Investigation of the bio-climatic needs of Thymus daenensis Celak: The case of Isfahan Province

Thyme is one of the most important medicinal plants in the world; some of its species are native to Iran. Given the necessity of thyme preservation and development, the vegetative climatic needs of this plant were addressed in this study. To this aim, 52 climatic parameters influential on the thyme growth were considered in 30 meteorological stations located in Isfahan province and the neighboring provinces. Factor analysis with varimax rotation was then conducted to determine the most important factors influencing the growth of thyme. Determination of the climatic zones of the thyme plant was done using hierarchical cluster analysis, leading to the identification of five climatic zones; according to effective climatic parameters, these included the cold and rainy zone, the semi-arid and cold zone, the dry and windy zone, the arid and cloudy zone, and the dry and hot zone. Cooling temperature factor, with a mean of 2.55, had the most positive effect, while the wind factor, with a mean score of -0.28, had the highest negative impact on the distribution of thymus species in the zones with this species. The precipitation factor, with a mean score of 0.8, had the second rank in the zone that could be suitable for the growth of thyme species. Overall, cooling temperature and precipitation could be regarded as the most important factors in determining the growth and distribution of this species; these factors could have a positive effect in rainy and cold zone and the semi-arid and cold one.