A large number of fallen trees that hinder recovery from power outages
On the 10th after the occurrence of a large-scale power outage in Chiba Prefecture due to Typhoon No. 15, one of the causes of a large number of fallen trees that prevented recovery was visible. When specialists examined the fallen tree site and its images, it was confirmed that cedars were broken one after another due to a disease in which the inside of the trunk was hollowed out, and specialists may be the same in places where this disease is common When there is a warning bell.
A large-scale power outage in Chiba Prefecture caused a large number of fallen trees, which caused not only the power outage and the power outage spreading in various places, but also obstructing recovery by blocking roads, etc. I am inviting you.
Professor Tatsuaki Kobayashi, a graduate school of horticulture at Chiba University, who is familiar with trees, examined in detail the sites of Sanmu City where many fallen trees remain and images of fallen trees taken at restoration sites throughout the prefecture.
Although some fallen trees other than cedars, such as cypresses, were seen at the site in Sanmu City, the majority of fallen trees suffered from a disease called “groove rot” in which the inside of the trunk was hollowed out.
In the image of fallen trees, cedars that appear to be ill have been confirmed in various places, and Professor Kobayashi points out that one of the causes of the mass fallen trees seems to have been broken one after another because cedars that were hollow due to illness were broken.
Prof. Kobayashi said, “I couldn't imagine a situation where a large number of fallen trees had affected my life so far, but it can be said that it happened to happen in the form of the decline in forestry so far.” In the place where there are many cedar diseases, a warning bell is sounded if the same thing may happen.
Confirmation of hollow cedar in various places
According to Professor Kobayashi, the disease called “groove rot” means that the fungus grows inside the trunk of the cedar and the central part rots and becomes hollow, so the strength decreases and it breaks easily.
The diseased cedar can be identified by a unique groove on the surface. Most of the fallen trees confirmed at the site of fallen trees in Sanmu City were cedars, most of which had a disease-specific groove.
Furthermore, even in images taken and published at the site of fallen tree processing, Professor Kobayashi points out that Kisarazu City and Narita City fallen cedar is also a disease, and Futtsu City fallen wood may also be a diseased cedar He pointed out that one of the causes of a large number of fallen trees was the fact that cedar trees were broken one after another.
A research conducted by a research institution in Chiba Prefecture on a special cedar called “Sambusugi” found that 54% of Japanese cedar had a type of “groove rot”, and this disease spread to Japanese cedar forests. It has been pointed out.
Prof. Kobayashi said, “As this time, falling trees not only cause power outages and prevent recovery, but there are also dangers such as the expansion of damage caused by landslide disasters,” and there are a lot of cedars that are sick during disasters. It has been pointed out that there is a risk that damage and impact will increase one after another in various places in the future.