1991, the protected area was divided into four zones according to their significance and protection regime. This study has revealed the presence of areas drained by systematic drainage systems (101 ha of grasslands) even in the zones of highest landscape protection degree (1st and 2nd protection zones). The inadequately executed drainage systems should be eliminated and the character of the land should be brought closer to its natural conditions. On the model part of the PLA we also performed a study of historical changes in the landscape in three time horizons (1839, 1950, 2014) to show differences in land use before building of drainage, at the time of building, and at present.

Alluvial meadows of Cnidion dubii Bal.-Tul. 1966 in the Middle Oder River Valley (Natura 2000 site “Łęgi Odrzańskie”, SW Poland)

The paper contains a phytosociological description and evaluation of alluvial meadows of Cni- dion dubii Bal.-Tul. 1966 at the Natura 2000 site Łegi Odrzanskie, the middle Oder river valley, presented in relation to local water conditions and grassland management. Phytosociological data of the C. dubii alli- ance from Poland and the Czech Republic have also been presented.

New localities of Viola stagnina in Poland

Abstract Viola stagnina Kit. is a species regarded as a river corridor plant because of its confinement to river valleys in Central Europe. It is a component of alluvial meadows with natural flooding regime (Cnidion dubii alliance). V. stagnina is rare and red-listed in some European countries. Seven new localities of V. stagnina, its distribution map in Poland and information about possible methods of protecting the species are presented.

Seasonal dynamics of bioenergy characteristics in grassland functional groups

AbstractSemi‐natural grasslands (SNG) are considered as bioenergy resources, either for combustion or for biogas production. To provide information on the seasonal (June–August) dynamics of herbage quantity and chemical composition, we studied the effects of factors on the proportions of four plant functional groups, chemical composition and total biomass yield at twelve sites representing three Estonian SNG types. Biomass yield increased only in alluvial meadows with the largest contribution of sedges/rushes (39%). Grasses dominated in dry‐to‐mesic meadows (62%) and other forbs in wooded meadows (55%). Concentration of fibre was highest in grasses and sedges/rushes (682 and 645 g NDF kg−1), and lignin was highest in legumes and other forbs (103 and 113 g kg−1). Legumes contained more C and N (447 and 25 g kg−1) and grasses more Cl (1 g kg−1). The highest concentrations of Mg, K and ash were in other forbs (4, 18 and 80 g kg−1), and Ca in legumes (16 g kg−1). The results are discussed in the context of suitability of different functional groups and SNG types for bioenergy conversion. Grasses and sedge‐/rush‐rich biomass are considered suitable for methane production. Biomass harvesting in July and minimizing the problems with N and Cl during combustion need to be considered. Forb‐rich biomass should be pre‐treated before direct combustion.

Alluvial grasslands along the northern upper Rhine – nature conservation value vs. agricultural value under non-intensive management

Semi-natural non-intensively managed grasslands are among the most species-rich and threatened ecosystems in Central Europe. Alluvial meadows along large European rivers are part of the European Union's Habitats Directive, and therefore part of conservation and restoration efforts. Sustainable management of these meadows should aim to reconcile the interests of both nature conservationists and farmers. In this context, we conducted a two-year comparative study in alluvial meadows of high and low nature conservation value, belonging to the alliances Arrhenatherion and Cnidion. Firstly, we aimed to assess how differences in fodder yield and quality are linked to abiotic and biotic factors. Secondly, we addressed the possibility of incorporating fodder from these meadows into livestock farming. Our results revealed that while yield tended to be higher in meadows of low nature conservation value, fodder quality (e.g. energy content) showed the reverse trend. These differences are most likely caused by differences in vegetation composition and soil fertility. In addition, the response seemed to be closely linked to the precipitation pattern. In 2006, when precipitation was evenly distributed, fodder quantity seemed to be mainly related to site conditions. In 2007, when a drought occurred in April, differences in the proportion of functional groups were additionally related to differences in yield. The degree to which this fodder can be integrated into farming systems depends on the intensity of livestock farming and marginal economic conditions. The present study confirms that under non-intensive management, meadows of high and low nature conservation value yield similar fodder qualities.

Comparative Study Of Alluvial Cnidion-Type Meadows In The Lower Danube River Basin

Abstract Alluvial Cnidion-type meadows (Habitat type 6440 of the Habitats Directive), mostly characteristic for the lower courses of large rivers in continental climate conditions of Europe are presented from the Lower Danube upstream the municipality of Giurgiu (river-km 510-524). The ecological requirements of the characteristic species, as well as their sensitivity to human-induced changes that derive from regular flooding, drainage, intensification of use and/or abandonment, are highlighted; these changes frequently lead to a decrease of biodiversity of the Cnidion-type meadows or to their total loss The studied meadows are compared with similar alluvial meadows from other sites of the lower Danube River basin. Finally, the strong interlocking of Cnidion type meadows with those of the Agropyro-Rumicion, Molinion and Deschampsion caespitosae alliances are discussed.