January 9, 2024
The Second Root System Research at the Four Rows of Ginkgo Trees
We embarked on our second stage of root system research for the Four Rows of Ginkgo Trees (the “Root SystemResearch”) today under the supervision of arborists and other such experts. We will perform the Root System Research
prior to formulating the basic and implementation design of the planned structure (the new baseball stadium) with the aimof thoroughly investigating the design and construction methods necessary for ensuring preservation of the Four Rows ofGinkgo Trees, which has been deemed an important matter of the redevelopment project.
We will include the research findings in a follow-up research report to be presented at an upcoming General Meeting of
the Tokyo Metropolitan Environmental Impact Council. We will also publicly release the research findings through theproject website and other platforms.
■Overview of the Root System Research
1. Research objective
The objective of the Root System Research is to thoroughly confirm the positioning of the roots and their growth condition(thickness, number of roots, etc.) with respect to the westernmost row of the Four Rows of Ginkgo Trees by assessing
effects that construction of the planned structure (the new baseball stadium) situated adjacent to the trees would have. TheRoot System Research will also involve conducting follow-up investigations at points west of those examined during thefirst root system research conducted in January 2023, given that there were locations at which it was not possible tosufficiently confirm positioning of the roots and their growth condition due to the presence of concrete blocks, gravel, andPVC pipes.
The first root system research conducted in January 2023 involved surveying an area extending approximately 6.5 metersfrom the sidewalk curb. Findings of the research with respect to all points of the research site did not pinpoint any locations
meeting the criteria presented in the main section of the Environmental Impact Assessment Report submitted for theredevelopment project in terms of there not being any locations with “four or more roots with a diameter of at least 30
millimeters within the bounds of a 10 centimeter section of mesh,” which serves as a benchmark with respect to tree
girdling*1.
*1. Girdling is a method of reducing stress on trees caused as a result of cutting their roots. It involves peeling a specificthickness of the root bark down to the cambium layer to stimulate root growth from the section that has been peeled.
2. Research period
From January 9, 2024 to early February 2024 (tentative)
3. Research company
IBIDEN Greentec Co., Ltd.
4. Locations subject to the Root System ResearchUpon having listened to the opinions of multiple arborists, we have designated more than 10 locations that are to besubject to the Root System Research. These locations include the area within the Meiji Jingu Gaien tennis courts andpathways of the Meiji Jingu Gaien Aoyama Parking Lot on the west side of the Four Rows of Ginkgo Trees.

5. Research methodology
The Root System Research will be carried out over an area extending approximately 10.5 meters from the sidewalk curb.
Expert arborists and researchers will survey root positioning and growth within soil cross sections in holes manually
excavated in principle and measuring approximately 1.0 meters deep, 1.0 meters wide, and 1.5 meters in length. Upon
having excavated holes from points situated approximately 12.0 meters from the sidewalk curb facing the ginkgo trees,
we will confirm the endpoints of root system growth by employing the “taguri-bori”*2 digging method upon
encountering big roots. Drawing on findings from the previous research, we do not plan to perform tree girdling as partof this phase of Root System Research.
*2. The “taguri-bori” digging method is a technique that involves carefully digging toward the tip of the roots without
cutting any roots.
【Diagram of Research Site】
Westernmost row of ginkgo trees

EastWest
PreexistingfenceHedge
Site of first
Fence research

Site of second research
Tennis courts
Area to be
excavated forresearch

CurbApprox 1.5 meters

New baseball stadiumLocation of undergroundstructure (anticipated)

Approx.
1.5 meters or more

Approx 6.5 meters

Approx 8.0 meters

From curb to site of second phase ofthe Root System Research
Approx 10.5 meters

Length: Approx. 1.5 meters

Surface
Width: Approx.
1.0 meter

ResearchcrosssectionDepth:
Approx.
1.0 meter

Location of soil cross section
for the Root System Research(Reference) Conceptual illustrations of scope of excavation and soil cross section for the Root System Research (tennis court side)

６. Other information
For inquiries regarding the Root System Research, contact the Jingu Gaien District Urban Redevelopment Project
Planning Office (Telephone: 03-6695-0539; Japanese language only). We place top priority ensuring safety of research
operations at the location and accordingly do not accommodate on-site visits or direct inquiries at the site.

【Reference】Preservation of the Four Rows of Ginkgo Trees
As we have noted previously thus far, we seek to preserve the Four Rows of Ginkgo Trees site without removing any trees.
The facility plan will be revised as necessary to ensure the preservation of the Four Rows of Ginkgo Trees, including
setting back the new baseball stadium from the trees, taking into account factors that include findings of vitality research

Road boundaryand root system research, as well as feedback from arborists.
Proposalunderconsideration

Outfield seats

Stores,etc.

Stores,etc.

Sidewalk

8.0 meters

Four Rows of Ginkgo Trees

Proposal under consideration for flatfoundation and reduction in pit size