Search

Ecosystem management often aims to maintain a diversity of habitats to benefit a large number of species within a landscape. We studied the effects of wetland management by low-intensity cattle-grazing and late-summer burning on marsh vegetation and globally declining anuran amphibians (frogs and toads) in a previously homogeneous reedbed. Burning effectively removed old reed and increased the variability of reed cover and marsh vegetation by the next spring. However, reed grew back strong in areas burned 2 or 3 years before the study, indicating that fire rejuvenates reedbeds. In contrast, cattle-grazing kept reed cover homogeneously low and created open water surfaces. The number of amphibian species and individuals decreased with mean reed cover and old reed density, and increased with variability in reed cover. Correspondingly, amphibian richness and counts were greatest in newly burned areas the next spring. In contrast, a year later, richness and counts were greatest in grazed-only areas, with large decreases in newly burned and control areas. Our results suggest that combined management with grazing and burning can create different habitat patches, some of which will be optimal for amphibians in one year, whereas other patches may become suitable in a subsequent year when successional changes alter previously optimal patches. To maximise optimal habitats, mosaic management should repeat burning once every 2 or 3 years in a rotational manner, and also maintain low-intensity cattle-grazing, which controls reeds and benefits amphibians more sustainably. Our study supports spatiotemporally varied management to facilitate habitat heterogeneity and complexity in dynamic landscapes.

Remains of aquatic biota preserved in mountain lake sediments provide an excellent tool to study lake ecosystem responses to past climate change. In the PROLONG project a multi-proxy study was performed on sediments of glacier-formed lakes from the Retezat Mountains, Southern Carpathians (Romania). The studied lakes (Lake Brazi and Gales) are situated on the northern slope of the mountain at different altitudes (1740 m and 1990 m a.s.l.). Our main objectives were 1) to describe the main limnological changes in these lakes during the last ca. 15,000 years and 2) to summarize the environmental history of the studied lakes based on taxonomical and functional patterns of the biological proxies. For this synthesis we used the results of diatom and chironomid analyses, and indirect biotic and abiotic parameters, including sediment organic matter (LOI) content, geochemical element concentrations (Al, Ca, S, Sr) and biogenic silica content. Using multivariate numerical approaches we analysed changes in the assemblage structure of siliceous algae and chironomids, compared temporal patterns among proxies, examined the relationship between potential driving factors, chironomid and diatom assemblage changes and identified paleolimnological phases of the lake successions. Changes in assemblage composition and aquatic ecosystem state apparently followed summer insolation, local climatic conditions and local productivity changes driven by these. Diatom and chironomid assemblages generally changed in a similar direction and at a similar time within a lake, but differed to some extent between Lake Brazi and Gales. At both lakes the strongest variations were observed in the Late Glacial and the first half of the Holocene. The strongest Holocene assemblage changes took place in the earliest Holocene in Lake Brazi, but extended into the mid-Holocene in Lake Gales, following long-term insolation changes and climatic changes. In addition, three common zone boundaries were identified: at ca. 14,200 and at ca. 6500 cal yr BP for every records and at ca. 3100 cal yr BP for diatom records in both of the lakes and for the chironomid record of Lake Brazi. This multi-proxy synthesis provides comprehensive data that increase our understanding of the past variability of lake ecosystem functioning and biodiversity in East-Central Europe.

The Middle to Upper Palaeolithic transition is one of the crucial periods of change in the prehistory of Europe due to the full emergence, continent-wide, of modern human lithic technologies, and detrimental of Neanderthal survival. Knowledge about the transition is growing, however, the evidence for cultural and technological developments for the Middle Palaeolithic in the Carpathian – Lower Danube Basin is still rather sparse. Here we discuss latest findings arising from a chronological investigation of Middle Palaeolithic assemblages within the Varghis karst, Eastern Transylvania, Romania. Combining our first chronological results with information from previous excavations, we can distinguish two main stages of habitation (albeit Middle Palaeolithic lithics and faunal remains appear scattered throughout the investigated profile) within the Abri 122 rock shelter. In order to augment the typological cultural considerations, we applied direct radiocarbon dating on bones and charcoal from within the occupation layers. Radiocarbon dating of bones suggests that the Middle Palaeolithic sequence is older than the upper dating limit of the method, whereas direct luminescence ages on the lowermost productive horizon and immediately above it indicate surprisingly old ages of ca. 106–141 ka (OSL – optically stimulated) or 99–174 ka (IRSL – infrared stimulated). Multiple-protocol dating of charcoal found within the two habitation layers produced ages >38 14 C ka BP, also suggesting that the lowermost lithic-rich horizon pertains to the Middle Palaeolithic industries. Overall, the recovered lithics, currently forming one of the most significant collections for Romania, are fully consistent with two main habitation phases connected to Middle Palaeolithic cultural affinities. The occurrence of a volcanic ash layer within Ursului Cave and originating from the Ciomadul volcanic complex (Carpathians) is first reported here. Recently dated to ∼ ≥ 43 (−50) ka, it might represent an important marker horizon, providing that it is identified within other Palaeolithic cave assemblages.

Forest edges are essential to the maintenance of biodiversity at the landscape level. according to the edge effect hypothesis, diversity is higher in an edge than in adjacent areas. We tested the edge effect hypothesis for carabids and staphylinids in an oak forest- forest edge-grassland complex in the Hajdusag Landscape Protection area (Hungary). The habitat types were as follows: (1) a closed oak forest with shrubs and herbaceous plants, (2) a forest edge with extensive ground vegetation and shrub cover and (3) grassland with dense herbaceous vegetation. We collected data from 60 pitfall traps (2 spatial replicates × 3 habitats × 10 traps). The gLM results showed that the species richness of carabids was higher at the edge of the forest than in the grassland and forest interior; the number of carabid individuals was highest in the grassland. The number of staphylinids and their species richness were significantly lower in the grassland than in the forest edge and interior. The results of principal coordinates analysis showed that the assemblages of both taxa in the forest edge and interior were separated from the assemblage in the grassland area. There were significant characteristic species for the edge habitat, as revealed by the IndVal (indicator species analysis) method. our findings suggest that forest edges play a vital role in the maintenance of the diversity of carabid and staphylinid assemblages.

Grasslands recovered by sowing low diversity seed mixtures of local prove- nance are usually managed by mowing. Besides restoration success only a few studies have focused on the direct effects of post-restoration mowing on recovered grassland vegetation. In this study we followed vegetation changes in 13 successfully recovered grasslands in 5 9 5-m-sized sites with continuous and ceased mowing at Hortobagy National Park, East- Hungary. We asked the following questions: (i) What are the effects of cessation of mowing on the vegetation structure and diversity of recovered grasslands? (ii) What are the effects of cessation of mowing on the abundance of sown grasses, target and undesirable species? (iii) Is yearly mowing an appropriate management tool for the maintenance of recovered grasslands? Our results showed that the cessation of mowing caused litter accumulation, while diversity, total vegetation cover and the cover of sown grasses decreased compared to the mown sites. The cover of undesirable perennial species was significantly higher in unmown sites than in mown ones. The species composition of mown sites remained more similar to near-natural grasslands than the unmown ones. Our results suggest that without regular post-restoration mowing the favourable status of recovered grasslands can rapidly decline due to litter accumulation and by the expansion of unde- sirable species, even in the short-run. We also stress that while yearly mowing is enough to maintain grasslands recovered by low-diversity seed sowing, it cannot be considered to be enough to recover target vegetation composition.

For an effective conservation and management in grasslands it is essential to understand mechanisms sustaining biodiversity. To gain knowledge is especially crucial in stressed grasslands harbouring a unique flora and fauna, like alkali grasslands. Aboveground vegetation, seed bank and environmental factors were studied in three stands of the following alkali grassland types: (i) Artemisia dry alkali grasslands at highest elevations; (ii) Puccinellia high and (iii) Puccinellia low grasslands at medium to low elevations, and (iv) Juncus wet alkali grasslands at the lowest elevations. We tested the following hypotheses: (i) Seed bank species diversity and density are the highest in the most stressed grassland types, where regeneration by seeds could have a major importance in sustaining vegetation diversity. (ii) Seed bank density of hygrophytes increases with decreasing elevation, because the cover of hygrophytes in the vegetation increases with decreasing elevation. The mean seed bank density ranged from 30,104 up to 51,410 seeds/m2, which is higher than in most dry grasslands. Both the lowest seed bank density and diversity were detected in the most stressed Puccinellia high grasslands; Spergularia salina was the only abundant seed bank species (possessing at least 1000 seeds/m2). These results not supported our first hypothesis. We detected the highest seed densities of almost all hygrophyte species in the lowest-elevated Juncus grasslands. But, we did not find a significant monotonous correlation between elevation and the overall hygrophyte seed bank density; because most of the hygrophyte species were missing from the seed bank at the medium-elevated, but most saline Puccinellia grasslands. Thus, our results only partly supported the second hypothesis. In total we detected more species in the seed bank than in the aboveground vegetation which emphasises that seed bank plays an important role in sustaining the diversity of alkali grasslands. However, characteristic graminoids possessed no considerable seed bank, except for Juncus compressus (up to 38,619 seeds/m2). We can conclude that persistence and establishment of most alkali grassland species are not supported by the local persistent seed bank.

Question Based on the spontaneous vegetation development of old-fields in the Nyirseg and Kiskunsag sand regions (Hungary), we aimed to answer the following questions using the chronosequence method: (1) how do the proportions of different functional groups change during succession; (2) which target species establish successfully in the old-fields during the course of succession; and (3) how successful is spontaneous succession in the recovery of target grasslands? Location Two sand regions of the Great Hungarian Plain: (1) the Nyirseg sand region (East Hungary, acidic sand, moderately continental climate) and the Kiskunsag (Central Hungary, calcareous sand, continental climate). Methods Altogether 24 old-fields were classified into young (

The role of fragment size, isolation and habitat diversity in the conservation of spider assemblages living in fragmented landscape were studied in dry sandy grasslands (East Hungary, Nyirseg). Spiders were collected using pitfall traps at eight dry grassland fragments from 2001 to 2009 from March to October fortnightly. We tested the rules of island biogeography, which suggest that the species richness increases with the size and decreases with the isolation of fragments. The habitat diversity is an important factor for species richness, since large areas usually have more habitats; therefore, the number of species may be higher in these areas. During the 9-year study period, altogether 10,544 individuals belonging to 106 species were collected. Contradicting the classical theory, we found a significant negative relationship between the total number of spider species and the grassland size, while the ratio of sandy grassland specialist spider species increased with fragment size. The relationship between the ratio of generalist species and the fragment size was not significant. The overall species richness and the isolation of studied grasslands did not show a significant relationship. The ratio of sandy grassland specialist species decreased, while the ratio of generalist species increased with the increasing of isolation. The habitat diversity did not show any effect on spider species richness. We concluded that to conserve the habitat specialist species it is recommended to preserve the large and least isolated grassland fragments, furthermore to increase the size of small fragments with the restoration of the adjacent croplands.

Climate change is a global problem. During the last century the increase of annual average temperature was 0.68°C, while the decrease of annual average of precipitation was 83 mm in Hungary. According to the long term meteorological data of Sikfőkut forest ILTER site the annual average temperature increased while average of yearly precipitation decreased, the forest climate became warmer and dryer. These processes could considerably contribute to forest decline, not only in the Quercetum petraeae-cerris stand of Sikfőkut, but everywhere in the country. Species composition and structure of the forest have changed considerably, as 68% of sessile oak (Quercus petraea) and 16% of Turkey oak (Quercus cerris) have died. Forest decline resulted in the breaking up of the formerly closed canopy, and consequently, in the formation of gaps in the forest. In the gaps, a secondary canopy developed with tree species of less forestry value. As a consequence, mass regeneration of field maple (Acer campestre) appeard in the gaps. The formation of gaps accelerated the warming and aridity of forests. In the article we answer the following question: how did climatic change and changing forest structure influence the leaf-litter production in the last four decades? oak forest / oak decline / Sikfokut Project / litter production / climate change

Ground beetles were studied among grassland — forest edge — beech forest habitats in Hungary, using pitfall traps. We hypothesised that the activity density and species richness of carabids were the highest in the forest edge, the activity density and the number of forest species were decreasing, while the activity density and the number of generalist species increasing from the forest towards the grassland. Carabid assemblage of the grassland was the most diverse and the forest was the least diverse if measured by Renyi diversity. The average species richness per trap was significantly higher in the grassland and in the edge than in the forest. The number of forest species was significantly higher in the edge than elsewhere. The number of generalist species was highest in the grassland and decreased towards the forest. The activity density of carabids was significantly higher in the forest and in the forest edge than in the grassland. The activity density of forest species was higher in the forest and in the edge than in the grassland. The activity density of the generalist species was higher in the grassland than in the forest edge and in the forest. There were seven species characteristic to the grassland as identified by IndVal; two species were characteristic to the edge, and two species were characteristic both to the forest and the edge. We found that humidity was the highest in the forest; Pterostichus oblongopunctatus and Molops piceus were associated with the forest habitat, while Abax ater and Pterostichus melanarius were associated with the forest edge according to the RDA. The the shrub cover was the most relevant factor in the edge; Abax ater and Pterostichus melanarius were associated with this habitat.

We studied the effect of sowing low-diversity seed mixtures (containing 2–3 competitive grass species) on the regeneration of vegetation on croplands previously used as alfalfa fields. In four permanent plots in 10 restored fields (four with alkali and six with loess seed mixture) the cover of flowering plants was recorded and phytomass was measured between 2006 and 2008. We asked three questions: (i) How fast will weedy, short-lived species decrease in abundance during secondary succession enhanced by sowing low-diversity seed mixtures? (ii) Can weeds be suppressed by sowing competitive native grasses, followed up by management by mowing? (iii) Can succession towards the target native grasslands be accelerated by sowing only low-diversity seed mixtures compared to set-aside old field succession? Our results showed that in just two years a vegetation dominated by perennial grasses has developed, which successfully prevented the establishment of weed species. These results suggested that sowing seeds of two or three competitive grass species is an effective tool to eliminate weed domination and to lead towards the restoration of species poor grasslands with grass domination such as alkali grasslands. However, the developed dense perennial grass cover and the accumulated litter may hamper the immigration of specialist species characteristic to reference grasslands. Therefore, the restoration of species-rich grasslands requires the facilitation of the immigration of grassland specialist species by further management (grazing, mowing and/or hay-transport).

We tested wetland-restoration management techniques to restore and increase the diversity of aquatic beetle assemblages. Three wetland treatments were examined that included: (i) unplanted surface flow (unplanted SF) wetland, (ii) surface flow (planted SF) wetlands planted with aquatic plants, and (iii) subsurface flow (SSF) wetlands. Species richness of aquatic beetles in SF wetlands was highest in spring, while the abundance was lower in the planted SF wetlands than in the unplanted SF wetland. Planted SF wetlands had a slightly higher diversity of beetles than that of the unplanted SF wetland. The planted and unplanted SF wetlands had similar attributes throughout the rest of the year. In SSF wetlands, beetles were significantly more abundant and species rich in spring than either in the planted or in the unplanted SF wetlands. Beetle diversity in SSF wetlands was higher than that in SF wetlands. During the summer, the differences between treatments disappeared. Our results suggested that: (i) vegetation planting was a successful wetland restoration technique, due to the increased habitat diversity, (ii) subsurface flooding provided fishless temporary waters with favorable breeding conditions for aquatic beetles, thus it was also a useful restoration technique, and (iii) significant seasonal differences in abundance and species richness reflected the characteristic breeding habits of aquatic beetles.

Maintaining connectivity among local populations in a fragmented landscape is crucial for the survival of many species. For isolated habitat patches, stochastic fluctuations and reduced gene flow can lead to high risk of extinction. The connectivity of the landscape is especially crucial for the carabid species living in the fragmented forests of the Bereg plain (NE Hungary and W Ukraine) because a highway will be constructed through the plain. Our purpose is to (1) evaluate the impacts of three possible highway tracks, (2) suggest a solution that is realistic with less impact on connectivity than other plans and (3) discuss how to decrease the disadvantageous effects of each track. Our results, based on a network analysis of landscape graph of patches and ecological corridors, indicate that the intended highway could have deleterious consequences on forest-living carabids. Relatively simple actions, like the establishment of stepping stones, could compensate for the loss of habitat connectivity and promote the survival of carabids, or minor modifications in one possible track could diminish its adverse effects. While many other studies would be needed for a comprehensive assessment of the biotic impact of the highway, we provide an example on the usefulness of network analysis for land use management.

To examine the impact of urbanisation on arthropod biodiversity, carabid (Coleoptera: Carabidae) assemblages were studied over 2 years along a rural–urban gradient representing increasing levels of human disturbance. Carabids were collected by pitfall trapping during their whole activity period in lowland oak forest patches in and near the city of Debrecen, Eastern Hungary, over two seasons (2001–2002). Carabid activity density was significantly higher in the rural than in the two other areas, but there was no significant difference in species richness (measured as mean number of species caught/trap). The proportion of forest specialists significantly decreased from the rural towards the urban area, and the proportion of forest specialist species was significantly higher in the rural and suburban areas than in the urban one. In contrast, the relative activity density of generalist species significantly increased along the rural–urban gradient. Both the relative number of open-habitat species and their activity density were significantly higher in the urban forest fragments than in the suburban and rural ones. The patterns found were consistent between the 2 years. Multidimensional scaling indicated pronounced changes in species composition along the gradient; the assemblages in urban forest fragments were more variable than in the other areas. A large proportion of the variation in overall activity density, species richness and the proportion of carabids with different habitat affinities could be explained by structural habitat variables (percentage cover by canopy, leaf litter, herbs and decaying wood), and prey availability.

The planning of the correct channel reconstruction is a priority in the rehabilitation of regulated surface streams. The present study examines the most important morphological and ecohydrological factors of a highly modified watercourse. A comparative analysis was performed among modelled and measured morphological, river geometrical, hydraulic, and vegetation status indicators. Reduction of data redundancy and examination of the relationships was done by factor analysis. This was found during the data reduction to six or seven attributes (component) and it was sufficient for imaging the original information content. There are mathematically derived hydrological background variables that are extremely significant in characterizing the watercourses, for example; the Reynolds number, Froude number, ratio of slope Froude-number, speed-to-depth ratio, depth-to-width ratio, etc. The partially regulated and artificial river sections were numerically separated from each other in the analysis. The functional aquatic plant habitats and Manning’s n Roughness have got a higher factor weight in the less regulated river section, than in artificial stage. The weakest factor weights were those status indicators which were most changed by the regulations. The results provide support for defining and monitoring the required environmental geometric riverbed interventions.

Free grazing and herding of local breeds have a long tradition in management and conservation of extended grassland habitats such as alkali steppes. However, there is a lack in studies evaluating the effects of grazing types and regimes on the vegetation composition and functional diversity. We selected Artemisia steppes, a widespread type of alkali steppes, to study the changes of vegetation composition and diversity along a grazing intensity gradient. We recorded the cover of vascular plant species, in altogether 150, 2 × 2-m-sized plots of 15 steppes in 2014. The steppes were managed by free grazing, traditional Hungarian Grey cattle grazing (low, moderate and high intensity), or by heavy grazing (Grey cattle and sheep, and additional donkey grazing). We answered the following questions: (i) How do the species richness, diversity and species evenness change along the increasing intensity of grazing? (ii) How does the grazing affect the functional trait composition along the intensity gradient? (iii) How similar is the composition and diversity of free grazed steppes to the pastoral grazed ones? We detected no significant differences in species richness but a humped-back curve with a peak at the medium grazing intensity was found for the Shannon diversity, evenness and the proportion of subordinated target species. The highest Rao’s quadratic entropy was found for low intensity grazing. The lowest scores of multi-trait functional evenness were detected for the medium grazing intensity, while for multi-trait functional divergence both medium and very high intensity displayed low scores. The intensity of grazing was negatively correlated with the plant height and LDMC, while positively with the rosette forming, SLA, thousand-seed weights, terminal velocity and flowering period. Our results suggest that for the highest functional diversity a low intensity traditional cattle grazing is recommended. A medium grazing intensity should be chosen to have the highest proportion of subordinated target species of conservation interest, and the highest species diversity and evenness. Our findings suggest that free grazing and low-intensity traditional grazing can be substitutive to each other; various grazing intensities from low to medium, alternating in space and/or time can be appropriate to maintain high compositional diversity.

The Upper Tisza floodplain region provides a mosaic of aquatic habitats including a series of oxbows. Inorganic contaminants can accumulate in the sediment; thus, the sediment is good indicator of the contamination of these oxbows. Our aim was to explore the effects of anthropogenic activities on the concentration of elements and also to study the influence of vegetation types on the element in surface sediment of oxbows. We studied eight oxbows: two of them were protected, four of them were used for fishing and two of them were contaminated with domestic sewage. The following elements were measured with MP-AES in surface sediment: Al, Cr, Cu, Fe, Mn, Pb and Zn. The elemental concentration was compared to the toxicity classes of Environmental Protection Agency (EPA), and the assessment of the level of toxicity was based on this comparison. We found that studied oxbows were different from each other based on the elemental concentrations of sediment using canonical discriminant analysis and analysis of variance. Based on the elemental concentration in surface sediment of oxbows, separation was also found among vegetation types. But significant difference was not found in the concentrations of elements based on vegetation types. Our results demonstrated that the anthropogenic activities had remarkable effects on the elemental concentration of surface sediment in oxbows. Our findings suggest that the sediment is useful to assess the effects of anthropogenic activities on elemental concentrations of oxbows.

We studied the distribution of millipedes in a forest interior-forest edge-grassland habitat complex in the Hajdúság Landscape Protection Area (NE Hungary). The habitat types were as follows: (1) lowland oak forest, (2) forest edge with increased ground vegetation and shrub cover, and (3) mesophilous grassland. We collected millipedes by litter and soil sifting. There were overall 30 sifted litter and soil samples: 3 habitat types × 2 replicates × 5 soil and litter samples per habitats. We collected 9 millipede species; the most abundant species was Glomeris tetrasticha, which was the most abundant species in the forest edge as well. The most abundant species in the forest interior was Kryphioiulus occultus, while the most abundant species in the grassland was Megaphyllum unilineatum. Our result showed that the number of millipede species was significantly lower in the grassland than in the forest or in the edge, however there were no significant difference in the number of species between the forest interior and the forest edge. We found significantly the highest number of millipede individuals in the forest edge. There were differences in the composition of the millipede assemblages of the three habitats. The results of the DCCA showed that forest edge and forest interior habitats were clearly separated from the grassland habitats. The forest edge habitat was characterized by high air temperature, high soil moisture, high soil pH, high soil enzyme activity, high shrub cover and low canopy cover. The IndVal and the DCCA methods revealed the following character species of the forest edge habitats: Glomeris tetrasticha and Leptoiulus cibdellus. Changes in millipede abundance and composition were highly correlated with the vegetation structure.

Timber-oriented forest management causes significant changes to the environments, threaten the survival of many native species and it is responsible for the primary forest loss. Recognition of the scale and effects of the primary forest loss has resulted in a considerable degree of interest in the restoration. One of the serious efforts at restoration is the compulsory reforestation of the clear-felled stands of any (native or non-native) forests with native species. To evaluate the success of restoration efforts it is important to answer whether the diversity and composition of indigenous assemblages can recover after reforestation with native trees and to know how long is the recovery time? We studied ground beetles and millipedes from mature (130-year-old) oak forest, and recently established (5-year-old), young (15-year-old), and middle-aged (45-year-old) reforestation with native English oak by pitfall trapping and leaf litter sifting to assess the recovery dynamics of their diversity and composition. The overall number of the ground beetle individuals and species were significantly the highest in the 5-year-old reforestation, while the overall number of millipede individuals and species were significantly the lowest in the recently established reforestation. The elevated overall number of ground beetle individuals and species in the 5-year-old reforestation were due to the colonization of good disperser open-habitat species. The number of forest-associated ground beetle individuals and species were significantly the lowest in the 5-year-old reforestation, whereas from 15 years after the reforestation, when the canopy has been closing, there was no significant difference in the number of forest species. The number of forest-associated millipede individuals and species were significantly the lowest in the 5-year-old reforestation; however, they were significantly the highest in the natural mature oak forest. Results of both the ordination and the quantitative character species analysis also confirmed that reforestation with native oak after mechanical soil treatment had detrimental effects on both studied ground-dwelling arthropod groups. The diversity and composition of ground beetles with high dispersal ability and less specific feeding habit recovers after the closure of the canopy, while similar recovery do not occur regarding millipedes with low dispersal ability and specific feeding habit. Our results suggest that soil preparation and light tilling should be omitted during the reforestation and cultivation of the reforested stands.

There is a conflict between nature conservation and thatching industry regarding the management of reedbeds. On one hand, reedbeds are of an economical importance by providing thatching material, on the other hand, they harbour several endangered species. Reedbeds are typically managed by winter cutting, but its impacts on biodiversity are poorly understood. Our aim was to study the effects of winter cutting on the habitat diversity and structural heterogeneity of wetlands in a lowland alkali landscape (East-Hungary). We tested the following hypotheses: (i) Both diversity of plant species and habitat diversity are lower in winter cut wetlands compared to unmanaged stands. (ii) The distribution of biomass (green biomass, litter and standing dead biomass) is more homogeneous in winter cut wetlands compared to unmanaged ones. We found that winter cutting decreased habitat diversity and structural heterogeneity at multiple scales. Number of plant species and all measures of habitat diversity (number of patches, vegetation types and the length of vegetation margins) had lower scores in cut wetlands than in unmanaged ones. We found that unmanaged wetlands harboured high amount of accumulated biomass and they also maintained high habitat diversity likely due to the heterogeneous distribution of the biomass. In unmanaged wetlands, biomass accumulation did not decrease habitat diversity and also contributed to a higher structural heterogeneity. In cut wetlands, expansion of reed was an important driver of the decrease in habitat diversity and structural heterogeneity. Reed expansion likely overrode fine-scale edaphic conditions (hydrology and salinity) in shaping vegetation patterns; thus we suggest to avoid intensive winter cutting.

The knowledge of the evapotranspiration of natura l ecosystems and plant populations is of fundamental importance in several branches of scien ce, research and practical uses. Nevertheless, the harmonisation of the large number of methods and user needs often causes problems. The objective of the analyses was to explore the output range and se nsitivity of models of different physical approache s under local conditions. We performed descriptive st atistical and sensitivity analysis of 10 commonly used estimation models - one of them with two varia nts. Correlation between modelled and measured evapotranspiration data series was assessed. The ma gnitude of the model outputs, their variability and responses to the changes of selected atmospheric pa rameters were evaluated. Priestley -Taylor, Penman -Monteith -FAO-56, Shuttleworth -Wallace (parameterized with alternative radiation balance), Szasz and Makkink proved to be the most s ensitive methods. As regards the systematic error, Makkink and Shuttleworth -Wallace showed the best agreement with pan evaporation, while Shuttleworth -Wallace, Blaney -Criddle and Makkink models were found to be the closest to the Penman -Monteith -FAO-56 method as a reference value. evapotranspiration /estimation models / sensitivity analysis Kivonat - A referencia parolgas nehany becslmodszerenek osszehasonlito vizsgalata. Szamos tudomanyterulet es kutatasi tema, valamint gyakorla ti alkalmazas szamara bir alapvetfontossaggal a novenyallomanyok, termeszetes okoszisztemak evapotranspiraciojanak ismerete. A nagyszamu modszer es a valtozo felhasznaloi igenyek osszeegye ztetese azonban gyakran problemat okoz. A vizsgalatok celja az volt, hogy helyi viszonyok koz ott is megismerhessuk az elterfizikai megkozelitest tukrozmodellek kimeneti ertektartomanyat, erzekenyseget. Leiro statisztikai-, valamint erzekenysegvizsgalatot vegeztunk 10 gyakran alkalmazott becslmodell eredmenyeire, ezek egyikenek eseteben ket modellvaltozatra is. Vizsgal tuk a kivalasztott modszerek korrelaciojat egymashoz, illetve mert adatsorhoz kepest. Ertekelt uk a modellkimenetek nagysagrendjet, azok valtozekonysagat, valamint az egyes legkori paramet erek valtozasara adott reakciojat. A vizsgalt modszerek kozul a Priestley -Taylor, Penman -Monteith -FAO-56, Shuttleworth -Wallace (egyedi sugarzasi egyenleggel parametrizalva), Szasz es Mak kink modell bizonyult a legerzekenyebbnek. Szisztematikus hiba tekinteteben a Makkink es a Shu ttleworth -Wallace mutatta a legjobb egyezest a mert ertekekkel, mig a Penman -Monteith -FAO-56 modszert referenciakent valasztva ahhoz a Shuttleworth -Wallace, a Blaney -Criddle es a Makkink modell allt a legkozelebb.

Question Explaining the biomass–species richness relationship is key to understanding vegetation dynamics. Several possible mechanisms have been suggested, but complex analysis of plant strategies, major biomass and species richness components along a long productivity gradient is still lacking. We provide a detailed analysis of the relationship between major biomass components (total above-ground biomass, green biomass and litter), plant strategies and species richness along a long gradient of alkali and loess grasslands in a steppe landscape in Central Europe. Location Hortobagy, Great Hungarian Plain, East Hungary. Methods Above-ground biomass of characteristic alkali and loess grassland stands was sampled along a gradient of increasing productivity. In each grassland stand, a 25-m2 sample site was randomly selected. Within each site, ten above-ground biomass samples (20 × 20 cm) were collected randomly in June 2009, at the peak of biomass production. We classified all species into mixed C-S-R strategy types. To obtain correlations between various biomass and species richness data, Spearman rank correlation was used. The relationship between plant strategies and species composition were displayed with a DCA ordination. Results The frequently detected humped-back relationship was valid for the relation of total biomass and species richness. With increasing amount of total biomass, we detected an increasing proportion of competitors, and a decreasing proportion of stress tolerators in green biomass. A low proportion of ruderals was detected at both low and high biomass levels. Species richness was affected positively by litter at low litter scores, but there was a negative litter effect from much lower scores than detected previously (from 400 g·m−2). There was a positive relationship between green biomass production and species richness. Conclusions The study revealed that at the initial part of a productivity gradient, stress is likely responsible for low species richness. Our results show that litter can shape changes in species richness along the whole biomass gradient, thus the litter effect is one of the major mechanisms structuring grassland diversity.

Grassland managers and scientists are increasingly interested in cost-effective alternative ways of grassland biodiversity conservation. Prescribed burning is a promising management tool which should be integrated in the planning of management efforts. In addition, small-scale prescribed burning is an effective fire suppression strategy to decrease the serious negative impacts of uncontrolled burnings on ecosystems and human life. Prescribed burning forms an integral part of the North-American grassland management practice, while in Europe it is rarely applied, despite the fact that uncontrolled burning occurs frequently in some regions. Our goal was to evaluate the use of prescribed burning as a promising but neglected management tool in European grasslands. We found that European studies on prescribed burning of grasslands are scarce and we conclude that annual burning is usually not an appropriate option for the conservation of species-rich grasslands. We reviewed burning studies from North-America to identify findings which might be adapted to the European grassland conservation strategy. In North-America, contrary to Europe, the application of burning is fine tuned in terms of frequency and timing, and usually combined with other restoration measures (grazing or seed sowing). Thus, we conclude that with the application of carefully designed prescribed burning, multiple conservation goals, e.g. invasion control and enhancing landscape-level heterogeneity, can be linked with an effective fire suppression strategy. We emphasize that for the application of prescribed burning in Europe, the general findings of carefully designed case studies should be combined with the practical knowledge of conservation managers concerning the local application circumstances to reach specific management objectives.

Effects of urbanization on rove beetles were studied along a rural-suburban-urban forested gradient characterized by increasing human disturbance in and around Debrecen city (Hungary). Three classical and six novel hypotheses regarding the response of species to urbanization were tested. We found that overall species richness increased significantly with decreasing urbanization (i) as it is predicted by the increasing disturbance hypothesis, and contradicting (ii) the intermediate disturbance hypothesis that predicts the highest species richness in the moderately disturbed suburban area. (iii) The number of forest-associated species was significantly lower in the urban area compared to suburban and rural areas, as predicted by the habitat specialist hypothesis. All of the proposed novel hypotheses are about habitat alteration caused by the urbanization were corroborated. The (iv) richness of hygrophilous species was the highest in the rural area (hygrophilous species hypothesis), while (v) the number of thermophilous species was higher in the urban area (thermophilous species hypothesis). The richness of species directly or indirectly feeding on decaying organic materials ((vi) saprophilous, (vii) phytodetriticol, (viii) myrmecophilous, (ix) mycetophilous species hypotheses) was also highest in the rural area compared to the urban one. We stress that overall species richness is not the most appropriate indicator of the impacts of urbanization and accompanying disturbance on these beetles. Instead, habitat affinity and ecological traits of the species give more information about what habitat properties and environmental variables change drastically during urbanization.

Question European landscapes have long been influenced by intensifying use by humans. Although habitat restoration can reverse this process, it is often limited in scope by socioeconomic constraints. Here we present a grassland restoration project that is exceptional in spatial scale in Europe. Location A total area of 760 ha of arable land was restored in the Egyek-Pusztakocs unit (50 km2) of Hortobagy National Park, east Hungary, between 2005 and 2008. Methods Restoration targeted alkali steppes and loess grasslands by sowing seeds of either two (alkali) or three (loess) foundation grass species. In 2009, we surveyed the vegetation in restored and target grasslands and quantified the factors influencing restoration success in a space-for-time substitution design. Results We recorded 100 species of flowering plants, of which 37 species were non-weed, ‘target’ species. Annual weeds dominated 1-yr-old fields but had decreased dramatically by the third year due to a developing perennial grass cover. Former alfalfa fields had proportionally fewer weeds than former cereal and sunflower fields. The diversity of common species and the cover of target species increased from 1- to 4-yr-old restored fields. Alkali-restored fields had more heterogeneous vegetation and more species than loess-restored fields. Distance to the target vegetation did not directly affect vegetation variables. There was significant spatial variability in vegetation development, possibly suggesting several local pathways of succession. Conclusions Grassland restoration was generally successful in accelerating secondary succession towards alkali steppes and loess grasslands. However, further management is necessary to counter the homogenizing effects of litter accumulation, to reduce perennial weeds and to enhance the colonization of target species. Our project provides useful practical insights into grassland restoration and in applying restoration at a number of sites within a larger area to conserve biodiversity at the landscape scale.

We studied ground-dwelling spiders along a rural–suburban–urban forest gradient representing increasing human disturbance using pitfall traps. We tested four known and two novel hypotheses: (1) increasing disturbance hypothesis (species richness is decreasing by disturbance); (2) matrix species hypothesis (the richness of open-habitat species is increasing by disturbance); (3) opportunistic species hypothesis (the richness of generalist species is increasing by disturbance); and (4) habitat specialist hypothesis (the number of the forest specialist species is decreasing by disturbance). As a consequence of urbanization, urban forests become drier and more open; thus, according to the new hypotheses, the number of (5) xerophilous species and (6) light-preferring species are increasing in the urban area. Our result did not support the increasing disturbance hypothesis, as the overall species richness increased from the rural sites to the urban ones. As predicted, the number of both the open-habitat and the generalist species increased towards the urban sites. The number of forest specialist species was higher in the suburban area than in the rural and urban area. Both xerophilous and light-preferring species were the most numerous in the urban area, supporting the xerophilous species and the light-preferring species hypotheses. Canonical correspondence analysis showed that the forest specialist species associated with the rural sites with higher amounts of decaying woods and more herbs or with the suburban sites with higher cover of leaf litter and higher relative humidity. Two generalist species and one open-habitat species were characteristic of urban sites with higher ground surface and air temperature.

Agricultural intensification threatens grasslands worldwide and the restoration of grasslands from arable lands can at least partially counter this threat. We studied grassland restoration by following early successional changes of arthropod assemblages (spiders, Araneae; true bugs, Heteroptera; orthopterans, Orthoptera; and ground beetles, Carabidae) on 1- and 2-year-old restorations using arable lands and native grasslands as two ends of the succession timescale. To examine the changes in species composition among the habitat types, we used habitat affinity indices based on fidelity and/or specificity of the species. We found that the number of species did not differ between habitat types, while species composition changed markedly with time. Species richness was thus not adequate to detect favorable changes after grassland restoration. Habitat affinity indices, on the other hand, were useful to detect compositional changes caused by the increasing numbers of species characteristic of target grasslands as early as the second year after restoration. Habitat affinity indices are easy-to-use, easy-to-interpret measures of restoration success; therefore, we recommend their use as measures complementary to species richness and simple similarity. Our results show that sowing low-diversity seed mixture followed by mowing and grazing can be particularly successful in grassland restoration in time periods as short as 2 years.

Past and present pressures on forest resources have led to a drastic decrease in the surface area of unmanaged forests in Europe. Changes in forest structure, composition, and dynamics inevitably lead to changes in the biodiversity of forest-dwelling species. The possible biodiversity gains and losses due to forest management (i.e., anthropogenic pressures related to direct forest resource use), however, have never been assessed at a pan-European scale. We used meta-analysis to review 49 published papers containing 120 individual comparisons of species richness between unmanaged and managed forests throughout Europe. We explored the response of different taxonomic groups and the variability of their response with respect to time since abandonment and intensity of forest management. Species richness was slightly higher in unmanaged than in managed forests. Species dependent on forest cover continuity, deadwood, and large trees (bryophytes, lichens, fungi, saproxylic beetles) and carabids were negatively affected by forest management. In contrast, vascular plant species were favored. The response for birds was heterogeneous and probably depended more on factors such as landscape patterns. The global difference in species richness between unmanaged and managed forests increased with time since abandonment and indicated a gradual recovery of biodiversity. Clearcut forests in which the composition of tree species changed had the strongest effect on species richness, but the effects of different types of management on taxa could not be assessed in a robust way because of low numbers of replications in the management-intensity classes. Our results show that some taxa are more affected by forestry than others, but there is a need for research into poorly studied species groups in Europe and in particular locations. Our meta-analysis supports the need for a coordinated European research network to study and monitor the biodiversity of different taxa in managed and unmanaged forests.

Effects of urbanization on ground-dwelling spiders (Araneae) were studied using pitfall traps along an urban-suburban–rural forest gradient in Debrecen (Hungary). We found that overall spider species richness was significantly higher in the urban sites compared to the suburban and rural ones. The increased diversity was due to the significantly more open-habitat species in the assemblages at the urban sites. This suggests that species from the surrounding matrix (grasslands and arable lands) penetrated the disturbed urban sites. The ratio of forest species was significantly higher in the rural sites than in the suburban and urban ones, suggesting that forest species are indeed sensitive to the disturbance caused by urbanization. Canonical correspondence analysis revealed that the species composition changed remarkably along the urbanization gradient. Open-habitat spiders were associated with the urban sites of higher ground and air temperature. Forest spiders were characteristic of the rural sites with higher amount of decaying woods. Our findings suggest that the overall diversity was not the most appropriate indicator of disturbance; species with different habitat affinity should be analyzed separately to get an ecologically relevant picture of the effect of urbanization.

Without robust and unbiased systems for monitoring, changes in natural systems will remain enigmatic for policy makers, leaving them without a clear idea of the consequences of any environmental policies they might adopt. Generally, biodiversity-monitoring activities are not integrated or evaluated across any large geographic region. The EuMon project conducted the first large-scale evaluation of monitoring practices in Europe through an on-line questionnaire and is reporting on the results of this survey. In September 2007 the EuMon project had documented 395 monitoring schemes for species, which represents a total annual cost of about 4 million euro, involving more than 46,000 persons devoting over 148,000 person-days/year to biodiversity-monitoring activities. Here we focused on the analysis of variations of monitoring practices across a set of taxonomic groups (birds, amphibians and reptiles, mammals, butterflies, plants, and other insects) and across 5 European countries (France, Germany, Hungary, Lithuania, and Poland). Our results suggest that the overall sampling effort of a scheme is linked with the proportion of volunteers involved in that scheme. Because precision is a function of the number of monitored sites and the number of sites is maximized by volunteer involvement, our results do not support the common belief that volunteer-based schemes are too noisy to be informative. Just the opposite, we believe volunteer-based schemes provide relatively reliable data, with state-of-the-art survey designs or data-analysis methods, and consequently can yield unbiased results. Quality of data collected by volunteers is more likely determined by survey design, analytical methodology, and communication skills within the schemes rather than by volunteer involvement per se.

The effects of size, isolation and grazing intensity on spider assemblages were studied in the fragments of sandy grasslands (East Hungary, Nyirseg). Spiders were sampled by sweep-netting at eight different-sized grassland fragments between 2001 and 2003 from April to October fortnightly. The following hypotheses were tested: (i) the rules of classical island biogeography are assessed for grassland fragments: the number of species increases with the size and decreases with the isolation of the fragment. (ii) Species richness of spiders decreases by the intensity of grazing. (iii) Grazing may have a negative influence on the large, web-builder spiders and on the diurnal hunters associated to the vegetation. During the 3-year study period, 3842 spider specimens belonging to 90 species were collected from the eight sandy grassland fragments. We found no significant relationship for the size and isolation of grassland fragments neither with the number of species nor the number of vegetation-dwelling species, species associated with sandy soils, and with the vegetation-dwelling species specific to sandy area. Our result suggests that even the small fragments had a relatively large species pool. There was a positive correlation of the average height of vegetation as a measure of grazing intensity with the total number of spider species, as well as with the number of vegetation-dwelling species, species associated with sandy soils, and also with the number of vegetation-dwelling species specific to sandy area. By indicator species analysis (IndVal) we found that the grazing had a negative influence on the large, web-builder spiders and also those diurnal hunters, which were associated to the vegetation.