Under global climate change, particularly warming, plant phenology may vary significantly thereby influencing a series of ecosystem functionalities. However, observational evidences of the variation of plant phenology and its association with climate change in temperate grassland are limited. In this study, we collated plant phenological records during the period from 1982 to 2019 at 26 sites in Inner Mongolian temperate grassland to elucidate the association of plant phenology with a series of environmental variables. The results showed that a trend of warming, particularly during May-September, occurred over the study period. However, this warming did not significantly influence plant phenology (e.g., green-up, flowering and brown-down) of four dominant plant species (i.e., Stipa, L. Chinensis, A. Cristatum and A. Frigida). Rather, multivariate regression considering a series of climatic and edaphic factors revealed that preseason climate predominantly regulates the dynamics of plant phenology. Specifically, heat requirement (HR) and days of precipitation (DOP) during the preseason were the two most influential controls on plant phenology. Our findings highlight the importance of incorporating precipitation as an additional predictor variable in current temperature-based phenology models for application in temperate grassland.

在全球气候变化，特别是变暖的情况下，植物物候可能发生显着变化，从而影响一系列生态系统功能。然而，温带草原植物物候变化及其与气候变化关联的观测证据有限。在这项研究中，我们整理了 1982 年至 2019 年内蒙古温带草原 26 个地点的植物物候记录，以阐明植物物候与一系列环境变量的关联。结果表明，在研究期间出现了变暖趋势，特别是在 5 月至 9 月期间。然而，这种变暖并没有显着影响四种主要植物物种（即针茅、中华针茅、尖顶针茅和冷针草）的植物物候（例如，绿化、开花和褐化）。相当，考虑一系列气候和土壤因素的多元回归表明，季前气候主要调节植物物候的动态。具体而言，季前的热量需求 (HR) 和降水天数 (DOP) 是对植物物候学影响最大的两个控制因素。我们的研究结果强调了在当前基于温度的物候模型中将降水作为额外预测变量用于温带草原的重要性。