Chilling Accumulation Is Not an Effective Predictor of Vegetation Green‐Up Date in Inner Mongolian Grasslands

Abstract Chilling accumulation (CA) might be reduced under a warming climate, which raises a critical question: is vegetation green‐up date (VGD) altered by varing CA? If the answer is yes, existing thermal‐time models should be modified to include a chilling component. By collating observations from eight long‐term (1982–2019) field experiments across Inner Mongolia, we quantitatively assessed the responses of VGD of 27 grass species to CA in this region. The results indicated that effect of CA on VGD is in general negligible for most grass species. As excepted, rather than CA, VGD was predominantly determined by other climatic attributes such as heat requirement (HR) and precipitation. These results demonstrate the robustness of existing thermal‐time models without a chilling component to predict variations in VGD of major plant species in Inner Mongolian temperate grasslands.