Asymmetric Impacts of Diurnal Warming on Vegetation Carbon Sequestration of Marshes in the Qinghai Tibet Plateau

• Published in: Global biogeochemical cycles 2022-07, Vol.36 (7), p.n/a
• Main Authors: Shen, Xiangjin, Liu, Yiwen, Zhang, Jiaqi, Wang, Yanji, Ma, Rong, Liu, Binhui, Lu, Xianguo, Jiang, Ming
• Format: Article
• Language: English
• Subjects: Annual; Annual temperatures; Asymmetry; Biogeochemical cycle; Biogeochemical cycles; Carbon cycle; Carbon sequestration; Climate change; Climatic data; Daytime; Diurnal; Ecosystems; Marshes; Maximum temperatures; Minimum temperatures; MODIS; Net Primary Productivity; Night; Night-time; Nighttime; Plateaus; Precipitation; Primary production; Productivity; Spring; Spring (season); Spring precipitation; Summer; Temperature; Temperature changes; Temperature effects; Vegetation; Vegetation growth; Winter
• ISSN: 0886-6236; 1944-9224
• DOI: 10.1029/2022GB007396

As the world's Third Pole, the Qinghai‐Tibet Plateau has a large area of marshes, which plays an important role in global carbon cycle. The net primary productivity (NPP) of vegetation is a crucial index for measuring the carbon flux of marsh ecosystems. Understanding the change in marsh NPP and its response to climatic change is important for assessing carbon sequestration of marsh ecosystems. Based on MODIS NPP data and climate data from 2000 to 2020, this study analyzed the spatiotemporal change in marsh NPP and determined its relationship with climate factors on the Qinghai‐Tibet Plateau. The results showed that the average annual NPP of marshes on the Qinghai‐Tibet Plateau increased significantly by 11.70 ± 1.07 g C·m−2/10a during 2000–2020, with an average value of about 184.37 ± 11.12 g C·m−2. Spatially, the annual marsh NPP showed obviously increasing trend in the northeast but decreasing trend in the southwest regions. Daytime maximum and nighttime minimum temperatures had asymmetric effects on marsh NPP, with a larger positive effect of minimum temperature. Warmed minimum temperatures in winter and spring significantly increased the annual marsh NPP on the Qinghai‐Tibet Plateau. The increasing maximum and minimum temperatures in the summer obviously promoted the vegetation growth in marshes. Additionally, the increasing spring precipitation could significantly increase the marsh NPP. Our results highlight that the asymmetric impacts of daytime and nighttime temperatures on marsh vegetation should be adequately considered in predicting marsh carbon sequestration on the Qinghai‐Tibet Plateau, especially in the context of global asymmetric diurnal warming. Plain Language Summary As the highest plateau in the world, the Qinghai‐Tibet Plateau has large areas of marshes, which has important effects on the biogeochemical cycle and carbon balance. The net primary productivity (NPP) of marsh vegetation is a crucial index for measuring the carbon sequestration of marsh ecosystems. Until recently, the vegetation NPP changes of marsh and its response to climate change in the Qinghai‐Tibet Plateau remain unclear. Using the NPP and climate data, this study analyzed the spatiotemporal variation in marsh NPP and its response to climate change in marshes of the Qinghai‐Tibet Plateau. This study analyzed, for the first time, the influences of daytime and nighttime temperature changes on vegetation NPP of marshes. Results show that the effects of day and night temp