LAUSR

Abstract Aristolochia contorta is a perennial vine with a narrow distribution range; it is also the only host plant for Sericinus montela (the dragon swallowtail), a vulnerable species in Korea. To better understand the optimal habitat characteristics of A. contorta, a field survey and a mesocosm experiment were conducted. A total of 86 quadrates in 10 sites were surveyed in Korea. Host types were classified into four categories: herb, shrub, tree, and artificial host. Detrended correspondence analysis showed that the host type had the greatest influence on the growth characteristics of A. contorta. The highest coverage (44.4%) and highest number of leaves (526.7 m−2) were observed on artificial support quadrats, whereas the longest stems (162.8 cm) and biggest leaves (46.6 cm2) were observed on tree host quadrats. Optimal growth of A. contorta seemed to need appropriate shade and physical support, such as a tree host. To establish the effects of shade and support on morphological and reproductive traits of A. contorta, we applied factorial treatments of two light conditions, 100% and 50% relative light intensity (100%RLI and 50%RLI, respectively) and two support conditions (with and without support) in the mesocosm experiment. The group with 50%RLI and support had the largest single leaf area with the longest stem, internode and petiole. Also, inflorescences developed only in the 50%RLI with support group. In order to improve the growth of A. contorta in artificial habitats established for conservation, it is necessary to provide proper shade (about 50%RLI) and install physical supports.