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Abstract:In order to develop adequate adaptation measures for environmental vulnerability, we need detailed knowledge on the climatic performance of forest ecosystems. In this study, we aim to explore climate function variability of lowland beech forest distribution at a landscape scale. We also construct the response profiles of these forests near their xeric limit under wet continental climatic conditions. We studied distribution responses using presence-absence forest records and 18 bioclimatic variables. We performed exploratory factor analysis and frequency estimation to evaluate climate function distribution responses. We found that temperature adjusted precipitation measures during summer were the most important, followed by winter rainfall indices. The relative Drought Response Range (rDRR) in the response profile presented the climate limitation function of the distribution. According to our results, higher level of climate function variability is associated with lower level of rDRR, presenting an ecological trade-off. Our results suggest that distribution functions of the rDRR, especially the Ombrothermic index, can be used as landscape indicators of drought stress. Consequently, rDRR could be a useful measure to assess regional climatic vulnerability of forest occurrence and distribution patterns.

European hornbeam is a deciduous tree in mixed forest ecosystems, making a valuable contribution to species richness at a community level. We investigated early-phase regeneration of saplings in canopy gaps under contrasting ecological conditions by analyzing relationships between site parameters, leaf nutrients, and light-regulated carbon and water exchange functions at ecosystem and forest levels. Using plant response variables, we also detected functional soft traits and trade-offs. Species abundance proved to be affected by the elevation and slope of the sites, air humidity, precipitation during the growing period, as well as light-dependent and light-saturated rate of the assimilation function. Relationship between leaf potassium and transpiration proved to be the most effective plant functional trait across the sites. Under seasonally fluctuating, warm-dry and cold-semidry climate conditions with limited light availability, nutrient-gas exchange trade-offs modulated sapling development. Specifically during autumn, we detected extended leaf phenology in gas exchange functions under light-amplified warm and humid climate conditions. Our results suggest that natural regeneration of European hornbeam can be improved by lower and higher irradiation adjusted by plant functional traits, depending on site-specific and climate-related ecological parameters. These conclusions can provide a scientific basis for decision-making and practical implementations in forest management.

Functional response traits influence the ability of species to colonize and thrive in a habitat and to persist under environmental challenges. Functional traits can be used to evaluate environment-related processes and phenomena. They also help to interpret distribution patterns, especially under limiting ecological conditions. In this study, we investigate landscape-scale functional distribution responses of beech forests in a climatic transitional zone in Europe. We construct empirical density distribution responses for beech forests by applying coping-resilience-failure climatic traits based on 27 bioclimatic variables, resulting in prevalence-decay-exclusion distribution response patterns. We also perform multivariate exploratory cluster analysis to reveal significant sets of response patterns from the resilience and adaptation aspects. Temperature-related distribution responses presented a prevalence-dominated functional pattern, with Annual mean temperature indicating the most favorable adaptation function. Precipitation indices showed climate-limited response patterns with the dominance of extinction function. Considering regional site-specific climate change projections, these continental beech forests could regress moderately due to temperature increase in the near future. Our results also suggest that both summer and winter precipitation could play a pivotal role in successful resilience. Functions and variables that indicate climate sensitivity can serve as a useful starting point to develop adaptation measures for regional forest management.

Ecological indicator values, widely used in botany, are empirical scales worked out for the most important factors. Values of environmental factors determine the position of the vegetation units in a multidimensional abstract space. Their latest version in Hungary is the category system of Borhidi (1995), which is adjusted to the European systems (e.g. Ellenberg et al. 1992). Indicator values or categories, respectively, can be found, according to European practice, in a relational computerised database (Horváth et al. 1995) which is accepted as a standard for the botanists.An example of isoline analysis, completed using ecological indicator values of vegetation samples, is presented on a model area in Mecsek Mts of South Hungary. It has varied vegetation with diverse kinds of human interference near Pécs. From the existing indicator values we applied here temperature (TB), water demand (WB) of plants and soil reaction (RB). Each single isocurve was constructed from the similar indicator values on a computerised way (Surfer 6.1). All the curves were made by the use of averages, single values and certain groups of ecological indicator values. Only the figures made by the averages are presented here, because there is no additional information in the case of the use of single curves.Curves of temperature and water indicators (isoTB, isoWB) show climatic conditions changed by human impact. Curves of soil reaction (isoR) show in a given moment the actual vegetation, in time dimension that parts of environment which are more sensitive to acidification.Analysing isoecological curves, human impact is easily recognisable (e.g. in the surroundings of clear-cuttings, etc.). On the basis of our results added to a monitoring system environmental impacts of future industrial and forestry establishments can be modelled. Isolines, using above-mentioned indicator values help to reveal and quantify environmental change, which is model-valued possibility for preparing environmental impact studies and making quick decisions.

We studied water loss performance in a model plant, the Tufted sedge (Carex elata All.), which is an active water balance component of subsurface flow constructed wetlands. Due to active regulation of transpiration, the volume and dynamics of water loss in these constructed wetlands are difficult to plan without preliminary and targeted measurements and calculations with regard to the specific plant component. We estimated transpiration values in the laboratory based on daytime transpiration ranges for spring, summer and autumn, and examined the transpiration effect of the hydraulic load. During spring, water loss via transpiration can reach 83% of the hydraulic load on certain days. During summer, this value can increase to 100% of the hydraulic load, which means that the daytime transpiration can significantly affect effluent concentration. Air humidity proved to be the most critical environmental factor for water loss resulting from transpiration, therefore a water discharge plan designed in such a way as to be able to also adjust soil moisture is the key to optimal water circulation at the system level.

In this study occurrence, proportion and landscape pattern of woodlands are analysed in KülsőSomogy based on MÉTA method at landscape scale. Relative importance of woody habitat types represent more than the half of the total number of habitats listed for Hungary in this region. Semi-natural woodlands have the relative greatest area, among them riverine swamp and mesic woodlands are dominating (J+K+P habitat types) in the central and western part of the region. Dry woody habitat types are in subordinated position in the central-northern and south-eastern parts (L habitat types), shrubs are concomitants or substituents of semi-natural habitat patches (P habitat types). In landscape elements which are poor in woodlands uncharacteristic woody habitats and dry woodland fringes (R and M habitat types) are significant. Regional land and forest management ought to have preserve actual condition of woodlands in Külső-Somogy.

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