Exploring the Physiological Response of Bromus tomentellus to the Change in Climatic Components in Central Zagros

The effect of climatic changes including: temperature, CO2, and moisture content on photosynthetic characteristics and dry matter yield of rangeland species Bromus tomentellus Boiss – an important forage plant in the West of Isfahan province pastures – was explored in a factorial experiment with a completely randomized design. After collecting a mother plant of this species and asexual reproduction to required number, the climatic variables on each time step in the future (based on A2 climate change scenario) were applied as a treatment on pots except for one group which was taken as control. The photosynthetic pigments, including chlorophyll a and b, total chlorophyll, carotenoids, and aerial dry matter (as the criterion to determine the amount of plant yield in each pot) were measured in these groups. By recording these parameters and relating them to the climatic variables, the impact of climatic changes on them were explored. The results showed that the physiological response of species to the changes in the climatic parameters of temperature, CO2, and moisture content was different. A change in these three parameters (temperature, CO2, & moisture content) significantly decreased chlorophyll a, chlorophyll b, total chlorophyll, and carotenoids in the species under the study. Dry matter yield of single pot also decreased significantly (p