PDF(Pubmed)
Abstract：
More and more studies have focused on responses of ecosystem carbon cycling to climate change and phenological change, and aboveground net primary productivity (ANPP) is a primary component of global carbon cycling. However, it remains unclear whether the climate change or the phenological change has stronger effects on ANPP. In this study, we compared the effects of phenological change and climate change on ANPP during 2000-2013 across 36 alpine grassland sites on the Tibetan Plateau. Our results indicated that ANPP showed a positive relationship with plant phenology such as prolonged length of growing season and advanced start of growing season, and environmental variables such as growing season precipitation (GSP), actual vapor pressure (Ea), relative humidity (RH), and the ratio of GSP to ≥5°C accumulated temperature (GSP/AccT), respectively. The linear change trend of ANPP increased with that of GSP, Ea, RH, and GSP/AccT rather than phenology variables. Interestingly, GSP had the closer correlation with ANPP and meanwhile the linear slope of GSP had the closer correlation with that of ANPP among all the concerned variables. Therefore, climate change, mainly attributed to precipitation change, had a stronger effect on ANPP than did phenological change in alpine grasslands on the Tibetan Plateau.
摘要：
越来越多的研究集中于生态系统碳循环对气候变化和物候变化的响应,地上净初级生产力(ANPP)是全球碳循环的主要组成部分。然而,目前尚不清楚气候变化或物候变化对ANPP的影响是否更强。在这项研究中,我们比较了2000-2013年青藏高原36个高寒草地的物候变化和气候变化对ANPP的影响。我们的结果表明，ANPP与植物物候呈正相关关系，如生长季节的延长和生长季节的提前开始。和环境变量，如生长季降水(GSP)，实际蒸气压（Ea），相对湿度(RH),以及GSP与≥5°C累积温度之比（GSP/AccT），分别。ANPP随GSP线性变化趋势增加,Ea,RH,和GSP/AccT，而不是物候变量。有趣的是,GSP与ANPP具有更紧密的相关性，同时在所有相关变量中，GSP的线性斜率与ANPP的线性斜率具有更紧密的相关性。因此,气候变化,主要归因于降水变化，与青藏高原高寒草地物候变化相比，对ANPP的影响更大。
