Impact of artificially simulated precipitation patterns change on the growth and morphology of Reaumuria soongarica seedlings in Hexi Corridor of China

Climate change has altered the existing pattern of precipitation and has an important impact on the resistance and adaptability of desert plants. However, the interactive impact and the main characteristics of changes in precipitation amount and precipitation frequency on desert plants are unclear. Reaumuria soongarica seedlings were treated by artificially simulating changes in precipitation (30% reduction and 30% increase) and its frequency (50% reduction). We first introduced three morphological indicators (i.e., main root length/plant height ratio ( RHR ), above-ground radial density ( ARD ), and below−ground radial density ( BRD )) and drew an abstract figure of seedling growth. This experiment confirmed the following: (1) The increase in precipitation noticeably increased the plant height, above-ground biomass, and total biomass of seedlings. (2) The plant height and the biomass of seedlings were more affected by precipitation amount than by precipitation frequency. No interaction was found between precipitation amount and precipitation frequency on the growth of seedlings. (3) The response of RHR to precipitation changes was extremely significant, increasing with decreasing precipitation and vice versa. (4) The ARD first increased then remained constant as precipitation increased, while ARD first decreased and then increased with decreasing precipitation. When precipitation increases, the BRD increases and the root system becomes relatively thicker and shorter, and vice versa. In this regard, R. soongarica seedlings mainly adapt to their resource supply by adjusting plant height, root length, thickness and biomass.