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

Abstract

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 °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.

Water content in soil afforested with a mixture of broadleaves or Scots pine

“…During the period from the end of March 2021 to the beginning of April 2022, the minimum temperatures (a depth of 20 cm) for every day ranged from 1.0 °C to 24.3 °C on the control plot, from 1.4 °C to 18.3 °C in case of broadleaves, and from 1.4 °C to 17.6 °C on the plot with Scots pine (Figure 1). The course of air temperatures (20-60 cm above the ground) in the period from April to the beginning of November 2021 is described by Vopravil et al (2022). Concerning air temperatures in the period from the end of March 2021 to the beginning of April 2022, the minimum daily values on the control plot (60 cm above the ground level) ranged from -12.8 °C to 18.1 °C and the maximum daily values from -4.3 °C to 36.9 °C (Figure 2 and Figure 3); the average daily temperatures ranged from -7.5 °C to 26.3 °C (Figure 4).…”

“…As described by Vopravil et al (2021Vopravil et al ( , 2022, the used experimental plots were established near the Hovorčovice village in the Czech Republic on Haplic Chernozem (IUSS Working Group WRB 2015) -a mean annual air temperature of 8-9 °C, mean annual precipitation of 500-600 mm, and a sum of air temperatures above 10 °C between 2 600 and 2 800 (warm, mildly dry region of the Czech Republic). The afforestation of agricultural land with Scots pine (Pinus sylvestris L.) or with a mixture of pedunculate oak (Quercus robur L.), red oak (Quercus rubra L.), and Norway maple (Acer platanoides L.) was performed in the year 2011 -three squares 10 m × 10 m (1 m × 1 m spacing, 100 trees per square) in case of each of the variants, the alternation of lines with individual forest tree species in the mixture of broadleaves.…”

“…A rain gauge [Pronamic Professional Rain Gauge, 200 cm 2 , accuracy 0.1 mm, datalogger Minikin ERi (EMS Brno, Czech Republic)] was placed on the control plot. As described by Vopravil et al (2022), volumetric water content and soil temperature at depths of 20 cm, 40 cm, and 60 cm and air temperature (20 cm, 40 cm, and 60 cm above the ground level) were continuously measured on the experimental plots using TMS-4 (TOMST, Czech Republic); see www.tomst.com). Selected physical and chemical soil properties on the study plots including seasonal changes in soil temperature and volumetric water content (and precipitation) in the period from April to the beginning of November 2020 are described by Vopravil et al (2021); seasonal changes of air temperature in the period from April to the beginning of November 2021 are described by Vopravil et al (2022).…”

“…As described by Vopravil et al (2022), volumetric water content and soil temperature at depths of 20 cm, 40 cm, and 60 cm and air temperature (20 cm, 40 cm, and 60 cm above the ground level) were continuously measured on the experimental plots using TMS-4 (TOMST, Czech Republic); see www.tomst.com). Selected physical and chemical soil properties on the study plots including seasonal changes in soil temperature and volumetric water content (and precipitation) in the period from April to the beginning of November 2020 are described by Vopravil et al (2021); seasonal changes of air temperature in the period from April to the beginning of November 2021 are described by Vopravil et al (2022). In this study, changes in volumetric water content at a depth of 20 cm (the control plot) or at depths 20 cm, 40 cm, and 60 cm (both afforested plots) in the period from the end of March 2021 to the beginning of April 2022 are presented.…”

“…Afforestation of agriculturally used land has many benefits, which are described in different publications, including the effects on local and regional climate or carbon storage (see the Introduction in Vopravil et al 2021Vopravil et al , 2022. Carbon stocks in tree biomass, mineral soil, organic layer on afforested land are described in the publications by Podrázský and Remeš (2008), Hiltbrunner et al (2013), Wasak and Drewnik (2015), Cukor et al (2017), Vacek et al (2021) etc.…”