Abstract: Current researches related to ecological restoration of Scirpus mariqueter wetland mainly focus on the statistics of external apparent data and experimental exploration of appropriate modes, with limited understanding on the internal material regulation mechanism of S. mariqueter under different elevations. A ¹⁵N labeling experiment was conducted to explore N distribution characteristics of S. mariqueter under different elevations in the middle and late growing seasons, aiming to provide ecological restoration suggestions. The results showed that in the middle growing season, aboveground allocation rate of new uptake ¹⁵N increased as the elevation decreased, indicating that S. mariqueter tended to allocate more N to the aboveground part to adapt to environmental stress. In the end of growing season, the new uptake ¹⁵N was strongly concentrated to underground part, indicating that S. mariqueter maintained its settlement potential for the following year by allocating more N to underground part in strongly disturbed areas with tidal flooding. The allocation rate of new uptake of ¹⁵N was much higher in corms than that in seeds, indicating that the allocation of N in the propagators was mainly in corms and secondarily by seeds. Based on the ¹⁵N tracing results, we present following suggestions: when ecological restoration is carried out by patch transplanting, patches should be dug out in the area with the same disturbance degree and transplanted nearby; when ecological restoration is carried out through propagules, corms should be preferentially selected to design restoration schemes, and seed banks should be constructed for future germination, while seeds and corms should be selected in relatively high altitude areas with better environment.

Key words: elevation, isotope, aboveground, underground, patch transplantation, propagule.