Family: Pinaceae
Origin, Description & Uses:
Pinus thunbergii (Japanese black pine, black pine) is native to Korea and central to southern Japan, where it is commonly found along coastal dunes, rocky shorelines, and low-elevation landscapes. It is a hardy evergreen conifer that can grow 20–35 meters tall, with dark gray to black bark, dense tufts of stiff, dark green needles, and a broad, irregular crown. The species is widely planted in its native range and internationally as an ornamental and landscape tree, especially in coastal areas because of its strong tolerance to wind, salt spray, poor soils, and drought. It is also used in bonsai cultivation and has cultural significance in Japanese garden design and coastal windbreak plantings.
Risks & Threats:
Although Pinus thunbergii is currently not known to be naturalized in the Hawaiian Islands, it does possess traits that are cause for concern in island ecosystems. It produces abundant wind-dispersed seeds and can tolerate a wide range of stressful environmental conditions, which may increase its ability to spread if introduced. Pines can also alter soil chemistry through needle litter, potentially inhibiting the growth of native plant species and changing habitat structure over time. In addition, dense stands may increase fire risk and reduce biodiversity by outcompeting slower-growing native vegetation. Because of these characteristics, caution is warranted, and choosing a low-risk or native alternative is strongly recommended whenever suitable options are available for planting in Hawaiʻi.
High Risk Traits:
- Broad climate tolerance
- Naturalized in Oregon and Virginia
- Invasive in New York
- Many Pinus species are invasive
- Grows on wide range of soils
- Hybridizes naturally with other pines
- Wind-dispersed seeds
- Prolific seed production (34,000 seeds/lb)
- Tolerates coppicing and mutilation
Low Risk Traits:
- Temperate zone species
- No spines, thorns, or burrs
- Non-toxic to humans or animals
- Poor shade tolerance
