Statistical evaluation of bud development theories: application to bud burst of Betula pendula leaves

Resampling methods were used to evaluate models based on alternative bud de velopment theories applied to Betula pendula Roth data. Statistical testing based on the bootstrap method showed that the mean square errors (MSE) of the predicted bud-burst dates of two models, in which the start of ontogene tic development depended on dormancy development only, did not differ signi ficantly However, the MSE of the model in which the start of ontogenesis de pended on a signal from light climate, indicated by using a fixed calendar date, was significantly smaller than that of the models depending on dorman cy development. Model parameters were highly multi-collinear; i.e., sensiti ve to changes in the data. The cross-validation method was used to determin e the prediction error of the models. The predictive ability of the models was not much less for an independent data set than for the original data.