To assess the effectiveness of conservation‐based transplantation of the endangered orchid (Cypripedium japonicum), we compared the morphology, physiology, stem‐count change, and population viability of natural versus transplanted populations undergoing habitat management (repeated removal of competing understory vegetation) between 2009 and 2015 in South Korea. The restored site had lower transmitted light and soil humidity than the natural site. The natural and transplanted populations differed in leaf morphology and total chlorophyll content (natural: 1.00 ± 0.04, restored: 0.53 ± 0.06). No recruitment occurred during the monitoring period. Population viability tended to decrease in the restored population (λG = 0.97, μ = −0.05, σ2 = 0.036) and increase in the natural population (λG = 1.07, μ = 0.03, σ2 = 0.075). The repeated removal of competing understory vegetation had different effects on leaf traits, abundance, and reproductive properties of the endangered orchids in both populations. Notably, habitat management increased the stem count and flowering rate in natural C. japonicum but did not increase the fruit‐setting rate. Thus, despite repeated habitat management efforts (removal of competing understory vegetation), we conclude that the population viability of transplanted populations of the endangered orchid C. japonicum had poor long‐term viability compared with naturally occurring populations, a difference that is mainly attributed to inappropriate transplant‐site selection.

Pine wood nematodes (PWN), Bursaphelenchus xylophilus, infect the pine host tree through maturation feeding wounds caused by Monochamus saltuarius (a long-horned beetle) and kill the host. This study investigated characteristics of the wound by M. saltuarius, infection behavior of PWN on the wound and distribution of PWN in stem tissues of 20-year-old Pinus densiflora that was artificially inoculated but not showing wilt symptoms. The vector beetle sucked resin and exposed cortical tissues, resin canals, phloem, cambium, ray parenchymatous cells and tracheids in xylem, while it fed on the bark of current shoots of pine tree. When PWN were inoculated on the fed shoot, they infected all of the exposed tissues. When placed on a cut current shoot disc with flowing resin profusely, PWN moved down the resin duct into the cortical layer gravitationally before the resin became sticky due to evaporation. In the artificially inoculated three-year-old stem of 20-year-old P. densiflora, PWN were distributed mostly in resin canals, some in cortical tissues and pith, but very rarely in tracheids. In conclusion, PWN can initially infect resin canals in cortical tissues of pine shoot after feeding by the long-horned beetle.

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