Vegetation history, recent dynamics and future prospects of a Hungarian sandy forest-steppe reserve: forest-grassland relations, tree species composition and size-class distribution

Pannonian forest-steppes host a high number of endemic species and contribute to landscape-scale heterogeneity. Alterations in the proportion of forests and grasslands due to changes in land-use practice and climatic parameters can have serious nature conservation consequences. Hypotheses about forest-steppe dynamics have rarely been verified by detailed analyses, especially for the sandy forest-steppes. We integrated historical analysis, aerial photo interpretation and field investigation to determine how vegetation of a sandy forest-steppe has changed, how current dynamical processes operate and how native and exotic tree species regenerate under present conditions. The vegetation of the study area before the onset of major anthropogenic environmental transformations in the Carpathian Basin may have been a mosaic of forested and unforested patches. However, there is strong evidence that after heavy deforestation, the region was almost completely treeless between the 15th and the 19th centuries. Forest cover was able to recover by the 1800s but the lack of forested areas in the region for centuries explains why forest patches are still poor in species. Grasslands, which existed continuously, are more diverse, supporting several rare and endemic species. From 1953 till 2013, 72.45% of the area proved to be stable, but 27.55% showed clear dynamical character, changing either from forest to grassland, or vice versa. Thus, cyclic dynamics can occur in sandy forest-steppes. We found that forest patches of different size, differently exposed edges and grasslands provide different habitats for the tree species. Exotic species were present in large numbers, probably due to the small size of the reserve and the lack of a buffer zone

Ecological conditions, flora and vegetation of a large doline in the Mecsek Mountains (South Hungary)

Vegetation-environment relationships were investigated in a large doline of the Mecsek Mts (South Hungary). To reveal the vegetation pattern, we collected vegetation data and environmental variables along a 243 m long transect. Atotal of 144 vascular plant species and 4 vegetation types were identified in the doline.We found that both the species composition and the vegetation pattern are significantly influenced by air temperature, air humidity, soil moisture and altitude. Our results confirm the putative temperature and vegetation inversion in the doline

Euphorbia prostrata (Euphorbiaceae), a new alien in the Carpathian Basin

During the study of the urban flora of the city of Szeged (southern Hungary) in 2011, about 100 specimens of Euphorbia prostrata Aiton, a new alien for the Hungarian flora, were found in a city park. Characterisation of the locality is provided. This record, being the one and only in the Carpathian Basin so far, confirms former observations that this meridional-subtropical species is in expansion in many parts of the world, including proper habitats of the temperate regions. A key for all species of the genus Euphorbia subgenus Chamaesyce for the region is given

Mineral content analysis of unifloral honeys from the Hungarian Great Plain

Honey is a key product of the traditional agriculture in Hungary and an important export commodity of the Hungarian commerce. The content of metals in honeys is essential for food quality and safety, in addition to which it provides elemental fingerprints about the region where the honey was collected. The aim of this study was to determine and compare the element content of black locust, oilseed rape and sunflower honey samples collected from the southern part of the Hungarian Great Plain. The major (K and Mg), trace (Fe, Zn, Cu, Mn, B, Al, Co, Ni, Se and Mo) and toxic elements (As, Pb and Cd) of the samples were determined by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). Principal Component Analysis (PCA) was performed to compare the mineral content of the different honey types. Our analyses revealed that K was the most abundant element in the investigated honey samples. Among the trace elements, B, Fe, Zn and Cu were found in the highest concentrations. Sunflower honey contained the highest concentrations of K, Mg and Mn, while oilseed rape honey showed the highest B content. The mineral content of honeys decreased in order of sunflower, oilsed rape and black locust. There were no differences among the honey types in the toxic element content (As, Pb and Cd), which was under the detection limit in many honey samples. According to the multivariate method, the Mg, B, Al, K and Zn contents are considered to be the most important indicator for distinguishing the investigated honey samples and types. The results obtained from the mineral content analyses showed that differences in major, trace and toxic elements between Hungarian unifloral honeys as well as a detailed comparison of honeys with different geographic origins can be used for quality assessment

Species composition and diversity of natural forest edges: edge responses and local edge species

Habitat boundaries in general and forest edges in particular belong to the central issues in ecology. Theories about community and environmental edge-responses are diverse, but there is a lack of sufficient supporting field evidence: no consensus exists about distinctness and diversity of edges, and the existence of edge-related species. Moreover, as most studies focus on man-made edges, natural forest edges are less understood. We studied xeric forest edges in a wooded-steppe area. Twelve forest patches were selected, and plots were set up within the edges, the forest interiors and the grasslands. Species composition, species richness and Shannon diversity were compared between the three habitat types as well as between differently oriented edges. We identified diagnostic species for all habitats. Local habitat preferences of the edge-related species were compared to their regional preferences. Environmental factors of the different habitats were assessed by using ecological indicator values. Forest edges differed both from forest interiors and grasslands, forming a narrow but distinct habitat type between them. Species composition of the edges was not simply a mixture of forest and grassland species, but there were several edge-related species, most of which are regionally regarded as typical of closed steppe grasslands. Neither shady conditions of the forests, nor dry conditions of the grasslands are tolerated by these species; this is why they are confined to edges. Species richness and Shannon-diversity were higher within edges than in either of the habitat interiors. Ecological indicator values suggested that light intensity and temperature were higher in the edges than in the forests, but were lower than in the grasslands. In contrast, soil moisture was lower in the edges than in the forests but was higher than in the grasslands. There were slight differences between differently exposed edges concerning species composition, species richness and Shannon diversity. We conclude that edges should be considered an integral part of wooded-steppes. Their high diversity may have nature conservation implications. Our study emphasizes that edge species may be confined to edges only locally, but may have a broader distributional range in other areas. These species may be referred to as local edge species. Our results also point out that the very same edge can be interactive and non-interactive at the same time, depending on the characteristics considered

Shrub Encroachment Under the Trees Diversifies the Herb Layer in a Romanian Silvopastoral System

Rangelands with scattered trees are complex and dynamic systems with a long history in Europe. Generally referred to as “wood-pastures,” they are considered to have outstanding conservation value. Thorny shrubs are important for supporting the biodiversity of these wooded rangelands, as well as facilitating the regeneration of trees by acting as nurse species. We assess the direct effects of temporary shrub encroachment under the cover of mature sparse trees on overall plant and habitat diversity. We surveyed the herb layer of the main landscape features of a wood-pasture: open pasture, trees with a grass understory, trees with shrubs, and adjacent forest edges. The herb layer under trees with shrubs resembled that of forest edges more than open pastures and trees with grass. Trees with grass had a higher cover of ruderal species than trees with shrubs, while forest edges and open pastures had a lower cover of them. Forest species were absent from open pastures but were well represented in the other sites. The herb layer of trees with shrubs and forest edges had similar cover values, while trees with grass had a significantly lower cover of herbs than the other types. Trees with shrubs had higher species richness than any of the other three landscape features and had a much higher proportion of diagnostic species. We conclude that the scattered trees and shrubs of the studied silvopastoral system have additive facilitative effects on their understory, probably through modifying the microenvironment and grazing pressure, leading to the formation of temporary diversity hot spots with distinct vegetation. Thus maintaining a moderate level of shrub-encroachment under sparse trees is recommended for not only creating safe havens for tree recruitment but also increasing the overall species and habitat diversity of wood-pastures.The Rangeland Ecology & Management archives are made available by the Society for Range Management and the University of Arizona Libraries. Contact [email protected] for further information