Mt. Koshikidake: Flora and Fauna
The lower slopes of Mt. Koshikidake are home to an untouched conifer forest that has been designated a National Natural Monument. At higher elevations, the forest’s red pines, firs, and hemlock thin out, ceding the rocky soil to smaller, tougher flora like Miyama-Kirishima azalea (Rhododendron kiusianum) and niga-ichigo (Rubus microphyllus L.f.) bushes.
A Wetland Pond
Inside the crater, a sea of silver grass surrounds the only wetland pond in southern Kyushu. The pond supports several species of insect-eating plants, including the common sundew and a species of bladderwort called mimikaki-gusa (Utricularia bifida). There is also the occasional jack-in-the-pulpit (Arisaema serratum), known in Japanese as mamushi-gusa, or “viper grass,” for its resemblance to a snake rearing its head to strike.
The color of the silver grass ranges from rich green in summer to rippling silver in autumn. In the warmer months, the crater’s interior is also colored by flowers such as bluish-purple haru-rindo gentians in early spring and reddish-pink Miyama-Kirishima azaleas some weeks later.
Dragonflies are present in abundance. Sharp-eyed visitors may spot wandering gliders, white-tailed skimmers, common hawkers, and autumn darters. In spring, the pond is alive with dragonfly nymphs and diving beetles. The mountain is home to the same birds that are found throughout the rest of the park, including jays, cuckoos, and bush warblers.
An Ecosystem in Transition
The crater is entirely ringed by trees, particularly red pines. In time, the pines will advance inward until they fill the crater. Like many parts of the park, Mt. Koshikidake is a post-volcanic ecosystem where the flora is gradually negotiating an equilibrium.