scholarly journals Variability in methane emissions from West Siberia's shallow boreal lakes

2016 ◽  
Author(s):  
Aleksandr F. Sabrekov ◽  
Benjamin R. K. Runkle ◽  
Mikhail V. Glagolev ◽  
Irina E. Terentieva ◽  
Victor M. Stepanenko ◽  
...  
Keyword(s):  
Pore Space ◽  
Temporal Variations ◽  
Methane Emissions ◽  
Boreal Lakes ◽  
Middle Taiga ◽  
Taiga Zone ◽  
Power Law Distribution ◽  
Small Lakes ◽  
The South ◽  
Environmental Controls

Abstract. Small lakes represent an important source of atmospheric CH4 from northern wetlands. However, spatio-temporal variations in flux magnitudes and the lack of knowledge about their main environmental controls contribute large uncertainty into the global CH4 budget. In this study, we measured methane fluxes from small lakes using chambers and bubble traps. Field investigations were carried out in July–August 2014 within the West Siberian middle and south taiga zones. The average and median of measured methane chamber fluxes were 0.32 and 0.30 mgCH4 m−2 h−1 for middle taiga lakes and 8.6 and 4.1 mgCH4 m−2 h−1 for south taiga lakes, respectively. Pronounced flux variability was found during measurements on individual lakes, between individual lakes and between zones. To analyze these differences and the influences of environmental controls we developed a new dynamic process-based model. It shows good performance with emission rates from the south taiga lakes and poor performance for individual lakes in the middle taiga region. The model shows that, besides well-known controls such as temperature, pH and lake depth, there are significant variations in the maximal methane production potential between these climatic zones. In addition, the model shows that variations of gas-filled pore space in lake sediments are capable to control the total methane emissions from individual lakes. The CH4 emissions exhibited distinct zonal differences not only in absolute values but also in their probability density functions: the middle taiga lake fluxes were best described by a lognormal distribution while the south taiga lakes followed a power law distribution. The latter suggests applicability of self-organized criticality theory for methane emissions from the south taiga zone, which could help to explain the strong variability within individual lakes.

scholarly journals Variability in methane emissions from West Siberia's shallow boreal lakes on a regional scale and its environmental controls

2017 ◽  
Vol 14 (15) ◽  
pp. 3715-3742 ◽  
Author(s):  
Aleksandr F. Sabrekov ◽  
Benjamin R. K. Runkle ◽  
Mikhail V. Glagolev ◽  
Irina E. Terentieva ◽  
Victor M. Stepanenko ◽  
...  
Keyword(s):  
Pore Space ◽  
Regional Scale ◽  
Methane Emissions ◽  
Southern Taiga ◽  
Boreal Lakes ◽  
Middle Taiga ◽  
Taiga Zone ◽  
Power Law Distribution ◽  
Small Lakes ◽  
Environmental Controls

Abstract. Small lakes represent an important source of atmospheric CH4 from northern wetlands. However, spatiotemporal variations in flux magnitudes and the lack of knowledge about their main environmental controls contribute large uncertainty into the global CH4 budget. In this study, we measured methane fluxes from small lakes using chambers and bubble traps. Field investigations were carried out in July–August 2014 within the West Siberian middle and southern taiga zones. The average and median of measured methane chamber fluxes were 0.32 and 0.30 mgCH4 m−2 h−1 for middle taiga lakes and 8.6 and 4.1 mgCH4 m−2 h−1 for southern taiga lakes, respectively. Pronounced flux variability was found during measurements on individual lakes, between individual lakes and between zones. To analyze these differences and the influences of environmental controls, we developed a new dynamic process-based model. It shows good performance with emission rates from the southern taiga lakes and poor performance for individual lakes in the middle taiga region. The model shows that, in addition to well-known controls such as temperature, pH and lake depth, there are significant variations in the maximal methane production potential between these climatic zones. In addition, the model shows that variations in gas-filled pore space in lake sediments are capable of controlling the total methane emissions from individual lakes. The CH4 emissions exhibited distinct zonal differences not only in absolute values but also in their probability density functions: the middle taiga lake fluxes were best described by a lognormal distribution while the southern taiga lakes followed a power-law distribution. The latter suggests applicability of self-organized criticality theory for methane emissions from the southern taiga zone, which could help to explain the strong variability within individual lakes.

scholarly journals Association Carici juncellae-Salicetum rosmarinifoliae (Alnetea glutinosae) on the south taiga section of the Ob River floodplain

2019 ◽  
Vol 10 (1) ◽  
pp. 40-49
Author(s):  
Georgy Semenovich Taran ◽  
Alexander Petrovich Dyachenko
Keyword(s):  
Vascular Plants ◽  
Middle Taiga ◽  
Taiga Zone ◽  
The South ◽  
Moss Species ◽  
Species Saturation ◽  
Ob River ◽  
Tree Layer ◽  
First Time ◽  
Geographical Space

The Carici juncellae–Salicetum rosmarinifoliae Korolyuk et Taran in Taran 1993 association (Salicion cinereae, Salicetalia auritae, Alnetea glutinosae) includes the communities of the shrub (Salix rosmarinifolia, S. cinerea)-birch (Betula pubescens) tussock (Carex juncella, C. cespitosa) mires spread on the big West Siberian river floodplains within the taiga zone. On the Ob River, the association is represented by the C.j.–S.r. spiraeetosum salicifoliae Taran 1993 subassociation. Its range covers the Ob floodplain 830-kilometer distance crossing the subtaiga, south taiga and middle taiga subzones of Western Siberia. In the south taiga subzone (surroundings of the former village Kaibasovo, Krivosheinskiy district of Tomsk Region, 57º14'44"N, 84º11'05"E), the C.j.–S.r. spiraeetosum salicifoliae subassociation is studied for the first time. Near the Kaibasovo, the subassociation is represented by two facies: shrubby (Spiraea salicifolia, Salix rosmarinifolia, Salix cinerea) and birch (betulosum pubescentis). The communities of these facies found some floristic differences, which made it possible to attribute them to different variants: var. Cicuta virosa and var. Kadenia dubia. Carex juncella, C. cespitosa and Comarum palustre dominate in the field layer of the tussock mires. In the C.j.–S.r. spiraeetosum salicifoliae subassociation communities near the Kaibasovo, the average total projective cover (TPC) of the tree layer is 7%, shrubs – 34%, grasses – 48%, tussocks – 20%, ground mosses – 14%. Average tussock height is 59 cm. Average species saturation of the communities is 27 species of vascular plants and 18 species of mosses per 100 m2, the volume of the local coenoflora is 39 species of vascular plants and 28 species of mosses. Six moss species (Brachytheciastrum velutinum, Bryoerythrophyllum recurvirostrum, Bryum moravicum, Fissidens bryoides, Plagiomnium cuspidatum, Pylaisia selwynii) were found in the Ob communities of the C.j.–S.r. spiraeetosum salicifoliae for the first time. Due to this, the total volume of the moss flora of the subassociation Ob stands increased to 74 species. The analysis of the variability of the main coenotic and floristic parameters of the C.j.–S.r. spiraeetosum salicifoliae subassociation in the geographical space of the Ob floodplain (from the subtaiga subzone to the middle taiga one) is carried out. The main regularities of these shifts are revealed. The volume of the subassociation local vascular coenoflora (52-53 species) and average species saturation of the communities by vascular plants (20-21 species per 100 m2) are stable on the most of the Ob floodplain sections. At the same time, changes are observed downstream of the Ob River, which can be interpreted as an intracoenotic response of the subassociation communities to smooth changes in the ecological regime of the floodplain when moving in geographical space from south to north. Thus, from the south to the north, many average parameters increase in the subassociation communities, namely: the height of trees, TPCs of tree layer, tussocks and ground mosses, the species saturation with mosses (from 4 to 18 species per 100 m2). The species richness of local moss floras also increases from 11 to 54 species. On the contrary, the average TPCs of shrub and field layers from south to north decrease. A number of deviations from general trends were found in the Kaibasovo birch-shrub tussock mires, namely: high species saturation with vascular plants (27 species per 100 m2), low reach of vascular coenoflora (39 species). The first can be explained by the proximity of the studied mires to the Ob riverbed, the second – by the crowding of the relevés in a relatively small area of the floodplain.

scholarly journals The Multiscale Monitoring of Peatland Ecosystem Carbon Cycling in the Middle Taiga Zone of Western Siberia: The Mukhrino Bog Case Study

Land ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 824
Author(s):  
Egor Dyukarev ◽  
Evgeny Zarov ◽  
Pavel Alekseychik ◽  
Jelmer Nijp ◽  
Nina Filippova ◽  
...  
Keyword(s):  
Carbon Cycling ◽  
Western Siberia ◽  
Carbon Accumulation ◽  
Middle Taiga ◽  
Taiga Zone ◽  
Field Station ◽  
Moss Species ◽  
Chamber Method ◽  
The Impact

The peatlands of the West Siberian Lowlands, comprising the largest pristine peatland area of the world, have not previously been covered by continuous measurement and monitoring programs. The response of peatlands to climate change occurs over several decades. This paper summarizes the results of peatland carbon balance studies collected over ten years at the Mukhrino field station (Mukhrino FS, MFS) operating in the Middle Taiga Zone of Western Siberia. A multiscale approach was applied for the investigations of peatland carbon cycling. Carbon dioxide fluxes at the local scale studied using the chamber method showed net accumulation with rates from 110, to 57.8 gC m−2 at the Sphagnum hollow site. Net CO2 fluxes at the pine-dwarf shrubs-Sphagnum ridge varied from negative (−32.1 gC m−2 in 2019) to positive (13.4 gC m−2 in 2017). The cumulative May-August net ecosystem exchange (NEE) from eddy-covariance (EC) measurements at the ecosystem scale was −202 gC m−2 in 2015, due to the impact of photosynthesis of pine trees which was not registered by the chamber method. The net annual accumulation of carbon in the live part of mosses was estimated at 24–190 gC m−2 depending on the Sphagnum moss species. Long-term carbon accumulation rates obtained by radiocarbon analysis ranged from 28.5 to 57.2 gC m−2 yr−1, with local extremes of up to 176.2 gC m−2 yr−1. The obtained estimates of various carbon fluxes using EC and chamber methods, the accounting for Sphagnum growth and decomposition, and long-term peat accumulation provided information about the functioning of the peatland ecosystems at different spatial and temporal scales. Multiscale carbon flux monitoring reveals useful new information for forecasting the response of northern peatland carbon cycles to climatic changes.

scholarly journals Sensitivity of wetland methane emissions to model assumptions: application and model testing against site observations

2012 ◽  
Vol 9 (7) ◽  
pp. 2793-2819 ◽  
Author(s):  
L. Meng ◽  
P. G. M. Hess ◽  
N. M. Mahowald ◽  
J. B. Yavitt ◽  
W. J. Riley ◽  
...  
Keyword(s):  
Soil Ph ◽  
High Latitude ◽  
Large Range ◽  
Rice Paddy ◽  
Temporal Variations ◽  
Methane Emissions ◽  
Biogeochemical Model ◽  
Atmospheric Methane ◽  
Rice Paddies ◽  
Community Land Model

Abstract. Methane emissions from natural wetlands and rice paddies constitute a large proportion of atmospheric methane, but the magnitude and year-to-year variation of these methane sources are still unpredictable. Here we describe and evaluate the integration of a methane biogeochemical model (CLM4Me; Riley et al., 2011) into the Community Land Model 4.0 (CLM4CN) in order to better explain spatial and temporal variations in methane emissions. We test new functions for soil pH and redox potential that impact microbial methane production in soils. We also constrain aerenchyma in plants in always-inundated areas in order to better represent wetland vegetation. Satellite inundated fraction is explicitly prescribed in the model, because there are large differences between simulated fractional inundation and satellite observations, and thus we do not use CLM4-simulated hydrology to predict inundated areas. A rice paddy module is also incorporated into the model, where the fraction of land used for rice production is explicitly prescribed. The model is evaluated at the site level with vegetation cover and water table prescribed from measurements. Explicit site level evaluations of simulated methane emissions are quite different than evaluating the grid-cell averaged emissions against available measurements. Using a baseline set of parameter values, our model-estimated average global wetland emissions for the period 1993–2004 were 256 Tg CH4 yr−1 (including the soil sink) and rice paddy emissions in the year 2000 were 42 Tg CH4 yr−1. Tropical wetlands contributed 201 Tg CH4 yr−1, or 78% of the global wetland flux. Northern latitude (>50 N) systems contributed 12 Tg CH4 yr−1. However, sensitivity studies show a large range (150–346 Tg CH4 yr−1) in predicted global methane emissions (excluding emissions from rice paddies). The large range is sensitive to (1) the amount of methane transported through aerenchyma, (2) soil pH (±100 Tg CH4 yr−1), and (3) redox inhibition (±45 Tg CH4 yr−1). Results are sensitive to biases in the CLMCN and to errors in the satellite inundation fraction. In particular, the high latitude methane emission estimate may be biased low due to both underestimates in the high-latitude inundated area captured by satellites and unrealistically low high-latitude productivity and soil carbon predicted by CLM4.

scholarly journals Environmental controls on the increasing GPP of terrestrial vegetation across northern Eurasia

2016 ◽  
Vol 13 (1) ◽  
pp. 45-62 ◽  
Author(s):  
P. Dass ◽  
M. A. Rawlins ◽  
J. S. Kimball ◽  
Y. Kim
Keyword(s):  
Forest Fires ◽  
Environmental Control ◽  
Negative Impact ◽  
Positive Impact ◽  
Terrestrial Ecosystems ◽  
Northern Eurasia ◽  
Terrestrial Vegetation ◽  
The South ◽  
Environmental Controls ◽  
Significant Negative Impact

Abstract. Terrestrial ecosystems of northern Eurasia are demonstrating an increasing gross primary productivity (GPP), yet few studies have provided definitive attribution for the changes. While prior studies point to increasing temperatures as the principle environmental control, influences from moisture and other factors are less clear. We assess how changes in temperature, precipitation, cloudiness, and forest fires individually contribute to changes in GPP derived from satellite data across northern Eurasia using a light-use- efficiency-based model, for the period 1982–2010. We find that annual satellite-derived GPP is most sensitive to the temperature, precipitation and cloudiness of summer, which is the peak of the growing season and also the period of the year when the GPP trend is maximum. Considering the regional median, the summer temperature explains as much as 37.7 % of the variation in annual GPP, while precipitation and cloudiness explain 20.7 and 19.3 %. Warming over the period analysed, even without a sustained increase in precipitation, led to a significant positive impact on GPP for 61.7 % of the region. However, a significant negative impact on GPP was also found, for 2.4 % of the region, primarily the dryer grasslands in the south-west of the study area. For this region, precipitation positively correlates with GPP, as does cloudiness. This shows that the south-western part of northern Eurasia is relatively more vulnerable to drought than other areas. While our results further advance the notion that air temperature is the dominant environmental control for recent GPP increases across northern Eurasia, the role of precipitation and cloudiness can not be ignored.

scholarly journals Methane emissions from global rice fields: Magnitude, spatiotemporal patterns, and environmental controls

2016 ◽  
Vol 30 (9) ◽  
pp. 1246-1263 ◽  
Author(s):  
Bowen Zhang ◽  
Hanqin Tian ◽  
Wei Ren ◽  
Bo Tao ◽  
Chaoqun Lu ◽  
...  
Keyword(s):  
Methane Emissions ◽  
Rice Fields ◽  
Spatiotemporal Patterns ◽  
Environmental Controls

scholarly journals Growth and Development of Introduced Larix Mill. Species in the Taiga Zone (Karelia)

2021 ◽  
pp. 61-83
Author(s):  
Ivan T. Kishchenko
Keyword(s):  
Plant Communities ◽  
Growth And Development ◽  
Growing Season ◽  
Botanical Garden ◽  
Larix Sibirica ◽  
Middle Taiga ◽  
Taiga Zone ◽  
State University ◽  
Residential Landscaping ◽  
Phenological Phases

The study reports results of research carried out from April to October during 1988–2016 at the Botanical Garden of Petrozavodsk State University (South Karelia, middle taiga subzones). Three introduced species of the genus Larix (Larix sibirica Ledeb., L. leptolepis (Sieb. et Zucc.) Gord, and L. dahurica Turcz. ex Trautv.) were studied. The growth of shoots and needles in different species begins, reaches its culmination, and ends almost simultaneously, differing by no more than one week across the species. L. sibirica shows the highest growth rate. The timing of growth, culmination, and the dynamics of growth of shoots and needles are largely determined by variations in precipitation, temperature, and humidity. The direction and strength of such an effect may vary from year to year. The dates of phenological phases of the Larix species studied here are chiefly determined by the air temperature in the current growing season and the dates of formation of wintering buds in the previous growing season. Bud swelling and opening begins almost simultaneously in the studied species. Most of the other phenological phases begin and end earliest in L. sibirica and latest in L. leptolepis. All the studied species, primarily L. sibirica, are promising for residential landscaping and creation of artificial plant communities in Karelia

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