5:15 PM - 6:45 PM
[HQR05-P08] When "Totoro's Forests" formed?
-Paleoenvironmental Research in the Mikajima Wetlands of the Sayama Hills-
Keywords:Sayama Hills, Totoro's Forests, Satoyama, Pollen analysis, CNS analysis, Paleoenvironment
The Sayama Hills, isolated from the Kanto Mountains, are a rich natural environment in the urban area with a total area of 3,500 ha. In the center of the hills are dammed lakes called Lake Tama and Lake Sayama. The northern parts of the Sayama Hills served as the model for the animated film " My Neighbor Totoro (Tonari no Totoro)" released in 1988. The movie depicted a rich natural environment as called “Satoyama” (Okuda, 1997). Since the release of the movie, the Sayama Hills have been the "Totoro's Forest" and there has been a campaign to preserve the secondary Quercus serrata forest (Okuda, 1997).
There have been no previous studies on the formation of wetlands in the Sayama Hills or vegetation changes related to "Totoro's Forest," and it is unclear when and how the “Satoyama” landscape was formed in these hills. Therefore, we collected peaty sediments from upstream to downstream in the Miajima wetland located at the northern foot of the Sayama Hills, and and paleoenvironmental analyze as both pollen and CNS analysis with multiple radiocarbon dating to clarify the formation period of the wetland and the development history of the secondary forest known as "Totoro's Forests".
The coring survey was conducted at four sites in the wetland using a Russian peat sampler to collect peaty sediments up to the base rocks. The collected sediments were observed for stratigraphy and then each core was divided for various analyses. Radiocarbon dating was performed on 21 samples with good plant fragments, which were acid-alkali-acid-treated, and radiocarbon dated using an accelerator mass spectrometer owned by Nagoya University. The obtained ages were calibrated to calendar years using the IntCal20 data set.
The results are summarized below.
The Sangashima wetland was formed about 1,700 years ago. The wetland environment has been maintained to the present.
The secondary forest of Quercus serrata "Totoro’s Forests" was established from about 500 cal AD. It is also suggested that rice cultivation started around 850 cal AD by artificially adjusting the wetland.
From about 1800 cal AD, the secondary forests of konara oak and red pine were abandoned, and the forests were restored to shrubland, and cedar plantations were started around the wetlands.
There have been no previous studies on the formation of wetlands in the Sayama Hills or vegetation changes related to "Totoro's Forest," and it is unclear when and how the “Satoyama” landscape was formed in these hills. Therefore, we collected peaty sediments from upstream to downstream in the Miajima wetland located at the northern foot of the Sayama Hills, and and paleoenvironmental analyze as both pollen and CNS analysis with multiple radiocarbon dating to clarify the formation period of the wetland and the development history of the secondary forest known as "Totoro's Forests".
The coring survey was conducted at four sites in the wetland using a Russian peat sampler to collect peaty sediments up to the base rocks. The collected sediments were observed for stratigraphy and then each core was divided for various analyses. Radiocarbon dating was performed on 21 samples with good plant fragments, which were acid-alkali-acid-treated, and radiocarbon dated using an accelerator mass spectrometer owned by Nagoya University. The obtained ages were calibrated to calendar years using the IntCal20 data set.
The results are summarized below.
The Sangashima wetland was formed about 1,700 years ago. The wetland environment has been maintained to the present.
The secondary forest of Quercus serrata "Totoro’s Forests" was established from about 500 cal AD. It is also suggested that rice cultivation started around 850 cal AD by artificially adjusting the wetland.
From about 1800 cal AD, the secondary forests of konara oak and red pine were abandoned, and the forests were restored to shrubland, and cedar plantations were started around the wetlands.