The comparative study between introduced Taraxacum officinale and native Taraxacum platycarpum in the inter- and intraspecific competition

Abstract

The invasive plant has a worldwide distribution, increases the competitive ability in the introduced range compared to their native range, and then outcompetes native plants. Within the introduced range, the invasive plant has the different strength of the interspecific competition depending on the sites, and this difference affects the plant invasion. A recent study suggests that the intraspecific competition could affect the plant invasion. Especially, the intraspecific ability of kin recognition, which means that genetically closed individuals reduce the competition with each other, helps the naturalization of the invasive plant. In this study, I compare introduced Taraxacum officinale and native T. platycarpum in the inter- and intraspecific competition. My goal finds the answer to three questions. 1) Does introduced T. officinale outcompete native T. platycarpum? 2) Does the interspecific competition between introduced T. officinale and native T. platycarpum differ among the site? And 3) Does introduced T. officinale have the intraspecific ability of kin recognition? For the comparison study, I grew two dandelion species from the two distant sites (Incheon and Jeonju) at the various competition types (interspecific competition to plants from the same and different site, or intraspecific competition to the kin from the same mother plant and to the stranger from different site) in a stable condition. During the experiment, I measured various traits, such as biomass and morphological characteristics of the root and leaf, and reproduction In my study, the introduced dandelion greatly competes over the growth of the native dandelion in the interspecific competition. Furthermore, the competitive abilities of two dandelion species were different between the sites. Within the Jeonju site, the introduced dandelion had more competitive and reduced the growth of the weaker native dandelion than the Incheon site. Unfortunately, I did not find any ability of the kin recognition in introduced T. officinale. These results suggest that, in the Jeonju site, introduced T. officinale could rapidly spread and exclude native T. platycarpum due to the different competitive ability. My study clearly shows that the invasive plant competes over the native plant and that this reduction to the growth of the native plant is different depending on the sites because of the competitive ability. Moreover, these differences could cause the rapid exclusion of the native plant by the invasive plant