## 1 Introduction  
The Tibetan Plateau (TP) is the largest and highest plateau in the world, and it contains almost all of the key elements of the entire system of the Earth, including the interconnected lithosphere, atmosphere, cryosphere, biosphere, and anthroposphere [1, 2, 3]. The average annual temperature at lower elevations of the TP is about \(-15\)\({}^{\circ}\)C, while temperatures at higher elevations can reach \(10\)\({}^{\circ}\)C [4]. In recent decades, the TP has undergone a significant warming [5, 6], with a warming rate more than twice as fast as the global average over the past 50 years [7]. This rapid warming trend could have a significant impact on the thawingprocesses of the permafrost and the seasonally frozen soil, and this would further affect the vegetation dynamics and the ecosystem stability of the TP [8]. There is an ongoing debate about how vegetation growth responds to climate warming, largely due to our limited understanding of the physical mechanisms that underlie this process. To understand the warming impact on vegetation growth, most studies select mean air temperature as the proxy variable of climate warming [9; 10; 11; 12; 13]. However, as the use of mean temperature smooths out the dynamic response of vegetation growth to climate warming, several studies suggest the use of maximum temperature (T\({}_{\rm max}\)) and minimum temperature (T\({}_{\rm min}\)) as alternative proxy variables for climate warming. The asymmetrical increase in T\({}_{\rm max}\) or T\({}_{\rm min}\) could play different roles on vegetation growth from mean air temperature [14]. Therefore, understanding the driving mechanisms of the T\({}_{\rm min}\) and T\({}_{\rm max}\) effect rather than the mean air temperature on the TP is crucial for developing adaptation strategies that will protect its fragile ecosystems and also for better understanding vegetation growth changes across the TP. Currently, an increasing number of studies investigate how maximum and minimum temperatures impact vegetation growth. A recent study has revealed that marsh vegetation exhibited asymmetric responses to nighttime minimum and daytime maximum temperatures on the Songnen Plain of China [15]. The impact of asymmetric warming between day and night on the NDVI of different vegetation types varies across different regions: it has been found to promote NDVI growth in the grasslands of Inner Mongolia, for example [16]. However, the dependence of plant growth on the daily maximum or minimum temperatures may differ on the TP due to its higher elevations and its colder and drier conditions. Recent studies have reported that a rise in the minimum temperature could alleviate the negative impacts of frost damage, while an increase in the maximum temperature in the arid regions could exacerbate the detrimental effects of drought. Both of these factors have the potential to influence plant growth [17]. In addition, many studies have shown the necessity of plants tolerating cold environments during dormancy [18; 19]. The nighttime warming may have a stronger impact on the ecosystems of the TP [17]. The latest study has indicated that the annual marsh net primary productivity (NPP) on the TP significantly increased with the rising minimum temperatures during winter and spring [20]. However, there is limited research that compares the impact of diurnal and nocturnal warming on vegetation growth across the TP [21]. Considering the asymmetric rise in daytime and nighttime temperatures worldwide, it is imperative to investigate how changes in these temperatures can impact plant growth on the TP, especially on different types of frozen soils. The aim of this study is to examine the intricate response of vegetation growth on the TP to various temperature driving factors, particularly in the context of asymmetric warming between day and night.