Species-specific sprouting pattern in two dioecious Lindera shrubs: The role of physiological integration

Sprouting is recognized as an important genet persistence strategy for clonal woody plants, but the role of sprouting may differ between species and between sexes, depending on physiological integration. We tested the effect of physiological integration on the mortality, recruitment and growth of the sprouting male and female ramets of two closely related dioecious shrubs of Lindera, in a field experiment using girdling manipulation. Although between-sex differences observed were obscure, we found between-species differences in the sprouting patterns. The rates of ramet mortality and recruitment were significantly lower for L. praecox than L. triloba. In L. praecox genets, the ramet production was low, and the main ramets might actively translocate assimilates towards the small sprouted ramets, which then facilitates high ramet growth and survival (sprout-nursing strategy). Meanwhile, in L. triloba genets, although many ramets were recruited, assimilate translocation from the main ramets to the sprouted ramets might be less abundant, which causes high ramet mortality (sprout-turnover strategy). For a more general knowledge of the various sprouting strategies in clonal plants, our study demonstrated that inter-specific comparisons using girdling experiments at the whole-plant level could reveal the role of physiological integration on the link between the sprouting pattern and above-ground structures of clonal plants.