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Plant transpiration, entropy production and gross primarily productivity
Šír, M. ; Tesař, Miroslav ; Lichner, Ľ.
The Earth is a self-organized system. The source of information for self-organization is the degradation of solar radiation. The solar energy is highly organized and carried by photons. Earth absorbs this energy and then releases it back to the Universe. However, energy released to the environment is in the form of electromagnetic radiation, which is on average at longer wavelengths than the absorbed photons. The flow of the entropy associated with the energy conversion, which is at disposal for the self-organization, is approximately equal to 1.16·10.sup.38./sup. bit·.sub.s./sub..sup.-1./sup. (Roland-Mieskowski, 1994). The nature of self-organization is a theme of contemporary scientific discussion. The core of this discussion is the role of biotic processes. Lovelock and Margulis (1974) formulated a theory that the self-organization in a global scale is an emergent characteristic of the Earth’s biota (Gaia theory).
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Hydrology of small watershed 2005
Šír, Miloslav ; Lichner, Ľ. ; Tesař, Miroslav ; Holko, L.
The book includes the full text of 48 scientific articles. These articles were prepared as the contributions for the Conference with international participation “Hydrology of a small basin 2011” that was held from September 14th to September 15th 2005 in Prague. The Conference was organized by the Institute of Hydrodynamics ASCR, v.v.i. in Prague; Institute of Hydrology SAS in Bratislava; the Czech Water Management Society in Prague and Czech Committee for Hydrology. The book was published by the Institute of Hydrodynamics ASCR, v.v.i. in Prague in 2005.
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Hydrology of small basin 2008
Šír, Miloslav ; Tesař, Miroslav ; Lichner, Ľ.
The book includes the full text of 48 scientific articles. These articles were prepared as the contributions for the Conference with international participation “Hydrology of a small basin 2011” that was held from April 23th to April 24th 2008 in Prague. The Conference was organized by the Institute of Hydrodynamics ASCR, v.v.i. in Prague; Institute of Hydrology SAS in Bratislava; the Czech Water Management Society in Prague and Czech Committee for Hydrology. The book was published by the Institute of Hydrodynamics ASCR, v.v.i. in Prague in 2008.
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Hydrologic extremes and gross primary productivity in the Liz catchment
Šír, Miloslav ; Tesař, Miroslav ; Lichner, Ľ. ; Váchala, J. ; Krejča, M.
The synergy between hydrologic extremes, plant transpiration, gross primary productivity, and soil water retention was studied in the experimental area Zábrod – meadow in the Bohemian Forest. Heat balance, potential and actual transpiration, entropy production and gross primary productivity were evaluated. It was found that the soil water retention is the crucial factor determining hydrologic pattern and gross primary productivity. Insufficient soil water retention leads to small entropy production by evaporation and small gross primary productivity, which results in the extremalization of the hydrologic cycle. On the other hand, in the case of sufficient soil water retention, high entropy production by transpiration and high gross primary productivity leads to the stability of the hydrologic cycle.
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Mikroskopická variabilita hydraulických vlastností půdy v borovicovém lese u obce Sekule na jihozápadě Slovenska
Orfánus, T. ; Lichner, Ľ. ; Šír, Miloslav ; Tesař, Miroslav
The variability of water repellency of pine-forest arenic Regosols and its influence on the infiltration process were estimated at the locality of Mláky II near Sekule in south-west Slovakia. The water drop penetration time (WDPT) tests of soil water repellency and infiltration tests with a miniaturized tension infiltrometer (3 mm diameter) at single-sample scale (100 cm3 volume, 22 cm2 surface) were performed. Extreme heterogeneity of water repellency and infiltration velocity was recorded. All the results suggested that the hydraulic properties of the soil are changing at millimetre scale due to the presence of unevenly distributed hydrophobic material.
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Formování odtoku v revitalizované podhorské pramenné oblasti v Senotíně
Tesař, Miroslav ; Syrovátka, O. ; Lichner, Ľ.
The purpose of the Senotín pilot project (1993–2000) was to determine methods of revitalisation of a sub-mountain headwater area (0.38 km2) in the Novobystřická Vysočina Highlands (610–725 m a. s. l.). Seven underground clay shields stopped pipe drainage, and four balks prevented surface and subsurface runoff. These adaptations improved the water retention capacity of the whole catchment, as demonstrated by the formation of runoff in the revitalised area. A typical rainstorm (amount 15 mm, duration 5.6 hours, max. intensity 1.8 mm/20 minutes) and consequent runoff was analysed, along with the role of soil in runoff retardation and water retention. The time course of the contributing area was also quantified. The contributing area was formed in the surface soil layer with a thickness of about 40 cm. Runoff retardation lasted two hours after the rain began. Retention reached 98% of the total rainfall. Runoff lasted for 85 hours.
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Vliv vegetace na tepelnou bilanci a výměnu entropie
Šír, Miloslav ; Weger, J. ; Tesař, Miroslav ; Lichner, Ľ.
The aim of this study is to quantify the synergy between the vegetation cover, solar radiation, air temperature and soil moisture. Heat balance, potential and actual transpiration, and net entropy exchange at three localities under different plant cover was studied in order to determine crucial factors determining phytomass productivity in cold climatic areas of Bohemian Forest. The phytomass productivity can be quantified by the entropy exchange associated with the latent heat flux. Water shortage is a crucial factor determining phytomass productivity in dry and warm seasons in cold climatic conditions of Czech mountains.
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Plant transpiration and self-organization of hydrologic cycle
Šír, Miloslav ; Lichner, Ľ. ; Tesař, Miroslav
We quantified the influence of plant transpiration on the entropy production associated with the degradation of solar energy on the Earth’s surface covered by plants. Two surfaces were studied: (1) biotic surface – plant transpiration taken as equal to the potential one, (2) abiotic surface – plant transpiration taken as if equal to zero. Two sources of entropy were taken into account – the entropy production associated with the conversion of solar radiation into (1) the sensible heat, and (2) latent heat. Surface processes in hydrologic cycle were examined in the experimental watershed Liz located in the Bohemian Forest (Czech Republic). We found that in the growing season 1992 the entropy production in humid hydrologic cycle (the Earth’s surface is biotic) was considerably higher than in the arid one (in 39 % of days the Earth’s surface behaved as biotic, in 61 % of days behaved as abiotic). Considering that the biotic effect on the Earth’s functioning can be assessed using the entropy production, we can assume that the hypothesis that biota – represented as a biotic surface – regulates Earth’s environment is proved in the watershed scale.
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