The impact of agricultural land afforestation on air temperatures near the surface

Many studies showed that afforestation increases carbon storage and it can have effects on physical, chemical and biological properties of soil. Afforestation can affect local and regional climate and these effects differ between tropical, temperate and boreal areas. Forests are also efficient in protecting soils against erosion and their flood mitigation functions or other benefits are described in different publications. In this study, the pattern of air temperatures (20 cm, 40 cm and 60 cm above the surface) was studied 10 years after the afforestation of agricultural land (warm, mild dry region of the Czech Republic) with a mixture of broadleaved tree species (Quercus robur L., Quercus rubra L. and Acer platanoides L.) or monospecific Pinus sylvestris L. stand. The aim of our study was to find out the pattern of air temperatures (20 cm, 40 cm and 60 cm above the surface) on two plots (one of the plots - old beech trees, the other plot - clearing) in a beech (Fagus sylvatica L.) forest in a mildly warm, mildly wet region of the Czech Republic. The afforestation of agriculturally used land led to air temperature cooling and to a reduction of the amplitude of maximum and minimum temperatures. The average air temperature (from April 2021 to the beginning of November 2021) decreased by 0.7-1.1 degrees C on the afforested plots compared with the agriculturally used plot. In the beech forest, the average temperature decreased on the plot with clearing compared with the old beech trees (from the middle of September 2021 to the middle of November 2021). Our results confirm the benefits of afforestation to climate change mitigation; buffering of extreme temperatures is important for the human thermal comfort.