Fu Gang, Sun Wei
Lhasa Plateau Ecosystem Research Station, Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China.
Sci Total Environ. 2022 Oct 15;843:157002. doi: 10.1016/j.scitotenv.2022.157002. Epub 2022 Jun 27.
Incessant argument on whether temperature sensitivity of aboveground biomass is primarily linked with temperature itself (local air temperature and increased magnitudes in air temperature) or other environmental variables restrains our capability to exactly forecast upcoming alterations in grass yield and high-quality development of animal husbandry in high-cold areas. Consequently, since May 2010, a field warming trial with open-top containers was achieved in high-cold grasslands at three elevations (i.e. 4313, 4513 and 4693 m) of the Tibet. The temperature sensitivities of normalized different vegetation indices (Q1_NDVI), soil adjusted vegetation indices (Q1_SAVI) and aboveground biomass (Q1_AGB) were detected in 2014-2015 and 2017-2018. Temperature itself had the greatest exclusive impacts on the Q1_NDVI, Q1_SAVI and Q1_AGB. Vegetation indices itself or aboveground biomass itself had the second greatest exclusive impacts on the Q1_NDVI, Q1_SAVI or Q1_AGB. The exclusive impact of vegetation indices itself or aboveground biomass itself was less than one-tenth that of temperature itself. Water availability and elevation & duration (elevation and warming length) only had exclusive impacts on the Q1_NDVI and Q1_SAVI. The total exclusive impact of water availability and elevation & duration on the Q1_NDVI or Q1_SAVI was around 11-12 % equivalent to that of temperature itself. Vegetation indices/aboveground biomass itself, water availability and elevation & duration had interactive impacts with temperature itself on the Q1_NDVI, Q1_SAVI or Q1_AGB. Compared to local air temperature, increased magnitudes in air temperature had the greater exclusive effects on the Q1_NDVI, Q1_SAVI and Q1_AGB. Consequently, temperature sensitivities of vegetation indices, and aboveground biomass were primarily linked with temperature itself (especially warming magnitude), and adjusted by water availability, vegetation indices/aboveground biomass itself, elevation and warming length in high-cold grasslands of the Tibet.
关于地上生物量的温度敏感性主要是与温度本身(当地气温及气温升高幅度)还是与其他环境变量相关的持续争论,限制了我们准确预测高寒地区未来牧草产量变化及畜牧业高质量发展的能力。因此,自2010年5月起,在西藏三个海拔高度(即4313米、4513米和4693米)的高寒草原上开展了一项开顶式容器的田间增温试验。在2014 - 2015年以及2017 - 2018年检测了归一化植被指数(Q1_NDVI)、土壤调节植被指数(Q1_SAVI)和地上生物量(Q1_AGB)的温度敏感性。温度本身对Q1_NDVI、Q1_SAVI和Q1_AGB具有最大的单独影响。植被指数本身或地上生物量本身对Q1_NDVI、Q1_SAVI或Q1_AGB具有第二大的单独影响。植被指数本身或地上生物量本身的单独影响不到温度本身影响的十分之一。水分有效性以及海拔与持续时间(海拔和增温时长)仅对Q1_NDVI和Q1_SAVI具有单独影响。水分有效性以及海拔与持续时间对Q1_NDVI或Q1_SAVI的总单独影响约为11 - 12%,相当于温度本身的影响。植被指数/地上生物量本身、水分有效性以及海拔与持续时间在Q1_NDVI、Q1_SAVI或Q1_AGB上与温度本身具有交互影响。与当地气温相比,气温升高幅度对Q1_NDVI、Q1_SAVI和Q1_AGB具有更大的单独影响。因此,在西藏高寒草原地区植被指数和地上生物量的温度敏感性主要与温度本身(尤其是增温幅度)相关,并受水分有效性、植被指数/地上生物量本身、海拔和增温时长的调节。