THE COMPARISON OF THE POTENTIAL EFFECT OF CLIMATE CHANGE ON THE SEGMENT GROWTH OF FRAXINUS ORNUS, PINUS NIGRA AND AILANTHUS ALTISSIMA ON SHALLOW, CALCAREOUS SOILS

Abstract

Growth patterns of different plant species are primarily determined by edaphic factors, climate conditions and their species-specific adaptation properties. Changing sub-regional aridity trends due to the projected climate change like soil erosion and the invasion of alien plant species threaten the ligneous vegetation of karst areas. We aimed to study and model the potential effect of aridity on the growth rate of young individuals of the native Fraxinus ornus and its two important two competitors, the exotic Pinus nigra and the aggressive invader Ailanthus altissima in a karstic forest-steppe of the Veszprem plateau, Hungary on different soil depths. Mean soil depth and the Thornthwaite agrometeorological index were used as covariates. Climate data were gained from the E-OBS gridded dataset for the period of 1950 to 2013 and from the MPI Echam5 climate model for the period of 2081 to 2100. We found significant correlation between the soil depth values and the measured heights and the average of monthly Thornthwaite agrometeorological indices. In conclusion, aridity and soil-depth have significant, but different effect on the growth patterns of the studied species. While the annual growth season of Pinus nigra and Fraxinus ornus are determined by the aridity of the months of January to May, and from February to June, respectively, the growth of Ailanthus altissima is mainly determined by the period of March to August. The climate prediction-based growth model predicts the decline of the growth patterns of each species for the 2081-2100 period in Hungary due to climate change.