Zoltán Elek

Diversity and composition of carabids during a forestry cycle

Carabids (Carabidae, Coleoptera) were studied for 2 yearsto explore changes in their diversity and composition during a forestry cycle inthe Hungarian Mountain Range. Native beech forest was clear-cut and replantedwith Norway spruce. Recently planted (5 years old), young (15years old), middle-aged (30 years old) and old spruceplantations (50 years old) were studied using pitfall traps. Ourresults showed that the species richness of carabids was significantly lower inthe plantations than in the native beech forest. Species composition washomogeneous in the beech forest. β-Diversity of the 15–30year old plantations was also low, and it increased slightlytowards ageing. Heterogeneity of the species composition of the 5year old plantation was higher than that of the others, whichreflected the patchiness of the young plantation. The main tendencies of thecompositional changes were as follows. Deciduous forest specialists decreasedsignificantly in abundance in the plantations; they appeared in highabundance only in the beech forest. Species characteristic of open habitatsincreased remarkably in abundance in the recently established plantation.Multiple linear regression between the diversity of carabids and of 12environmental variables shows that the pH and compaction of the soil, and thecover of leaf litter had a significant effect in determining diversity ofcarabids.

Ground beetles (Carabidae) and edge effect in oak-hornbeam forest and grassland transects

We evaluated ground beetle diversity in relation to forest edge between an oak-hornbeam forest and adjacent herbaceous grassland. To test our hypothesis that the diversity of ground beetles was higher in the forest edge than the interior, pitfall trap samples were taken along two forest-grassland transects in northern Hungary. The diversity of ground beetles was significantly higher at the forest edge and in the grassland than in the forest interior. Ground beetle assemblages in the forest interior, forest edge and grassland could be separated from each other by ordination. Indicator species analysis detected five groups of species: habitat generalists, grassland-associated species, forest generalists, forest specialists, and edge-associated species. Rank correlation indicated leaf litter, herb, canopy cover, and prey abundance as the most important factors influencing carabid diversity. The high diversity of the forest edge resulted from the presence of edge-associated species and of species characteristic of adjacent habitats. Forest edges seem to play an important role in maintaining diversity. Serving as source habitats, edges also contribute to the recolonisation by ground beetles after habitat destruction or other disturbance in the adjacent habitats.

Functional beetle diversity in managed grasslands: effects of region, landscape context and land use intensity

Current biodiversity conservation policies have so far had limited success because they are mainly targeted to the scale of individual fields with little concern on different responses of organism groups at larger spatial scales. We investigated the relative impacts of multi-scale factors, including local land use intensity, landscape context and region, on functional groups of beetles (Coleoptera). In 2008, beetles were suction-sampled from 95 managed grasslands in three regions, ranging from Southern to Northern Germany. The results showed that region was the most important factor affecting the abundance of herbivores and the abundance and species composition of predators and decomposers. Herbivores were not affected by landscape context and land use intensity. The species composition of the predator communities changed with land use intensity, but only in interaction with landscape context. Interestingly, decomposer abundance was negatively related to land use intensity in low-diversity landscapes, whereas in high-diversity landscapes the relation was positive, possibly due to enhanced spillover effects in complex landscapes. We conclude that (i) management at multiple scales, from local sites to landscapes and regions, is essential for managing biodiversity, (ii) beetle predators and decomposers are more affected than herbivores, supporting the hypothesis that higher trophic levels are more sensitive to environmental change, and (iii) sustaining biological control and decomposition services in managed grassland needs a diverse landscape, while effects of local land use intensity may depend on landscape context.

Relationships between wild bees, hoverflies and pollination success in apple orchards with different landscape contexts

Pollination is an important ecosystem service because many agricultural crops such as fruit trees are pollinated by insects. Agricultural intensification, however, is one of the main drivers resulting in a serious decline of pollinator populations worldwide. In the present study, pollinator communities were examined in 12 apple orchards surrounded by either homogeneous or heterogeneous landscape in Hungary. Pollinators (honey bees, wild bees, hoverflies) were surveyed in the flowering period of apple trees. Landscape heterogeneity was characterized within a radius of 300, 500 and 1000 m around each orchard using Shannons diversity and Shannons evenness indices. We found that pollination success of apple was significantly related to the species richness of wild bees, regardless the dominance of honey bees. Diversity of the surrounding landscape matrix had a marginal positive effect on the species richness of hoverflies within a radius of 300 m and a positive effect on the species richness of wild bees within a radius of 500 m, whereas evenness of the surrounding landscape enhanced the abundance of wild bees within a radius of 500 m. Flower resources in the groundcover within the orchards supported honey bees. Therefore, the maintenance of semi‐natural habitats within 500 m around apple orchards is highly recommended to enhance wild pollinator communities and apple production.

Quantitative RT-PCR based platform for rapid quantification of the transcripts of highly homologous multigene families and their members during grain development

BackgroundCereal storage proteins represent one of the most important sources of protein for food and feed and they are coded by multigene families. The expression of the storage protein genes exhibits a temporal fluctuation but also a response to environmental stimuli. Analysis of temporal gene expression combined with genetic variation in large multigene families with high homology among the alleles is very challenging.ResultsWe designed a rapid qRT-PCR system with the aim of characterising the variation in the expression of hordein genes families. All the known D-, C-, B-, and γ-hordein sequences coding full length open reading frames were collected from commonly available databases. Phylogenetic analysis was performed and the members of the different hordein families were classified into subfamilies. Primer sets were designed to discriminate the gene expression level of whole families, subfamilies or individual members. The specificity of the primer sets was validated before successfully applying them to a cDNA population derived from developing grains of field grown Hordeum vulgare cv. Barke. The results quantify the number of moles of transcript contributed to a particular gene family and its subgroups. More over the results indicate the genotypic specific gene expression.ConclusionsQuantitative RT-PCR with SYBR Green labelling can be a useful technique to follow gene expression levels of large gene families with highly homologues members. We showed variation in the temporal expression of genes coding for barley storage proteins. The results imply that our rapid qRT-PCR system was sensitive enough to identify the presence of alleles and their expression profiles. It can be used to check the temporal fluctuations in hordein expressions or to find differences in their response to environmental stimuli. The method could be extended for cultivar recognition as some of the sequences from the database originated from cv. Golden Promise were not expressed in the studied barley cultivar Barke although showed primer specificity with their cloned DNA sequences.

High breeding performance of European Rollers Coracias garrulus in heterogeneous farmland habitat in southern Hungary

Capsule Rollers showed slightly higher breeding performance in farmland mosaics than in natural grasslands in southern Hungary, where both habitats were supplied with nest-boxes. Aim To establish which factors affect Rollers’ breeding success in agricultural and their more traditional grassland habitats. Methods Rollers’ reproductive success in farmland mosaics and grassland habitats were compared. Laying date, clutch size, feeding rate, as well as prey abundance and diversity, as estimated by sweep netting and pitfall trapping, were evaluated. Their effects on breeding performance were analysed by generalized linear models. Results In the agricultural habitat Rollers showed an even higher reproductive output than in their traditional habitat of natural grassland. Prey composition showed differences between the two habitats, with the lower abundance of orthopterans in farmland mosaics being substituted by the higher abundance of coleopterans and the diversity of arthropods (Orthoptera, Coleoptera, Heteroptera, Arachnida, Hymenoptera, Lepidoptera, Diptera, Homoptera, Mantidae, Myrmeleonidae and Odonata). Conclusion Rollers can reproduce well where good quality resources are available, even outside of their typical habitat, where nest-box erection schemes may benefit this threatened species.

Overlapping generations can balance the fluctuations in the activity patterns of an endangered ground beetle species: long-term monitoring of Carabus hungaricus in Hungary

Carabus hungaricus is a ground beetle inhabiting the Pannonian steppes. It is highly endangered by fragmentation and abandonment of its habitat. For five consecutive years, from 2006 to 2010, we used the mark–release‐recapture technique in a grid of 270 live‐capture pitfall traps to study its population ecology in sandy grasslands on Szentendrei Island in the Northern vicinity of Budapest, Hungary. In total, 3950 individuals of C. hungaricus (1874 females and 2076 males) were marked. Population size was estimated at∼2000 individuals per year; the estimates for females were consistently higher than those for males. The minimum population size was 1317 ± 60.1 individuals in 2007, whereas the maximum was 2169.7 ± 108.8 individuals in 2008. Adults older than a year formed∼32–42% of the population, whereas individuals surviving for 3 years formed∼10%, and those surviving for 4 years formed∼2% of the population. Individuals older than 4 years comprised <1% of the population. Female survival rate was higher than that of male, but the capture rate also differed between sexes. Although the studied population showed considerable fluctuations in the pattern of activity during the 5 years, its size seemed to be relatively stable, underlining the importance of overlapping generations.

Combined effects of agrochemicals and ecosystem services on crop yield across Europe

Simultaneously enhancing ecosystem services provided by biodiversity below and above ground is recommended to reduce dependence on chemical pesticides and mineral fertilisers in agriculture. However, consequences for crop yield have been poorly evaluated. Above ground, increased landscape complexity is assumed to enhance biological pest control, whereas below ground, soil organic carbon is a proxy for several yield-supporting services. In a field experiment replicated in 114 fields across Europe, we found that fertilisation had the strongest positive effect on yield, but hindered simultaneous harnessing of below- and above-ground ecosystem services. We furthermore show that enhancing natural enemies and pest control through increasing landscape complexity can prove disappointing in fields with low soil services or in intensively cropped regions. Thus, understanding ecological interdependences between land use, ecosystem services and yield is necessary to promote more environmentally friendly farming by identifying situations where ecosystem services are maximised and agrochemical inputs can be reduced.

STUDY OF HEAVY METALS IN THE SOIL-PLANT SYSTEM

Our objectives were to assess and rank 3 soil condition variants - root zone improving (RI), mulch leaving (NIL) and minimum disturbing (MD) - suitability to soil quality improvement and demonstrate the plant responses to different soil state and rind a possible relation between soil condition and plant growth under extreme climate. To rank the soil-plant interrelations twelve soil and plant factors were assessed; quality and depth of loosening state, surface protection by plants and stubble residues, soil aggregation, earthworm number, water supply in the root zone, tillage-induced C-flux, rooting depth of plants, yield, dry biomass and biomass recycling. Finally, seven fundamental requirements were selected to mitigate climate-stress and to improve plant resistance to the heat damage. A climate damage mitigation soil tillage strategy can establish a harmony between soil conservation and the demands of crop production.The results of a small-pot experiment of cadmium-loading (5 mgkg) with the addition of zinc (5 mgkg) carried out are introduced in this paper. For this, soil samples were taken from 4 sites of plough-land, grassland and forest land-use types. Accumulation characteristics of the two metals as well as their interaction with the soil properties were analysed. The results show that land-use has significant effect on zinc uptake. There is close correlation between the zinc and cadmium uptake of plants as well as that cadmium concentration of soils plays an important role in it. Zinc shows positive correlation while cadmium shows negative correlation with organic matter. Beside organic colloids, inorganic colloids i.e. clay fraction also showed close correlation.The effects of soil and climatic properties was studied on the winter wheat (Triticum aestivum L.) concerning on the heavy metal content of the plants. During this study the distribution of cobalt, copper, iron, manganese, nickel, and zinc was studied within a plant. Sampling was carried out in the same period of subsequent three years between 1995 and 1997. Our hypothesis was that the individuals of the same species has similar physiological answer for the same environmental properties. In this study we found no significant differences among the different plant’s parts and years. Our results can reveal that the ecological indication of plants could be major driver of agro-environmental studies to recognize unusual patterns of soil attributes.

Climate-induced phenological shift of apple trees has diverse effects on pollinators, herbivores and natural enemies

Climate change is altering the phenology of trophically linked organisms, leading to increased asynchrony between species with unknown consequences for ecosystem services. Although phenological mismatches are reported from several ecosystems, experimental evidence for altering multiple ecosystem services is hardly available. We examined how the phenological shift of apple trees affected the abundance and diversity of pollinators, generalist and specialist herbivores and predatory arthropods. We stored potted apple trees in the greenhouse or cold store in early spring before transferring them into orchards to cause mismatches and sampled arthropods on the trees repeatedly. Assemblages of pollinators on the manipulated and control trees differed markedly, but their overall abundance was similar indicating a potential insurance effect of wild bee diversity to ensure fruit set in flower-pollinator mismatch conditions. Specialized herbivores were almost absent from manipulated trees, while less-specialized ones showed diverse responses, confirming the expectation that more specialized interactions are more vulnerable to phenological mismatch. Natural enemies also responded to shifted apple tree phenology and the abundance of their prey. While arthropod abundances either declined or increased, species diversity tended to be lower on apple trees with shifted phenology. Our study indicates novel results on the role of biodiversity and specialization in plant-insect mismatch situations.