Exploring the relative importance of preseason climatic drivers on spring phenology dynamics in the Greater Khingan Mountains, Northeast China

Abstract

AbstractExploring spring phenology dynamics driven by climate change is crucial for investigating land–climate feedback. However, a thorough assessment of the influence of climatic drivers on spring phenology remains lacking. Here, we investigated spatiotemporal variations at the start of the growing season (SOS) in the Greater Khingan Mountains, Northeast China, during 1982–2015 using the normalized difference vegetation index third‐generation dataset from Global Inventory Modelling and Mapping Studies. To investigate the influence of preseason climatic factors on the SOS, partial correlation analysis was employed to assess correlations as well as to identify dominant regional drivers. Overall, the SOS dates in the study area showed obvious regional characteristics from 1982 to 2015, with a gradual delay from north to south, with more than 90% of the SOS dates occurring from Julian days 125–140. Advancement trends were observed in all ecogeographical regions, thus accounting for 94.6% of the entire research area, with an average of 7.14 days in advance. The partial correlation analysis revealed spring phenology was most significantly influenced by preseason temperature, and temperature promoted the advancement of SOS in almost the entire study area, but for semi‐humid/semi‐arid regions, the effects of total precipitation was greatest. Interestingly, preseason radiation also dominated earlier SOS dates by a few pixels, albeit in a fragmented distribution. Generally, the preseason temperature had a prominent influence on the SOS dates across all ecogeographical regions, whereas the roles of preseason precipitation and radiation varied by region. In addition to analysing a single climatic factor, our study aimed to analyse the comprehensive impacts of climatic factors on spring phenological processes, with a focus on the composite effects, helping us to improve predictions of spring phenology and provide a better understanding of land–climate interactions.