Dynamics of CO2 emission from chernozems under agricultural use

2017 ◽  
Vol 4 (3) ◽  
pp. 43-49
Author(s):  
M. Miroshnychenko ◽  
O. Siabruk
Keyword(s):  
Carbon Dioxide ◽  
Agricultural Practices ◽  
Growing Season ◽  
Warm Period ◽  
Direct Seeding ◽  
Soil Tillage ◽  
Plant Residues ◽  
Hydrothermal Conditions ◽  
Organic Mineral ◽  
Mineral System

Aim. The comparison of the effect of hydrothermal conditions and various agricultural practices on the emission of CO 2 from chernozems in the Left-Bank Forest-Steppe of Ukraine. Methods. The dynamics of the intensity of carbon dioxide emissions from chernozem calcic (typical chernozem – in Ukrainian classifi cation) was studied during the growing season of 2011–2012. The observations were based on two fi eld experiments with various methods of soil till- age (6–7 years from the beginning of the experiment) and fertilization systems (21–22 years from the beginning of the experiment). Particularly, plowing at 20–22 cm, disking at 10–12 cm, cultivation at 6–8 cm and direct seeding using Great Plains drill were studied among the soil tillage methods. Mineral system (N 45 P 50 K 45 ), organic system (manure 8 t/ha) and combined organic-mineral system (manure 8 t/ha + N 45 P 50 K 45 ) were studied among fertilization systems. The intensity of CO 2 fl ux was determined using the non-stationary respiratory chambers by the alkaline absorption method, with averaging of the results during the day and the frequency of once a month. Results. During the warm period, the emission of carbon dioxide from the soil changes dynamically depending on temperature and humidity. The maximum of emission coincides with the periods of warm summer showers in June-July, the minimum values are characteristic for the late autumn period. The total emission losses of carbon in chernozems over the vegetation period ranged from 480 to 910 kg/ha and varied depending on the methods of tillage ± (4.0–6.0) % and fertilization systems ± (3.8–7.1) %. The changes in the intensity of CO 2 emission from the soil under different methods of soil tillage are associated with hydrothermal regime and the depth of crop residues location. The biggest difference is observed im- mediately after tillage, but in the spring period the differences are only 12–25 %, and after drying of the top layer of soil become even less. Direct seeding technology provides the greatest emission of CO 2 from chernozem, which is fa- cilitated by better water regime and more complete mineralization of plant residues on the soil surface. Annual losses of carbon are the least under disking of soil at 10–12 cm. The changes in the intensity of CO 2 emission from the soil under different fertilization systems are associated with the involvement of the additional organic matter from plant residues and manure to the microbiological decomposition. The greatest emission was observed under the organic- mineral fertilization system, which increased the loss of carbon by 7–8 % in comparison with the mineral system in the unfavorable hydrothermal year and by 11–15 % in the more favorable year. These differences are observed mainly during the fi rst half of the growing season when there is a clear tendency to increase the intensity of soil respiration. Conclusions. The hydrothermal conditions of the warm period of the year are decisive in the formation of the CO 2 emission fl ow from chernozems. Due to the improvement of agricultural practices, emissions might be reduced but not more that by 15 % of natural factor contribution.

WEED INFESTATION OF WINTER TRITICALE, DEPENDING ON AGRICULTURAL PRACTICES OF CULTIVATION

2016 ◽  
Vol 11 (3) ◽  
pp. 16-19
Author(s):  
Шашкаров ◽  
Leonid Shashkarov ◽  
Кузнецов ◽  
Leonid Kuznetsov
Keyword(s):  
Humus Content ◽  
Agricultural Practices ◽  
Growing Season ◽  
Soil Tillage ◽  
Winter Triticale ◽  
Perennial Weeds ◽  
Mobile Phosphorus ◽  
Significant Difference ◽  
Weed Infestation ◽  
Salt Extract

The investigations were carried out in 2014-2015, on a light gray forest heavy loamy soil. The humus content in the arable layer was 5.9%. The mobile phosphorus was 162 and exchangeable potassium was 172 mg per kilogram, respectively, pH of salt extract was 5.6. The total area of the plot was 200 m2, the discount area - 150 m2. Replication - fourfold, placing of plots was successive. Experience scheme: Factor A - preplant soil tillage: 1. Cultivation - 10-12 cm. 2. Milling – 10-12 cm. Factor B – fertilizers: 1. Without fertilizers (control). 2. Fertilizers, aimed to 4.0 tons per hectare (N120P75K90). The following varieties were used as the object of the study: Kornet, Kristal and Nemchinovskaya 56. The norms of fertilizers is calculated by the balance method, based on their removal from the crop and in the soil. The options, treated with a cultivator, were the most clogged. There are no significant difference among tested varieties of Kornet, Nemchinovskaya 56 and Kristal, but Nemchinovskaya 56 was the most clogged - 36 units per square meter, and less weedy was Cornet. When milling , the most clogged was Nemchinovskaya 56 variety - 30 units per square meter. In the way of without fertilization (control), Kristal variety was the most clogged - 21 units per square meter. The weed infestation of winter triticale at the beginning of growing season of Kristal variety was more to 21.3%, Nemchinovskaya 56 variety to 17% and Kristal to 21.6% more, than in milling. At the end of the growing season of winter triticale during cultivation the weeds increased by 71% and 74%. The same pattern was preserved debris perennial weeds early in the growing season 2.4-4.2 units per square meter, at the end of the growing season 4.6-4.7 units per square meter. The most clogged varieties were Nemchinovskaya 56 – 2.8-4.6 units per square meter and Kristal 2.7-4.7 units per square meter.

Microagrogenesis of chernozem in agrocenosis

2017 ◽  
Vol 4 (1) ◽  
pp. 28-45
Author(s):  
O. Demydenko ◽  
V. Velichko
Keyword(s):  
Humic Substances ◽  
Soil Formation ◽  
Mineral Fertilizers ◽  
Forest Steppe ◽  
Left Bank ◽  
Hydrothermal Conditions ◽  
Typical Chernozem ◽  
Theoretical Substantiation ◽  
Organic Mineral ◽  
Mineral System

The aim of the study was to provide scientifi c and theoretical substantiation for the process of microaggrega- tion of typical chernozem via the simulation of natural processes of soil formation under the effect of systemat- ic application of soil-protecting technologies of crop cultivation with surface packing of root and after-harvest remains, humus, and mineral fertilizers in agrocenoses of the Left-Bank Forest-Steppe of Ukraine. Methods. Laboratory-analytical, experimental fi eld, statistical. Results. During tillage (for over 75 years) the number of free and friable-linked aggregates in the 0–40-cm chernozem layer decreased down to 17–20 %, and on the background of organic-mineral system of fertilization (15 t/ha of humus + N 80 P 75 K 60 ) there was an increase in the content of the mentioned groups of microaggregates up to 20–25 %. The systematic implementation of soil protective technologies promoted the increase in the content of free and friable-linked microaggregates up to 29–32 %. During tillage, the coeffi cient of saturation with humus for physical clay (PC) decreased 1.3–1.4 times compared to the grassland. The value of PC saturation during the soil protective tillage was optimal, as humus was neither accumulated in the form of free humates, nor stored like “fat” in animal organisms.aAnd there was no blocking of nutrients with free humates. Humus acts as a connective tissue, promoting the improved water-resistance of chernozem structure on the micro- and macroaggregate levels. The ability of chernozems to have aggregation was determined by the dispersion factor (DF), which was 12–14 % during tillage without introducing any fertilizers, and 10 % – with the introduction of fertilizers, which testifi ed to a weak degree of microaggregation. With minimal tillage on the background of the organo-mineral system of fertilization, DF = = 6–7 %, and by the end of rotation it decreased down to 3-5 %. Conclusions. Enhanced microaggregation in soil protective technologies is explained by the fact that detritus and newly formed humic substances enhance their role in the formation of organo-mineral complexes in case of optimization of hydrothermal conditions in the seasonal cycle and decreased tempo of humus mineralization. The correlation coeffi cient between the num- ber of microaggregates, sized 0.01–0.25 mm and the content of peptized humic substances during tillage was as follows: R = +0.480.01, and for soil protective technologies it was: R = (+0.70–0.75) 0.01. The increase in microaggregation in conditions of soil protective tillage occurred in the direction of wild land analogs and fallow, which testifi ed to the simulation of the natural process of typical chernozem microaggregation in the agrocenoses of the Left-Bank Forest-Steppe of Ukraine.

Soil biological activity of short rotation crop at the maximum saturation with sunflower

2021 ◽  
pp. 105-115
Keyword(s):  
Carbon Dioxide ◽  
Organic Matter ◽  
Biological Activity ◽  
Crop Rotation ◽  
The State ◽  
Soil Tillage ◽  
Plant Residues ◽  
Field Crops ◽  
Tillage System ◽  
Favorable Conditions

In the field stationary experiment, the dynamics of the general biological activity of chernozem, depending on the biomass of plant residues, maximum saturation with sunflower, methods of the basic soil tillage under different hydrothermal conditions was studied. The issue of arable layer differentiation at different methods of the basic soil tillage in the crop rotation on fertility and biological activity and dynamics of these parameters depending on the intensity of mechanical action on the soil and the cycle of organic matter is a very important aspect for the theoretical study of innovative soil protecting technologies of growing of field crops. The research was carried out at the State Enterprise "Experimental Farm of Dnipro" of the State Institution of the Institute of Grain Cultures of the National Academy of Sciences of Ukraine in the stationary field experiment of laboratory of the crop rotation and environmental protection systems of soil tillage in five-year crop rotation: peas - winter wheat - sunflower - barley spring - corn according to generally accepted techniques of experimental work, during 2010-2019. The soil of the experimental site is common chernozem heavy-clayey loam with content in the arable layer: humus – 4.2%, nitrate nitrogen – 13.2 mg / kg, mobile phosphorus and potassium compounds, respectively 145 and 115 mg / kg. According to the results of the research, the minimization of soil tillage causes the significant changes in the differentiation of the arable layer (0-30 cm) relative to the positional disposition of nutrients, the concentration of potential humus substances in the aerobic zone and the intensification of microbiological activity, as evidenced by the volumes of carbon dioxide releases. The largest organic mass in crop rotation naturally left itself corn, and the minimum - barley spring and sunflower. Substantial redistribution of the projective coverage of the surface of the field with plant residues and their mixing with the soil in the profile of the arable layer was carried out by various methods and systems of basic soil tillage. For example, after harvesting of corn and carrying out of soil tillage on the surface of the field, the minimum number of plant residues remains for the moldboard soil tillage system - 0.61 t/ha. The intermediate position was occupied by the differentiated (discing) cultivation system – 3.12 t/ha, and the maximum amount of vegetative substrate was logically marked for zero soil tillage – 4.34 t/ha. The intensity of the decomposition of organic matter in the soil is a heterogeneous process, which primarily depends on the determining factors - moisture, temperature and aeration level of the treated layer of chernozem. The intensity of the processes of breathing of soil microorganisms makes it possible to estimate the total biological activity of the soil, which is based on the amount of carbon dioxide released, depending on the different methods of soil tillage per unit area of the field surface. As our studies have shown, the biological activity of the soil depended on the phases of development of plants of field crops and had a sufficiently wide amplitude of variation. Thus, as an example of the mouldboard plowing, it is evident that insufficient soil warming at normal humidification at the time of corn sowing has led to the decrease in biological activity to 35.0 mg CO2/kg of soil/day. The maximum intensity of soil respiration (49.2 mg СО2 /kg of soil /day) occurred at 30 days after sunflower sowing, when the optimal combination of temperature and humidity of the soil was noted. Similar regularities and tendencies in the release of СО2 from the soil during certain phases of sunflower development are also noted for differentiated and zero cultivation systems, but with somewhat lower overall CO2 release, respectively, by 0.3-5.3 mg СО2/kg ha/day (10-12%) and 5.5-7.2 mg СО2/kg ha/day (12-22%) compared to the mouldboard soil tillage system. Generally, this tendency took place both in the maximum and at the minimum amplitude of the activity of respiration processes, that is, the indicators of the general biological activity of the soil were higher in the background of plowing and prevailed other systems of mechanical cultivation of chernozem (differentiated, zero system). Thus, the biological activity of the soil is the derived indicator, which depends on the features of the technology of growing of cultures in the crop rotations, the presence of organic matter of plant residues in the chernozem, the level of compaction of arable layer and the methods of basic soil tillage. The use of deep plowing due to the creation of favorable conditions for the expansion of the root system of crops with sufficient aeration and moisture absorbtion properties provides maximum biological activity under all crops of crop rotation, decomposition of residues and intensive mineralization processes. However, methods of unploughed treatment of the soil contributed to increasing the antierosion stability of the surface of chernozem from the shock energy of rain drops, as well as providing more favorable conditions for the humification of organic residues instead of undesirable intensive mineralization.

Ecosystem modeling of methane and carbon dioxide fluxes for boreal forest sites

2001 ◽  
Vol 31 (2) ◽  
pp. 208-223 ◽  
Author(s):  
Christopher Potter ◽  
Jill Bubier ◽  
Patrick Crill ◽  
Peter Lafleur
Keyword(s):  
Carbon Dioxide ◽  
Boreal Forest ◽  
Land Surface ◽  
Net Primary Production ◽  
Ground Cover ◽  
Methane Flux ◽  
Growing Season ◽  
Ecosystem Model ◽  
Heat Fluxes ◽  
Water Levels

Predicted daily fluxes from an ecosystem model for water, carbon dioxide, and methane were compared with 1994 and 1996 Boreal Ecosystem–Atmosphere Study (BOREAS) field measurements at sites dominated by old black spruce (Picea mariana (Mill.) BSP) (OBS) and boreal fen vegetation near Thompson, Man. Model settings for simulating daily changes in water table depth (WTD) for both sites were designed to match observed water levels, including predictions for two microtopographic positions (hollow and hummock) within the fen study area. Water run-on to the soil profile from neighboring microtopographic units was calibrated on the basis of daily snowmelt and rainfall inputs to reproduce BOREAS site measurements for timing and magnitude of maximum daily WTD for the growing season. Model predictions for daily evapotranspiration rates closely track measured fluxes for stand water loss in patterns consistent with strong controls over latent heat fluxes by soil temperature during nongrowing season months and by variability in relative humidity and air temperature during the growing season. Predicted annual net primary production (NPP) for the OBS site was 158 g C·m–2 during 1994 and 135 g C·m–2 during 1996, with contributions of 75% from overstory canopy production and 25% from ground cover production. Annual NPP for the wetter fen site was 250 g C·m–2 during 1994 and 270 g C·m–2 during 1996. Predicted seasonal patterns for soil CO2 fluxes and net ecosystem production of carbon both match daily average estimates at the two sites. Model results for methane flux, which also closely match average measured flux levels of –0.5 mg CH4·m–2·day–1 for OBS and 2.8 mg CH4·m–2·day–1 for fen sites, suggest that spruce areas are net annual sinks of about –0.12 g CH4·m–2, whereas fen areas generate net annual emissions on the order of 0.3–0.85 g CH4·m–2, depending mainly on seasonal WTD and microtopographic position. Fen hollow areas are predicted to emit almost three times more methane during a given year than fen hummock areas. The validated model is structured for extrapolation to regional simulations of interannual trace gas fluxes over the entire North America boreal forest, with integration of satellite data to characterize properties of the land surface.

scholarly journals The Effect of Different Soil Tillage Systems and Crop Residues on the Composition of Weed Communities

Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1276
Author(s):  
Vaida Steponavičienė ◽  
Aušra Marcinkevičienė ◽  
Lina Marija Butkevičienė ◽  
Lina Skinulienė ◽  
Vaclovas Bogužas
Keyword(s):  
Soil Ph ◽  
Crop Residues ◽  
Soil Tillage ◽  
Reduced Tillage ◽  
Plant Residues ◽  
No Tillage ◽  
Agricultural Crops ◽  
Weed Species ◽  
Tillage Systems ◽  
Weed Communities

The composition of weed communities in agricultural crops is dependent on soil properties and the applied agronomic practices. The current study determined the effect of different tillage systems and crop residue on the soil weed community composition. The research programme encompassed 2013–2015 in a long-term field experiment located in the Experimental Station of Vytautas Magnus University in Lithuania. The soil type in the experimental field was qualified as Endocalcaric Stagnosol (Aric, Drainic, Ruptic, Amphisiltic). Weeds were categorised into communities according to soil pH, nitrogen and moisture indicators. The results of investigations were grouped using cluster analysis. Agricultural crops were dominated by different weed species depending on the soil pH and moisture. Weed species were relatively more frequent indicating nitrogen-rich and very nitrogen-rich soils. In the reduced tillage and no-tillage systems, an increase in the abundance of weed species indicating moderate acidity and low acidity, moderately wet and wet, nitrogen-rich and very nitrogen-rich soils was observed. The application of plant residues decreased the weed species abundance. In the reduced tillage and no-tillage systems, the quantitative distribution of weed was often uneven. By evaluating the association of weed communities with groups of different tillage systems with or without plant residues, their control can be optimised.

scholarly journals The growing season greenhouse gas balance of a continental tundra site in the Indigirka lowlands, NE Siberia

2007 ◽  
Vol 4 (6) ◽  
pp. 985-1003 ◽  
Author(s):  
M. K. van der Molen ◽  
J. van Huissteden ◽  
F. J. W. Parmentier ◽  
A. M. R. Petrescu ◽  
A. J. Dolman ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Soil Temperature ◽  
Greenhouse Gas ◽  
Growing Season ◽  
Light Limitation ◽  
Greenhouse Gas Balance ◽  
Area Index ◽  
North East ◽  
Methane Fluxes ◽  
Gas Balance

Abstract. Carbon dioxide and methane fluxes were measured at a tundra site near Chokurdakh, in the lowlands of the Indigirka river in north-east Siberia. This site is one of the few stations on Russian tundra and it is different from most other tundra flux stations in its continentality. A suite of methods was applied to determine the fluxes of NEE, GPP, Reco and methane, including eddy covariance, chambers and leaf cuvettes. Net carbon dioxide fluxes were high compared with other tundra sites, with NEE=−92 g C m−2 yr−1, which is composed of an Reco=+141 g C m−2 yr−1 and GPP=−232 g C m−2 yr−1. This large carbon dioxide sink may be explained by the continental climate, that is reflected in low winter soil temperatures (−14°C), reducing the respiration rates, and short, relatively warm summers, stimulating high photosynthesis rates. Interannual variability in GPP was dominated by the frequency of light limitation (Rg<200 W m−2), whereas Reco depends most directly on soil temperature and time in the growing season, which serves as a proxy of the combined effects of active layer depth, leaf area index, soil moisture and substrate availability. The methane flux, in units of global warming potential, was +28 g C-CO2e m−2 yr−1, so that the greenhouse gas balance was −64 g C-CO2e m−2 yr−1. Methane fluxes depended only slightly on soil temperature and were highly sensitive to hydrological conditions and vegetation composition.

scholarly journals Environmental influences on carbon dioxide fluxes over three grassland ecosystems in China

2009 ◽  
Vol 6 (12) ◽  
pp. 2879-2893 ◽  
Author(s):  
Y. Fu ◽  
Z. Zheng ◽  
G. Yu ◽  
Z. Hu ◽  
X. Sun ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Soil Moisture ◽  
Alpine Meadow ◽  
Growing Season ◽  
Co2 Fluxes ◽  
Meadow Steppe ◽  
Temperate Steppe ◽  
Area Index ◽  
Grassland Ecosystems ◽  
Alpine Shrub

Abstract. This study compared carbon dioxide (CO2) fluxes over three grassland ecosystems in China, including a temperate semiarid steppe in Inner Mongolia (NMG), an alpine shrub-meadow in Qinghai (HB), and an alpine meadow-steppe in Tibet (DX). Measurements were made in 2004 and 2005 using the eddy covariance technique. Objectives were to document the seasonality of the net ecosystem exchange of CO2 (NEE) and its components, gross ecosystem photosynthesis (GEP), and ecosystem respiration (Reco), and to examine how environmental factors affect the CO2 exchange in these grassland ecosystems. The 2005 growing season (from May to September) was warmer than that of 2004 across the three sites, and precipitation in 2005 was less than that in 2004 at NMG and DX. The magnitude of CO2 fluxes (daily and annual sums) was largest at HB, which also showed the highest temperature sensitivity of Reco among the three sites. A stepwise multiple regression analysis showed that the seasonal variation of GEP, Reco, and NEE of the alpine shrub-meadow was mainly controlled by air temperature, whereas leaf area index can likely explain the seasonal variation in GEP, Reco, and NEE of the temperate steppe. The CO2 fluxes of the alpine meadow-steppe were jointly affected by soil moisture and air temperature. The alpine shrub-meadow acted as a net carbon sink over the two study years, whereas the temperate steppe and alpine meadow-steppe acted as net carbon sources. Both GEP and Reco were reduced by the summer and spring drought in 2005 at NMG and DX, respectively. The accumulated leaf area index during the growing season (LAIsum) played a key role in the interannual and intersite variation of annual GEP and Reco across the study sites and years, whereas soil moisture contributed most significantly to the variation in annual NEE. Because LAIsum was significantly correlated with soil moisture at a depth of 20 cm, we concluded that the available soil moisture other than annual precipitation was the most important factor controlling the variation in the CO2 budgets of different grassland ecosystems in China.

scholarly journals Carbon Dioxide Fluxes and Carbon Stocks under Conservation Agricultural Practices in South Africa

Agriculture ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 374 ◽  
Author(s):  
Patrick Nyambo ◽  
Chiduza Cornelius ◽  
Tesfay Araya
Keyword(s):  
South Africa ◽  
Carbon Dioxide ◽  
Soil Moisture ◽  
Carbon Stock ◽  
Crop Residue ◽  
Agricultural Practices ◽  
Carbon Stocks ◽  
Residue Management ◽  
Co2 Fluxes ◽  
Carbon Dioxide Fluxes

Understanding the impacts of agricultural practices on carbon stocks and CO2 emission is imperative in order to recommend low emission strategies. The objective of this study was to investigate the effects of tillage, crop rotation, and residue management on soil CO2 fluxes, carbon stock, soil temperature, and moisture in the semi-arid conditions in the Eastern Cape of South Africa. The field trial was laid out as a split-split-plot design replicated three times. The main plots were tillage viz conventional tillage (CT) and no-till (NT). The sub-plots were allocated to crop rotations viz maize–fallow–maize (MFM), maize–oat–maize (MOM), and maize–vetch–maize (MVM). Crop residue management was in the sub-sub plots, viz retention (R+), removal (R−), and biochar (B). There were no significant interactions (p > 0.05) with respect to the cumulative CO2 fluxes, soil moisture, and soil temperature. Crop residue retention significantly increased the soil moisture content relative to residue removal, but was not different to biochar application. Soil tilling increased the CO2 fluxes by approximately 26.3% relative to the NT. The carbon dioxide fluxes were significantly lower in R− (2.04 µmoL m−2 s−1) relative to the R+ (2.32 µmoL m−2 s−1) and B treatments (2.36 µmoL m−2 s−1). The carbon dioxide fluxes were higher in the summer (October–February) months compared to the winter period (May–July), irrespective of treatment factors. No tillage had a significantly higher carbon stock at the 0-5 cm depth relative to CT. Amending the soils with biochar resulted in significantly lower total carbon stock relative to both R+ and R−. The results of the study show that NT can potentially reduce CO2 fluxes. In the short term, amending soils with biochar did not reduce the CO2 fluxes compared to R+, however the soil moisture increases were comparable.

scholarly journals Carbon dioxide and methane exchange of a patterned subarctic fen during two contrasting growing seasons

2021 ◽  
Author(s):  
Lauri Heiskanen ◽  
Juha-Pekka Tuovinen ◽  
Aleksi Räsänen ◽  
Tarmo Virtanen ◽  
Sari Juutinen ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Global Warming ◽  
Plant Community ◽  
Carbon Balance ◽  
Growing Season ◽  
Drought Period ◽  
Annual Carbon ◽  
Ecosystem Level ◽  
Community Types ◽  
Annual Carbon Balance

&lt;p&gt;Abstract&lt;/p&gt;&lt;p&gt;Northern mires have sequestered substantial amounts of atmospheric carbon since the last glacial period forming one of the largest carbon pools in the biosphere (Hugelius et al., 2020). Current global warming is causing the subarctic and arctic regions warm rapidly, two to three times as fast as the rest of the world (Masson-Delmotte et al., 2018), which will affect the carbon balance of these mires.&lt;/p&gt;&lt;p&gt;In Kaamanen, northern Finland, we studied carbon dioxide (CO&lt;sub&gt;2&lt;/sub&gt;) and methane (CH&lt;sub&gt;4&lt;/sub&gt;) exchange between patterned mesotrophic fen and the atmosphere, both on ecosystem and plant community level. The ecosystem level measurements were conducted by utilizing eddy covariance method, while the fluxes on plant community scale were measured with flux chambers. The studied fen can be described as a mosaic of strings and flarks (or hummocks and hollows, respectively). The microtopography of the string-flark continuum form four main plant community types with varying water table conditions and vegetation composition. The measurements took place in 2017&amp;#8211;2018. The two years in question were contrasting in their meteorological and environmental conditions. The 2017 growing season had average temperature, but high precipitation sum, while 2018 growing season was warm and dry. In July 2018 a north-western Europe-wide heatwave caused a month-long drought period at the site. Compared to 2017, the annual carbon balance of the Kaamanen fen was affected by earlier onset of photosynthesis in spring and the drought event during summer 2018.&lt;/p&gt;&lt;p&gt;We found that the annual carbon balance of the fen did not differ markedly between the studied years, even though the meteorological and environmental conditions did. The earlier onset of growing season in 2018 strengthened the CO&lt;sub&gt;2&lt;/sub&gt; sink of the ecosystem, but this gain was counterbalanced by the later drought period. Additionally, we found strong spatial variation in CO&lt;sub&gt;2&lt;/sub&gt; and CH&lt;sub&gt;4&lt;/sub&gt; dynamics between the main plant communities. Most of the variation in ecosystem level carbon exchange could be explained by the variation in water table level, soil temperature and vegetation characteristics, which were also the environmental factors that varied between the plant community types.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;References&lt;/p&gt;&lt;p&gt;Hugelius, G., Loisel, J., Chadburn, S., Jackson, R. B., Jones, M., MacDonald, G., Marushchak, M., Olefeldt, D., Packalen, M., Siewert, M. B., Treat, C., Turetsky, M., Voigt, C. and Yu, Z.: Large stocks of peatland carbon and nitrogen are vulnerable to permafrost thaw, Proceedings of the National Academy of Sciences - PNAS, 117, 20438&amp;#8211;20446, doi:10.1073/pnas.1916387117, 2020.&lt;/p&gt;&lt;p&gt;Masson-Delmotte, V., Zhai, P., P&amp;#246;rtner, H.-O., Roberts, D., Skea, J., Shukla, P. R., Pirani, A., Moufouma-Okia, W., P&amp;#233;an, C., Pidcock, R., Connors, S., Matthews, J. B. R., Chen, Y., Zhou, X., Gomis, M. I., Lonnoy, E., Maycock, T., Tignor, M. and Waterfield T. (Eds.): Global Warming of 1.5&amp;#176;C. An IPCC Special Report on the impacts of global warming of 1.5&amp;#176;C above pre-industrial levels and related global greenhouse gas emission pathways, in the context of strengthening the global response to the threat of climate change, sustainable development, and efforts to eradicate poverty, World Meteorological Organization, Geneva, Switzerland, 2018.&lt;/p&gt;

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