Abstract: Climate change is a global problem. During the last century the increase of annual average temperature was 0.68°C, while the decrease of annual average of precipitation was 83 mm in Hungary. According to the long term meteorological data of Sikfőkut forest ILTER site the annual average temperature increased while average of yearly precipitation decreased, the forest climate became warmer and dryer. These processes could considerably contribute to forest decline, not only in the Quercetum petraeae-cerris stand of Sikfőkut, but everywhere in the country. Species composition and structure of the forest have changed considerably, as 68% of sessile oak (Quercus petraea) and 16% of Turkey oak (Quercus cerris) have died. Forest decline resulted in the breaking up of the formerly closed canopy, and consequently, in the formation of gaps in the forest. In the gaps, a secondary canopy developed with tree species of less forestry value. As a consequence, mass regeneration of field maple (Acer campestre) appeard in the gaps. The formation of gaps accelerated the warming and aridity of forests. In the article we answer the following question: how did climatic change and changing forest structure influence the leaf-litter production in the last four decades? oak forest / oak decline / Sikfokut Project / litter production / climate change

Abstract: Aims In eroded lands of the French Southern Alps, burial of early established seedlings under marly sediment weakens the effect of vegetation on soil stabilization and sediment trapping. Therefore, this protective role is largely dependent on species’ resistance to burial, and the understanding of species’ tolerance to this environmental disturbance is highly valuable for basic knowledge on plant succession and for ecological restoration purposes. Methods The response of five woody species with contrasting ecological requirements and natural habitats—three tree species, Pinus nigra, Robinia pseudoacacia and Acer campestre, and two shrubs, Ononis fruticosa and Hippophae rhamnoides—to experimental burial under marly sediment was studied. Seedlings were exposed to three burial levels: no burial (control), partial burial (50% of seedling height) and complete burial (100% of seedling height). Burial tolerance was evaluated based on seedling survival, height and biomass. Biomass allocation to shoots and roots and soluble sugar and starch contents in roots and stems were measured to identify plant traits that determine species response to burial. Important Findings All species survived partial burial but only A. campestre seedlings emerged from complete burial. Tree species were more tolerant to burial and buried plants showed no significant differences with control. The two shrubs were found less tolerant and buried plants showed slower growth than controls. The results showed that species response was not related to initial soluble and starch content in roots and stems, but instead to biomass allocation pattern flexibility.

Abstract: We evaluated photosynthetic reactions in Acer campestre L. in a multi-factorial field experiment near Hodonin, Southern Moravia, Czech Republic. In this experiment, selected plots were amended with three different supplementary soil substances, that is, zeolite, lignite, and hydroabsorbent Agrisorb , and were compared with unamended control plots. Microclimatic parameters, that is, temperature, relative humidity, soil moisture, and solar radiation were measured. In the spring of 2008, supplementary soil substances were applied, and in the autumn of the same year, experimental A. campestre L. plants were harvested. The basic physiological parameters, chlorophyll content and fluorescence, stomatal conductance, and sap flow were determined in the experimental plants. Determination of the above-mentioned parameters showed higher vitality of plants cultivated on plots supplemented by lignite, followed by zeolite. In comparison with the control plants, the application of lignite led to increase of average chlorophyll content and fluorescence by 37 and 20%, respectively, stomatal conductance by 29%, and sap flow by 44% in plants. In comparison with the control plants, the application of zeolite resulted in the enhancement of average chlorophyll content and fluorescence by 14 and 15%, respectively, stomatal conductance by 16%, and sap flow by 36% in plants. The monitored parameters of plants cultivated on plots supplemented with hydroabsorbent Agrisorb were similar to those measured in control plants. In addition, the results obtained are related to actual weather. Correlations between type of the applied supplementary soil substances, soil moisture, and physiological parameters were found. Data of short-time measurement of photosynthesis response correspond with data of long-time measurement of morphological characteristics. The highest height increments were determined in experimental group cultivated under lignite application, followed by zeolite. Statistically insignificant plant height increases were observed in plants cultivated on the soil supplemented with hydroabsorbent Agrisorb . Key words: Abiotic stress, soil conditions, microclimatic data, photosynthetic reactions, morphological characteristic, environmental sensors.