[Effects of herbivory on the clonal integration of and ].

Many alien invasive plants were clonal species. Examining the relationship between clonal integration characteristics and invasiveness of alien clonal plants is important for clarifying their ecological adaptability and invasion mechanisms. Here, with the invasive plant species and its native congener as the studying objects, we compared the effects of clonal integration on the growth and the biomass allocation of the apical ramets, basal ramets, and the whole fragment of both species under herbivory by the biocontrol beetle The results showed that under herbivory by , leaf number, stolon length, and ramet number of the apical ramets as well as the ground diameter of the whole fragment of were significantly higher under clonal integration treatment compared to that without clonal integration, whereas belowground biomass and total biomass of the basal ramets and the whole fragment of were conversely decreased by 78.2%, 60.9 % and 48.7%, 37.2%, respectively, under clonal integration treatment compared to that without clonal integration. Ground diameter of the apical ramets and leaf number of the whole fragment of were significantly higher, but the number of basal ramets was 21.7% lower under clonal integration treatment compared to that without clonal integration. The biomass of the apical ramets, basal ramets, and whole fragment of . did not significantly differ between clonal integration and without clonal integration treatments. The results of cost-benefit analysis showed that the ramet number and biomass of the apical ramets of as well as the ramet number of the apical ramets of were significantly benefited from clonal integration, but the cost-benefit of the ramet number and biomass of the basal ramets of both species were not affected by clonal integration treatment. These results suggested that clonal integration could partly alleviate herbivory pressure by on the apical ramets of both species, and that the clonal integration ability of was stronger than . However, both species seemed not able to gain significant benefits from cloning integration at the whole fragment level.