The effect of artificial forest plantations on the thermophysical properties of chernozems

Abstract

As a result of a study of the effect of artificial forest plantations formed by Robinia pseudoacacia L. and Quercus robur L., on the thermophysical features of the chernozems of the Komissarovsky reserve (Pyatykhatsky district, Dnepropetrovsk region, Ukraine), it was found that the stand of robinia reduced air temperature by 4, 5 °С, oak – by 9.4 °С in comparison with the open area. The maximum temperature of the soil surface is found in ordinary chernozem. The effect of robinia plantation manifested itself in the form of a decrease in the temperature of the soil surface by 5.4 °C, and the oak surface by 8.0 °C. The maximum soil temperature at a depth of 50 cm is also found in ordinary chernozem. At the same depth, the soil under robinia plantation turned out to be 7.6 °C, under oak – 6.9 °C colder. According to the average temperature of the 50-centimeter layer of all the studied soils, ordinary chernozem is distinguished, the soils under the plantations almost do not differ according to this indicator. The smallest difference between the air temperature and the average temperature of the soil layer 0–50 cm was in the soil under oak plantation, the largest – in the soil under robinia plantation. The smallest difference between the temperature of the soil surface and at a depth of 50 cm was found in the soil under oak plantation, and the greatest difference in the soil under robinia plantations. Based on the analysis of the results obtained, an assumption was made about the thermal features of the upper horizons, which fall within the interval of 0–50 cm, of each of the three studied soils. The soil under robinia plantation is characterized by maximum values of thermal diffusivity, and ordinary chernozem – minimal. The soil under the oak plantation occupies an intermediate value for this indicator. Ordinary chernozem is characterized by maximum values of heat capacity, slightly smaller values are characteristic of soil for robinia plantations. The minimum values of heat capacity are characteristic of oak plantation soil. The soil under robinia plantation is sharply distinguished by the maximum values of thermal conductivity compared to ordinary chernozem and the soil under oak planting. The actual study of thermophysical properties confirmed the correctness of the assumption in only one of the three indicators for each of the studied soils. This indicates a significant limitation of predicting the thermophysical indicators of soils, based only on measuring their temperature. The influence of robinia plantation on the thermal physical properties of ordinary chernozems is manifested in an increase in their thermal diffusivity and thermal conductivity, as well as in a certain decrease in heat capacity. The influence of oak stands is characterized by an increase in thermal diffusivity and heat capacity, as well as a decrease in thermal conductivity of ordinary chernozem.