23 research outputs found
The effects of stand characteristics on the understory vegetation in Quercus petraea and Q. cerris dominated forests
The shelterwood system used in Hungary has many effects on the composition and structure of the herb layer. The aim of our study was to identify the main variables that affect the occurence of herbs and seedlings in Turkey oak-sessile oak (Quercus cerris and Q. petraea) stands. The study was carried out in the BĂŒkk mountains, Hungary. 122 sampling plots were established in 50-150 year old oak forests, where we studied the species composition and structure of the understorey and overstorey. The occurence of herbs was affected by canopy closure, the heterogenity and patchiness of the stand, the slope and the east-west component of the aspect. The composition of saplings was significantly explained by the ratio of the two major oak species in the stand and the proximity of the adult plants. An important result for forest management was that sessile oaks were able to regenerate almost only where they were dominant in the overstorey
Evolution and environment of the eastern linear pottery culture: A case study in the site of PolgĂĄr-PiĂłcĂĄsi-DƱlĆ
A salvage excavation preceding a major investment project was conducted in 2006â2007, during which associated settlement features of a Middle Neolithic, Eastern Linear Pottery Culture (Alföld Linearbandkeramik â ALBK) were uncovered in an area called PiĂłcĂĄsi-dƱlĆ on the eastern outskirts of PolgĂĄr. The features of the ALBK settlement date from two periods. The cluster of multi-functional pits yielding a rich assortment of finds, the handful of post-holes and an unusual ritual well found in the southern part of the investigated area formed one unit from the earliest phase of the Middle Neolithic (ALBK I). The settlementâs other occupation can be assigned to the late phase of the Middle Neolithic (ALBK IV). Five houseplans representing the remains of timber-framed buildings outlined a distinct area with three multi-functional pits. Associated with the above features were 8 burials.
The preliminary archaeobotanical results from PolgĂĄrâPiĂłcĂĄsi-dƱlĆ are based on the plant material found within the sediments of 11 archaeological structures, which mainly represent pits and a welI. It can be stated that the natural environment offered habitats in which oak trees dominated in the local vegetation, forming floodplain forests and wooded steppes. They also provided food in the form of fruits and formed an optimal habitat for domestic animals. Arable fields were probably also established in the vicinity of the settlements, suggested by findings of macroscopic plant remains that represented cultivated species.
In both settlement phases lithic production activities are manifested both by the local on-site lithic production and â most importantly â by the presence of imported, mainly mesolocal, raw materials that point to contacts with deposit areas, or off-site preliminary working of obsidian and limnoquartzites. The kit of harvesting tools and a large number of grinding stones â especially in the younger phase â for the preparation of plant food suggest a major role of plant cultivation
Classification of mesic grasslands and their transitions of South Transdanubia (Hungary)
RelevĂ©s from meadows and pastures of South Transdanubia (Hungary) are evaluated by clustering and ordination methods. The relevĂ© selection focused on the Arrhenatheretalia order but its transitions towards other types were also included. The groups of relevĂ©s 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 LolioâCynosuretum, however, they show a stronger relationship with wet meadows. Within Arrhenatherion, PastinacoâArrhenatheretum is recognised as a hay meadow of nutrient-rich soils. The other meadow type is similar to FilipenduloâArrhenatheretum, 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
Naturalness-based habitat quality of the Hungarian (semi-)natural habitats
Effective conservation of (semi-)natural habitats needs knowledge on the naturalness, the actual quality of a habitat or vegetation patch. Nevertheless, there are only a few studies have been published in this topic so far. During the MĂTA project, between 2002â2005, we have surveyed the semi-natural vegetation of Hungary and assessed the naturalness of the predefined 86 habitat types. In this paper we present the country scale analysis on the naturalness of these habitat types. We compared the naturalness of the individual habitat types and also habitat groups, as well as the naturalness of the physical macroregions of Hungary. Euhydrophyte habitats and habitats deserving high abiotic stress are the most natural ones, while secondary shrublands, uncharacteristic forests and grasslands are the less natural. For the forest habitats we compared and discussed the naturalness values given by the MĂTA mappers and the values gained in the TERMERD (assessing forest naturalness in Hungary) project. In case of regions, Kisalföld has the lowest naturalness, and surprisingly the quality of the Alföld and the KözĂ©phegysĂ©g is nearly equal if we consider only the remained vegetation
Analytical calculation of interaction force between orthogonally magnetized permanent magnets
In an advanced micro-lithographic system, it is of critical importance that components are resiliently isolated from external vibrations. A passive/active electromagnetic device is a feasible solution to perform such vibration isolation. Within this device, passive permanent magnets provide the gravity compensation and active electromagnets accurate positioning. The focus of this article is on permanent magnet modeling, since a precise model is inevitable to achieve the high accuracy required for such application. This article describes a study on interaction force along three degrees of freedom (DoF) between permanent magnets having an unaligned magnetization direction for use in a permanent-magnet based suspension application. Feasibility of finite element modeling (FEM) and analytical modelling for such structures is discussed, implemented and verified with measurements