Juha E. P. Heikkinen's research while affiliated with University of Kuopio and other places

... Further, this CO2 release process results from root respiration, microbial respiration in the rhizosphere, respiration from the decomposition of litter and organisms, and soil organic matter oxidation (Luo and Zhou 2010;Moyano et al. 2009). Environmental factors such as the depth of the groundwater table, temperature, humidity, and pH of peat soil significantly influence the amount of CO2 emissions released from peatland (Jauhiainen et al. 2001;Hooijer et al. 2006;Strack et al. 2008;Agus et al. 2010). If Carbon is released through carbon dioxide emissions in large quantities and lasts for a long time, then this, in addition to threatening the existence of the peat function as a carbon repository, is also a source of greenhouse gases whose contribution reaches 48% (Pirkko and Nyronen 1990). ...

... Many research show that ex-logging abandoned peat lands and rice field are sources of carbon dioxide emissions. Clean logged peat lands with scrubland cover, without reforestation, is able to produce CO 2 emissions around 34.0 t/ha/year (Jauhanien et al., 2004). ...

... To determine the net exchange of CO 2 or CH 4 from different landcover types, researchers use eddy covariance techniques which result in integrated landscape-scale fluxes. Chamber measurements, automated or manual, can help to partition these fluxes to plant community types at metre square scales [15][16][17]. For open water surfaces too small for eddy covariance techniques, like those often found in thawing environments, estimates of the rate of hydrodynamic advection of trace gases are measured directly using floating chambers [18,19] or by estimating fluxes using dissolved concentration measurements in combination with transfer coefficients [20,21]. ...

... Судлаачид дэлхийн бусад улс оронд газар ашиглалтын төрлүүдээс ялгарах хүлэмжийн хийн хэмжилт, судалгааг нилээдгүй хийсэн байдаг. Жишээлбэл хээрийн шууд хэмжилтийн арга зүйгээр ялгарлын коэффициентийг чийг намагтай газарт бодсон судалгааны зарим үр дүнгээс хархад ОХУ-ын Сибирийн нутаг дэвсгэрт 133.0 гр [CO2] м -2 жил -1 , 8.0 гр [CH4] м -2 жил -1 [14], АНУ-ын Охая мужид 524.0 гр [CO2] м -2 жил -1 , 76.0 гр [CH4] м -2 жил -1 [15], БНХАУ-ын Шинжаны Тэгш өндөрлөгт 46.8 гр [CH4] м -2 жил -1 [16] тус тус байна. Монгол орны хэмжээнд газар ашиглалтын төрлүүд дээрх хээрийн судалгааг урт хугацаанд тогтвортой хийхэд тухайн газруудад хөрсний органик агууламжийг нарийн тодорхойлох нь чухал. ...

... Methane emissions varied strongly across the palsa peatlands with consistent differences among vegetation types over space and time. The low emissions from the intact dry palsa areas and trends of increased emission following degradation and flooding were comparable with those reported from other part of Scandinavia and Russia (Nykänen et al., 2003;Olefeldt et 440 al., 2013;Liebner et al., 2015;Miglovets et al., 2021;Varner et al., 2022;Glagolev et al., 2011). However, there was strong variation in the magnitude of that response depending on the degradation stage, level of flooding and vegetation community present. ...

... Various agricultural production systems and uses of peatland also affect the groundwater level, soil's physical, chemical, and biological qualities, and air temperature, which can be affected the peatlands' CO2 emissions. Information related to the CO2 emissions from peatland comes from the forests, open land (Jauhiainen et al. 2005), and agricultural land (Hatano et al. 2004) of the Kalimantan region, while the information regarding the CO2 emissions from peatlands utilized for oil palm, rubber, biennial aloe vera, and seasonal corn and mustard greens production in the central Kalimantan and west Kalimantan have not been estimated in any previous study. ...

... We postulate three interrelated hypotheses: We expect an overall good agreement between plot and ecosystem-scale carbon fluxes (H1), as plots are located within a representative area of the EC footprint consisting of homogeneous land cover, but we also expect large uncertainty imposed by tidal cycles and salinity changes. Previous studies examining CO 2 exchange in peatlands (Heikkinen et al., 2002;Lees et al., 2021) and a reed marsh (Acosta et al., 2019) reported lower fluxes from chambers, while studies examining CH 4 emissions have found higher fluxes from chambers in a variety of different wetlands (Chaichana et al., 2018;Hendriks et al., 2010;Meijide et al., 2011;Sun et al., 2013). Only two previous studies have performed similar comparisons in a salt marsh where CH 4 and CO 2 emissions from chambers were found to be 2 times higher than ecosystem-scale fluxes , and NEE derived from chambers was of greater magnitude than ecosystem-scale fluxes (Czapla et al., 2020). ...

... Knowledge about the rate of carbon accumulation and its changes over time is an important step in modern research. According to [23,24], peat and tundra ecosystems are able to shift from a carbon sink into its source due to increased soil respiration under warmer and drier conditions. Therefore, in order to better understand current and future ecosystem pyrogenic changes, it is necessary to study and understand their relationship with vegetation and climatic changes in the past [25]. ...