Abstract
The purpose of the present study is to determine bioclimatic zones in Isfahan province using multivariate statistical method. Thirtyβnine climatic variables, which were more important in plant ecological conditions (especially Artemisia sieberi and Artemisia aucheri that include more than half of rangeland surface in Isfahan province), were selected and investigated with factor analysis. Results of factor analysis showed the first three factors that explain 92.3% of total variance in selected variables were precipitation, temperature and radiation and wind with 41.91, 40.18 and 10.23% of variance, respectively. According to results and using hierarchical cluster analysis in Ward's method, bioclimatic classification in Isfahan province was performed and seven bioclimatic zones were found. In addition, to compare the results of this study with the other climatic classification methods, Isfahan province was classified by four traditional climatic classification methods (Koppen, Gaussen, Emberger and De Martonne) and its results were compared to climatic classification by multivariate statistical method. It showed that multivariate statistical method gives better classification in comparison with other methods. Beside that precipitation is the most important factor in vegetation distribution of humid and cold and subβhumid and cold regions in west and south parts of Isfahan province. In addition, temperature is the most important factor in vegetation distribution of hyper warmβarid and warmβarid climatic regions in eastern low elevation parts of province. Furthermore, dominant species were determined for each climatic region. Copyright Β© 2008 Royal Meteorological Society