Drought decreases the positive impact of warming on an alpine grassland community  

作　　者：Wang A Wangwang LV Yang ZHOU Bowen LI Jianping SUN Jingya LV Lanying CHEN Dorji TSECHEO Shiping WANG 

机构地区：[1]Key Laboratory of Tibetan Plateau Earth,Resources and Environment,Institute of Tibetan Plateau Research,Chinese Academy of Sciences,Beijing 100101,China [2]School of Ecology and Environment,Tibet University,Lhasa 850000,China [3]University of the Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Science China Earth Sciences》2024年第10期3226-3238,共13页中国科学（地球科学英文版）

基　　金：supported by the Projects of Naqu Science and Technology Bureau of Xizang Autonomous Region (Grant No.NQKJ2023-03);the National Natural Science Foundation of China (Grant Nos.42230504 and 32201358);the Joint Key Research Fund (Grant No.U20A2005) under a cooperative agreement with the National Natural Science Foundation of China (NSFC);Ali Science and Technology Bureau of Xizang Autonomous Region (Grant No.QYXTZX-AL2022-05)。

摘　　要：Temperature and precipitation are the main factors determining plant community succession and aboveground net primary productivity(ANPP)in natural grasslands.However,most climate manipulative experiments have mainly focused on their impacts in isolation,especially in alpine regions.Here we explored the relative effects and interaction of warming and precipitation alteration on succession and ANPP using a 7-year experiment involving warming with precipitation alteration(increase(IP)or decrease(DP))in precipitation relative to ambient precipitation(AP)on the Tibetan Plateau.Our results showed that warming and warm-wet conditions increased species richness,diversity index,height and cover of overall species.Conversely,decreasing precipitation reduced them,but increased S.purpurea and the rate of change in community composition.Importantly,warming mitigated the impacts of decreased precipitation on plant community composition,and the interactive effects of warming and altered precipitation on cover,height and plant ANPP varied with year and plant species.Generally,warming increased community ANPP through increases in forb ANPP or non-dominant species ANPP and biodiversity regardless of change in precipitation.However,decreased precipitation reduced community ANPP via decreases in the ANPP of sedges and forbs and biodiversity.Precipitation alteration affected the relationship between biodiversity and community ANPP regardless of warming(IP<AP<DP).Therefore,generally warming and decreased precipitation have opposite effects on ANPP in the alpine grassland,suggesting that warming mitigated the negative impacts of drought on the ANPP of the alpine grassland.

关 键 词：Alpine grassland Climate warming Precipitation alteration Community composition BIODIVERSITY Above-ground net primary productivity 

分 类 号：P426.616[天文地球—大气科学及气象学]