Leaf and flower development intervals gave no common residual link in four US shrub samples in 1965-2008

We tested whether leaf expansion and flower opening took more time in the same shrub-years. Four separate event dates avoid the shared-date variance term in adjacent intervals. Plant and year models with March-April and May temperature controls used 9,569 plant-years in four East and West samples in 1965-1986 and 1987-2008. Residual correlations ranged from -0.100 to +0.051. All four primary covariance intervals included zero after correction for four comparisons. A negative later western estimate did not repeat across samples. A plant-trend sensitivity gave an isolated negative interval. The test does not show biological independence. Missing visits, selected complete records, mixed taxa, coarse weather, and approximate state-year uncertainty limit inference. The package includes the derived panel, raw source hashes, code, a separate numerical check, all model results, and a figure.

phenology · observation bias · leaf expansion · flower opening · separate endpoints · residual covariance · null result