Babaee A, Vahabi M, Eshghizadeh H, Tarkesh M. Effects of changing the air carbon dioxide concentration, temperature and soil moisture on growth and some physiological parameters of two species, Agropyron trichophorum (Link) Richt and Bromus tomentellus Boiss. مرتع 2019; 13 (2) :139-151
URL:
http://rangelandsrm.ir/article-1-746-en.html
Department of Range and Watershed Mamnagement, Faculty of Natural Resources, Isfahan University of Technology, Isfahan
Abstract: (5811 Views)
In this study, the effects of three climatic variables including air temperature, air carbon dioxide concentration and soil moisture investigated on growth and some physiological parameters of two main rangeland species Bromus tomentellus Boiss pasture and Agropyron trichophorum (Link) Richt. For this purpose, a rootstock from each species collected, asexually reproduced in sufficient numbers and then the treatments of carbon dioxide concentration, temperature and soil moisture were applied at two levels and four replications. The results showed that elevated carbon dioxide concentration from 380 to 700 µmol mol-1, increased SPAD value (36.5%), chlorophyll a concentration (27.1%), chlorophyll b concentration (54.9%) and shoot dry weight (23.4%), but reduced stomatal conductance (33.1%). Increasing air temperature from 20±5 to 25±5 °C, reduced stomatal conductance, chlorophyll a concentration, chlorophyll b concentration and shoot dry weight by 13.5, 44.7, 44.2 and 23.5%, respectively. Insufficient rainfall caused to reduction of stomatal conductance (41%), SPAD value (32.9%), chlorophyll a concentration (56.7%), chlorophyll b concentration (54.8), carotenoid concentration (47.0%) and shoot dry weight (36.9%). In terms of studied traits, two rangeland species was significantly different, so that the means values of SPAD, chlorophyll a concentration, chlorophyll b concentration, carotenoid concentration and dry matter weight of A. trichophorum was higher than B. tomentellus. Therefore, based on forecast conditions in the A2 scenario for 2080s, the performance of A. trichophorum will be better due to positive response to increasing CO2 and ameliorating the negative effects of rising temperature and decreasing rainfall.
Type of Study:
Research |
Subject:
Special Received: 2019/07/9 | Accepted: 2019/07/9 | Published: 2019/07/9