|
|
Quo Vaditis Agriculture, Forestry and Society under Global Change? From understanding past and present Earth´s processes to adaptations for the future
Šprtová, Miroslava ; Bartošová, Lenka ; Acosta, Manuel ; Klem, Karel ; Leventon, Julia ; Červený, Jan
International conference „Quo vaditis agriculture, forestry and society under Global Change? From understanding past and present Earth’s processes to adaptations for the future“, whose scientific sponsor is the European Center of Excellence CzechGlobe, should prove that science has an irreplaceable role in addressing mitigation and adaptation to climate change, in meeting international commitments to climate change and tasks of the EU Strategy on adaptation to climate change.
|
|
|
Stem CO2 efflux on Norway Spruce trees: uncertainty in sap flow effect
Bužková, Romana ; Dařenová, Eva ; Acosta, Manuel
Uhlíková bilance lesa je dána dynamickou rovnováhou mezi procesy zabudovávání uhlíku (fotosyntéza atd.) a procesy uvolňujícími uhlík jako např. respirace. Právě respirace je důležitou složkou uhlíkové bilance lesa, protože uvolňuje až 80% uhlíku fixovaného v autotorofních a heterotrofních potravních řetězcích. S rostoucí teplotou prostředí respirace exponenciálně roste. Ovšem vlivy dalších faktorů na respiraci, jako např. transpirační proud, nejsou jednoznačně známé. Nárůst toku CO2 z kmene může být spojen s poklesem transpiračního toku (Levy et al. 1999), jeho nárůstem (Bowman et al. 2005) a nebo se vzájemně neovlivňují (Cerasoli et al. 2009). Cílem této případové studie bylo (i) zlepšení poznatků o potenciálním vztahu mezi traspiračním proudem a respirací kmene a (ii) průzkum faktorů prostředí potenciálně ovlivňujících tento vztah.
|
|
|
Is it possible to measure CO2 effluxes in an arable ecosystem using chambers without soil frames?
Juszczak, R. ; Acosta, Manuel ; Sakowska, K. ; Leśny, J. ; Uździcka, B. ; Chojnicki, B. H. ; Urbaniak, M. ; Olejnik, Janusz
The push-in chamber and chambers with alternative gaskets were tested under fi eld conditions in order to estimate the rates of under- or overestimation of the CO2 effl uxes measured with chambers placed directly on a soil surface (without collars). Th e experiment was conducted on a spring barley fi eld which was harvested just before the measuring campaign. Th e following were tested: 1) a pushed-in chamber with a sharp metal blade installed on the edge of the chamber walls which was inserted to a depth of 1–2 cm to the soil, 2) a chamber with a 10 cm wide and 3 cm high rubber gasket, and 3) a chamber with a 10 cm wide and 2 cm high neoprene gasket. Th e results indicated that the application of the pushed-in chamber led to overestimation of the fl uxes by 55%, while application of chambers with alternative gaskets led to underestimation of the fl uxes by 30–40% due to the leakage of the gas from the chamber headspace through holes beneath the gaskets. Our experiment confi rmed that soil frames should be applied in fi eld conditions to assure the tightness of the chambers. Other tested solutions increase the biases of the chamber measurements and increase the uncertainties of the estimated CO2 effl uxes.
|
|
| |
|
|
Seasonal course of CO2 efflux in grassland and forest ecosystem in Beskydy mts
Dařenová, Eva ; Pavelka, Marian ; Acosta, Manuel ; Janouš, Dalibor
Our aim was to determine seasonal changes of CO2 efflux of the grassland and of the soil and stems in the Spruce forest at Bílý Kříž (Beskydy Mts). For elimination of the temperature dependency of CO2 efflux, standardized CO2 efflux R10 is used. Mean R10 was about 2.50, 5.0 and 0.97 umolCO2 m-2 s-1 for grassland, forest soil and stems. In grassland the R10 course did not show obvious trend. Whereas in the forest soil, the significant increase in R10 at the beginning and decrease at the end of the season occurred, but without any distinct maximum. Similar increase and decrease in R10 was observed in the stem CO2 efflux course as well. But there was a maximum in June and July. The temperature CO2 efflux sensitivity (Q10) was 3.04, 1.90 and 2.25 for the grassland, forest soil and stems. The temperature sensitivity in the forest soil increased shortly after rain. It resulted in a rapid increase in CO2 efflux of the soil as a response to rain.
|
|
|
Sources of CO2 efflux in a Norway spruce ecosystem: soil and woody-tissue
Acosta, Manuel
The aim of this paper is to compare different sources of CO2 efflux measured in August 1999 in a Norway spruce stand in the Beskids Mts. CO2 efflux were divided in three differents components: Soil respiration, stem woody-tissue respiration and branch woody-tissue respiration. Measurements were carried out with an infrared gas analyser (IRGA)system working in a close system. A omthly Co2 efflux for each component were modelled on the base of realised measurements and individual(soil, stem and branch) measured temperature.
|
|
| |
|
| |
|
|
Soil CO2 efflux in a Norway spruce forest stand
Acosta, Manuel
Soil respiration was measured during 1999 vegetatice period in Norway spruce /Picea Abies L.Karst/ forest stand.A infra-redgas analyser technique /Li-cor/ was used.The daily course of soil respiration during the vegetative period was modelled using the Arrhenius model.
|
|
|
Dopad extrémů počasí na tok uhlíku ve smrkovém porostu
Janouš, Dalibor ; Urban, Otmar ; Pavelka, Marian ; Acosta, Manuel ; Havránková, Kateřina ; Pokorný, Radek ; Zvěřinová, Zuzana ; Klimánková, Zdeňka
V celkové uhlíkové bilanci ekosystému se v extrémních dnech uplatnila významná deprese fotosyntézy, vysoká autotrofní respirace, ale utlumená heterotrofní respirace.
|
host ::
RSS.