Correlation dynamics of transpiration intensity of pinus nigra subsp. Pallasiana with photosynthesis, temperature of needles and some environmental factors during vegetation under the conditions of the southern coast of the Crimea

Abstract

The relationship dynamics of the intensity of transpiration of Pinus nigra subsp. pallasiana with photosynthesis, pine needles temperature and some environmental factors in the process of active plant growth in the Southern Coast of the Crimea was examined. The display function response of transpiration to environmental factors allowed to determine the optima of these dependencies, and to obtain numerical coefficients of nonlinear regression equations for their correlations. During the period of active growth of the plant (June and September), the intensity of transpiration and the studied environmental factors changed: transpiration intensity - by 53.34%, air temperature - by 17.86%, air humidity level - by 42.86% and illumination - by 35.72%. Critical value of optimal temperature of phytosynthesis and transpiration. P. nigra subsp. pallasiana has a high potential for acclimatization at elevated ambient temperatures. The critical temperature of pine needles for this species is 38°C. The relative speed of xylary flow in the plant shoot and changes in its diameter combine the indicators of available moisture in the soil for the plant and the parameters of the environment. The data obtained allow us to interpret the intensity of transpiration as a potential ecological and physiological characteristic of this species. There is an opportunity to compare the results of our research with known from literary sources for the various species and subspecies of pines growing in similar climatic conditions using identical techniques.