The two main hypotheses that explain why invasive alien plants successfully colonize new environments are: 1) invasive alien plants are functionally different from native plants in a community, and 2) the plants can adapt well to new environments because they are functionally similar to native plants. The present study investigated the functional traits of naturalized alien herbaceous plants and their native neighbors in a riparian park area near the Hapcheon-Changyeong weir along the Nakdong River to determine which of the two hypotheses applied to the study area. According to the results, leaf functional traits, such as leaf area, specific leaf area, leaf thickness, leaf dry matter content, leaf nitrogen content, and leaf carbon content differed between naturalized alien and native plants, which could be attributed to the higher leaf nitrogen contents in naturalized alien plants than in native plants. The high leaf nitrogen contents are associated with high photosynthetic rates, which lead to effective resource use and rapid growth; therefore, naturalized alien plants growing in the study area were considered to have such functional traits. The results of the present study support the hypothesis that the successful establishment of invasive alien plants is attributed to the functional trait differences between invasive and native plants.

• 손민정(경상국립대학교 생물교육과) | Min-Jeong Son (Department of Biology Education, Gyongsang National University, Jinju 52828, Republic of Korea)
• 남기정(경상국립대학교 농업생명과학연구원) | Ki-Jung Nam (Institute of Agriculture & Life Science, Gyeongsang National University, Jinju 52828, Republic of Korea) Corresponding author