Figures and data
A diagram showing the relationships among forcing change (FC, difference in spring forcing (degree days) between baseline ∑1i TCi and warmer ∑1i TWi climates at budburst with the baseline climate OCi), expected response (NE, difference between baseline and warmer climates in reaching species forcing threshold, i.e., ∑1i TCi at OCi), budburst temperature (FC/NE, average temperature or rate of forcing accumulation at budburst with the warmer climate), and phenological lag (NC, difference between expected NE and observed NO responses or between expected EWi and observed OWi phenology with the warmer climate).
Observed responses and phenological lags (least square means ± standard errors) in leafing and flowering (left and right set of bars in each pair, respectively) by research approach (observational and experimental), species origin (native and exotic), climatic region (boreal and temperate), and growth form (tree, shrub, herb, and grass) extracted from reported plant phenological changes in spring. Phenological lags are calculated from the differences between observed responses and those expected from species-specific changes in spring temperatures. Different letters indicate means differ significantly (p<0.05).
Mean values of climatic, phenological, and biological variables by budburst (leafing or flowering), research approach (observational or experimental), species origin (native or exotic), climatic region (boreal or temperate), and growth form (tree, shrub, herb, or grass).
Budburst temperature = average temperature at budburst under the warmer climate, forcing change = warming-induced changes in spring forcing prior to budburst, spring warming = average spring temperature change, and phenological lag = difference between observed response and that expected from forcing change and budburst temperature.
