We compiled more than 2,five-hundred 14 C schedules from nine some other prefectures: Tokyo, Kanagawa, Saitama, Chiba, Ibaragi, Tochigi, and you can Gunma (aggregated since the Kanto region), Aomori, and you will Hokkaido (Fig step 1). We and removed 14 C schedules centered on ples (we.e. layer and you may fishbone), along with charred remains with a high ? 13 C you to definitely could be probably affected by a tank perception (i.age. >-24‰, considering a selection –twenty-four.0 ± 0.eight having terrestrial animals and –twenty-five.9 ± 2.0 for C3 flowers shown into the ; a far more conservative method having a threshold put in the -26‰ don’t inform you major qualitative differences in 
the outcome, get a hold of S1 Document). I excluded websites dated so you’re able to Incipient and you may Initial Jomon periods (when the standard of sedentism are somewhat lower), and the ones of this Finally Jomon (if total try dimensions is too tiny on Kanto region). We ergo minimal all of our data amongst the Very early therefore the Later Jomon months, leaving out most of the 14 C dates outside of the period 7,500
Regarding the Kanto part, the population lose when you look at the changeover on Very early in order to Center Jomon months was confirmed on statistical comparison into the consistent design, having significant bad deviations doing 5,700 cal BP
dos,five-hundred fourteen C decades BP. The final attempt dimensions (letter = step 1,433; pick Fig step 1 having site shipping) utilized for the analysis is 406 14 C times out of 47 sites regarding Kanto region, 432 fourteen C dates off 58 websites from inside the Aomori Prefecture, and you can 595 fourteen C times out-of 82 websites into the Hokkaido. So you can slow down the effect of “ascertainment” or “wealth” prejudice i binned the newest fourteen C dates based on the clustering of your indicate 14 C decades BP, having fun with a limit regarding 2 hundred years (cf. ). The brand new ensuing number of bins was 87 to possess Kanto, 128 to have Aomori Prefecture, and 186 having Hokkaido. Studies, supply requirements and you can programs utilized in it functions exists from inside the S2 File plus in new zenodo on the web databases (doi: /zenodo.47339).
Abilities
The statistical testing of noticed SPD of each and every research urban area against its particular installing uniform and you can great null activities (Fig dos) produced a mathematically extreme globally p-worthy of (Desk step one), proving you to a few of the observed fluctuations is legitimate, and never the result of sampling error, taphonomic losses, otherwise a gradual rapid populace boost. Regional deviations regarding the null models emphasized throughout nations good standard go up and you may slide pattern, having a steady increases creating within the start of seven th century BP, and you can standard decline peaking into middle cuatro th century BP (Fig 2). When put next contrary to the rapid model, it decline has stopped being tall, but the total gradual decline carrying out after 5,100000 cal BP prospects the newest occurrence of fourteen C dates lower than the latest hopes of the fresh null model on step 3,900 cal BP basic, and you may next, shortly after a temporary data recovery, at the step three,three hundred cal BP.
The new heavy lines show the fresh 2 hundred-age going mean, whilst the grey ring signifies the fresh new 95% count on period for the null design (top line: consistent shipment; all the way down line: exponential shipment). Reddish and you can blue straight groups portray periods which have high positive and you will bad deviations.
When you look at the Aomori Prefecture, the general trajectory delineated from the SPD is much like a great logistic contour, toward density regarding 14 C dates interacting with a higher tolerance during the 5,five-hundred cal BP. The next interval between 5,500 and you may 4,100 is apparently seemingly stable, with several minor fluctuations deviating regarding null uniform model. In comparison resistant to the great design, the initial moments associated with high-occurrence phase was highlighted because the significant confident deviation, while the temporary (and you can relatively clear) get rid of seen as much as step 3,800–3,700 cal BP.