Adaptation strategies of Tamarix ramosissima seedlings in the hinterland of Taklimakan Desert, China

Abstract

Abstract Purpose Salt cedar (Tamarix ramosissima Ledeb.) is an excellent species of shrub that is used for windbreaks and to fix sand in desert of northwest China. The successful settlement of T. ramosissima seedlings and their growth into mature individuals require their adaptation to various adverse conditions, which is the key to naturally regenerating the Tamarix population. Methods We measured the morphological characteristics of the T. ramosissima seedlings, such as rooting depth, root: shoot ratio, taproot diameter, specific root length (SRL), specific root area (SRA), and specific leaf area (SLA), physiological characteristics, such as stable isotope ratios of xylem water, soil water, and leaves, as well as the leaf water content (LWC). Results The distribution of primary and lateral roots of T. ramosissima seedlings with larger BSD was more apparent than that of the small ones. As the BSD increased, the taproot depth and diameter of the T. ramosissima seedlings increased, and the root: shoot ratio, SRL, SRA, and SLA decreased. For the T. ramosissima seedlings shallow soil water was an important component of the water source. The mean LWC of T. ramosissima seedlings with different BSDs was 68.80%. The leaf carbon stable ratios (δ13C) trend was not obvious. Conclusion These results showed that with better soil water conditions in their habitat, the T. ramosissima seedlings were less likely to develop deeper root systems downward, allocated more biomass to the aboveground, and their growth rate diminished as the BSD increased.