UV-B Radiation Effects on the Alpine Plant <i>Kobresia humilis</i> in a Qinghai-Tibet Alpine Meadow

Abstract

Enhanced UV-B radiation resulting from stratospheric ozone depletion has been documented both globally and on the Qinghai-Tibet Plateau in China. The response of Kobresia humilis, an important alpine meadow plant species, to enhanced UV-B radiation was experimentally investigated at the Haibei Alpine Meadow Ecosystem Research Station (37°29′–37°45′ N, 101°12′–101°23′ E; alt. 3200 m). K. humilis was exposed to UV-B radiation including ambient UV-B and enhanced UV-B (simulating a 14% reduction in the ozone layer) in a randomized design with three replications of each treatment. Enhanced UV-B radiation resulted in a significant increase of both leaf area and fresh weight chlorophyll and carotenoid but had no effect on UV-B absorbing pigments. Similarly, enhanced UV-B radiation did not significantly change the photosynthetic O2 elevation rate while leaf thickness, width, and length significantly increased (p K. humilis have adapted to the strong solar UV-B radiation intensity presented on the Qinghai-Tibet Plateau, but the interspecies differences and their influence on trophic level should be more concerning.

Keywords

• <i>Kobresia humilis</i>
• leaf morphology
• ozone depletion
• photosynthesis
• Qinghai-Tibet Plateau
• UV-B radiation