Analysis of time lag relationships between climate factors and vegetation on the Loess Plateau

Against a backdrop of ongoing global climate change, investigating the response of vegetation to climatic factors is of particular practical importance with respect to the preservation of regional ecological services and the judicious utilization of water and soil resources. However, whereas previous studies have focused predominantly on the concurrent interplay between meteorological factors and vegetation indices at a regional scale, few have taken into consideration the effects of the temporal lag between vegetation and meteorological factors. In this study, we used a MODND1T/normalized difference vegetation index (NDVI) time series, along with temperature and precipitation datasets, to examine the temporal lag effects of different climatic factors on vegetation distributed across the Loess Plateau. In addition to identifying the primary climate-driven factors for distinct vegetation types, we established multivariate linear regression and partial correlation models. We accordingly found that with respect to climate change, different vegetation types and regions across the Loess Plateau are characterized by differing response patterns and temporal lag effects. After accounting for temporal lag effects, we established that climatic factors can explain 58.2% of the observed variation in vegetative growth on the Loess Plateau. Compared with models that do not factor in temporal lag effects, this represents a 10% increase in explanatory power. Furthermore, for regions on the Loess Plateau with significant trends in MODND1T/NDVI between 2000 and 2018 (P < 0.05), we identified temperature as the primary driving factor.