BIOCLIMATIC CLASSIFICATION OF CENTRAL IRAN USING MULTIVARIATE STATISTICAL METHODS

Effective management and proper exploitation of each ecosystem requires a comprehensive understanding of its components. Climate can exert direct and indirect effects on all components of ecosystems. While most systems of bioclimatic classification depend on limited variables such as precipitation, temperature, and their combinations, describing the climate of a region requires the evaluation of more factors. The present study was an attempt toward the bioclimatic classification of central areas of Iran (including Isfahan, Yazd, and Kerman Provinces). Using multivariate statistical methods, 156 climatic variables, which affected the distribution of dominant plant species in the study area, were selected. After performing principal component analysis to identify the main factors, cluster analysis was conducted to determine the bioclimatic classes and their characteristics. Overall, seven climatic factors (i.e. temperature, warm season precipitation and relative humidity, spring and cold season precipitation, wind speed, cloudy and partly cloudy days, Radiation, and dust) were found to explain 91.01% of the total variance in primary variables. Cluster analysis Ward's method divided the study area into 13 bioclimatic zones. The comparison of the obtained results with the results of four common methods of climate classification (Koppen's, Gaussen's, Emberger's, and de Martonne's methods) suggested the higher ability of multivariate statistical methods to discriminate between bioclimatic zones. The dominant species in each zone were finally described.