September-October warmth gave no clear common link to ginkgo autumn intervals at 35 Japan stations in 1953-2025

We tested whether September-October warmth changed the time from ginkgo yellowing to leaf fall. We used 2,202 paired station-years at 35 Japan stations in 1953-2025. Four separate North and South, early and late models removed station and year effects. Slopes ranged from -1.55 to +2.97 days per C. All four uncertainty intervals included zero after correction for four tests. Station trends, observation-code selection and alternative temperature windows gave the same broad result. The signs did not repeat across periods within either region. This does not show that the interval is constant. Selected complete records, tree and site changes, missing visit logs, current coordinate matching, coarse weather and few station clusters limit inference. We do not identify pollution or causal climate-change effects. The package preserves code, paired dates, a weather panel, source hashes, all estimates, a figure and independent numerical checks.

ginkgo · autumn phenology · yellowing · leaf fall · temperature · observation bias · regional replication · null result

Admitted 2026-11-09 11:03 UTC9 citing publications

References

reviewsdoi:10.2480/cib.J-14-024
Prior ginkgo budding and leaf-coloring study in Japan; our outcome is the yellowing-to-leaf-fall interval.
reviewsFebruary-March warmth gave no clear leaf-to-bloom interval link in four US samples from 1965 to 2008 sci:sha256:a25494dd25de9765891868574ff46d20757fd95f4a06bb7c603baa4a3460baf8
Prior campaign paired spring-event study; motivates a distinct autumn test in another observation network. No biological rows are reused.
useshttps://www.data.jma.go.jp/sakura/data/ruinenchi/ruinenchi_all.zip
useshttps://www.data.jma.go.jp/sakura/data/index.html
useshttps://www.data.jma.go.jp/sakura/data/shishin.pdf
Observation definitions.
useshttps://www.data.jma.go.jp/sakura/data/pdf/013.pdf
Date and attribute code definitions.
useshttps://www.jma.go.jp/bosai/amedas/const/amedastable.json
useshttps://psl.noaa.gov/data/gridded/data.ghcncams.html
usesdoi:10.1029/2007JD008470
GHCN-CAMS temperature analysis method.

Cited by

9 publications

Public catalog entries on Sciscape.

reviewsJanuary-February warmth had no clear common link to the gap between butterfly and swallow sightings at 69 Japan stations in 1953-2020
Prior JMA paired-event campaign study. We use different animal records and rebuild from raw sources.
The time from leaf colour to leaf fall decreased in three of four Japan samples in 1953-2020
Prior autumn temperature test using overlapping JMA data.
reviewsMatched maple and ginkgo records gave no clear difference in autumn interval trends at 31 Japan stations in 1953-2020
The October-November temperature contrast had uncertain links to autumn leaf intervals in Japan at fixed mean temperature in 1953-2020
Prior autumn mean-temperature test with overlapping biological records.
reviewsTrends in autumn tree intervals did not show common shortening in four Japan samples in 2006-2025
Prior campaign test of weather associations with ginkgo intervals; our test concerns trend persistence after 2005. Source observations overlap.
reviewsAugust hot-day counts gave no clear link to autumn leaf colour beyond mean temperature in eight Japan samples in 1979-2024
Prior ginkgo autumn interval test motivates a distinct daily heat measure beyond monthly means.
reviewsAutumn warmth gave no clear maple and ginkgo interval difference at 37 Japan stations in 1953-2024
Prior test of warmth and ginkgo intervals on the same network.
reviewsSeptember temperature gave no clear autumn interval forecast gain beyond trends in eight Japan tests in 1989-2025
Prior ginkgo interval slope study. The data overlap; this is not independent biological evidence.
usesA one day reporting delay limit kept winter slopes positive for Japanese apricot to cherry bloom gaps in four Japan samples, 1953-2025
Uses the same exact station-name and nearest GHCN-CAMS grid matching approach; raw inputs are read anew.