Snow cover is an important water source for vegetation growth in arid and semi-arid areas, and grassland phenology provides valuable information on the response of terrestrial ecosystems to climate change. The Mongolian Plateau features both abundant snow cover resources and typical grassland ecosystems. In recent years, with the intensification of global climate change, the snow cover on the Mongolian Plateau has changed correspondingly, with resulting effects on vegetation growth. In this study, using MOD10A1 snow cover data and MOD13A1 Normalized Difference Vegetation Index (NDVI) data combined with remote sensing (RS) and geographic information system (GIS) techniques, we analyzed the spatiotemporal changes in snow cover and grassland phenology on the Mongolian Plateau from 2001 to 2018. The correlation analysis and grey relation analysis were used to determine the influence of snow cover parameters (snow cover fraction (SCF), snow cover duration (SCD), snow cover onset date (SCOD), and snow cover end date (SCED)) on different types of grassland vegetation. The results showed wide snow cover areas, an early start time, a late end time, and a long duration of snow cover over the northern Mongolian Plateau. Additionally, a late start, an early end, and a short duration were observed for grassland phenology, but the southern area showed the opposite trend. The SCF decreased at an annual rate of 0.33%. The SCD was shortened at an annual rate of 0.57 d. The SCOD and SCED in more than half of the study area advanced at annual rates of 5.33 and 5.74 DOY (day of year), respectively. For grassland phenology, the start of the growing season (SOS) advanced at an annual rate of 0.03 DOY, the end of the growing season (EOS) was delayed at an annual rate of 0.14 DOY, and the length of the growing season (LOS) was prolonged at an annual rate of 0.17 d. The SCF, SCD, and SCED in the snow season were significantly positively correlated with the SOS and negatively correlated with the EOS and LOS. The SCOD was significantly negatively correlated with the SOS and positively correlated with the EOS and LOS. The SCD and SCF can directly affect the SOS of grassland vegetation, while the EOS and LOS were obviously influenced by the SCOD and SCED. This study provides a scientific basis for exploring the response trends of alpine vegetation to global climate change.

积雪是干旱和半干旱地区植被生长的重要水源，而草原物候学为陆地生态系统对气候变化的响应提供了有价值的信息。蒙古高原既有丰富的积雪资源，又有典型的草地生态系统。近年来，随着全球气候变化的加剧，蒙古高原的积雪也发生了相应变化，从而对植被生长产生了影响。在这项研究中，使用MOD10A1积雪数据和MOD13A1归一化植被指数（NDVI）数据，结合遥感（RS）和地理信息系统（GIS）技术，我们分析了蒙古高原积雪和草地物候的时空变化从2001年到2018年。相关分析和灰色关联分析用于确定积雪参数（积雪分数（SCF），积雪持续时间（SCD），积雪开始日期（SCOD）和积雪结束日期（SCED））的影响。不同类型的草地植被。结果表明，蒙古高原北部积雪覆盖范围广，开始时间早，结束时间晚，积雪时间长。此外，草原物候学观察到起步晚，提早结束和持续时间短，但南部地区却呈现相反的趋势。SCF以每年0.33％的速度下降。SCD以每年0.57 d的速度缩短。研究区域一半以上的SCOD和SCED分别以每年5.33和5.74 DOY（每年的日）的年增长率增长。对于草原物候，生长季节的开始（SOS）以每年0.03 DOY的速度增长，生长季节的结束（EOS）以0.14 DOY的年增长率被延迟，生长季节的长度（LOS）延长了年增长率为0.17 d。积雪季节的SCF，SCD和SCED与SOS呈显着正相关，与EOS和LOS呈负相关。SCOD与SOS显着负相关，与EOS和LOS正相关。SCD和SCF可以直接影响草地植被的SOS，而EOS和LOS明显受到SCOD和SCED的影响。该研究为探索高山植被对全球气候变化的响应趋势提供了科学依据。生长季（EOS）的延迟以0.14 DOY的年率延迟，生长季节（LOS）的长度以0.17 d的年率延长。积雪季节的SCF，SCD和SCED与SOS呈显着正相关，与EOS和LOS呈负相关。SCOD与SOS显着负相关，与EOS和LOS正相关。SCD和SCF可以直接影响草地植被的SOS，而EOS和LOS明显受到SCOD和SCED的影响。该研究为探索高山植被对全球气候变化的响应趋势提供了科学依据。生长季（EOS）的延迟以0.14 DOY的年率延迟，生长季节（LOS）的长度以0.17 d的年率延长。积雪季节的SCF，SCD和SCED与SOS呈显着正相关，与EOS和LOS呈负相关。SCOD与SOS显着负相关，与EOS和LOS正相关。SCD和SCF可以直接影响草地植被的SOS，而EOS和LOS明显受到SCOD和SCED的影响。该研究为探索高山植被对全球气候变化的响应趋势提供了科学依据。雪季的SCED和SCED与SOS呈显着正相关，与EOS和LOS呈负相关。SCOD与SOS显着负相关，与EOS和LOS正相关。SCD和SCF可以直接影响草地植被的SOS，而EOS和LOS明显受到SCOD和SCED的影响。该研究为探索高山植被对全球气候变化的响应趋势提供了科学依据。雪季的SCED和SCED与SOS呈显着正相关，与EOS和LOS呈负相关。SCOD与SOS显着负相关，与EOS和LOS正相关。SCD和SCF可以直接影响草地植被的SOS，而EOS和LOS明显受到SCOD和SCED的影响。该研究为探索高山植被对全球气候变化的响应趋势提供了科学依据。