Responses of Ephemeral Plants to Precipitation Changes and Their Effects on Community in Central Asia Cold Desert

In the context of global climate change, changes in precipitation patterns will have profound effects on desert plants, particularly on shallow-rooted plants, such as ephemeral plants. Therefore, we conducted an experiment on artificial control of precipitation for four dominant ephemeral plants, , , , and , in the southern edge of Gurbantunggut Desert. We measured the importance value and some growth parameters of the four species under increased or decreased precipitation and constructed trait correlation networks for each of the four species. We also compared the response of increased or decreased precipitation to vegetation coverage. The results show that drought significantly reduced the survival rate, seed production and weight, and aboveground biomass accumulation of ephemeral plants. The four ephemeral plants showed different tolerance and response strategies to precipitation changes. and can avoid drought by accelerating life history, and , and can alleviate the negative effects of drought by adjusting leaf traits. However, the response of different species to the wet treatment was not consistent. Based on the results of the trait correlation network, we consider belongs to the ruderal plant, and belong to the competitive plants, and belongs to the stress-tolerant plant. The outstanding trait coordination ability of makes it show absolute dominance in the community. This indicate that ephemeral plants can adapt to precipitation changes to a certain extent, and that distinct competitive advantages in growth or reproduction enabled species coexistence in the same ecological niche. Nevertheless, drought significantly reduces their community cover and the ecological value of ephemeral plants. These findings established the basis to predict vegetation dynamics in arid areas under precipitation changes.