What secrets does a swamp hold? Here at the edge of Inokashira Park’s Hannnoki Grove, a quiet mystery unfolds. Hannnoki Grove, a rare and precious woodland, is a haven for the Hannnoki tree, known in Japanese as “Hari-no-ki.” This unique ecosystem, designated as a threatened species in Tokyo, thrives in the damp, swampy conditions found here, a remnant of the Edo-era “Nagaike” pond and its vital water source forest. This grove isn’t just a stand of trees; it’s a time capsule, a sanctuary for rare plants like the Nohanashobu and Sawagikyou. These delicate species find refuge here, drawing strength from the rich, damp earth.
Hannnoki Grove faces an ongoing battle against time and the elements. The constant threat of dryness and swamp decay requires careful management. Regular clearing of weeds, fallen branches, and dead trees is essential to maintain the delicate balance. Here, right at our feet, this ecosystem clings to life, showcasing the resilience of nature amidst urban sprawl. The Hannnoki trees themselves, with their purplish-gray bark and distinctive cone-like fruits, play a crucial role in the local ecosystem. Their roots house nitrogen-fixing bacteria, enriching the soil and supporting the diverse plant life found within the grove.
In 2018, Typhoon Trami wreaked havoc on Hannnoki Grove, toppling many trees. This devastation, however, sparked a renewed effort to restore this vital woodland. Volunteers and park staff worked tirelessly, replanting saplings and nurturing the fallen trees to encourage regrowth. This grove, once decimated, now boasts over 200 new Hannnoki trees. The project not only saved the trees but also restored the wetland environment they thrive in. This, in turn, attracted various water-dependent species back to the park.
One remarkable success story is the resurgence of the Tokyo Daruma Pond Frog. In the summer of 2024, frog spawn was discovered in abundance, a sign of the ecosystem’s remarkable recovery. The Hannnoki Grove, reborn from the ashes of a natural disaster, stands as a testament to the power of human intervention and the enduring strength of the natural world. It’s a quiet victory, whispered among the rustling leaves and the chirping of frogs, right here in Hannnoki Grove.