Authors:D. Cserhalmi, J. Nagy, D. Neidert and D. Kristóf
The study area is the peaty bed of Nyíres-tó mire which is situated in the northeastern Alföld on the Bereg Plain. For this paper we used a digital photo interpretation method with which we reconstructed the former vegetation from black and white aerial photos, and made chronosequence of vegetation maps. The image segmentation method dissolves the photo into different objects (segments) by spectral and textural parameters. The segments consist of similar pixels, representing a unique ground object. We made the segmentation with the Definiens Inc. eCognition software. The stability of the mire was calculated with GRID-files. The historical vegetation maps show, that after many arid years, the tree or shrub dominant associations increased until the eighties. Later, the sufficient precipitation and the artificial flooding stabilised the tree covering. The analysis of GRID-files shown, that 45.77% of the pixels get code 1 (stable), 44.32% get code 2 (slightly changeable) and only 9.91% get code 3 (changeable). It means that almost half of the mire’s vegetation is the same as in 1952.
Authors:F. Samu, C. Szabóky, A. Horváth, D. Neidert and M. Tóth
Semi-natural grassland islands have a key role in slowing down biodiversity decline in intensively cultivated agricultural landscapes. Assemblages in such habitat patches are not only limited by local habitat quality, but are also influenced by the suitability and distribution of different habitat types in the surrounding landscape. If we want to preserve a functionally diverse Lepidoptera fauna, both local and landscape scale environmental effects, including land use and management, should be considered. In the present study, we describe trait-based characteristics of noctuid dominated macro-moth assemblages (MMAs) in grassland remnants of an intensively cultivated agricultural area. By gathering environmental data from local to landscape scales, we aimed to identify the most influential scales, possible interactions between scales and the role of integrated arable fields in shaping MMAs. We conducted abundance weighted trait-based multivariate analysis of the assemblages based on six trait groups. Both local and landscape scale variables had important influence, acting on different traits of the assemblages. By variance partitioning, we could identify variables that exerted maximal effect at 50 m and 250 m radii circles. Variables describing local vegetation and identity of neighbouring crop were responsible for species richness and rarity status, while the area of arable and wooded habitats within 250 m were responsible for total catch and pest status related traits. There was significant interaction between principal components axes representing local and landscape variables. Rarity, more than other traits, was influenced by the interaction. Integrated fields had no effect on MMAs. The present study highlights the contributions of both local and landscape scales to the shaping of MMAs and suggests that the preservation of both local habitat quality and landscape heterogeneity are important if we would like to maintain species rich and functionally diverse Lepidoptera fauna.
Authors:F. Kozár, F. Samu, É. Szita, Z. Konczné Benedicty, B. Kiss, E. Botos, K. Fetykó, D. Neidert and A. Horváth
Sixty three scale insect species are reported from the Mezőföld area (Hungary), a mosaic area of predominantly intensive agricultural land and scattered grassland and forested areas. In comparison, from the Kőrös-Maros National Park, dominated by natural grassland areas, only 31 species were reported. From the Mezőföld data 4 species were new for the Hungarian fauna and almost all species from Mezőföld were new for the given locality. The Mezőföld fauna could be characterised by more rare species and a lower Global Frequency Value (=higher level of species rarity), suggesting a higher overall conservation value. Scale insect species numbers show a strong negative correlation with the ratio of woody plantations. There was an overwhelming presence of a steppic scale insect species in grassland assemblages, and impoverished woody fauna of the studied wooded areas. However, there was no correlation with plant species number, with the area of natural vegetation, or with the area of loess steppe patches, which shows that the original loess step fauna is impoverished, heavily disturbed. In summary we can say, that the Mezőföld loess scale insect fauna is relatively poor, could be characterised by widely distributed, mezophilous, common species. However, it also has several important steppic elements, and therefore deserves protection.
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.