Investigation on variation of soluble carbohydrates of some rangeland species in different phenological stages

Knowing the compounds that provide food reserves of plants is an important factor in range management. Perceiving how these compounds are produced and in which parts of plants are stored and what their concentration is helps determining the most suitable time for grazing, as well as the frequency and duration of grazing. The objective of this study was to examine to how factors such as being the member of a certain species, the phenological stage, plant parts and growth form affect soluble carbohydrates concentration. The six species studied were Bromus tomentellus and Dactylis glomerata as grass, Frula ovina and Coronila varia as forb, Salsola rigida and Artemisia aucheri as shrob. Samples were collected from two highland ranges in Vard Avard and Gachsar regions. The samples were dried, ground and finally analyzed according to standard phenol-sulfuric acid method. The results showed statistically significant differences in soluble carbohydrate concentrations among the species in three stages of their growth. The soluble carbohydrate concentration were measured in different life forms and various plant parts including root, collar root and above ground (P<0.01). According to the results, highest soluble carbohydrate obtained from Coronilla varia in seeding stage. Among three life forms, forbs produce highest soluble carbohydrates with the concentration highest in above-ground part as compared to root and collar root.