Method for the evaluation of thermal requirements for development based on phenological observations

Abstract

A new method for the evaluation of threshold temperature of development involving phenological observations and based on hyperbolic imaging of dependence between the day of development and temperature values close to the threshold was proposed. The rare species Clematis integrifolia was used as an example to evaluate thermal requirements for six stages of its development. The method proposed in this study was also compared with some common methods for the estimation of threshold temperature basing on phenological data.