Vol. 116, No. 3 * Pages 173–236 * July - September 2012

Projection for future climate conditions is an increasingly popular application of distribution modeling. However, good performance of a model under current climate does not guarantee similar performance under future climate, particularly where prediction is outside the range of environmental conditions on which the original model was set up. The objective of this study was to model the habitat suitability for beech forests during three terms (2025, 2050, and 2100) in the 21st century in Hungary using species distribution models (SDMs).
Six out of the eight methods were unsuited for predicting climate change effects on the future distribution of beech. This underlines that predictions for conservation and management issues should be based on multimodel assessments. Spatial inconsistency appeared mainly in regions, where beech is situated close to its distributional range limit (xeric limit). This suggests that the basic theoretical assumption of species distribution models may not hold at the trailing edge.

This paper intends to give a brief overview on the different approaches existing in plant phenological studies. The history of plant phenological observations in Europe and Hungary shows that the aim of the observations turned from the pure scientific interest to the application in agricultural practice, and recently, to climatic studies. Modeling of phenological development is demonstrated via examples for wheat and maize. The analysis of historical data has got new horizons by the international efforts done by COST Actions. New perspectives in observations of vegetation are remote sensing data. Vegetation indices like normalized difference vegetation index (NDVI) and enhanced vegetation index (EVI) are also used for tracking the seasonal development of plants, and they give opportunity to analyze the year by year change.

Yield samples of winter wheat Triticum aestivum L. and maize Zea mays L. taken from consecutive series of crop years at the Nagygombos experimental field of the Szent István University have been evaluated. Impact of precipitation on yield quantity and quality was studied. In case of wheat protein, wet gluten, farinographic value, and Hagberg sedimentation, while in case of maize, protein, starch, oil, and fibre content were examined.
Yield performance of wheat and maize varieties has been highly variable regarding crop years. Wheat was less affected by precipitation in general, however, extremely high precipitation as well as drought caused yield depression. Water demand of yield formation was in accordance with that of C3 – C4 physiological patterns. Yield quality was highly influenced by different crop years. In case of wheat, wet gluten content proved to be a most stable characteristic. Protein, farinographic values, and Hagberg sedimentation figures were more variable in relation with the precipitation of crop years. Yield quantity of maize crop proved to be more variable than quality parameters. Protein values were smaller, and starch values higher in rainy years. Other parameters, like oil and fibre have shown no consequent changes that could be related to the amount of annual precipitation.

Impact of atmospheric black carbon (BC) on albedo, evapotranspiration, and growing characters of field grown maize was investigated at Keszthely, Hungary, over the 2010–2011 growing seasons. Chemically “pure” black carbon was used in weekly pollution (3 g m^–2). Low doses simulated the effect of particulates derived from vehicle exhaust and abrasion of tyres. Albedo of crop stand (0.3 ha/treatment) was measured with CMA-11-type pyranometers every 6 seconds. Maize grown in Thornthwaite-type compensation evapotranspirometers was included in the study. Dry matter yield of maize cob was determined in the end of the growing season.
Surprisingly, BC did not influence significantly the phenological phases and length of the crop year. Due to wet weather in 2010, seasonal water loss of BC treated maize increased only with 4%. Amount of seasonal total evapotranspiration of polluted crops was about threefold higher in dry 2011. The mean albedo of polluted canopy declined in both seasons. The surplus energy retention of BC polluted crops increased the canopy surface temperature of about 0.5–1.5 °C in midday hours, independently of the studied year. Significant yield loss in BC polluted maize stands was observed only in rainfed canopy. The production loss of dusted maize amounted 8.7% and 19.8%, in 2010 and 2011, respectively. Extra water of evapotranspirometers prevented yield drop-out of soot polluted plants. In arid years, BC had more severe impacts on maize characteristics and yield.