Abstract: The study on the clonal growth characteristics of Zostera marina L. in Shuangdao Bay of Weihai, East China showed that in the clonal fragments of the Z. marina, only three connected ramet generations were observed. The Z. marina was found to have a phalanx clonal architecture, with spacer length and internodal length being 3.85 cm and 0.92 cm, respectively. From August, 2010 to March, 2011, the total length of the rhizomes of each clonal fragment elongated by 20.39 cm, and a total of 22.17 nodes and 5.41 ramets were produced, suggesting the limited clonal expansion. As compared with daughter and granddaughter ramets, mother ramets had higher biomass and node number, longer rhizome, and bigger size. The clonal fragment allocated the largest proportion of total net production and total biomass to leaves due to the resource and energy requirements from the leaf-replacing growth type of Z. marina. Mother ramets allocated the similar proportion of biomass to leaves, rhizomes, and roots, whereas daughter and granddaughter ramets allocated their most amounts of biomass resources to leaves. The different patterns of biomass allocation for mother and daughter (and granddaughter) ramets could reflect the functional specialization of ramets. Our results implied that it was more feasible to transplant healthy Z. marina ramets in Chinese northern sea area in autumn.

Key words: plant photosynthesis, stable isotope tracing technique, soil carbon cycling., elevated atmospheric CO₂ concentration