Near-natural Habitats Research Articles

Latitudinal and anthropogenic effects on the structuring of networks linking blood-feeding flies and their vertebrate hosts.

Biting flies (Diptera) transmit pathogens that cause many important diseases in humans as well as domestic and wild animals. The networks of feeding interactions linking these insects to their hosts, and how they vary geographically and in response to human land-use, are currently poorly documented but are relevant to understanding cross-species disease transmission. We compiled a database of biting Diptera-host interactions from the literature to investigate how key interaction network metrics vary latitudinally and with human land-use. Interaction evenness and H2' (a measure of the degree of network specificity) did not vary significantly with latitude. Compared to near-natural habitats, interaction evenness was significantly lower in agricultural habitats, where networks were dominated by relatively few species pairs, but there was no evidence that the presence of humans and their domesticated animals within networks led to systematic shifts in network structure. We discuss the epidemiological relevance of these results and the implications for predicting and mitigating future spill-over events.

Effects of mosquito resting site temperatures on the estimation of pathogen development rates in near-natural habitats in Germany

BackgroundEnvironmental temperature is a key driver for the transmission risk of mosquito-borne pathogens. Epidemiological models usually relate to temperature data from standardized weather stations, but these data may not capture the relevant scale where mosquitoes experience environmental temperatures. As mosquitoes are assumed to spend most of their lifetime in resting sites, we analysed mosquito resting site patterns and the associated temperatures in dependence on the resting site type, resting site height and the surrounding land use.MethodsThe study was conducted in 20 areas in near-natural habitats in Germany. Ten areas were studied in 2017, and another 10 in 2018. Each study area consisted of three sampling sites, where we collected mosquitoes and microclimatic data in artificial (= garden pop-up bags) and natural resting sites at three height levels between 0 and 6 m. Land use of the study sites was characterized as forest and meadows based on reclassified information of the CORINE (Coordination of Information on the Environment) Land Cover categories. The hourly resting site temperatures and the data from the nearest weather station of the German meteorological service were used to model the duration of the extrinsic incubation period (EIP) of mosquito-borne pathogens.ResultsAnopheles, Culex and Culiseta preferred artificial resting sites, while Aedes were predominantly collect in natural resting sites. Around 90% of the mosquitoes were collected from resting sites below 2 m. The mosquito species composition did not differ significantly between forest and meadow sites. Mean resting site temperatures near the ground were approximately 0.8 °C lower than at a height of 4–6 m, which changed the predicted mean EIP up to 5 days at meadow and 2 days at forest sites. Compared with temperature data from standardized weather stations, the resting site temperatures near the ground would prolong the mean estimated EIP 4 days at forest sites and 2 days at meadow sites.ConclusionsThe microclimate of mosquito resting sites differs from standardized meteorological data, which can influence the transmission of mosquito-borne pathogens. In a near-natural environment, colder temperatures at mosquitoes’ preferred resting sites near the ground would prolong the EIP of mosquito-borne pathogens relative to data from weather stations.Graphical

Seasonality of Carabid Beetles on an Organic Agricultural Field and Its Effect on Foraging Use

Ground beetle species from marginal areas invade organically farmed fields in a higher abundance and species richness than conventionally farmed fields. Seasonal invasion into organic fields was studied at Ritzerau Manor, converted to organic farming 18 years ago. Carabid species were explored with 123 pitfall traps within the field and in marginal near-natural habitats over the 18 years after conversion. For 56 species, seasonality could be studied in a distance gradient from the field margin to the field center. The results revealed that ground beetles from marginal habitats can use the fields differently depending on their seasonal activity. Early and fast-moving species can reach the center of the field at a 240 m distance from margin; late and slowly moving species only reach the 120 to 60 m distance level. The foraging effect of species, thus, depends on the seasonality and duration of activity. Overall, marginal species make up to 35% of the total foraging of ground beetles. Thus, organic farming not only supports a closer interaction between farmland and the adjacent near-natural landscape, but also benefits from higher biological pest control by immigrating marginal species.

Behavior of domestic pigs under near-natural forest conditions with ad libitum supplementary feeding

Today's livestock agriculture faces major changes in domestic pig husbandry—besides animal health and productivity, aspects of animal welfare and animal-friendly husbandry systems for pigs increasingly gain attention. To get a basic and current overview of the behavior of pigs in a near-natural habitat, we studied two groups of 20 domestic fattening pigs kept in two free-range forest enclosures in southern Germany. The pigs had ad libitum access to supplementary concentrate feed (CF), green fodder (GF), water and shelters. During the 6-month observation period, we found that the pigs showed no biphasic activity rhythm. The activity phase began at ca. 05:15 and ended at 21:00 in summer, and it shortened in winter. The peak of activity was between 14:00 and 18:00. The individual behaviors were assessed on 16 observation days during three direct-observation-intervals each (morning: 08:00 to 10:00; midday: 12:00 to 14:00; evening: 16:00 to 18:00). In the course of a day, some of the occurring behaviors such as rooting and locomotion continually increased from morning to evening. In contrast, resting occurred the least in the evening. Feed and water uptake were observed without noticeable influence of the daytime during the entire daylight period. Despite ad libitum availability of CF and GF at the feeding place, the pigs spent only about 13% of the observation time eating (including food uptake in the forest), with the total time and average duration being greater for GF than for CF uptake. Furthermore, the pigs spent about 24% of the time rooting. Thus, rooting seems to be an essential behavior of domestic pigs without the primary motivation of hunger. Resting made up 47% of the total observation time. The remaining 16% of the observation time was spent with several short-lasting active behaviors, such as interacting with the environment, locomotion, playing and comfort behavior. Based on the results of our study, we provide recommendations for adequate management practices in modern, animal-friendly pig stalls and free-range enclosures.

Gene flow in a highly dynamic habitat and a single founder event: Proof from a plant population on a relocated river site

River relocations due to realization of infrastructure projects or flood protection provide a high potential for ecological restorations and the creation of near-natural habitats. Colonization success of new riparian habitats in the dynamic riverine zone is rarely predictable, as the survival of sessile plants is highly dependent on flood events. Relocated rivers offer a unique opportunity to study restoration success, and using genetic information allows tracing to source populations and assessing connectivity. This study focuses on the colonization of a new, 3.4 km long river stretch in the Inn catchment (Switzerland), with an artificial, stable shoreline and a dynamic riverine zone with gravel bars. We assess the colonization success of Myricaria germanica, a flagship species for floodplain pioneer vegetation, 14 years after river relocation. The population with over 600 individuals of which 147 were used for genetic analysis based on 22 microsatellite markers in comparison to 11 potential source populations up- and downstream of the new site. Our results on demography and genetic composition together with information on flood events allow tracing the origin of the subpopulation along the stable shoreline to a single founder event but several founder individuals further upstream. The subpopulation in the dynamic zone is younger and more likely strongly dependent on gene flow from the stable shoreline subpopulation, but allows for rejuvenation at the site. Genetic patterns along the catchment indicate ongoing gene flow, suggesting potential for colonization success for further restorations in the catchment. Our data reveals that near-natural flood dynamics with repeated larger flood events is a key factor for successful colonization of dynamic riparian habitats.

Assessing Habitat Vulnerability and Loss of Naturalness: Applying the GLOBIO3 Model in the Czech Republic

Global and regional biodiversity loss is caused by several drivers including urban development, land use intensification, overexploitation of natural resources, environmental pollution, and climate change. The main aim of our study was to adapt the GLOBIO3 model to the conditions of the Czech Republic (CR) to assess loss of naturalness and biodiversity vulnerability at the habitat level on a detailed scale across the entire CR. An additional aim was to assess the main drivers affecting the biodiversity of habitat types. The GLOBIO3 model was adapted to CZ-GLOBIO by adapting global to local scales and using habitat quality and naturalness data instead of species occurrence data. The total mean species abundance (MSA) index of habitat quality, calculated from the spatial overlay of the four MSA indicators by our new equation, reached the value 0.62. The total value of MSA for natural and near-natural habitats was found to be affected mainly by infrastructure development and fragmentation. Simultaneously, intensity of land use change and atmospheric nitrogen deposition contributed primarily to the low total value of MSA for distant natural habitats. The CZ-GLOBIO model can be an important tool in political decision making to reduce the impact of the main drivers on habitat biodiversity in the CR.

Quality and use of habitat patches by wild boar (Sus scrofa) along an urban gradient

Expansion and urbanization process of wild boar (Sus scrofa) populations lead to serious human–wildlife conflicts in many cities, e.g. in Budapest, Hungary. In this study we evaluated the penetration potential of the species into the inner urban areas by identifying the occurrence of wild boar and the quality of the habitat patches for them along an urban gradient from the periphery towards the centre. Wild boar rooting intensity, shrub cover and the availability of woody species giving favourable food to wild boar were measured in four different habitat patches. The availability of hiding shrub patches was much higher in the outer areas than in the inner ones. Similarly, the proportion of shrub and tree species providing favourable food for wild boar decreased towards the centre. Accordingly, we found rooting only in two areas nearer to the city boundary. Based on our results at the peripheral areas permanent presence of wild boar in near-natural habitats should be expected, but not in the inner green zones. We recommend to monitor the urban wild boar presence and evaluate the quality of urban green patches to mitigate problems related to the wild boars.

Near-natural habitats near almond orchards with presence of empty gastropod shells are important for solitary shell-nesting bees and wasps

Solitary bees serve as important native pollinators of wild plants and crops. Several species of bees, which form strong populations in open habitats of European landscapes, nest in empty snail shells. In the present study, we focused on shell-nesting bees in near-natural habitats neighbouring almond orchards near the town Lleida in north-east Spain. We performed a series of manipulative experiments, which aimed to elucidate the importance of empty shells of four common large- and medium-sized gastropod species for nesting bees in near-natural and ruderal habitats surrounding the almond orchards. We also matched these data with findings of bees in naturally occurring shells at each examined site. All study sites consisted of habitats with naturally present shells and evidence of the natural presence of the study species of bees. In total, we recorded 15 nesting bee and wasp species and eight species of hymenopteran parasites in collected shells, one of which, the spider wasp Priocnemis propinqua, was recorded nesting in empty gastropod shells for the first time. In total, the deployed shells hosted eight nesting species and two species of parasitic Hymenoptera. The prevalence of nests in experimentally deployed shells was low, with only a single nest present near irrigated orchards. The abundance of nests was also low at sites where the naturally present shells were highly abundant. Combined, available evidence suggests the importance of near-natural habitats for the presence of shell-nesting bees and wasps in South-European landscapes. The abundance of shell nesting bees and wasps does not increase proportionally with the increase in empty snail shell abundance and other factors should be considered limiting at such sites.

Polyploid evolution: The ultimate way to grasp the nettle.

Polyploidy is one of the major forces of plant evolution and widespread mixed-ploidy species offer an opportunity to evaluate its significance. We therefore selected the cosmopolitan species Urtica dioica (stinging nettle), examined its cytogeography and pattern of absolute genome size, and assessed correlations with bioclimatic and ecogeographic data (latitude, longitude, elevation). We evaluated variation in ploidy level using an extensive dataset of 7012 samples from 1317 populations covering most of the species’ distribution area. The widespread tetraploid cytotype (87%) was strongly prevalent over diploids (13%). A subsequent analysis of absolute genome size proved a uniform Cx-value of core U. dioica (except for U. d. subsp. cypria) whereas other closely related species, namely U. bianorii, U. kioviensis and U. simensis, differed significantly. We detected a positive correlation between relative genome size and longitude and latitude in the complete dataset of European populations and a positive correlation between relative genome size and longitude in a reduced dataset of diploid accessions (the complete dataset of diploids excluding U. d. subsp. kurdistanica). In addition, our data indicate an affinity of most diploids to natural and near-natural habitats and that the tetraploid cytotype and a small part of diploids (population from the Po river basin in northern Italy) tend to inhabit synanthropic sites. To sum up, the pattern of ploidy variation revealed by our study is in many aspects unique to the stinging nettle, being most likely first of all driven by the greater ecological plasticity and invasiveness of the tetraploid cytotype.

Revisiting restored river reaches – Assessing change of aquatic and riparian communities after five years

Hydromorphological restructuring of river sections, i.e. river restoration measures, often has little effects on aquatic biota, even in case of strong habitat alterations. It is often supposed that the biotic response is simply delayed as species require additional time to recolonize the newly generated habitats and to establish populations. To identify and specify the supposed lag time between restoration and biotic response, we investigated 19 restored river reaches twice in a five-year interval. The sites were restored one to ten years prior to the first sampling. We sampled three aquatic (fish, benthic invertebrates, macrophytes) and two riparian organism groups (ground beetles and riparian vegetation) and analyzed changes in assemblage composition and biotic metrics. With the exception of ground beetle assemblages, we observed no significant changes in richness and abundance metrics or metrics used for biological assessment. However, indicator taxa for near-natural habitat conditions in the riparian zone (indicators for regular inundation in plants and river bank specialists in beetles) improved significantly in the five-year interval. Contrary to general expectations in river restoration planning, we neither observed a distinct succession of aquatic communities nor a general trend towards “good ecological status” over time. Furthermore, multiple linear regression models revealed that neither the time since restoration nor the morphological status had a significant effect on the biological metrics and the assessment results. Thus, the stability of aquatic assemblages is strong, slowing down restoration effects in the aquatic zone, while riparian assemblages improve more rapidly. When defining restoration targets, the different timelines for ecological recovery after restoration should be taken into account. Furthermore, restoration measures should not solely focus on local habitat conditions but also target stressors acting on larger spatial scales and take other measures (e.g. species reintroduction) into consideration.

Resurveying hedgerows in Northern Germany: Plant community shifts over the past 50 years

Resurveying is a powerful approach to investigate responses of plant species communities to a changing environment. We present a resurvey of hedgerows from the “Knick” landscape of eastern Schleswig-Holstein, Germany. The original survey was done by H. E. Weber in 1967 and new data from totally 51 semi-permanent plots was sampled in 2015. Hedgerows are a key near-natural habitat that can harbour a great biodiversity in otherwise agriculturally intensified landscapes.Our study reveals a distinct shift in the herbaceous species composition of the hedgerows over the past five decades. To understand the reasons for these changes, we compared the mean Ellenberg indicator values (EIVs) and measured pH values, as well as hedge shape parameters of the hedgerows between the recent and the original study. The main driver behind the change in species composition appeared to be the increase in nutrient supply. The hedge shape changed as well, indicating an altered hedgerow management. Interestingly, we found a contradictory relationship between measured pH values and mean EIVs for reaction: while the former showed a decrease over time, the latter suggested an increase.Species richness decreased in some groups (shrubs and herbaceous forest species) but increased in others (grass species and arable weed species), with an overall decline in species richness. An analysis of the species' changes in frequency in relation to their EIVs showed that species with higher nitrogen and temperature scores were more likely to have increased.

Industrial and post-industrial habitats serve as critical refugia for pioneer species of newly identified arthropod assemblages associated with reed galls

Gravel-sand river terraces were nearly eliminated from central European landscape by river channelization. Monotypic stands of common reed (Phragmites australis) growing on such terraces are often stressed by drought, which makes them vulnerable to Lipara spp. (Diptera: Chloropidae) gallmakers. Although Lipara are considered ecosystem engineers, only fragmentary information is available on the biology of their parasitoids and inquilines. We analyzed the assemblages of arthropods (Arachnida, Collembola, Dermaptera, Psocoptera, Thysanoptera, Hemiptera, Raphidioptera, Neuroptera, Coleoptera, Diptera, Lepidoptera and Hymenoptera) that emerged from 17,791 Lipara-induced galls collected in winter from 30 reed beds in the Czech Republic, 15 of which were situated at (post)industrial sites (gravel-sandpits, tailing ponds, limestone quarries, colliery dumps, and reclaimed lignite open-cast mines) and 15 were in near-natural habitats (medieval fishponds, and river and stream floodplains). The Chao-1 estimator indicated 229.3 ± 18.1 species in reed galls at (post)industrial and 218.1 ± 23.6 species at near-natural sites, with the Sorensen index reaching only 0.58. We identified 18 red-listed species and four new species for the Czech Republic (Gasteruption phragmiticola, Echthrodelphax fairchildii, Haplogonatopus oratorius and Enclisis sp.), representing mostly obligate (64 %) or facultative (9 %) reed specialists. We propose that Lipara gall-associated assemblages undergo a long-term cyclic ecological succession. During first 10 years after reed bed formation, only Lipara spp. and several other species occur. During next decades, the reed beds host species-rich assemblages with numerous pioneer species (Singa nitidula, Polemochartus melas) that critically depend on presence of prior disturbances. Middle-aged reed beds (near medieval fishponds) are prevalently enriched in common species only (Oulema duftschmidi, Dimorphopterus spinolae). Habitats with the longest historical continuity (river floodplains) host again species-rich assemblages with several rare species that probably require long-term habitat continuity (Homalura tarsata, Hylaeus moricei). Landscape dynamics is thus critical for the persistence of a full spectrum of reed gall inquilines, with (post)industrials serving as the only refugia for pioneer species ousted from their key nesting habitats at once cyclically disturbed gravel-sand river terraces.

Resurrection of the Comoran fish scale gecko Geckolepis humbloti Vaillant, 1887 reveals a disjunct distribution caused by natural overseas dispersal

Fish scale geckos (Geckolepis) are taxonomically poorly resolved, mainly because of the difficulty of applying standard morphological characters to diagnose taxa. Three species, Geckolepis maculata, G. polylepis, and G. typica, are currently recognized from Madagascar and the Comoro Islands. Molecular studies suggested a number of operational taxonomical units within the G. maculata complex, but none of these has been formally described. The Comoran population was described as Geckolepis humbloti Vaillant 1887 but later synonymized. Prior to our study, no genetic data and little other information were available for this taxon. We revised the status of G. humbloti using molecular genetics, external morphology, and osteological characters retrieved from 3D skeletal models created using micro-computed tomography (micro-CT). Our results demonstrate that G. humbloti represents a genetic lineage strongly distinct from all other Geckolepis species. It is furthermore distinguished by a combination of external morphological characters and probably by osteology. We therefore resurrect G. humbloti Vaillant, 1887 from synonymy with G. maculata. Remarkably, this lineage is not restricted to the Comoros: A specimen from Tsingy de Bemaraha in western Madagascar falls as a closely related sister lineage to all Comoran Geckolepis in our molecular phylogenetic analysis and is osteologically almost identical with a specimen from the type locality Grand Comoro. We therefore include it in G. humbloti. The phylogenetic topology and the intraspecific genetic divergences suggest that the Comoros were colonized naturally from western Madagascar by overseas dispersal. G. humbloti is not considered as threatened, but its presence is indicative of natural or near-natural habitats.

Effects of germination time on seed morph ratio in a seed-dimorphic species and possible ecological significance.

Diaspores of heteromorphic species may germinate at different times due to distinct dormancy-breaking and germination requirements, and this difference can influence life history traits. The primary aim of this study was to determine the effect of germination time of the two seed morphs of Suaeda corniculata subsp. mongolica on life history traits of the offspring. Germinated brown and black seeds were sown on the 20th of each month from April to September in a simulated but near-natural habitat of the species. Phenological and vegetative traits of the maternal plants, and number, size and germination percentage of the offspring were determined. Germinated seeds sown late in the year produced smaller plants that had a higher proportion of non-dormant brown than dormant black seeds, and these brown seeds were larger than those produced by germinated seeds sown early in the year. The length of the seedling stage for brown seeds was shorter than that for black seeds, and the root/shoot ratio and reproductive allocation of plants from brown seeds were more variable than they were for plants from black seeds. Late-germinating brown seeds produced larger plants than late-germinating black seeds. Altering the proportion of the two seed types in response to germination timing can help alleviate the adverse effects of delayed germination. The flexible strategy of a species, such as S. corniculata, that produces different proportions of dimorphic seeds in response to variation in germination timing may favour the maintenance and regeneration of the population in its unpredictable environment.

Biotic homogenization and differentiation of the flora in artificial and near-natural habitats across urban green spaces

Shenzhen, a new city existed for less than three decades, experienced dramatic biological invasions of alien plants resulting from the construction of urban green spaces. In an investigation of plant species from 390 plots in 186 sites across five main types of green space (public parks, forests, vegetation corridors, residential and industrial area), a total of 474 plant species, including 221 alien species (46.6%), were recorded. Our study witnessed the spread and establishment of alien species across all urban green spaces and revealed significantly greater proportions of alien species in artificial green spaces than in natural ones. Furthermore, we found the positive relationship between native and alien species richness existed across all the green spaces and was particularly prevalent in the artificial ones. Additionally, successful establishment of alien species instigated by anthropogenic disturbances and most frequent species assemblages caused biotic homogenization in the artificial habitats. In contrast, biotic differentiation in the near-natural habitats was still preserved due to a greater level of protection for native species, which showed some resistance against the establishment of alien species. Therefore, urbanization was proven distinct effects on the flora of artificial and near-natural habitats, coexisting in the new city.

Traditional coppice forest management drives the invasion of Ailanthus altissima and Robinia pseudoacacia into deciduous forests

The non-native tree species Black Locust (Robinia pseudoacacia L.) from N America and Tree of Heaven (Ailanthus altissima (Mill.) Swingle) from E Asia are invading both anthropogenic and near-natural habitats throughout Europe. So far, few studies have focused on their invasion into forests and none has addressed the influence of coppice management, which is characterized through regular clear-cuts. To retrace the invasion during the last 50years, we studied the abundance in the canopy as well as the natural regeneration of these species in the coppice forest of Gargazon (South Tyrol, Northern Italy), which was ideal due to its patchy mosaic of different forest age (time since last coppicing). We analyzed which factors favor the presence and abundance of A. altissima and R. pseudoacacia regeneration. Tree saplings were sampled on 113 plots each measuring 7m2 in a total study area of 25.5hectares. On each plot, the following environmental variables were recorded: canopy cover per species, total herb layer cover, distance to clearing, stone cover, slope, and aspect. Soil moisture was derived from herbaceous indicator species. Hurdle models were used for data analysis to account for the zero-inflated data structure. The results showed that R. pseudoacacia has established earlier in the studied forest than A. altissima, but A. altissima has been spreading with higher speed during the last 30years. Our study exemplifies the invasion of both species synchronously to the coppice cycle, that means they colonize fresh clear-cuts, establish, and remain. We conclude that the currently applied coppice management, which consists of repeated clear cuttings each 20–30years, favors the spread of both invasive species. Thus, an adaptation of the management system is needed to avoid further invasion.

Species introduction – a major topic in vegetation restoration

Holzel, N. (corresponding author, nhoelzel@uni-muenster.de): Institute of Landscape Ecology, University of Munster, Robert-Koch-Str. 28, 48149, Munster, Germany Buisson, E. (elise.buisson@univ-avignon.fr) & Dutoit, T. (thierry.dutoit@univ-avignon.fr): Institut Mediterraneen d’Ecologie et de Paleoecologie (UMR CNRS/IRD), IUT, Universite d’Avignon et des Pays de Vaucluse, site Agroparc BP 61207, 84 911, Avignon Cedex 09, France

Earthworm diversity in urban habitats of Basel (Northwestern Switzerland)

The diversity and ecology of the soil fauna in Central European towns is not yet well known. There are references that earthworms, by their biomass, dominate all other animal groups in cities – surpassed only by man. Basel (11 km2) is, with its 170 000 inhabitants, Switzerland’s third largest community. Open green spaces in the city are scarce; the green belt is narrow. Nevertheless, in more than 60 locations studied between 1999 and 2010, 22 species (12 genera) of Lumbricidae were found. Eleven near-natural habitats could be sampled: private front gardens and backyards, wooded river sides, industrially watered flood plain forest plots, and a Zoological Garden with a large number of green spaces built up from imported soil. Nearly a dozen of these species are quite rare in their natural distribution area and in Basel; many of them are riparian, e.g. Aporrectodea georgii, Fitzingeria platyura depressa, and Helodrilus oculatus – while two are strictly endogeic (Allolobophora satchelli, Murchieona muldali). The sampling method “digging and hand-sorting plus mustard meal suspension” yielded the best possible quantitative results in urban habitats. A maximum of earthworm species (18) was sampled in the Zoological Garden, and the intensely used public lawns had the highest mean density and biomass (450 individuals resp. 280 g fresh mass/m2).

Macrophyte development in unimpacted lowland rivers in Poland

Freshwater classification according to the Water Framework Directive (WFD) is based on estimation of the deviation between biological elements found on river stretch in comparison with communities detected in the same river type under reference conditions (undisturbed and near-natural habitats). We present analyses to describe macrophyte development in pristine lowland rivers and to reveal the variation among various stream types. The study is based on a country-wide survey of Poland with a dataset of 642 sites on 367 water courses. Surveyed rivers covered the whole lowland area of Poland. Field surveys were conducted using the Polish macrophyte approach, which enabled calculation of several macrophyte metrics. Firstly, a numerical index MIR (Macrophyte Index for Rivers) was computed, which reflects river degradation, especially eutrophication. Furthermore, five diversity metrics were calculated. Each survey, in addition to macrophyte assessment, was supplemented by a complex suite of environmental records. Reference conditions were defined using four criteria: (1) catchment land use, (2) hydromorphological features, (3) water quality and (4) biological assessment. The selected reference lowland rivers included 40 sites. To classify plant data, two-way indicator species analysis Twinspan was used. This resulted in distinguishing four end-clusters which were heterogeneous according to plant composition: organic rivers and three types of siliceous rivers (small with sandy substrate, small with stony substrate and large rivers). The differentiation of environmental factors between river types was confirmed by a variance analysis (ANOVA). Furthermore, the environmental database was explored with principal component analysis (PCA). The PCA principal components were analysed against river types with the canonical correspondence analysis (CCA). Finally botanical differences between identified river types have been detected, using botanical metrics the share of different macrophyte groups and relationships with particular species were defined.

Gyűrűfűn a Biodiverzitás Napokon gyűjtött kabócák (Auchenorrhyncha)

Present paper contains the results of the faunistic survey carried out between 2006-2008 near Gyűrűfű, in a near-natural habitat. The material collected during this period contains specimens of 188 species belonging to 116 genera of 10 families of Auchenorrhyncha. Two of these species are firstly found in Hungary (Fruticidia bisignata Mulsant & Rey, 1855 and Balclutha rosea Scott, 1876 respectively).