Differences in clonal integration between the sexes: long-term demographic patterns in the dioecious, multi-stemmed shrub Lindera triloba

Abstract

In clonal plants, ramets connected within a genet can share resources through clonal integration, and clonal integration often facilitates the growth and survival of young ramets. However, in dioecious plants, it is not fully understood whether female and male genets differ in their integration patterns affecting the demographic processes. To test between-sex differences in the demographic process in relation to clonal integration, we conducted a long-term census for the dioecious sprouting shrub Lindera triloba (Sieb. et Zucc.) Blume. In an old-growth forest, we selected 73 female and 82 male genets, and the recruitment, growth, and mortality of ramets within those genets were monitored over six years. Ramet recruitment was greater in males than in females, whereas ramet growth and survival rates did not differ, on average, between sexes. Females and males showed different sensitivities to factors affecting their ramet dynamics. The ramet recruitment, growth, and survival within male genets were significantly positively affected by the largest main ramet size, whereas females were not sensitive to the effect. This suggested that demographic patterns of ramets within male genets were more sensitive to assimilates translocated from the main ramets than those within female genets, and the role of clonal integration worked differently on ramet dynamics between sexes.