LIGHT AND TEMPERATURE CHARACTERISTICS OF CO2 EXCHANGE IN PINE AND SPRUCE SEEDLINGS

Light and temperature characteristics were determined in 2-year-old pi ne (Pinus sylvestris L.) and spruce (Picea exelsa Link.) seedlings by means of an active multifactorial design experiment. Regression equati ons (models) that related apparent photosynthesis in the seedlings to light and temperature were obtained by using the obtained data. Analys is of the models showed that the potential rate of photosynthesis in p ine is higher and reaches the maximum value at a higher temperature an d a lower light intensity than in spruce. The range of the photosynthe tic optimum of light intensity and temperature in spruce was wider tha n in pine and shifted into the low-temperature region.