|
|
Response of Soil Respiration, Temperature and Moisture to the Harvest of a Sessile Oak Forest\n
Dařenová, Eva
Forest management, particularly thinning and harvesting measures, has a significant impact on the forest carbon balance. In this study, we investigated the effect of the harvest of a sessile oak forest on soil respiration as a main source of CO2 emissions in forest ecosystems. Soil respiration, temperature and moisture were measured during the two growing seasons, one before and one after the harvest applied on six out of nine studied plots in April 2018. The harvest increased soil temperature by up to 6 °C. Soil moisture did not differ between the plots in 2017, but it was higher in the harvested plots compared to the control in 2018. In the first half of the growing season 2018, the difference between the control and harvested plots ranged between 5 and 100 % in proportion while in the second half the differences decreased only up to 5%. Soil respiration ranged between 1.2 and 3.3 µmol CO2 m-2s-1 during 2017 with no difference between the following variants. In 2018, soil respiration ranged between 1.2 and 7.0 µmol CO2 m-2s-1 and it tended to be higher in the harvested plots compared to the control. The exception was observed shortly after heavy rainfall on 5th September when soil respiration in the control significantly exceeded that in the harvested plots.
|
|
|
Soil Respiration of the Spruce Forest during Four Years after the Application of the Different Dolomitic Limestone Dosage
Rosíková, J. ; Dařenová, Eva ; Kučera, A.
The study focuses on an in situ response of soil respiration at 10 °C (R10) of the Norway spruce monoculture to the application of the different dolomitic limestone dosages (0, 2, 3, 4, 6, 9 a 26 t.ha-1) over a period of four years. Soil respiration was measured within the growing seasons 2016 – 2019. Moreover, the pH was determined in the H and Ah horizons during each season. The effect of liming on soil respiration was statistically significant during all the seasons except for 2017. The greatest effect was observed within the first season after liming. In May 2016, R10 in the limed plots increased as much as by 97% compared to the non-limed ones. However, soil respiration did not increase in the direct proportion to the liming intensity. We found out the correlation between soil respiration and the micrometeorological parameters (temperature and moisture) when both low temperature moisture limited soil respiration. Due to the strong soil buffering capacity, the small effect of liming on the soil acidity was observed in the first study season. In the following seasons, the differences in the pH among the plots with the different liming intensity started to increase, which was, however, observed only in the H horizon. The substantial increase in the soil microbial activity accompanied with faster respiration after liming can lead to the increased threat of rapid mineralization and the loss of soil organic matter with all its negative impacts
|
|
|
The Influence of traditional ways of management on the State of Coppice - Results in 2018
Balková, M. ; Dařenová, Eva ; Friedl, M. ; Hloucalová, P. ; Kadavý, J. ; Kneifl, M. ; Knott, M. ; Kučera, A. ; Slach, T. ; Skládanka, J. ; Uchytilová, Tereza ; Uherková, B. ; Vichta, T. ; Volařík, D.
The most pronounced increase in number of herb species was remarked in the clear cut+litter gathering treatment. Harvest led to an increase in soil temperature and moisture. TheCO2efflux was the highest in September, namely in control treatment. The lowest intensity of root growth was remarked in the control treatment. Variants with litter gathering had smaller (28.9%) relative growth ratio.
|
|
|
CO2 efflux in different types of ecosystems
Dařenová, Eva
CO2 efflux from soil at three different ecosystems (spruce forest, beech forest, wetland) and from the whole ecosystem at one site (grassland) was measured during campaigns of manual measurements or automated continuous measurements during growing seasons 2008 -- 2012. There were determined factors driving spatial variability and temporal dynamics of CO2 efflux. Soil temperature was mostly the driving factor responsible for temporal dynamics and soil water content contributed to both temporal dynamic and spatial variability. Also the amount of grass or litter affected the variability. We also determined that time of the day when the measurements of soil CO2 efflux are done can influence estimation of seasonal sum of released carbon from soil. Finally, it was determined that changing precipitation pattern with simulated drought in the first half of the growing season has both immediate and long-term impact on CO2 efflux from the grassland ecosystem.
|
|
|
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.
|
|
|
Forest floor respiration of tuczno scots pine stands
Urbaniak, M. ; Pavelka, Marian ; Heronim Chojnicky, B. ; Juszczak, R. ; Dařenová, Eva ; Baran, M. ; Danielewska, A. ; Ziemblinska, K. ; Olejnik, Janusz
Tuczno forest is a 60-year-old Scots pine stand that is located in the North-West part of Poland. During the period between 20th and 25th August 2012 an experiment consisting of the measurement of forest fl oor CO2 effl ux was carried out. For this purpose, manual chamber systems were used. Measurements were taken at 60 collars located on a rectangular plot 25m x 45m. Th is research area was located in the range of footprint of the Eddy-covariance (EC) tower. Th e preliminary results indicate that the average CO2 effl ux from the forest fl oor, as measured during the experiment (5.09 μmol m-2 s-1), is lower than the total ecosystem respiration, estimated from EC data (6.25 μmol m-2 s-1). Spatial variability of soil CO2 effl ux (Rs) can be explained by humus thickness (Ht) variability; however, the tree root respiration can be considered a valuable part of CO2 emission from the forest bottom.
|
|
|
Spatial heterogeneity of soil CO2 efflux in four different ecosystems
Dařenová, Eva
Manual measurements of soil CO2 effl ux on a larger number of positions can give precise estimation of CO2 effl ux from the investigated area and together with temporal dynamics, observed in continuous measurements, can provide a good view on the ecosystem carbon balance. In this study we investigated the spatial heterogeneity of soil CO2 effl ux in four diff erent ecosystems (spruce forest, beech forest, wetland, grassland). Soil CO2 was measured on a net of 25–65 positions using a manual measurement system. We tried to fi nd responsible factors for the heterogeneity and to determine a measurement protocol for the most precise estimation of soil CO2 effl ux. Th e highest respiration activity was observed in the spruce forest, the lowest in the wetland ecosystem, where it was caused by a high water table. In the wetland ecosystem, there was the highest spatial heterogeneity of respiration activity, which reached almost 60 %. Th is high heterogeneity was caused by the gradient of the water table depth. Contrary to this, the lowest heterogeneity was found in the grassland where it was only about 15 %. In the spruce and beech forest the heterogeneity ranged between 35 and 45 %. As infl uencing factors we investigated e.g. soil moisture, tree distance and amount of the above ground biomass.
|
|
|
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.
|
guest ::
