In our 3-year study ground beetle assemblages were investigated in habitats with different weed coverage and insecticide treatments in an apple orchard in Hungary. The aim of the study was to compare the effects on the activity density and composition of carabid assemblages of two insecticide disturbance levels; 1) applications of selective insecticides (integrated plant protection, IPM - representing lower degree of disturbance); 2) applications of broad-spectrum insecticides (conventional plant protection - representing a higher degree of disturbance). Particular attention was paid to the joint effects of weed patterns in the orchard and insecticide treatments as well as to the carabid assemblages in the two neighbouring semi-natural habitats. The less intense insecticide disturbance significantly increased the activity density and species richness of the apple orchard carabid assemblages. The mosaic habitats of the orchard herb layer, where higher and lower herb coverage alternate, altogether maintained more abundant and diverse carabid assemblages, than the habitat of closed, dense vegetation. The intra-orchard habitats with higher weed coverage enhanced the post-disturbance re-colonisation from the hedges, and therefore resulted carabid assemblages more similar to those of the semi-natural hedge vegetation. However, this re-colonisation was not great enough to compensate for the high mortality of the orchard carabid assemblage, which mostly consisted of species rare in the hedges. The high insecticide disturbance, affected the diversity of carabid assemblages in the intra-orchard habitats of high and low weed coverage differently, probably because of induced inter-habitat movement. Habitat attachment and post-disturbance recovery of Amara aenea, A. bifrons, A. fulva, A. ingenua, Broscus cephalotes, Calathus ambiguus, C. erratus, C. fuscipes, Cicindela hybrida, Harpalus albanicus, H. distinguendus, H. flavescens, H. froelichi, H. hirtipes, H. picipennis, H. rufipes, H. serripes, H. servus and H. tardus are also discussed.
Authors:A. Lugasi, J. Hóvári, G. Kádár and F. Dénes
For prevention of non-infectious diseases such as cancer, and cardiovascular disorders consumption of more and more fruits and vegetables is highly advised. Fruits of Ribes and Rubus species are very popular in Hungary. Antioxidant properties of these fruits are well known, but the values of the characteristics depend on several factors including species, cultivars, soil and climate conditions, water and nutrition supply, and so on. Phenolics in several cultivars of raspberry, blackberry and currants grown in Hungary were measured. Total polyphenols and anthocyanins were detected by spectrophotometric methods while flavonoids including apigenin, luteolin, kaempferol, myricetin, quercetin and also ellagic acid were quantified by RP-HPLC technique. Total polyphenol contents of raspberry (yellow and red cultivars), blackberry and currants (white, red and black cultivars) were 219, 244, 379, 333, 192 and 533 mg/100 g, respectively. The concentrations of anthocyanins in the same order were 1.0, 41.9, 145, 0.2, 46 and 354 mg/100 g. Apigenin, luteolin and kaempferol could not been detected in any of the samples. Ellagic acid (2.0 to 23.7 mg/100 g) could be measured in white and red raspberries, in blackberries, and in some red and white currant cultivars. Quercetin could be detected in all berry species ranging from 0.1 to 14.4 mg/100 g. Measurable amount of myricetin was observed only in black currant cultivars between 1.5 and 7.7 mg/100 g. Polyphenols including flavonoids and anthocyanins in berry fruits are important forms of natural antioxidants. These molecules play essential role in the prevention of diseases in the pathomechanism of which free radicals are involved. Berry fruits are good sources of antioxidants consumed either in fresh or in processed forms because of great susceptibility of polyphenols to heat and other physicochemical processes.
Authors:F. Samu, F. Kádár, G. Ónodi, M. Kertész, A. Szirányi, É. Szita, K. Fetykó, D. Neidert, E. Botos and V. Altbäcker
Recent environmental and land use changes have made wildfires more frequent in natural habitats of the Kiskunság Sand Ridge on the Hungarian Plain. In a study initiated 2.5 years after an extensive fire that destroyed half of the area of a sand grassland — juniper, poplar forest steppe habitat, we assessed the effects of fire on two generalist arthropod groups: spiders and carabid beetles, as well as on the vegetation. Utilizing the natural experiment situation, samples were taken by pitfalls and suction sampling during a 1.5 years period in four 1 ha blocks, two of which were on the burnt part of the habitat, and two in the unburnt control. At the time of the investigation, in the burnt area the vegetation in the grass layer showed a quick but not complete recovery, while the canopy layer of the juniper bushes burnt down with no sign of regeneration. Carabid beetles and spiders showed differences in recovery after fire. In the carabid assemblages of the burnt parts — compared to the unburnt control — there were over three times more beetles, out of which significantly more represented the macropterous life form and granivorous feeding strategy. There was a higher ratio of pioneer species and a simplified assemblage structure in the burnt area, which meant that the conservation value of the carabid assemblage became lower there. In contrast, for the spider assemblage quantitative changes in abundance and species numbers were not significant, and the differences in species composition did not lead to a decrease in conservation value. Spider species in the burnt plots could not be described as pioneer species, rather they had ecological characteristics that suited the changed vegetation structure. Comparing the two groups, to repopulate the burnt areas, dispersal abilities proved to be more limiting for carabids. However, in both groups a strong assemblage level adaptation could be observed to the postfire conditions. In spiders, species with a stratum preference for the grass layer prevailed, while in carabids individuals with granivore strategy gained dominance. Thus, despite the differences in their speed, basically both assemblages tracked vegetation changes. The effect of future fires will depend on their scale, as well as land-use practices, such as grazing, that interact with fire frequency and recovery. If extensive fires in the future permanently change the vegetation, then it would also lead to a fundamental change in the arthropod fauna.