2007 г., Том 12, Спец. выпуск, с.178-193

The distribution ranges of Geranium robertianum L. and Acer negundo L. are climatically modelled using its archeophytic range and the monthly means of precipitation and temperature. In a first step, the frequency distribution of the ranges and buffer areas along the climatic gradients are calculated and presented in frequency diagrams. Sharp and gradual climatic range boundaries have been observed and their implications for climatic models of plant ranges are discussed. The buffer area proved to be valuable in assessing apparent climatic range boundaries where the range is not limited by environmental factors but by geography. In the climatic model of the range of G. robertianum there were considerable congruencies in its archeophytic and its neophytic parts. Climatic modelling of plant distribution ranges may thus contribute significantly to the understanding of the adventitious plants' spread. This modelling process has been applied to the range of A. negundo, a neophytic plant from North America, whose neophytic Eurasian range is only roughly known. The model revealed that the species has apparently almost filled its potential climatic range. Climatic suitability of areas is, however, only one factor that determines the potential of a plant for an adventitious behaviour.