Impact of relative temperature changes on vegetation growth in China from 2001 to 2017

Currently, studies on vegetation are limited to absolute temperature changes, with insufficient attention directed to the intricate and complex connections between relative temperature (Tr) changes and vegetation productivity. This study analyzed the impact of Tr change on vegetation growth by estimating the effects of temperature change, CO2 levels, and precipitation on the vegetation index. The analysis used changes in temperature ordination as a sign of Tr change and employed ridge regression analysis, trend analysis, correlation analysis, and contribution methods. The results indicated that the mean trend of Tr change in China was negative, suggesting that the rate of Tr decreased as compared to the rate of Tr increase, leading to most regions in China becoming relatively colder. Regions experiencing a decrease in Tr were more favorable to vegetation growth due to stable temperatures, while regions with increasing Tr faced intensified water stress and inhibitory effects on vegetation, except in cold regions with sufficient precipitation. Overall, the study predicted the impact of Tr change, temperature, CO2, and precipitation on NIRv in China. Overall, Tr in China had a beneficial impact on the vegetation index, with a lesser effect compared to CO2 and precipitation, but more than temperature, highlighting the significance of Tr in promoting vegetation growth. This study expanded the understanding of the impact of global warming on vegetation by incorporating the novel idea of Tr change and quantifying its consequences for vegetation.