Hydrometeorological dataset of West Siberian boreal peatland: a 10-year record from the Mukhrino field station

Northern peatlands represent one of the largest carbon pools in the biosphere, but the carbon they store is increasingly vulnerable to perturbations from climate and land-use change. Meteorological observations taken directly at peatland areas in Siberia are unique and rare, while peatlands are characterized by a specific local climate. This paper presents a hydrological and meteorological dataset collected at the Mukhrino peatland, Khanty-Mansi Autonomous Okrug – Yugra, Russia, over the period of 8 May 2010 to 31 December 2019. Hydrometeorological data were collected from stations located at a small pine–shrub–Sphagnum ridge and Scheuchzeria–Sphagnum hollow at ridge–hollow complexes of ombrotrophic peatland. The monitored meteorological variables include air temperature, air humidity, atmospheric pressure, wind speed and direction, incoming and reflected photosynthetically active radiation, net radiation, soil heat flux, precipitation (rain), and snow depth. A gap-filling procedure based on the Gaussian process regression model with an exponential kernel was developed to obtain continuous time series. For the record from 2010 to 2019, the average mean annual air temperature at the site was −1.0 ∘C, with the mean monthly temperature of the warmest month (July) recorded as 17.4 ∘C and for the coldest month (January) −21.5 ∘C. The average net radiation was about 35.0 W m−2, and the soil heat flux was 2.4 and 1.2 W m−2 for the hollow and the ridge sites, respectively. The presented data are freely available through Zenodo (https://doi.org/10.5281/zenodo.4323024, Dyukarev et al., 2020), last access: 15 December 2020) and can be used in coordination with other hydrological and meteorological datasets to examine the spatiotemporal effects of meteorological conditions on local hydrological responses across cold regions.

Estimation of Daily Water Table Level with Bimonthly Measurements in Restored Ombrotrophic Peatland

Daily measurements of the water table depth are sometimes needed to evaluate the influence of seasonal water stress on Sphagnum recolonization in restored ombrotrophic peatlands. However, continuous water table measurements are often scarce due to high costs and, as a result, water table depth is more commonly measured manually bimonthly with daily logs in few reference wells. A literature review identified six potential methods to estimate daily water table depth with bimonthly records and daily measurements from a reference well. A new estimation method based on the time series decomposition (TSD) is also presented. TSD and the six identified methods were compared with the water table records of an experimental peatland site with controlled water table regime located in Eastern Canada. The TSD method was the best performing method (R2 = 0.95, RMSE = 2.48 cm and the lowest AIC), followed by the general linear method (R2 = 0.92, RMSE = 3.10 cm) and support vector machines method (R2 = 0.91, RMSE = 3.24 cm). To estimate daily values, the TSD method, like the six traditional methods, requires daily data from a reference well. However, the TSD method does not require training nor parameter estimation. For the TSD method, changing the measurement frequency to weekly measurements decreases the RMSE by 16% (2.08 cm); monthly measurements increase the RMSE by 13% (2.80 cm).

The potential significance of ericoid mycorrhizal fungi in ombrotrophic peatland biogeochemistry

<p>Northern peatlands have sequestered a huge amount of carbon through exceptionally low microbial activity which is partly attributed to their nutrient-poor conditions. Evergreen shrubs, a dominant species in ombrotrophic bogs, adapt to this nutrient-poor condition by developing organic nutrient acquisition strategies, mediated by ericoid mycorrhizal association. However, the mycorrhizal symbionts together with nutrient cycling have been omitted in peatland models, precluding our ability to simulate the significance of nutrient limitation in peatlands following environmental changes. To address this issue, we further developed the well-established peatland model MWM by incorporating a mechanistic mycorrhizal fungi model and both nitrogen and phosphorus cycles. The new model was adopted to simulate the fertilization effect on peatlands and evaluated against measurements from the long-term fertilization experiments at Mer Bleue, a raised ombrotrophic bog located in southern Ontario, Canada. The model successfully reproduced the observed dramatic changes with fertilization in mycorrhizal performance, vegetation composition and carbon cycle. Greater availability of inorganic nutrients diminished the role of mycorrhizal fungi in plant nutrient uptake. More assimilated carbon was allocated to shrub growth, which then inhibited the growth of sphagnum moss and ultimately posed a threat to the carbon-sequestration capacity of peatlands. Therefore, mycorrhizal activities, which have been overlooked in past peatland studies, could play a significant role in understanding how peatlands respond to increased nutrient deposition in the future.</p>

Constraints on microbial communities, decomposition and methane production in deep peat deposits

Peatlands play outsized roles in the global carbon cycle. Despite occupying a rather small fraction of the terrestrial biosphere (∼3%), these ecosystems account for roughly one third of the global soil carbon pool. This carbon is largely comprised of undecomposed deposits of plant material (peat) that may be meters thick. The fate of this deep carbon stockpile with ongoing and future climate change is thus of great interest and has large potential to induce positive feedback to climate warming. Recent in situ warming of an ombrotrophic peatland indicated that the deep peat microbial communities and decomposition rates were resistant to elevated temperatures. In this experiment, we sought to understand how nutrient and pH limitations may interact with temperature to limit microbial activity and community composition. Anaerobic microcosms of peat collected from 1.5 to 2 meters in depth were incubated at 6°C and 15°C with elevated pH, nitrogen (NH4Cl), and/or phosphorus (KH2PO4) in a full factorial design. The production of CO2 and CH4 was significantly greater in microcosms incubated at 15°C, although the structure of the microbial community did not differ between the two temperatures. Increasing the pH from ∼3.5 to ∼5.5 altered microbial community structure, however increases in CH4 production were non-significant. Contrary to expectations, N and P additions did not increase CO2 and CH4 production, indicating that nutrient availability was not a primary constraint in microbial decomposition of deep peat. Our findings indicate that temperature is a key factor limiting the decomposition of deep peat, however other factors such as the availability of O2 or alternative electron donors and high concentrations of phenolic compounds, may also exert constraints. Continued experimental peat warming studies will be necessary to assess if the deep peat carbon bank is susceptible to increased temperatures over the longer time scales.

STUDI FLUKS KARBON DIOKSIDA PADA BERBAGAI TIPE PENGGUNAAN DI LAHAN GAMBUT PASANG SURUT DAN PEDALAMAN (Study of Carbon dioxide Fluxes (CO2 fluxes) on Various Land Use in Low Tide and Ombrotrophic Peatland)

ABSTRACT The aim of this study to known Co2 fluxes in low tide and ombrotrophic peatland on forest land, ex- burns land, rubber tree land, and maize land and to known amount of microbial populations there. Observation method was carried out at the village Kalampangan (ombrotrophic peatland) , Sebangau, Palangka Raya, and at the village Purwodadi (low tide peatland), Maliku, Pulang Pisau, from May to July 2014. Observation variables consist of CO2 fluxes, fluctuations of groundwater levels, soil temperature, soil humidity and microbial populations. The results show that overall carbon dioxide fluxes higher in low tide peatland, with the highest fluxes in burnt areas, 430.24 mg C m-2 h-1, whereas in Ombrotrophic peatland, the highest on 292 forested land, 92 mg C m-2h-1. In Ombrotrophic peatland, relation between fluxes of carbon dioxide and the soil temperature is significant in the burnt areas with a value of R = 0.856 with a quadratic pattern, with the average temperature of 28.89 ° C. Fluxes of carbon dioxide significantly effected by soil moisture that is at a rubber plantation with a value of R = 0.640 with quadraticpatterned, average soil moisture of 0.61 m3/m-3. Fluxes of carbon dioxide to the groundwater depth is significant on a rubber plantation with a value of R = 0.872 with a quadratic pattern, and depth of groundwater on average of 83.74 cm. The populatuin of microorganisms, in forest land 137 sel/ml, rubber plantations 154 sel/ml, cornfields 157 sel/ml and ex-burnt is 80 sel/ml. In Low Tide peatland, fluxes of carbon dioxide to the soil temperature is significant in forest land with the value of R = 0.545 with cubic pattern, and the average temperature of 27,39 oC. Soil moisture has the siginificant effect to fluxes of carbon dioxide that is in the burnt areas with a value of R = 0.617 with patterned quadratic, and average soil moisture of 0.50 m3/m-3. The ground water depth has a siginificant effect to fluxes of carbon dioxide in a cornfield with a value of R = 0.743 with a quadratic pattern, and the depth of soil water on average of 68.98 cm. Population of soil microorganisms, in forest land 73 sel/ml, rubber plantations 36 sel/ml, cornfields 51 sel/ml and ex-burnt 18 sel/ml. Soil temperature, soil moisture, groundwater depth and microoganisms effect on carbon dioxide fluxes. Key words : carbondioxide, fluxes, microorganisms, peatland ABSTRAK Tujuan Penelitian adalah untuk mengetahui pengaruh tipe penggunaan lahan gambut pasang surut dan lahan gambut pedalaman, baik pada hutan alami, eks kebakaran, lahan pertanian (jagung) dan perkebunan karet terhadap fluks karbon dioksida dan mengetahui pengaruh jumlah mikroorganisme terhadap fluks karbon dioksida pada hutan alami, eks kebakaran, lahan pertanian (jagung) dan perkebunan karet pada kedua tipe lahan gambut tersebut. Penelitian dilaksanakan dari tanggal 23 Mei sampai dengan 19 Juli 2014 (2 bulan) di Kalampangan dan Purwodadi (Kanamit). Hasil Penelitian menunjukkan, fluks karbon dioksida secara keseluruhan lebih tinggi di Gambut Pasang Surut dibandingkan dengan di Pedalaman. Rata-rata fluks karbon dioksida di Gambut Pasang Surut, Jurnal AGRI PEAT, Vol. 18 No. 2 , September 2017 : 68 - 81 ISSN :1411 - 6782 69 pada lahan berhutan 285, 22 mg C m-2h-1, pada kebun karet 264,69 mg C m-2h-1, pada kebun jagung 232,08 mg C m-2h-1, pada lahan bekas kebakaran 430,24 mg C m-2h-1. Meskipun demikian, di Gambut Pedalaman, pada lahan berhutan lebih tinggi dibanding di Pasang Surut yaitu 292, 92 mg C m-2h-1, pada kebun karet 224,93 mg C m-2h-1, pada kebun jagung 211,30 mg C m-2h-1, pada lahan bekas kebakaran 228,07 mg C m-2h-1. Di Gambut Pedalaman, hubungan fluks karbon dioksida terhadap suhu tanah yang berpengaruh nyata yaitu pada areal bekas kebakaran dengan nilai R = 0,856 dengan berpola kuadratik, suhu rata-rata 28,89 oC. Fluks karbon dioksida terhadap kelembaban tanah yang berpengaruh nyata yaitu pada kebun karet dengan nilai R = 0,640 dengan berpola kuadratik, kelembaban tanah rata-rata 0,61 m3/m-3. Hubunganfluks karbon dioksida terhadap kedalaman air tanah yang berpengaruh nyata yaitu pada kebun karet dengan nilai R = 0,872 berpola kuadratik dengan kedalaman air tanah rata-rata 83,74 cm. Mikroorganisme, di lahan hutan 137 sel/ml, kebun karet 154 sel/ml, kebun jagung 157 sel/ml dan dilahan bekas kebakaran 80 sel/ml. Di Gambut Pasang Surut, hubungan fluks karbon dioksida terhadap suhu tanah yang berpengaruh nyata yaitu pada lahan hutan dengan nilai R = 0,545 dengan berpola kubik, suhu rata- rata 27,39 oC. Hubungan fluks karbon dioksida terhadap kelembaban tanah yang berpengaruh nyata yaitu pada lahan bekas kebakaran dengan nilai R = 0,617 dengan berpola kuadratik, kelembaban tanah rata-rata 0,50 m3/m-3. Hubungan fluks karbon dioksida terhadap kedalaman air tanah yang berpengaruh nyata yaitu pada kebun jagung dengan nilai R = 0,743 berpola kuadratik dengan kedalaman air tanah rata-rata 68,98 cm. Mikroorganisme, di lahan hutan 73 sel/ml, kebun karet 36 sel/ml, kebun jagung 51 sel/ml dan dilahan bekas kebakaran 18 sel/ml. Suhu tanah, kelembaban tanah, kedalaman air tanah berpengaruh terhadap fluks karbon dioksida dan mikroorganisme pengaruhnya kecil. Kata kunci : carbondioxide, fluxes, microorganisms, peatland