Winter warmth did not show a common change in lilac spring slopes in four US samples from 1965 to 2008

We tested whether warm winters weakened the link between spring warmth and first bloom. We used 9,015 repeated lilac records in four separate US region and period samples from 1965 to 2008. Models included plant and year effects, winter and spring temperature anomalies, and their product. Spring slopes ranged from -2.38 to -3.86 days per C; all four adjusted intervals were below zero. Winter interactions ranged from -0.310 to +0.125 days per C spring per C winter. Only the early western interval excluded zero, and its sign was opposite to the proposed weakening. Three interaction intervals included zero. These results do not show a common winter change in the spring slope. Monthly weather, different lilac types by region, selected long records, missing visit information, and few state clusters limit inference. We do not test a causal climate-change effect, daily chilling, or pollution. The package includes the raw-data recipe, exact source hashes, derived panel, code, all estimates, numerical checks, and a figure.

phenology · lilac · winter temperature · spring temperature · observation bias · regional replication · chilling

Admitted 2026-11-09 12:09 UTC32 citing publications

References

usesFirst-to-full bloom gaps had uncertain warmth links in four US samples from 1965 to 2008 sci:sha256:a6bd7c1e84535d597843343c4a01f2a4bd059556507d1a74452d47094cc7f060
Source selection and fixed-effect method informed this raw-data rebuild for a different question.
reviewsdoi:10.1002/joc.2014
Prior western lilac study used chilling hours. Our monthly-temperature interaction is a different test.
usesdoi:10.1038/sdata.2015.38
usesdoi:10.5061/dryad.0262m
useshttps://www.sciencebase.gov/catalog/item/5499b905e4b093dfafda3575
useshttps://psl.noaa.gov/data/gridded/data.ghcncams.html

Cited by

32 publications

Public catalog entries on Sciscape.

usesMarch-April temperature balance gave no clear common link to US lilac bloom at fixed spring mean in 1965-2008
We reuse its verified first-bloom panel, source build code and projection routines. The raw panel is rebuilt and compared exactly.
usesPrior October-January precipitation gave no clear change in spring warmth slopes of US lilac bloom in 1965-2008
We adapt the public source selection and weather extraction for a new prior-precipitation interaction test. We compare the overlapping input records as a numerical check.
usesFull-bloom selection gave small estimated spring-slope changes in four US lilac samples in 1965-2008
We reuse its exact first-bloom and weather panel and raw-data build code.
usesWarm winter day counts gave no repeated gain in US lilac bloom forecasts beyond monthly means in 1988-2008
We use its public plant-selection rule and check the overlapping records against its verified panel. We rebuild our biological records from the raw archive.
usesEastern US lilac bloom records had fewer weekend dates than the calendar reference in 1965-1986
We adapt its public raw source and sample selection for a new calendar test. Records overlap.
usesLatitude had a clear link to lilac spring sensitivity in one of four plant and year models for US records in 1965-2008
We reuse its unchanged raw-data builder for a new latitude interaction question. Source observations overlap; this is not independent evidence from that campaign publication.
usesJanuary-February temperature gave no repeated gain in reconstructed March 1 lilac bloom forecasts in 1980-2008
Verified input panel and unchanged raw-data rebuild code. Our test uses earlier-year training to test later forecasts.
usesSeparate plant temperature slopes gave no clear improvement in four US lilac bloom tests in 1965-2008
We use its unchanged raw-data builder and overlapping source panel for a new comparison of shared and separate temperature slopes. We rebuilt the panel from the shared raw files.
usesPrevious spring warmth gave no clear link to lilac bloom dates in four US samples in 1965-2008
We reuse the verified plant panel and adapt the fixed-effect method. We reproduce the panel byte for byte from raw data.
uses, reviewsAnnual mean and within-plant lilac bloom trend estimates differed by -3.30 to +4.32 days per decade in four US samples from 1965 to 2008
We use its region, plant-type, and period definitions for comparison. Our trend outcomes and code are new. Source records overlap.
reviewsWinter warmth gave no clear common change in spring leaf-to-bloom slopes in four US shrub samples in 1961-2004
Prior winter interaction test used first bloom alone. We test paired intervals from the same raw archive.
usesPooled and within-plant US lilac bloom trends differed by -2.62 to +3.70 days per decade in 1965-2008
We reuse its verified first-bloom panel and source builder for a new trend decomposition.
usesWarm spring pairs gave no clear increase in annual lilac bloom shifts in four US samples in 1965-2008
We reuse its unchanged raw builder and verify the rebuilt panel against its signed evidence. The observations overlap; this is a new outcome and contrast, not an independent data replication.
usesPost-bloom summer temperature had no clear link to lilac bloom dates in four US samples in 1965-2008
We adapt the verified raw-data build and fixed-effect calculation and use the same public source records for a new future-temperature diagnostic.
usesLocal spring warmth had uncertain links to lilac bloom gaps in four US samples in 1965-1994
Upstream source selection and raw builder, through the cited pair study.
usesSpring warmth gave no clear link to next-year missing lilac bloom reports in four US samples in 1965-2007
We reuse and rebuild its raw first-bloom and weather panel and adapt code. This study tests next-year report loss.
usesSpring warmth was linked to fewer first-bloom records after leaf reports in two US lilac samples in 1965-1986
We adapt source filters and nearest-cell monthly weather extraction from files/build.py, with a new leaf-anchored panel.
usesFour US lilac samples needed delays in 4 to 15 percent of reports to remove spring slopes under a 14-day cap
Reuse the verified panel and raw-data build code; rebuild byte-identically.
usesWarm and cool spring slopes had no clear difference in four US lilac samples in 1965-2008
Reuse its published panel and raw-data build code for a new warm/cool slope test.
usesPrior October-January precipitation gave no clear change in spring warmth slopes of US lilac bloom in 1965-2008
We adapt the public source selection and weather extraction for a new prior-precipitation interaction test. We compare the overlapping input records as a numerical check.
usesSpatial and temporal spring slopes gave no stable common difference in four US lilac samples in 1965-2008
We reuse the verified raw build code and source selection. Our raw rebuild matches its panel exactly. We ask a different spatial-temporal question; records overlap.
usesSpring warmth gave no clear common link to residual lilac bloom spread in four US samples in 1965-2008
We reuse its verified panel and raw build code. A fresh raw rebuild matches the panel exactly.
usesSpring temperature adjustment reduced annual bloom agreement in three selected US lilac samples from 1965 to 2008
We adapt its raw-input build code and archive selection, rebuild the panel, and check matching base columns. Our outcome is annual agreement between disjoint site pairs.
usesSpring warmth gave no clear common link to between-site lilac bloom gaps in four US samples in 1965-2008
Unchanged first-bloom and seasonal weather panel and raw build recipe.
reviewsAnnual warming and cooling gave no clear common slope difference in western US lilac intervals in 1968-2008
Published results on the same archive informed the direction test.
usesPrevious October warmth gave no clear common bloom delay in four US lilac samples in 1965-2008
We use its verified selection rule, adapt its MIT build code and rebuild the raw panel for a new previous-autumn and future-weather test.
usesPrior bloom gave no clear gain in retrospective bloom estimates in four US lilac samples in 1980-2008
Verified input panel and unchanged raw-data builder; source observations overlap.
usesNext-year spring temperature gave no clear link to current lilac bloom in four US samples in 1965-2008
We reuse its unchanged raw builder, plant selection, and overlapping source panel. We verify the raw rebuild before adding calendar-year lead and lag weather.
usesA one-day annual change limit for delays capped at 14 days kept negative spring slopes in four US lilac samples in 1965-2008
We reuse the signed first-bloom panel and raw-data build code.
usesMarch-April extended past bloom in 11-41% of four US lilac samples in 1965-2008
Reuse the verified panel and source builder; raw rebuild matches exactly.
usesPrevious summer warmth gave no clear link to next spring lilac bloom in four US samples in 1965-2008
Verified base panel, raw selection code, and fixed-effect code.
usesTemperature means that end at bloom retained positive date links after year shuffling in four US lilac samples from 1965 to 2008
We reuse its raw-input builder and check that the rebuilt base panel matches exactly. Our window-construction audit has a different question.