|
|
Vliv srážkových a teplotních poměrů v období 1961–2100 na možnosti pěstování smrku ztepilého v ČR
Cudlín, Pavel ; Štěpánek, P. ; Macků, J. ; Kohout, M. ; Rožnovský, J.
Pro zjištění pravděpodobnosti rozpadu smrkových ekosystémů vlivem klimatické změny, byly nejprve spočítány pro dva hlavní klimatické parametry (teploty a srážky) a dva klimatické extrémy (délka suchých období a počet tropických dnů) prostorové průměry pro všechny lesní vegetační stupně (LVS), vyskytující se v jednotlivých přírodních lesních oblastech (PLO). Riziko rozpadu pro hlavní typy vývoje lesa pro jednotlivé LVS v rámci PLO bylo odhadnuto na základě srovnání klimatických parametrů v 5 obdobích (1961–2099). Pro období A (1961–1990) a B (1991–2009) byla použita data z měřicích stanic, pro období C (2010–2039), D (2040–2069) a E (2070–2099) byla data získána z klimatického modelu ALADIN-Climate/CZ. Tento postup umožnil rozlišit pro jednotlivá období tzv. “teplé” PLO, které již alespoň v některých klimatických parametrech překročují ekologickou valenci smrku pro dané období,a “studené PLO”, které ještě těmto nárokům vyhovují.
|
|
|
The dynamics of temperature in birdboxes
Slavíková, Z. ; Žalud, Z. ; Bartošová, Lenka ; Fischer, Milan ; Trnka, Miroslav
The aim of the study was to detect the changing temperature in bird boxes of two bird species-collared flycatcher (Ficedula albicollis, T.) and great tit (Parus major, L.). The work is the result of the monitoring of nesting bird species for two years (2009 and 2010) by temperature sensors. Data was continuously recorded for several different breeding pairs with the micro-datalogers MINIKIN. Temperature sensors were fixed directly into the nest with eggs and also in the upper part of bird boxes or outside the boxes. Temperature data was then processed and analyzed. Experimental work was carried out in a floodplain forest in nature reserve Plačkův les a říčka Šatava near Vranovice, altitude: 170; latitude: 48°56´54´´; longitude: 16°35´50´´. The forest is dominated by full-grown, multi-aged canopy with no forestry management. Experimental site belongs to the same natural biogeocenoses group (i.e. Ulmi-fraxineta carpini) and to the same geobotanical group (i.e. suballiance Ulmenion of the Alnion incanae alliance). Our initial hypothesis assumed that the temperature of eggs in the nest and also the time spent in the bird boxes by both bird species (collared flycatcher and great tit) do not differ significantly. The results showed that during the period when the eggs were layed (by both bird species) the temperature were significantly however the temperature of eggs of collared flycatcher and great tit during the period of incubation were very.
|
|
|
Stomatal conductance of short rotation coppice based on sap flow measurements and its response to chosen meteorological variables
Orság, Matěj ; Trnka, Miroslav ; Fischer, Milan ; Kučera, J. ; Žalud, Zdeněk
The main aim of this study was to derive stomatal conductance (gs) from sap flow measurements and explore some of possible applications of this method. Sap-flow and other meteorological variables were continuously monitored in poplar-based short rotation coppice (SRC) plantation in Bystřice nad Pernštejnem during growing season 2012. Sap flow of 8 trees was measured using heat dissipation method, then expressed as transpiration per square meter of projection area and by adding into rewritten Penman-Monteith equation the canopy conductance (gs) was obtained. Compared with direct measurements on leaf level this approach is advantageous for obtaining gs, because of integrating all leaf categories of tree or whole canopy. Further analysis also proved, that gs is strongly driven by VPD. Finally, it was found that the relationship between gs and VPD is also influenced by available soil moisture content.
|
|
|
Using remotely sensed NDVI for drought impact assessment within selected crops
Hlavinka, Petr ; Trnka, Miroslav ; Semerádová, Daniela ; Dobrovolný, P. ; Balek, J. ; Možný, M. ; Štěpánek, P. ; Hayes, M. ; Svoboda, M. ; Wardlow, B. ; Žalud, Zdeněk
The relationship between Normalized Difference Vegetation Index (NDVI) and selected agrometeorological parameters (yields of selected crops, water balance) was investigated. The source for NDVI was Spectroradiometer MODIS within satellite Terra and it was available for grids in resolution 500 x 500 m from 2000 to 2010. The analysis was conducted within 12 grids spread through Southern and Central Moravian region. The information about cultivated crops (including spring barley, winter wheat, maize for grains, sugar beet and winter rape) were collected from the farmers and water balance simulated using SoilClim model.
|
|
|
The responses of two resident and one long-distance migrant bird species to weather conditions in Czech Republic
Bartošová, Lenka ; Trnka, Miroslav ; Bauer, Z. ; Možný, M. ; Štěpánek, P. ; Žalud, Zdeněk
This analyse include three bird species: Sitta europaea L., Parus major L., and Ficedula albicollis T. The data was available for the period from 1961 to 2008 from 3 locations in Czech Republic (centered on 48 48N, 16 46E). S. europaea and P. major are residents, F. albicollis is long-distance migrant species and their phenological development (terms of laying eggs) passed over the different time periods during spring. Phenological phases of birds populations were analyzed and the shifts in the phenophases and also response to climate conditions differed among the bird species.
|
|
|
Transpiration and biomass increment in short rotation poplar coppice
Orság, Matěj ; Fischer, Milan ; Trnka, Miroslav ; Kučera, J. ; Žalud, Zdeněk
This paper deals with interaction between amount of water lost by tree transpiration and aboveground biomass increment in poplar based short rotation coppice in conditions of CzechMoravian highlands. Stem sap-flow measured on 8 poplar trees by Granier heat dissipation method was put in relation with biomass increments measured both with automated dendrometers so with manual measurements with caliper gauge. Transpiration totals ranged between 28.3–175.6 liters per tree in executed period 3.8.–31.8.2011. Above-ground biomass increments in this period varied between 30.07–519.28 g per tree and mean value of water use efficiency of all monitored trees reached 2.76 g.kg–1. Mean diurnal sap-flow total of all sampled trees was 3.25 liters. Results show that it is possible to establish relationship between transpiration totals and biomass increments (coefficient of determination R2 = 0.90) and also relationship between transpiration totals and stem diameter (R2 = 0.81). These results (especially after obtaining experimental data from spring growth conditions) can be further used for calculations of biomass increments and transpiration as scaling factors from tree level to whole stand level.
|
|
|
Evapotranspirace vybraných druhů zemědělských a lesních porostů
Kučera, J. ; Urban, J. ; Trnka, Miroslav ; Fischer, Milan ; Krofta, K. ; Duffková, R.
Cílem článku je porovnat evapotranspiraci (ET) z porostů různých plodin (trávník, jetel luční (Trifolium pratense), ozimá pšenice (Triticum aestivum), chmel (Humulus lupulus) a plantáž topolu (J-105, Populus nigra x Populus Maximowiczii) s potenciální evapotranspirací (PET) a rámcově popsat vývoj ET těchto porostů v průběhu vegetační sezóny. Druhým cílem je stanovit podíl transpirace na celkové ET u dvou kontrastních porostů – chmele a plantáže topolu. Denní suma ET trávníku, stejně jako většiny dalších porostů, dosahovala maximálně 5 – 6 mm, což odpovídá 85 – 93 % PET. Výrazně vyšší ET byla naměřena v porostu jetele, naopak nejnižší v porostu topolu v prvním roce po jeho smýcení. Podíl transpirace na ET činil u chmelu 40 - 70 %, kdežto u topolu 80 - 90 %.
|
|
|
Water balance in short rotation poplar coppice and reference grass-plot in conditions of Czech-Moravian Highlands
Orság, Matěj ; Fischer, Milan ; Trnka, Miroslav ; Hlavinka, Petr ; Kučera, J. ; Balek, J. ; Žalud, Zdeněk
This text presents results of a study focusing on differences of water balance between two contrasting cultures - short rotation poplar coppice and grass plot in conditions of Czech-Moravian Highlands. Actual evapotranspiration (by Bowen ratio energy balance method), precipitation and soil moisture in two layers (0 – 0.45 m and 0.45 – 0.90 m) were measured on both plots during seasons 2008 – 2010. The seasonal water lost through evapotranspiration was higher for the grass (560.4 and 508 mm for grass and 523.8 and 351.8 mm for poplar during growing season 2009 and 2010 respectively), but generally the observed amounts of ETa are comparable for both cultures and within the range of values described in literature. Results of soil moisture measurements expressed as soil water availability [mm] were compared with simulations obtained from water balance model SoilClim. The model a little bit underestimated the amount of available water in the system, since based on water balance closure we suggest that there is a higher water income than was recorded from precipitation. This extra water found in observed systems may be supplied probably by lateral underground water inflow from the upper fields.
|
|
|
Energetická bilance lesního porostu. Definice, význam a použití
Slípková, Romana
Sluneční záření dopadající na zemský povrch dává do pohybu procesy využití a přeměny této energie. Rovnováhu mezi dostupnou energií a turbulentními toky zjevného a latentního tepla nazýváme energetickou bilancí. Studium energetické bilance lesního porostu bylo provedeno na Experimentálním ekologickém pracovišti Bílý Kříž v Moravskoslezských Beskydech v roce 2009. Pozorovali jsme o 29% vyšší množství dostupné energie ve srovnání s turbulentními toky. Průměrné množství energie chybějící do rovnovážného stavu bylo tedy v této studii o 9 % vyšší než na jiných výzkumných stanicích sítě FLUXNET (20%). Důvodem může být nadhodnocení množství dostupné energie a nebo také podhodnocení turbulentních toků. Obě tyto hypotézy budeme dále zkoumat.
Plný tet: Slípková_Romana_SilvaNet-WoodNet -  PDF
Plný text: content.csg - PDF
|
|
|
Potentials of the hyperspectral remote sensing - Aisa Eagle system and future perspectives
Lukeš, Petr ; Hanuš, Jan ; Kaplan, Věroslav ; Zemek, František
Since 2004 the Global Change Research Centre (CVGZ) operates a hyperspectral airborne imaging system AISA Eagle. A basic introduction to hyperspectral remote sensing and its potential applications in science as well as for commercial and military uses are presented, followed by a description of the system together with an overview of the key data pre-processing steps. The application of a rapidly developing technology, hyperspectral remote sensing, is presented within the field of quantitative remote sensing of plant health status. Finally, the future development of hyperspectral remote sensing at the CVGZ is outlined.
|
host ::
RSS.