CLIMATE CHANGE CONSEQUENCES IN STEPPE - FOREST TRANSITION ZONE IN MORAVIA

摘要

There are climatic changes registered in the area of South Moravia. They can be documented by both climatic values and evaluation of phenological data. The elongation of the big vegetation period is especially important. It is particularly caused by its earlier beginning over the last 50 years period. At the same time vegetation summer would begin earlier and earlier. A growth in number of days (frequency) with effective temperatures over +5°C and over +15°C was revealed. A gradual increase in yearly totals of effective temperatures over +5°C is remarkable. The above facts represent a change in growth conditions of plants, especially forest trees. Direct relationship has been proved between the onset of phenophases and mean air temperatures. The increase in need of humidity for plants in steppe area of South Moravia in respect to elongation of assimilation period can be documented as well. The water regime of ecosystems has considerably changed after the hydraulic engineering adjustments and transformation from nival regime to evaporative regime. The future utility of the ecosystems is unthinkable without effective revitalization measures. The above stated facts indicate a change in growth conditions of plants, particularly long-term adapted forest trees.