The effect of grass transpiration on the air temperature

0436767 - ÚH 2015 RIV SK eng J - Journal Article
Šír, M. - Tesař, Miroslav - Lichner, Ľ. - Czachor, H.
The effect of grass transpiration on the air temperature.
Biologia. Roč. 69, č. 11 (2014), s. 1570-1576. ISSN 0006-3088. E-ISSN 1336-9563
Institutional support: RVO:67985874
Keywords : air temperature oscillations * embolism * plant transpiration * soil water * tensiometric pressure * xylem tension
Subject RIV: DA - Hydrology ; Limnology
Impact factor: 0.827, year: 2014

Oscillations of the air temperature and tensiometric pressure of the soil water were measured in the experimental slope Tomšovka (Czech Republic, Jizera Mts, 822 m a.s.l.). The brown forest soil (Dystric Cambisols) is covered with Calamagrostis villosa, Avenella flexuosa and Vaccinium myrtilus. Thermometers were placed at a height of 5 and 200 cm above the grassland. The tensiometer was installed in the root zone of grass at a depth of 15 cm. Oscillations in a cloudless day, August 24, 2001, (sunshine duration 12.1 hour/day, daily total of global radiation 22.4 MJ/m² /day, maximum intensity of global radiation 1008 W/m² , transpiration 13.7 MJ/m² /day) were analysed in detail. The oscillations with a period of about 30 to 60 minutes were recorded in the air temperature course taken from 11 am to 5 pm. At the height of 200 cm oscillations ranged from 24 to 28°C. Concurrently, in the depth of 15 cm, the oscillations of tensiometric pressure in the range of –6 to –11 kPa were recorded from 8 am to 4 pm. It was concluded that the oscillations in the air temperature resulted from autonomous and self-regulated oscillations in the intensity of transpiration. It is evident that the 2-m air temperature was significantly influenced by transpiration of plants around the large area. The fact that the air temperature oscillated sharply confirms that the rate of transpiration was synchronized in this area. Vegetative cover thus created a self-regulated superorganism that substantially affected the temperature of the near-ground atmosphere layer.
Permanent Link: http://hdl.handle.net/11104/0240471