Shoot Elongation in Scots Pine: Diurnal Variations and Response to Temperature

Publisher Website
Google Scholar
Abstract
Kanninen, M. 1985. Shoot elongation in Scots pine: Diurnal variations and response to temperature.—J. exp. Bot. 36: 1760–1770. Time series analysis is used to study the diurnal variations in the rate of shoot elongation of Scots pine (Pinus sylvestris L.) seedlings, and its response to temperature. The shoot elongation of three 5-year-old Scots pine seedlings was measured at 2 h intervals over a 12 d period in June 1979. Ambient temperature, measured with a thermocouple, was continuously recorded during the same period. The measurements were carried out in the field. Time series analysis of the data was carried out by estimated auto-correlation and partial auto-correlation functions. A multiplicative ‘seasonal’ model was applied to both the input and output series to ‘prewhiten’ the data set. Serial cross-correlation analysis of the prewhitened series was used to identify the structure of the transfer function model between temperature and growth rate. There was a phase shift between the air temperature and shoot extension. The cross-correlation function peaked at 2 h lag value. The influence of temperature on the growth rate was adequately described by a first-order transfer function model. The characteristic feature of the model was a time constant of 3.3 h and a base temperature of 6.3 °C for the response of shoot elongation to temperature.