UV-B Radiation Effects on the Alpine Plant Kobresia humilis 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 < 0.01). The enhanced UV-B radiation was associated with 2–3 days earlier flowering and a larger number of flowers per spikelet. The enhanced UV-B generally resulted in larger leaves and more flowers but earlier phenology. In summary, these findings suggest that alpine species of 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.

UV-B Radiation in the Acclimatization Mechanism of Psidium guajava in Sunlight

“…The prevention of chlorophyll degradation may be related to the lower anthocyanin accumulation in plants subjected to UV-B, suggesting that the latter pigment may have assisted the antioxidant system due to reactive oxygen species neutralization, excess light filtration, or reflection. These results are in agreement with Shi et al [59].…”

Mapping and evaluating plant phenology in the Qinghai-Tibet Plateau: A digital approach using the plant Phenological Index (PI)

“…For example, the total PI for Alpine Shrub in the growing season is 131.23, and the total LD is 231.3; the total PI for Alpine Meadow in the growing season is 137.41, and the total LD is 238.16 from Table 3. The calibrated annual growing days for Alpine Shrub in the study area is 153.5 ± 14.8 [7,21] and 164.16 ± 10.22 for Alpine Meadow [13,30]. Moreover, to study phenology at a regional scale, it is highly recommended to use the Seasonal Phenological Index (SPI), which considers seasonal and interannual variations.…”

“…Therefore, modeling, assessing, and monitoring phenological dynamics are fundamental to understanding how plants and communities respond to the changing climate and how these changes in uence the ecosystems and their functions [7,12,13,14]. An initial phenology study at Alpine Meadow was conducted in 1983 and 1984 [21]. Twentyone plant species were observed to study the relationship between plant biomass and phenological stages.…”

“…Twentyone plant species were observed to study the relationship between plant biomass and phenological stages. However, the phenological two-dimension diagram raised a question [21,22] about obtaining the Digital mapping result, Phenological Index [7].…”

Molecular Mechanism of Exogenous ABA to Enhance UV-B Resistance in Rhododendron chrysanthum Pall. by Modulating Flavonoid Accumulation

“…It has been demonstrated that UV-B stress causes Kobresia humilis (C. A. Mey ex Trauvt.) Sergievskaya leaves to thicken while also causing their epidermal cells to shrink and lose water [4]. Enhanced UV-B radiation can cause crop plant growth to be stunted and dwarfed, with one study showing that winter wheat plants exposed to UV-B radiation were dwarfed by 31.3 per cent compared to a control group not exposed to UV-B radiation [5].…”