János Balogh

Hungarian University of Agriculture and Life Sciences · Department of Plant Physiology and Plant Ecology

Summer droughts projected to increase in central Europe due to climate changes strongly influence the carbon cycle of ecosystems. Persistent respiration activities during drought periods are responsible for a significant carbon loss, which may turn the ecosystem from a sink into a source of carbon. There are still gaps in our knowledge regarding th...

Spatial patterns of ecosystem processes constitute significant sources of uncertainty in greenhouse gas flux estimations partly because the patterns are temporally dynamic. The aim of this study was to describe temporal variability in the spatial patterns of grassland CO2 and N2O flux under varying environmental conditions and to assess effects of...

Diel variability of soil respiration is influenced by several factors including temperature and carbon allocation as the most significant ones, co-varying on multiple time scales. In an attempt to disentangle their effects we analyzed the dynamics of soil respiration components using data from a three-year soil respiration study. We measured CO 2 e...

Aims Soil respiration (Rs) is a complex process including a wide range of soil biota and pathways of carbon cycling, all being under the control of various drivers. The most important biotic driver is the photosynthetic activity of the vegetation providing supply mainly for the autotrophic component of Rs: roots and their symbiotic partners. The ob...

Drought stress occurrence and recovery from drought can be detected using a single spatial set of simultaneous observations of SIF and canopy temperature records. Temporal and spatial responses to drought and heat stresses by plant stands of a drought-adapted diverse grassland ecosystem were studied using sun induced fluorescence (SIF,O2A and O2B b...

Overuse of chemical fertilizers in agroecosystems leads to the increased economic burden, low crop production in terms of input and environmental pollution. Due to its improved nutrient management and degrading properties, synthetic slow release fertilizers have become a significant advancement in the fertilizer sector. In this study we evaluated t...

Only a small amount of the light absorbed by the photosynthetic pigments including chlorophylls and carotenoids is de-excited via emission as heat or red and far-red chlorophyll fluorescence under normal physiological conditions. Most of the energy is utilized for photosynthetic quantum conversion. In contrast, photosynthetic performance decreases...

Aims: Soil respiration (Rs) is a highly complex process including a wide range of soil biota and different pathways of carbon cycling, all being under the control of various drivers. The most important biotic driver is the photosynthetic activity of the vegetation providing supply mainly for the autotrophic component of Rs: roots and their symbioti...

Abstract Aims: The relative importance of species within an ecosystem shows spatio-temporal variability related to both the terrain features and numerous rapidly changing factors. Accordingly, functional and species patterns may show some level of persistence, or, due to various disturbances, fluctuations. Communities with high species richness wer...

2017. októberétől 2021. októberéig terjedő időszakban vizsgáltuk egy középmagyarországi szántóföld szénforgalmát gázcseremérések segítségével. A mért nettó ökoszisztéma gázcsere (NEE) adatokból kumulált összegeket számoltunk éves bontásban, illetve az egyes növényállományok és ugar időszakok szerint. Gazdálkodási adatok segítségével számoltuk a ter...

Forest–steppe habitats in central Hungary have contrasting canopy structure with strong influence on the spatiotemporal variability of ecosystem functions. Canopy differences also co-vary with terrain feature effects, hampering the detection of key drivers of carbon cycling in this threatened habitat. We carried out seasonal measurements of ecosyst...

Egy élőhelyen a növényfajok növekedését és elterjedését a környezeti faktorok határozzák meg. Ezek közül a legjelentősebbek a léghőmérséklet és a légnedvesség, melyek a fő mikroklíma komponensek. Vizsgálatunkat a fülöpházi homokbuckás (Kiskunsági Nemzeti Park) egy kis méretű, laza facsoportján és az azt körülvevő gyepterületen végeztük. A vegetáció...

Microclimate and vegetation architecture are interdependent. Little information is available, however, about the fine-scale spatio-temporal relationship between the microclimate and herb layer of forest-steppe mosaics. In 2018 a three-season-long vegetation sampling and measurements of air temperature and air humidity were performed along 4 transec...

Grasslands could play an important role in supporting livestock, in carbon sequestration and in biodiversity conservation. Different grassland managements may change the vegetation composition of grasslands, which could alter these ecosystem services. We studied the effects of grazing vs. mowing on the vegetation composition (2012–2016) and on the...

Soil respiration of grasslands is spatio-temporally variable reflecting the changing biological activities of the soil. In our study we analysed how the long-term soil respiration activities of dry grasslands would perform in terms of resistance and resilience. We also investigated how terrain features are responsible for response stability. We con...

The transition zones of the vegetation are sensitive to changes of environmental variables. Therefore, the impact of global climate change may be observable in spatio-temporal changes of habitats’ abiotic and biotic factors, such as microclimate variables, soil parameters, indices that typify vegetation etc. In this study, a grove of poplar trees (...

A globális klímaváltozás finom léptékű változásokat is okozhat. Ezek a változások az élőhelyek biotikus és abiotikus tényezőinek tér-időbeli mintázatain figyelhetők meg legkönnyebben, például a mikroklíma komponensek, a talajban mérhető háttérváltozók, a növényzet szerkezetével összefüggő, azt jellemző indexek alakulásában. Vizsgálatunkat a fülöphá...

Edges between the different ecosystems are important habitats maintaining high biodiversity and having special microclimate pattern. In our study, physiognomic and coenological structure of forest-steppe vegetation were investigated in forest-grassland edges in relation to microclimate patterns in Central Hungary (Fülöpháza region of Kiskunság Nati...

Az eltérő ökoszisztémák közötti átmeneteknek, szegélyeknek fontos szerepük van, mert fenntartják a biodiverzitást és a környező területektől eltérő mikroklímával rendelkeznek. Vizsgálatunk során összefüggéseket kerestünk a vegetációszerkezet és a mikroklíma-mintázat között homoki erdőssztyepp élőhelyen, Fülöpházán. Szelvények mentén 0.5*0.5 méteres...

The main objective of the present study was to determine the contributions of autotrophic and heterotrophic components to the total soil CO2 efflux over three years with high-frequency data acquisition by means of automated measurements. Soil CO2 efflux was measured continuously by using an automated open system of 10 soil respiration chambers in a...

Livestock is both threatened by and contributing to climate change. The contribution of livestock to climate change and greenhouse gas (GHG) emission greatly vary under different management regimes. A number of mitigation options comprise livestock management, although there are a lot of uncertainties as to which management regime to use for a give...

In this study eight temperate grassland sites were monitored for soil CO2 efflux (Rs) and the spatial covariate soil water content (SWC) and soil temperature (Ts) at fine scale in over 77 measurement campaigns. The goals of this multisite study were to explore the correlations between environmental gradients and spatial patterns of Rs, SWC and Ts,...

Different management practices may change the rate of soil respiration, thus affecting the carbon balance of grasslands. Therefore, we investigated the effect of grazing and mowing on soil respiration along with its driving variables (soil water content, soil temperature, above and below ground biomass, vegetation indices and soil carbon) in adjace...

Summer droughts projected to increase in Central Europe due to climate change strongly influence the carbon cycle of ecosystems. Persistent respiration activities during drought periods are responsible for a significant carbon loss, which may turn the ecosystem from sink to source of carbon. There are still gaps in our knowledge regarding the chara...

Az utóbbi évtizedben zajló kutatások kimutatták, hogy a talajok CO 2 -kibocsátása jelentős napi és szezonális változékonyságot mutat. A manuális mérőrendszerekkel azonban ez nehezen követhető nyomon. Éppen ezért megjelent az igény a nagyobb időbeli felbontású automata mérőrendszerekre, több gyártó készítette el saját fejlesztésű műszerét. Ezeknek a...

Aims Our aim was to study the effect of potential biotic drivers, including evapotranspiration (ET) and gross primary production (GPP), on the soil CO2 production and efflux on the diel time scale. Methods Eddy covariance, soil respiration and soil CO2 gradient systems were used to measure the CO2 and H2O fluxes in a dry, sandy grassland in Hungary...

High variability of soil respiration measured at fine spatial scale increases the uncertainty when trying to determine the representative average soil respiration (Rs) flux. A possible way to decrease the uncertainty, while also optimising measurement effort, could be the calculation of required number of Rs measurements (Nopt) together with the op...

Grasslands play an important role in carbon sequestration. Different management regimes may change the species composition of plants in grasslands, thus may affect the carbon sequestration potential. Therefore, we investigated if short-term changes in species composition occurred in response to shift in grazing to mowing in a semi-arid grassland in...

An automated open system for measurement of soil CO2 efflux (Rsc) was developed and calibrated against known fluxes. The system was tested in the field, while estimating soil respiration simultaneously by the gradient method (Rsg) at a dry, sandy grassland site (Bugac, Hungary). Ecosystem respiration (Rego) was measured using the eddy covariance te...

The effects of abiotic and biotic drivers on soil respiration (Rs) were studied in four grassland and one forest sites in Hungary in field measurement campaigns (duration of studies by sites 2–7 years) between 2000 and 2008. The sites are within a 100 km distance of each other, with nearly the same climate, but with different soils and vegetation....

An automated open system for measurement of soil CO₂ efflux ( R _sc) was developed and calibrated against known fluxes and tested in the field, while measuring soil respiration also by the gradient method ( R _sg) at a dry sandy grassland (Bugac, Hungary). Ecosystem respiration ( R _eco) was measured by the...

Fluxes of carbon dioxide, methane, nitrous oxide, and carbon stocks were measured at selected Hungarian forests and at a Croatian stand 120 km far from the Hungarian border. Annual carbon balance for Hungarian forests was also determined. Carbon stock of dendromass in selected Hungarian beech, hornbeam-pedunculate oak, and Turkey oak forests was be...

Measurement of biosphere–atmosphere exchange of various greenhouse gases requires different techniques. In case of carbon dioxide, the net ecosystem exchange (NEE) is usually measured by the eddy covariance method. In the lack of these measurements in forests, the carbon dioxide uptake can be estimated by detecting changes in sequestrated carbon st...

In this chapter, exchange dynamics of greenhouse gases over Hungarian grassland ecosystems are analyzed. Carbon dioxide (CO2) exchange was measured by eddy covariance technique at three sites (Bugac, Mátra, and Hegyhátsál). Methane (CH4) and nitrous oxide (N2O) fluxes were occasionally measured by static chamber method partly at the same grassland...

Measurement of biosphere–atmosphere exchange of various greenhouse gases requires different techniques. In case of carbon dioxide, the net ecosystem exchange (NEE) is usually measured by the eddy covariance method. In the lack of these measurements in forests, the carbon dioxide uptake can be estimated by detecting changes in sequestrated carbon st...

Fluxes of carbon dioxide, methane, nitrous oxide, and carbon stocks were measured at selected Hungarian forests and at a Croatian stand 120 km far from the Hungarian border. Annual carbon balance for Hungarian forests was also determined. Carbon stock of dendromass in selected Hungarian beech, hornbeam-pedunculate oak, and Turkey oak forests was be...

Nitrous oxide (N2O) is emitted into the atmosphere in substantial quantities as an intermediate product of mainly denitrification processes and soil nitrification. N2O emission from Hungarian sandy and loess type soils has been measured between August 2002 and December 2004. The effects of soil parameters and different farming activities (grazing e...

Static chamber measurements of nitrous oxide (N2O) and methane (CH4) fluxes were made from five characteristic vegetation types, representing three different natural ecosystems (grasslands, deciduous forest and wetlands) in the Pannonian basin, Hungary. The main objective of the study was to determine the drivers of average seasonal, annual and int...

The carbon balance of the sandy pasture (Bugac) and the mountain meadow (Mátra) varied between -171 and 96 gC m(-2) year-1, and -194 and 14 gC m(-2) year(-1), respectively, during the study period (2003-2009). Large part of interannual variability of net ecosystem exchange (NEE) was explained by the variation of the annual sum of precipitation in t...

Spatial variability and pattern of soil respiration and soil water content were examined in uniform patches of two different temperate grasslands and on bare soil. Soil respiration was measured by using hemisphere gas exchange chamber of 20 cm diameter along 15 m long transects at 20 cm spacing. The most simple, but commonly used expression of vari...

Interannual variation of carbon fluxes of grasslands on sandy (5 years data) and heavy clay soils (4 years data) have been analysed. The sandy grassland was carbon sink in 3 (2004,2005,2006) out of the investigated 5 years. Its annual C-balance is precipitation limited, the relation seems strongly conservative, with r 2 of 0.83. More than half of t...

Remnants of the former semiarid forest-steppe vegetation of Hungary are suspected to undergo degradation processes because of recent land-use changes. Secondary succession towards closing of the vegetation starts with shrub invasion, mainly with species of the shrub layer of loess steppe oak forest. Soil respiration (SR) activity of the intercanopy...

Grassland ecosystems in the Carpathian Basin may be particularly vulnerable to current and predicted changes in precipitation, and ecosystem responses to potential effects of water are not well understood. To examine how water addition can affect the species composition and structure, and CO 2-flux of a Central European natural steppe plant communi...

Soil fluxes of methane and nitrous oxide were determined for grasslands on sandy, loess and clay soils in Hungary. As the direction of methane flux (emission or uptake) depends on the soil characteristics bi-directional fluxes were observed. For sandy and loess grasslands the sink and source processes are practically balanced showing a negligible l...

Significant carbon losses from temperate grasslands oil different soils may Occur due to interannual variations in microclimatic patterns most notably due to increased drought and heat stress extremities. The investigated grassland ecosystems can take up 186 gC m(-2)year(-1) or loose 73 gC m(-2) year(-1) depending on the precipitation supply and te...

The autotrophic (root and rhizomicrobial) and heterotrophic (basal) components of soil respiration were determined in the carbon balance study on a (try sandy grassland with the main objectives of determining the ratio of these components and the effect of root water content on root respiration. The respiration of root and rhizomicrobial component...

The main goal of this paper is to determine the short-term (3-years period, from 2002 through 2004) effect of different land use changes (grazing exclusion, fertilization and irrigation) on the carbon and nitrogen content of above- and below-ground biomass, and different soil layers, as well as to provide data for model development. The C content o...

Measurements of CO2 and H2O fluxes were carried out using two different techniques—eddy-covariance (EC) and open system gas exchange chamber (OC)—during two-years’ period (2003–2004) at three different grassland sites. OC measurements were made during fourteen measurement campaigns. We found good agreement between the OC and EC CO2 flux values (n =...

Data on net ecosystem exchange (NEE) dynamics and carbon balance of a dry, extensively managed sandy grassland, as measured in Hungary in the years 2003 and 2004 are reported. The grassland was a weak source of carbon in 2003 (80 g C m−2), owing to the exceptionally hot and dry conditions while it was a strong sink in 2004 (−188 g C m−2), when the...

A number of C3 temperate dry grassland species and winter wheat plants were grown in open top chambers either at 365 µmol mol -1 (AC) or at 700 µmol mol -1 (EC) air CO2 concentrations. Gas exchange measurements were made at several air CO2 concentrations. When measured at higher CO2 concentrations, net photosynthetic rate was higher in plants grown...

Production, dry matter (including reproductive) allocation, photosynthesis, transpiration, water use efficiency and carbon and nitrogen responses of a Hungarian sweet pepper (Capsicum annum L.) under continuous elevated CO2 concentrations are reported. Plants were grown in open top chambers under a temperate-continental climate in Hungary from plan...

CO2 exchange components of a temperate semi-desert sand grassland ecosystem in Hungary were measured 21 times in 2000–2001 using a closed IRGA system. Stand CO2 uptake and release, soil respiration rate (R s), and micrometeorological values were determined with two types of closed system chambers to investigate the daily courses of gas exchange. Th...

Significant part of our work was developing a new type of CO2 and H2O gas exchange chambers fit for measuring stand patches. Ground areas of six chambers (ranged between 0.044–4.531 m2) constituted a logarithmic series with doubling diameters from 7.5 to 240.0 cm. We demonstrate one of the first results for stand net ecosystem CO2 exchange (NEE) ra...

The specific objectives of this study were to determine the effects of different land use changes (extensive grazing, fertilization and irrigation) on the botanical and soil parameters, plant biomass production and CO2 gas exchanges and to provide data for model development. Experimental work has been carried out for 3 years in two characteristic s...

Within the frame of an EU sponsored study (Greengrass) CO2 flux measurements were started on differently managed grassland ecosystems. We utilized two techniques - eddy-covariance (EC) and open system gas exchange chamber (OC) - to measure CO2 fluxes and compare the results of the two different methods. The study period presented in this paper cove...

Parallel coenological and synphysiological examinations were carried out on three typical xerophilous loess grassland stands of Salvio-Festucetum rupicolae community in the Gödöllö Hills, near Isaszeg village. Three stand types, a Carex humilis, a Chamaecytisus austriacus and a Stipa dasiphylla dominated ones were investigated at the same spatial s...

In the photosynthetically most active spring, summer and autumn vege­ tation period the investigated grassland did maintain a relatively strong daytime carbon gain. During winter the grassland displayed a slight daytime carbon loss. These data suggest that the grassland was a weak sink for carbon in the investigated period. CO2 exchange variability...

Species composition and ecosystem CO2 exchange measurements/examinations were carried out on three typical dry loess grassland stands (Carex humilis, Chamaecytisus austriacus and Stipa dasiphylla dominated) of Salvio-Festucetum rupicolae community under present-day and experimentally elevated CO2 concentration. The loess steppe vegetation contents...

Botanical (coenological) composition, leaf area index (LAI) and ecosystem CO2 exchange (synphysiological) investigations were carried out in the stands of a semi-desert sand grassland in Hungary under present-day and experimentally elevated CO2 concentrations. Present-day results prove the presence of three different types of the Festucetum vaginat...

Leaf anatomy and eco-physiology of Elymus repens, a temperate loess grassland species, were determined after seven years of exposure to 700 μmol (CO2) mol−1 (EC). EC treatment resulted in significant reduction of stomatal density on both surfaces of couch-grass leaves. Thickness of leaves and that of the sclerenchyma tissues between the vessels and...

Carbon dioxide fluxes over vegetation have been measured by the eddy-covariance technique at two flatland sites in Hungary. One of the sites currently in operation lies near Hegyhátsál, in the western part of Hungary. The other station has been installed in Bugac-puszta, in the central region of the country. It is planned to measure the CO2 flux in...

Three plant communities, a loess, a sand and an old-field grassland showed considerable differences in synphysiological variability during an investigation at the same spatial scale in 2000. The two former are widely distributed in the Carpathian Basin and with the latter the Hungarian non-arborescent, herbaceous vegetation is well represented. To...

Temperate grassland ecosystems are important components of the global carbon cycle. Our object of investigation, the semi-arid sand grassland community (Festucetum vaginatae danubiale) occurs widely in Hungary. A closed-loop portable IRGA system connected to a chamber appropriate for stand-scale measurements was used to measure CO2-exchange over a...

Seasonal change in diurnal CO2 exchange of the desiccation-tolerant ectohydric moss Tortula ruralis was investigated in situ to determine its contribution to CO2 exchange of the carbon balance of the temperate semi-arid sandy grassland ecosystem. A hemisphere perspex chamber (20 cm in diameter) was used to measure the C02 gas exchange of the moss c...

Our goal was to investigate the spatial scale-dependence of synphysiological measurements in three different vegetation types: a loess steppe grassland, a sandy grassland and a ruderal weed community. The former two are widely distributed in the Carpathian Basin and completed with the weed association these are well representing the Hungarian nonar...

The lack of community-level, synphysiological investigations inspired us to plan a study on Brachypodium pinnatum grasslands, well-known objects of local long-term coenological and dynamical examinations in Hungary. After removing every species but B. pinnatum, CO2 gas exchange responses by the grass stands indicated the difference in the degree of...