Guiding the Biodiversity Coexistence Area Review at Hōin-ji Bamboo Forest

On July 28, 2025, Sentei-ya Sora attended the on-site inspection for the “Kameyama City Biodiversity Coexistence Area Certification.” This program,

launched in 2023, designates and supports areas of high biodiversity value within the city. On this day, we had the honor of guiding staff from Kameyama City’s Industry & Environment Division and the official certification reviewers through the bamboo forest at Hōin-ji Temple.

Although slightly nervous, it was a valuable opportunity to share the progress of bamboo forest management, methods for enhancing biodiversity, and the ongoing ecological surveys directly in the field.

■What is the Biodiversity Coexistence Area Certification?

ntroduced in FY2023, this certification program highlights areas of significant biodiversity within Kameyama City. Recognized areas receive support for conservation and ecological restoration, with a focus on native species protection and rebuilding local ecosystems.

Hōin-ji Temple’s bamboo forest is currently a candidate site, and ongoing restoration work and ecological monitoring are being carried out toward certification.

Current Challenges of the Bamboo Forest

The forest was previously dominated by over 90% Moso bamboo, leading to ecological imbalance. The main issues identified are:

• Loss of understory vegetation due to over-dense bamboo

• Soil desiccation and nutrient depletion

• Habitat unsuitability for diverse flora and fauna

• Spread of bamboo from forest edges and invasive plant intrusion

  
  

To address these, we are conducting phased thinning and gradual transition toward a mixed broadleaf forest, while minimizing ecological disturbance.

Annual Bamboo Forest Management Schedule (since April 2024)

Spring (Apr–May):

• Selective removal of ~70% of bamboo shoots (preventing edge expansion)

• Protection of natural seedlings (Mukunoki, Aoki, etc.) and understory care

Summer (Jun–Aug):

• Monitoring with trail cameras and pitfall traps

• Clearing fallen/damaged bamboo after storms

• Pitfall results confirmed species such as millipedes and isopods (as of May 2025)

Autumn (Sep–Nov):

• Selective weeding, prioritizing removal of invasive plants

• Protection of native herbaceous plants and saplings

• Preparing work paths for the following year

Winter (Dec–Mar):

• Stepwise thinning of 15–20% of bamboo annually

• Target density: ~250 culms per 10a

• Reuse of pruned branches as mulching material

■Soil Conservation & Habitat Restoration

To stabilize soil and enhance biodiversity, the following measures are being incorporated:

• Planned “Shigara-bosa” erosion control work (by 2027)

• Introduction of leaf litter from broadleaf forests to form humus

• Exploring microbial activation (e.g., EM bacteria)

• Recycling bamboo into chips/powder for mulch and humus formation

Transition to a Broadleaf Forest

Alongside natural regeneration, supplemental planting of local native species is being considered:

• Tall canopy species: Keyaki (Zelkova), Mukunoki, Enoki

• Understory species: Camellia (Camellia japonica), Kakuremino, Shirodamo

  
  

竹林生物多様性モニタリングと調査結果

Biodiversity Monitoring & Results

A combination of survey methods is being applied to visualize ecological changes:

• Quadrat surveys (5×5 m) for vegetation structure

• Line census for bird species (e.g., Japanese White-eye, Great Tit)

• Pitfall traps for ground-dwelling insects and spiders

• Trail cameras for mammals (wild boar, deer, civet, etc.)

  
  

New species confirmed in spring 2025 (examples):

• Akebi (Akebia)

• Ubajirisō (Cardiocrinum cordatum)

• Aralia (Aralia elata)

• Japanese raspberry (Rubus microphyllus)

• Jack-in-the-pulpit (Arisaema)

• Fern species (Dryopteris crassirhizoma)

• アケビ、ウバユリ、タラノキ、ミヤマニガイチゴ、マムシグサ、イノデ など

  
  
  
  

Future Vision: From Bamboo Monoculture to Diverse Ecosystems

The goal is not to eradicate bamboo, but to restore a balanced ecosystem where bamboo coexists with diverse species. Key steps include:

• Adjusting light conditions through phased thinning

• Introducing and protecting broadleaf species

• Maintaining water features and wetlands for amphibians

• Using natural erosion control (shigara, bosa)

• Installing artificial nest boxes for birds

  
  

Importantly, adaptive management—adjusting strategies based on observed ecological changes—will be the key to long-term success.

Closing Thoughts

This field inspection provided an opportunity to directly showcase our efforts, and to share in the collective step toward reconnecting people with nature.

At Sentei-ya Sora, we believe management should never be uniform. Instead, it should respond to natural change, leaving room for discovery each time.

We will continue to manage and document the Hōin-ji bamboo forest so that it may become a hub of biodiversity, passing down a rich natural heritage to future generations.