Root dynamics plays a fundamental role in determining carbon allocation and other main ecological processes in grasslands. Understanding the responses of root activities to ongoing warming in grazed alpine meadows enable us to predict the potential changes in the carbon budget and ecosystem functions in alpine regions. We conducted a controlled 4-year field experiment with warming and grazing in an alpine meadow on the Qinghai-Tibetan Plateau. Our objective was to explore the responses of root standing crop, production, mortality and turnover rate to warming and grazing using minirhizotrons. Warming only significantly inhibited root mortality while grazing promoted all the four root metrics, which were also significantly influenced by the interaction of warming and grazing. Warming oppositely affected the four metrics under grazing versus non-grazing conditions. It significantly reduced root mean standing crop, annual production and mortality without grazing, but significantly stimulated only mean standing crop under grazing. Grazing had significantly negative and positive effects on mean standing crop in the no warming and warming plots. It promoted annual root production and mortality regardless of warming, whereas the effects were significant only under warming condition. Moreover, grazing significantly increased turnover rate in no warming plots but slightly decreased it in warming plots. These findings highlight the non-additive interactions on the alpine meadow root dynamics between warming and grazing. Therefore, grazing regimes should be considered to better model the ecosystem feedback to global warming and to improve the prediction of future ecosystem functions.

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变暖和放牧相互作用影响高山草甸的根系动态

根系动态在决定草地碳分配和其他主要生态过程中起着基础性作用。了解高山放牧草甸根系活动对持续变暖的反应，使我们能够预测高山地区碳收支和生态系统功能的潜在变化。我们在青藏高原的高寒草甸进行了一项为期 4 年的有控制的田间加温放牧试验。我们的目标是使用微型根际加速器探索生根作物、产量、死亡率和周转率对变暖和放牧的反应。变暖仅显着抑制根系死亡率，而放牧促进了所有四种根系指标，这也受到变暖和放牧相互作用的显着影响。在放牧和非放牧条件下，变暖对四个指标产生了相反的影响。它在不放牧的情况下显着降低了根平均立草、年产量和死亡率，但仅显着刺激了放牧下的平均立草。在不变暖和变暖的地块中，放牧对平均立地作物有显着的负面和正面影响。无论变暖如何，它都能促进年根产量和死亡率，而仅在变暖条件下效果才显着。此外，放牧显着增加了未变暖地块的周转率，但在变暖地块中略有降低。这些发现强调了变暖和放牧之间高寒草甸根动态的非加性相互作用。所以，