The Role of Individual Trees in the Protection of Urban Image

The protection of urban image and cityscape has become the target of professional attention in Hungary since the introduction of Urban Image Handbooks and urban image regulations. Trees are a major part of local image in Hungary. Using GIS methods we established that built-in areas are usually surrounded by sparsely wooded areas and groves, which are taller than the vast majority of buildings. Therefore, trees play a dominant role in shaping urban character. Effects of trees on urban living conditions, livability and the ecosystem services they provide, have been intensively researched in recent years. However, the role of individual trees in determining local image has been out of the focus of research. Although trees located on public property have been inventoried in past decades, information about their aesthetic properties and image value is scarce. In addition, there is an almost complete lack of knowledge regarding trees standing on private land, even though a large proportion of these are also visible from public areas, therefore having an impact on urban image. Tree protection regulations also fail to adequately address the topic. Identifying the individual trees with the most profound effect on the visual image of an urban area is a difficult task – not only due to of the lack of information, but also because there are no established methods for determining the aesthetic and image value of urban trees. At the Szent István University, Department of Landscape Protection and Reclamation, we attempted to develop a methodology to evaluate the importance of individual trees from the standpoint of urban image and streetscape, with District XXII of Budapest as the study area. Using a three-step method based on the analysis of aerial photographs and fieldwork, we identified the top 1% of all individual trees with the most dominant impact on the surrounding urban landscape – 706 out of an estimated 70.000. We inventoried and analyzed several aspects of these trees and their environment (e.g. soil, condition, health). The results show that there is no direct connection between the urban image value of trees and their ecological, dendrological or nature conservation importance. Our research suggests that trees with the most profound impact on the cityscape are different from those with the highest ecological value. This makes it clear that efficient protection of urban image requires a new approach towards tree evaluation as well

The perceptual value of individual trees as cityscape elements – a case study in Albertfalva, Budapest

Trees are both popular and underappreciated elements of the urban landscape. They are often in the focus of conservation efforts and movements against overdevelopment. On the other hand, they are often overlooked elements of the urban landscape, frequently seen as a nuisance or source of conflicts. Historically, urban trees were considered rare and therefore special elements of the urban landscape, but with the mass plantation of trees and tree lines in urban areas in recent decades, the connection of people to individual trees has diminished. In our research, we studied the role of individual trees in the urban image using a perception-based method. 73 volunteers were asked to visit a study area in Albertfalva, Budapest and choose the trees that they consider the most significant from an urban image standpoint. Afterwards, we analysed the results and mapped the individual trees that received the most votes in order to examine the characteristics that made them especially popular. Using multi-factor statistical analysis methods, we also studied whether the professional background of volunteers had a strong impact on their preferences in trees. The results show that certain trees are clearly objectively more important elements of the cityscape than others. Our analysis also confirms that their location and urban context are the stronger factors in their popularity than their taxon-based dendrological value. Furthermore, our results suggest that perception-based methods can be used for the selection of individual trees of special importance in a community- and participation-based way

Probing pattern and dynamics of disulfide bridges using synthesis and NMR of an ion channel blocker peptide toxin with multiple diselenide bonds

Anuroctoxin (AnTx), a 35-amino-acid scorpion toxin containing four disulfide bridges, is a high affinity blocker of the voltage-gated potassium channel Kv1.3, but also blocks Kv1.2. To improve potential therapeutic use of the toxin, we have designed a double substituted analog, [N17A/F32T]-AnTx, which showed comparable Kv1.3 affinity to the wild-type peptide, but also a 2500-fold increase in the selectivity for Kv1.3 over Kv1.2. In the present study we have achieved the chemical synthesis of a Sec-analog in which all cysteine (Cys) residues have been replaced by selenocysteine (Sec) forming four diselenide bonds. To the best of our knowledge this is the first time to replace, by chemical synthesis, all disulfide bonds with isosteric diselenides in a peptide/protein. Gratifyingly, the key pharmacological properties of the Sec-[N17A/F32T]-AnTx are retained since the peptide is functionally active. We also propose here a combined experimental and theoretical approach including NOE- and Se-77-based NMR supplemented by MD simulations for conformational and dynamic characterization of the Sec-[N17A/F32T]-AnTx. Using this combined approach allowed us to attain unequivocal assignment of all four diselenide bonds and supplemental MD simulations allowed characterization of the conformational dynamics around each disulfide/diselenide bridge

High levels of effective long-distance dispersal may blur ecotypic divergence in a rare terrestrial orchid

Background: Gene flow and adaptive divergence are key aspects of metapopulation dynamics and ecological speciation. Long-distance dispersal is hard to detect and few studies estimate dispersal in combination with adaptive divergence. The aim of this study was to investigate effective long-distance dispersal and adaptive divergence in the fen orchid (Liparis loeselii (L.) Rich.). We used amplified fragment length polymorphism (AFLP)-based assignment tests to quantify effective long-distance dispersal at two different regions in Northwest Europe. In addition, genomic divergence between fen orchid populations occupying two distinguishable habitats, wet dune slacks and alkaline fens, was investigated by a genome scan approach at different spatial scales (continental, landscape and regional) and based on 451 AFLP loci. Results: We expected that different habitats would contribute to strong divergence and restricted gene flow resulting in isolation-by-adaptation. Instead, we found remarkably high levels of effective long-distance seed dispersal and low levels of adaptive divergence. At least 15% of the assigned individuals likely originated from among-population dispersal events with dispersal distances up to 220 km. Six (1.3%) ‘outlier’ loci, potentially reflecting local adaptation to habitat-type, were identified with high statistical support. Of these, only one (0.22%) was a replicated outlier in multiple independent dune-fen population comparisons and thus possibly reflecting truly parallel divergence. Signals of adaptation in response to habitat type were most evident at the scale of individual populations. Conclusions: The findings of this study suggest that the homogenizing effect of effective long-distance seed dispersal may overwhelm divergent selection associated to habitat type in fen orchids in Northwest Europe

Classification of mesic grasslands and their transitions of South Transdanubia (Hungary)

Relevés from meadows and pastures of South Transdanubia (Hungary) are evaluated by clustering and ordination methods. The relevé selection focused on the Arrhenatheretalia order but its transitions towards other types were also included. The groups of relevés are delimited and described according to differential, dominant and constant species. Ecological conditions of the groups were compared using indicator values. Nine groups were distinguished, four of them belonging strictly to the order Arrhenatheretalia. Each alliance of Arrhenatheretalia presented in the study area (Cynosurion, Arrhenatherion) was represented by two groups. Groups from these two alliances are separated along a light gradient, while groups of the same alliance differ in nutrient values. Within Cynosurion, the nutrient-poor group cannot be identified unambiguously as any syntaxa previously known from Hungary. The nutrient-rich Cynosurion meadows are similar to Lolio–Cynosuretum, however, they show a stronger relationship with wet meadows. Within Arrhenatherion, Pastinaco–Arrhenatheretum is recognised as a hay meadow of nutrient-rich soils. The other meadow type is similar to Filipendulo–Arrhenatheretum, thus raising syntaxonomical problems. There are transitional groups towards semi-dry and wet meadows, one dynamic phase and one outlier group among the other five clusters

Patch and landscape factors affecting the naturalness-based quality of three model grassland habitats in Hungary

Effective conservation of (semi-)natural grasslands requires an understanding of the factors affecting naturalness (i.e. the actual quality of a habitat or vegetation patch) and the importance of the particular factors. Both local or patch and landscape or matrix variables affect habitat quality, and the proportions of the effects need to be identified. Therefore, we performed a hypothesis generating and testing analysis with generalised linear models on three typical grassland habitat types (forest steppe meadows, Artemisia alkali steppes, and lowland wet meadows), differing in their fragmentation, ecology and history, and representing characteristic types of grassland habitats with the use of the national database of the vegetation of Hungary (MÉTA). Our results, in general, show that naturalness depends upon both intra-habitat and matrix attributes: presence or proportion of other habitat types in the surrounding landscape, threatening factors and landscape ecological attributes. Higher number of habitat types and higher proportions of (semi-)natural habitats in the landscape have significant effects: presence of other grassland types similar in ecological demands to the model habitat positively affect the naturalness, while non-characteristic, secondary or disturbed habitats and invasive alien species have negative effects. However, there are clear differences among the three habitat types, indicating that for effective conservation, good knowledge of conserved habitat types is essential. Landscape or matrix factors, both compositional and structural, affecting habitat patch quality have significant effects that cannot be overlooked. In the case of fragmented grasslands, matrix factors might be even more important than patch or local factors

Changes in the diversity of the mycorrhizal fungi of orchids as a function of the water supply of the habitat

Studies were made on the symbiotic associations of orchids in four habitats with diverse water regimes in order to determine whether there was any difference in the diversity of the symbiotic fungi of orchids in the various habitats. The habitats were classed along an environmental gradient based on the water supplies as follows: 'floating': an extremely wet floating mat, 'wet': terrestrial fens, 'variable': wet habitats that dry out periodically, and 'dry': drier steppe areas in the vicinity of wet habitats. Nine photosynthesising orchid species were included in the study, some of which were habitat-specific (Liparis loeselii, Hammarbya paludosa), while others had a broader range of habitats and were found on several of the habitats examined (Orchis laxiflora ssp. pallustris, Dactylorhiza incarnata, Epipactis palustris). A total of 94 fungal strains were isolated from the orchid roots and seedlings and were identified using nrITS sequence analysis. Representatives of four widely occurring groups of orchid mycobionts were identified, but they were present in different ratios in each habitat. Opposing habitat preferences were observed for two groups of the anamorphic fungus genus Epulorhiza, which are frequent orchid symbionts. The first group (Epulorhiza 1), which includes the fungal partner of Liparis loeselii, was dominant in the floating habitats, where no members of the Epulorhiza 2 group were found, while the latter were more typical of drier habitats, where they were dominant. The Ceratobasidiaceae fungi, also isolated in considerable numbers, were more dominant in habitats with moderate water supplies, which were also home to representatives of the Sebacinaceae, though these were isolated in smaller numbers. The great variability in the composition of the symbiotic fungi of orchids in the different habitats suggests that efforts to preserve orchids require an accurate knowledge of orchid habitats, including data on potential fungal partners

The most recent results on orchid mycorrhizal fungi in Hungary

Symbionts and endophytes of Hungarian orchids were studied at diverse habitats. Mycobionts of roots and in situ germinated protocorms of 15 orchid species were identified by molecular methods. Four fungal groups could be distinguished from orchids living at diversely wet treeless habitats: Ceratobasidiaceae, Epulorhiza 1, Epulorhiza 2 and Sebacinaceae. While the groups Ceratobasidiaceae and Sebacinaceae were detected only at habitats with medium water supply, members of clade Epulorhiza occurred at all of the treeless study sites. These observations suggest that fungi belonging to the genus Epulorhiza are more tolerant of water-stress than the other investigated genera. An ascomycetous fungus from the family Pezizaceae could be identified from the roots of Orchis coriophora. Further Ascomycetes were identified at forest habitats. Tuber maculatum was detected from the roots of Epipactis helleborine and Cephalanthera damasonium, and Tuber excavatum from Epipactis microphylla