Effects of simulated warming on the growth, leaf phenology, and leaf traits of Salix eriostachya in sub-alpine timberline ecotone of Western Sichuan, China.
Abstract:By using open-top chamber (OTC), the effects of simulated warming on the growth , leaf phenology, and leaf traits of Salix eriostachya in sub-alpine timber line ecotone of Western Sichuan were studied. The results showed that comparing with the control, the mean air temperature at 12 m above the ground through out S. eriostachya growth season in OTC increased by 29 ℃, while the soil temperature at the depth of 5 cm only increased by 04 ℃. The temperature inc rease in OTC made S. eriostachya budding advanced and defoliation postpon ed obviously, and the leaf life-span longer. The leaf and branch growth rates a s well as the specific leaf area in OTC increased obviously, whereas the leaf ni trogen concentration decreased significantly. In OTC, the stomata conductance, n et photosynthetic rate, photorespiration, and dark respiration rate of S. erio stachya all exhibited an increasing trend. It was suggested that S. eriostac hya had stronger capability to adapt to warming, and, under the background of future global climate change, the elevation of S. eriostachya distribution i n the timberline ecotone would be likely to ascend.