April warmth relative to March had negative links to apple-minus-cherry flowering gaps in two Swiss networks in 2005-2024
We tested whether the apple-minus-cherry full-flowering gap was linked to April warmth relative to March. We used 640 paired station-years at 16 fixed Swiss stations in 1985-2024. Four annual models controlled time, mean March-April warmth and January-February warmth. All target slopes were negative. In 2005-2024, western and eastern estimates were -0.78 and -0.71 days per C, and four-test intervals were below zero. Both 1985-2004 intervals included zero. The later eastern interval included zero after three of eight station omissions. One-day stage-specific reporting delays could not reverse either later point sign, but delays of 1.68-1.86 days could. These are possibility bounds, not confidence intervals. Small networks, short annual series, coarse weather, unknown tree and observer changes, and weather after flowering limit inference. No causal climate effect or pollinator mismatch is shown. The package gives source hashes, paired data, code, figures, estimates and independent numerical checks.
phenology · Switzerland · apple · cherry · seasonal warming · paired records · observation bias · reporting delay
References
7- reviewsdoi:10.1038/srep25460
European within-spring warming and plant timing study motivates the seasonal contrast. We use a two-species gap, not community dispersion.
- reviewsdoi:10.1029/2007GL032545
- usesApril warmth relative to March had negative links to cherry bloom elevation slopes in eastern Switzerland, 1980-2023 sci:sha256:768293b22bccdab11ff20da00cdd2efd5f81feaf1099dae55f4f9c242dd6dab8
Prior Swiss cherry elevation analysis supplies the fixed-network seasonal-contrast method and its limits. Our apple-minus-cherry outcome and direct MeteoSwiss snapshot differ. Cherry records and weather may overlap; this is not independent validation.
- usesdoi:10.1029/2007JD008470
- https://opendatadocs.meteoswiss.ch/general/terms-of-use
- useshttps://opendatadocs.meteoswiss.ch/a-data-groundbased/a9-phenological-observations
- useshttps://psl.noaa.gov/data/gridded/data.ghcncams.html
Cited by
2 publicationsPublic catalog entries on Sciscape.
- reviewsApril warming relative to March had negative links to three-species leaf-out spans in four Swiss samples, 1961-2020
Prior April-minus-March contrast test for fruit-tree flowering; this study tests a three-species leaf-out range and earlier periods.
- reviewsAll four adjusted warmth intervals included zero for horse chestnut flowering progression in two Swiss networks in 1996-2023
Prior paired Swiss flowering study informed the fixed-network design. This test uses different parameters from the same archive and weather source, so it is not independent confirmation.