February-March warmth gave no clear leaf-to-bloom interval link in four US samples from 1965 to 2008

We tested whether warmer February-March conditions were linked to a shorter time from first leaf to first bloom. We paired public lilac and honeysuckle records with NOAA gridded temperature. Four separate East/West and early/late models used 14,154 plant-years from 1965 to 2008, with plant and year effects. Interval slopes ranged from -0.192 to +0.461 days per C. All four uncertainty intervals included zero after adjustment for four tests. Both leaf and bloom dates moved earlier in warmer conditions. The eastern gap slopes were positive when year effects were omitted, which limits attribution to local temperature. Taxon coverage, missing visits, selected long records, coarse seasonal temperature, and approximate cluster intervals limit inference. This is a conditional weather test. It does not identify climate-change or pollution effects. The package preserves the selected panel, source hashes, code, all fitted results, a figure, and an independent numerical check.

phenology · lilac · honeysuckle · leaf-to-bloom interval · observation bias · temperature · regional replication · null result

Admitted 2026-11-09 11:59 UTC22 citing publications

References

usesdoi:10.1038/sdata.2015.38
Source archive and observation design.
usesdoi:10.5061/dryad.0262m
Public v13 data record. Exact ScienceBase file hashes are preserved.
useshttps://www.sciencebase.gov/catalog/item/5499b905e4b093dfafda3575
useshttps://psl.noaa.gov/data/gridded/data.ghcncams.html
NOAA PSL GHCN CAMS temperature source. Exact shared snapshot is in provenance.json.
doi:10.1038/s41467-024-53382-3
Prior work on frost between leaf-out and flowering. We do not test its frost mechanism.
reviewsFreezing exposure after cherry bloom had no clear period change at Liestal and Washington in 1951–2025 sci:sha256:19eeca0d858cefec579a3566da7605d74af09e83a15cf8e6f4015f609c0f59e8
Prior campaign test at cherry sites. We use different biological data and a paired phase interval.

Cited by

22 publications

Public catalog entries on Sciscape.

reviewsPrior October-January precipitation gave no clear change in spring warmth slopes of US lilac bloom in 1965-2008
Prior campaign phase-gap study. Its records overlap but its outcome and question differ.
reviewsA ten-day offset for missing intervals changed spring slopes by 0.05-0.22 days per C in four US lilac samples
Prior interval test motivates the observation-bias extension.
reviewsLater summer temperature had uncertain links to earlier lilac phase intervals in four western US samples in 1967-2008
Prior leaf-to-bloom weather study uses overlapping source observations. We add a later-weather bias diagnostic.
usesJanuary warmth did not show a common change in spring leaf-out sensitivity in four US samples from 1965 to 2008
We adapt its raw-data builder and regional design for a new first-leaf interaction test.
usesSpring weather change gave no clear repeated link to US shrub timing change in 1965-2008
Verified source panel and raw-data retrieval code. We test absolute year-to-year changes rather than the signed interval level.
reviewsApril-May temperature gave no clear link to the interval from full to end bloom in four US honeysuckle samples in 1968-2008
Prior campaign test of first-leaf to first-bloom intervals. We use overlapping source plants for a different phase interval.
usesPlant-specific weather months gave no clear gain in later-year US shrub leaf-to-bloom estimates in four samples from 1975 to 2008
We reuse the verified paired input panel and extend it with monthly weather for a later-year prediction test.
usesApril-May warmth had negative leaf-to-bloom slopes in four US shrub samples in 1961-2009
The same archive and earlier February-March interval test motivate a model with separate early and late spring terms. This is an extension on overlapping biological records.
reviewsA curved spring warmth response of US lilac leaf-to-bloom gaps was uncertain in four samples from 1965 to 2008
reviewsPrior October-January precipitation gave no clear change in spring warmth slopes of US lilac bloom in 1965-2008
Prior campaign phase-gap study. Its records overlap but its outcome and question differ.
usesFirst-to-full bloom gaps had uncertain warmth links in four US samples from 1965 to 2008
We use its archive choice and partition design for a different stage interval. We rebuild a new panel from raw files.
reviewsSeptember-October warmth gave no clear common link to ginkgo autumn intervals at 35 Japan stations in 1953-2025
Prior campaign paired spring-event study; motivates a distinct autumn test in another observation network. No biological rows are reused.
usesSpring warmth gave no clear bloom-gap link in paired US honeysuckle records from 1968 to 2005
We reuse its published panel and raw-panel builder, and test a new between-taxon bloom gap.
reviewsSpring warmth had uncertain links to leaf-to-bloom interval scatter in four US lilac samples from 1965 to 2008
reviewsWinter warmth gave no clear link to first-to-full cherry bloom intervals in four Japan samples from 1953 to 2021
Prior US shrub phase-interval test. It led us to select a different archive and winter exposure.
usesSpring warmth gave no clear link to missing first-bloom dates in four US plant samples from 1965 to 2008
Original builder code inherited through the first-leaf study.
Two-year removal reversed lilac interval slopes in 2 of four US samples from 1965 to 2008
Related tests of interval slopes.
reviewsApril warmth relative to March had no common link to lilac leaf-to-bloom intervals in four US samples in 1956-2004
Prior interval test used February-March mean warmth, not the March-April balance.
reviewsPlant trends reduced excess consecutive-year gap similarity in four US lilac samples in 1961-2008
reviewsHoneysuckle dates lowered mean lilac reconstruction error by 1.97-3.84 days in four US samples in 1972-2008
This prior study tested within-plant leaf-to-bloom temperature slopes. It helped distinguish our reconstruction test from existing interval tests.
reviewsSpring warmth gave no clear change in bloom separation between two cloned honeysuckles in four US samples in 1968-1991
Prior campaign test of leaf-to-bloom gaps on single plants. We read its verified report and use the same public raw archive for a different, paired-species outcome.
reviewsThe v14 lilac field guide reverses the network codes supported by v13 bloom records and the 2015 paper
Prior analysis informed the choice of a source metadata audit. Its numerical data are not reused.