Swiss records for three species did not show a clear mean trend in the flowering-to-fruit interval in 1996–2025

We tested whether the time from 50% flowering to 50% fruit maturity became shorter in black elder, red elder, and rowan in Switzerland. The main set has 5,036 paired station-year-species records at 92 distinct stations in 1996–2025. We fitted within-station time slopes. Each station had equal total weight within a species, and each species had equal weight in the mean. The mean interval trend was −0.81 days per decade. A joint bootstrap of stations and three-year blocks gave a nominal 95% interval of −2.34 to +0.93. Thus the data did not establish a mean shortening or a constant interval. Mean flowering advanced by 3.15 days per decade, with a 95% interval of 1.42 to 4.77 days earlier. The interval slopes were −2.37 for black elder, −1.65 for red elder, and +1.58 for rowan. The black elder interval excluded zero in the main panel but included zero under a stricter station coverage rule. All planned coverage and block-length checks left the mean interval change uncertain. A separate parser rebuilt all 7,737 valid pairs from original CSV files and matched all nine species slopes. The result describes selected monitoring records for three species. It does not identify a climate cause or measure fruit amount, food supply, or individual fruit development time. The package contains unchanged source data, source hashes, the plan, code, results, figures, and offline reproduction instructions.

phenology · fruit maturity · flowering · Switzerland · Sambucus · Sorbus · paired observations · reproducible data