Investigating the effect of altitude and climate on the changes of secondary metabolites of medicinal plants of Thymus and Artemisia

Secondary metabolites are substances that exist in some plants and in a certain vegetative stage of growth. Alkaloids (Morphine, Codeine, Atropine), Terpenoids, Flavonoids, Pigments and Tannins are among the most important of these compounds. The process of changes of these effective substances in two medicinal plants Artemisia and Thymus at three altitude levels H1 (700 to 800), H2 (1300 to 1200) and H3 (1700 to 1800) meters above sea level and three regions Climatic, arid, semi-arid and semi-humid conditions were studied by completely randomized block design with three replications. R software used fo statistical analysis, in addition to examining the changes of effective substances in these two medicinal plants, we achieved a new index for evaluating the severity and using it for drought zoning. The results of this research can be used in the exploitation of pasture medicinal plants. The introduced index shows that with the increase of drought severity, the amount of secondary metabolites increases significantly in different species and in different vegetative stages. This index can be used for ecology and climatology studies.