Browsing by Subject "Peat"

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  • Gauranvi (Helsingin yliopisto, 2021)
    It is important to study the factors which inhibit the cultivation of major crops which serve as a source of food and feed, with various other medicinal values as well. One of these factors is soil degradation and infertility which could be due to high amounts of toxic elements or unfavourable pH conditions. Faba bean is one such crop and is widely affected by the acidity and aluminium toxicity in soil. In this study, an effort has been made to observe the varying tolerance of faba bean accessions and understand the underlying mechanisms used by them under stress conditions. The accessions selected were Aurora, Babylon and Kassa. Each accession was subjected to three treatments and were grown in pH 7 (control), pH 4.5 (acid treatment) and pH 4.5 + Al3+ (aluminium treatment). The pH of peat for acidic treatment was reduced to 4.5 using Sulphuric acid (H2SO4) and for aluminium treatment, Aluminium sulphate (Al2(SO4)3) was added in addition to the acid. At 16 Day after Sowing (DAS) and 30 DAS the physiological data was collected which comprised of chlorophyll concentration (SPAD value), stomatal conductance, leaf temperature and photosynthesis rate. At 35 DAS, the experiment terminated and the shoot data (fresh and dry weights of leaves and stem; and leaf area) of each plant was recorded. Then the root data (tap root length, quality and quantity of nodules and photographs of roots) was taken for each plant. ICP samples for peat, shoot and shoot were also analysed. The data collected were subjected to analysis of variance using R version 4.0.3. (means separated by 5% significance level). From the plant data, Aurora was found to be tolerant. Kassa was sensitive (especially the roots) and Babylon was sensitive to both acid and aluminium treatments. The ICP results provided the reason for this tolerance pattern and a higher concentration of elements needed for plant growth such as P and S were found to be higher in aluminium and acid treatments.
  • Mannisto, Elisa; Ylanne, Henni; Losoi, Mari; Keinänen, Markku; Yli-Pirilä, Pasi; Korrensalo, Aino; Bäck, Jaana; Hellen, Heidi; Virtanen, Annele; Tuittila, Eeva-Stiina (2023)
    Peatland ecosystems emit biogenic volatile organic compounds (BVOC), which have a net cooling impact on the climate. However, the quality and quantity of BVOC emissions, and how they are regulated by vegetation and peatland type remain poorly understood. Here we measured BVOC emissions with dynamic enclosures from two major boreal peatland types, a minerotrophic fen and an ombrotrophic bog situated in Siikaneva, southern Finland and experimentally assessed the role of vegetation by removing vascular vegetation with or without the moss layer. Our measurements from four campaigns during growing seasons in 2017 and 2018 identified emissions of 59 compounds from nine different chemical groups. Isoprene accounted for 81 % of BVOC emissions. Measurements also revealed uptake of dichloromethane. Total BVOC emissions and the emissions of isoprene, monoterpenoids, sesquiterpenes, homoterpenes, and green leaf volatiles were tightly con-nected to vascular plants. Isoprene and sesquiterpene emissions were associated with sedges, whereas monoterpenoids and homoterpenes were associated with shrubs. Additionally, isoprene and alkane emissions were higher in the fen than in the bog and they significantly contributed to the higher BVOC emissions from intact vegetation in the fen. During an ex-treme drought event in 2018, emissions of organic halides were absent. Our results indicate that climate change with an increase in shrub cover and increased frequency of extreme weather events may have a negative impact on total BVOC emissions that otherwise are predicted to increase in warmer temperatures. However, these changes also accompanied a change in BVOC emission quality. As different compounds differ in their capacity to form secondary organic aerosols, the ultimate climate impact of peatland BVOC emissions may be altered.
  • Mäkelä, Minna; Kabir, Kazi Md. Jahangir; Kanerva, Sanna; Yli-Halla, Markku; Simojoki, Asko (2022)
    Factors limiting the production of the greenhouse gases nitrous oxide (N2O) and carbon dioxide (CO2) were investigated in three incubation experiments conducted with soil from top- and subsoil horizons of a peatland which had an acid sulphate mineral subsoil derived from black schists. The effect of moisture was investigated by equilibrating undisturbed soil samples from three horizons (H-2, Cg and Cr) at -10, -60 or -100 cm matric potential and measuring the gas production. In the second experiment, the effects of temperature and various substrates were studied by incubating disturbed soil samples in aerobic conditions at 5 or 20 degrees C, and measuring basal respiration and N2O production before and after adding water, glucose or ammonium into the soil. In the third experiment, the effects of added glucose and/or nitrate on the denitrification in soil samples from four horizons (H1, H2, Cg and Cr were investigated by acetylene inhibition and monitoring of N2O production during a 48-h anaerobic incubation. The production of CO2 in the topmost peat horizon was largest at -10 cm matric potential, and it was larger than those in the mineral subsoil also at -60 and -100 cm potentials. In contrast, drainage seemed to increase N2O production, whereas in the wettest condition the production of N2O in the mineral subsoil was small and the peat horizon was a sink of N2O. Lowering of temperature (from 20 degrees C to 5 degrees C) decreased CO2 production, as expected, but it had almost no role in the production of N2O in aerobic conditions. Glucose addition increased the aerobic production of CO2 in peat, but it had a minor effect in the mineral horizons. Lack of C source (glucose) was limiting anaerobic N2O production in the uppermost peat horizon, while in all other horizons, nitrate proved to be the most limiting factor. It is concluded that peatlands with black schist derived acid sulphate subsoil horizons, such as in this study, have high microbial activity in the peaty topsoil horizons but little microbial activity in the mineral subsoil. These findings are contrary to previous results obtained in sediment-derived acid sulphate soils.
  • Ingves, Jonas (Helsingin yliopisto, 2021)
    The underlying bedrock is known to have effects on metal contents in soil and water, and thereby onto the major and trace nutrient balances in plants. Heavy metal contents in different rock types are highly variable and changes in the composition of the bedrock can happen over small distances. In Finland, the locally relatively abundant black shales in the eastern part of the country contain elevated amounts of several heavy metals, while the generally more common felsic rock types are in comparison depleted in them. The influence of elemental contents in bedrock on metal distribution in nature can be assessed through comparing metal amounts in various kinds of environmental samples, which at the same time enables identification of areas of potential environmental concern. The aim of this study is to assess the influence of bedrock on heavy metal contents in peat, ditch water, and needle samples between areas underlain by felsic or black shale bedrock in nine peatland catchments in Kainuu in eastern Finland. In addition to comparing differences in elemental contents, effort is put into evaluating strengths of correlations between metal concentrations and ash contents in peat samples and to assess which metals have a tendency of occurring together in peat. For ditch water samples, correlations will be evaluated between concentrations of metals and of dissolved organic carbon (DOC) and of amounts of precipitation. In addition to influences of bedrock, other possible reasons behind differences in heavy metal amounts between areas will be looked at. Comparisons with data from other publications will in places also be made. The study is based on material collected by the Natural Resources Institute Finland in the years 2008–2015, which here includes 70 peat, 634 ditch water, and 80 needle samples. All samples were collected in nine separate forestry drained peatland catchments. Five of the catchments were located on areas underlain by felsic bedrock and four by black shales. The peat samples examined in this study range from the surface of the peat layers to 40 cm depth. The ditch water samples were collected from outlet ditches from all nine peatland catchments and needle samples were taken in eight catchments from either Scots pine (Pinus sylvestris L.) or Norway spruce (Picea abies [L.] Karst). Half of the samples were of current year’s and half of previous year’s needles. Laboratory analyses of peat samples included measurements of As, Cd, Co, Cr, Cu, Mn, Ni, Pb, U, and Zn concentrations by either ICP-MS or ICP-AES -methods and of ash contents through loss-on-ignition (LOI). Ditch water samples were analysed for Cd, Cr, Cu, Mn, Ni, Pb, and Zn concentrations with the ICP-AES method, for DOC concentrations by TOC-V CPH/CPN analysis and for sulphate (SO4-S) by ion chromatography. Tree needles were measured for contents of Cr, Cu, Mn, Ni and Zn with ICP-AES. Statistical differences in metal amounts in samples by bedrock were tested with the Mann–Whitney U test and correlations using Spearman’s rank correlation coefficient or the Pearson correlation coefficient. Metal concentrations in peat samples were for some tests recalculated to take into account ash contents using a linear general model. Metal stocks in peat layers (mg/m2) were also calculated for the sampling sites. As the main results, the ash corrected metal concentrations in peat were statistically significantly higher in samples collected on black shale as opposed to felsic bedrock in terms of As, Cd, Co, Mn, Ni, and Zn, while metal stocks in peat were significantly different in terms of Ni. In ditch water, samples from black shale areas had significantly higher concentrations of Cd, Cr, Cu, Ni, and Zn, and in tree needle samples similar significances were observed for Ni. The only cases were samples from felsic areas had significantly higher concentrations than those form black shale areas were the ash corrected concentrations of U and Cu concentrations in needle samples. Regardless of the underlying bedrock, large variations in metal amounts in all sample types were observed between catchment areas. Correlations between metal concentrations and ash contents in peat were generally relatively strong. Correlations between metals in peat were variable, and often stronger in samples collected in felsic areas. In water samples, correlations between metal and DOC concentrations were variable both between metals and catchments. The correlations between precipitation and metal concentrations in ditch water were generally weak. Overall, the composition of the bedrock was noticed to have some effects on metal concentrations in all sample types. But it was evident by the results that there are also other factors controlling metal amounts between catchments.
  • Kabir, Kazi Md. Jahangir (Helsingin yliopisto, 2017)
    Plenty of CO2 is commonly emitted from cultivated peat soils and substantial N2O emissions have occasionally been measured from acid sulphate soils. The factors limiting the emission of CO2 and N2O from the different layers of organic acid sulphate soil in Pärnänsuo were studied by aerobic and anaerobic incubation experiments. Two topsoil peat layers (upper and lower) and two mineral soil layers (upper and lower) were investigated. An aerobic experiment was carried out to see the emission of CO2 and N2O after application of glucose and ammonium, at two different temperatures (5o and 20o C). The water content of the soils was adjusted to 60% water- filled pore space (WFPS). Anaerobic experiment was carried out to assess the denitrification potential of different layers and the effect of glucose and nitrate alone and in combination as at 20oC using the acetylene inhibition technique. The lower peat layer exhibited more CO2 emission comparing to upper peat in the aerobic experiment. Additionally, in both peat layers and upper mineral soil layer, CO2 emission was increased exceedingly after glucose application. In the anaerobic experiment, potential denitrification from the upper peat was significantly higher than from other soil layers. Besides, the soil layers responded differently to C and N application. N2O emission from the upper peat was limited by easily available C whether it was applied as glucose alone or, in the presence of nitrate. On the contrary, N2O emission from lower peat layer was limited by nitrate with or, without glucose, but not by glucose alone. Both upper and lower mineral soil denitrification was limited by nitrate without glucose or, in combined with glucose, and not by glucose alone. Nitrogen mineralization pattern was different in upper and lower peat. A very high amount of NO3- was found in the upper peat, while there was a high amount of NH4+ in lower peat. Both the NO3- and NH4+ showed an increasing trend in lower mineral comparing to upper mineral, depicting an exceedingly high amount of mineral N at deeper layers
  • Turtiainen, Harri (Helsingin yliopisto, 2020)
    A promising Cu-Ni-PGE containing sulphide ore deposit was discovered in 2009 by Anglo American and since the company has continued studies aiming towards utilisation of the deposit. The discovered deposit lies underneath a Natura 2000 protected mire complex, Viiankiaapa, in Sodankylä municipality in Finnish Lapland. The research and exploration activities in the area are performed with mitigation and preventing actions in order to minimize the deterioration impact to the delicate ecosystem. The more detailed understanding of the hydrogeochemistry of the mire environment in its current state can assist: in monitoring, mitigating and preventing of potential environmental effects due to future mining operations as well as planning the monitoring program. Hydrogeochemical studies, consisting of water and peat sampling at eight sampling points, were carried out along a 1.6 km long study line. Water samples were collected from the surface of the mire as well as within the peat layer and the bottom of the peat layer. Water samples were collected using a mini-piezometer. The analyses for the water samples involved: major components, trace elements and δ18O & δ2H. Groundwater influence in the different sampling points as well as different sections of the peat was investigated using the mentioned chemical and isotopic properties. Peat sampling focused on finding samples which would have different hydraulic properties in order to find the influence of peat in the hydrology in the mire. Hydraulic conductivity of peat samples was determined using rigid wall permeameter test setup. The chemical and physical methods were supplemented by a ground penetrating radar survey completed with 30 and 100 MHz antennas. Studies of peat showed that the hydraulic conductivity varies substantially even inside the rather small study area. Widely recognized correlation between hydraulic conductivity and depth was not observed statistically, but the sampling sites individually show a clear connection with depth and hydraulic conductivity. The influence of the hydraulic properties of peat on to the flow of water in the mire was observed to be significant. In cases where the hydraulic conductivity of peat was very low, water flow may be prevented altogether. This was confirmed with the use of chemical analyses. With higher hydraulic conductivity, groundwater influence was seen more or less throughout the peat profile.
  • Takalo, Mimmi (Helsingin yliopisto, 2021)
    In 2011 Anglo American published a promising multi metal ore deposit in Sodankylä, Northern Finland. The ore is named Sakatti, after a small pond in the vicinity of the discovering place. The ore is under the Viiankiaapa mire, which is part of national mire protecting program and Natura 2000 program. Viinkiaapa is at the eastern side of river Kitinen, which is known to have flooded, bringing mineral material to the mire. To prevent the possibly environment effects in the future, it is essential to know present conditions of the mire. The study area is at the southern part of the Viiankiaapa mire and consist of eight sampling sites for peat. The basal sediment of the study area was determined with ground penetrating radar profiles that pass the sampling sites. To study the mineral supply of the mire, nine elements (Na, Mg, Al, S, P, K, Ca, Mn, and Fe) were chosen for geochemical analyses and the ash content of the peat profiles was determined. The basal sediment is highly affected by the vicinity of the river Kitinen. Fluvial channels have eroded till, which was deposited during the last glacial period. At the eastern side of the study area possibly aeolian sand is detected. Depressions eroded by fluvial channels are filled by gyttja, typically below 179 m a.s.l. The geochemistry of the peat indicates that the early phase of the mire was characterized with higher mineral supply. At the eastern part of Viiankiaapa the mineral supply has decreased after the early phase of the mire. The mineral supply has been higher at the middle parts of the mire throughout the Holocene. The floods of the river Kitinen are the main source of the mineral supply. The decrease in the mineral supply indicates that the flooding events have reduced, and the normal floods inundate smaller area than the early floods.
  • Lappalainen, Mari; Palviainen, Marjo; Kukkonen, Jussi V. K.; Setälä, Heikki; Piirainen, Sirpa; Sarjala, Tytti; Koivusalo, Harri; Finer, Leena; Launiainen, Samuli; Lauren, Ari (2018)
    Terrestrial export of dissolved organic carbon (DOC) to watercourses has increased in boreal zone. Effect of decomposing material and soil food webs on the release rate and quality of DOC are poorly known. We quantified carbon (C) release in CO2, and DOC in different molecular weights from the most common organic soils in boreal zone; and explored the effect of soil type and enchytraeid worms on the release rates. Two types of mor and four types of peat were incubated in laboratory with and without enchytraeid worms for 154 days at + 15 A degrees C. Carbon was mostly released as CO2; DOC contributed to 2-9% of C release. The share of DOC was higher in peat than in mor. The release rate of CO2 was three times higher in mor than in highly decomposed peat. Enchytraeids enhanced the release of CO2 by 31-43% and of DOC by 46-77% in mor. High molecular weight fraction dominated the DOC release. Upscaling the laboratory results into catchment level allowed us to conclude that peatlands are the main source of DOC, low molecular weight DOC originates close to watercourse, and that enchytraeids substantially influence DOC leaching to watercourse and ultimately to aquatic CO2 emissions.
  • Salomaa, Anna; Paloniemi, Riikka; Ekroos, Ari (2018)
    Peatlands that are close to a natural state are rich in biodiversity and are significant carbon storages. Simultaneously, peat resources are of interest to industry, which leads to competing interests and tensions regarding the use and management of peatlands. In this case study, we studied knowledge-management interactions through the development of participation and the resulting representation of nature (how nature was described), as well as the proposed and implemented conservation policy instruments. We focused on the years 2009-2015, when peatland management was intensively debated in Finland. We did an interpretative policy analysis using policy documents (Peatland Strategy; Government Resolution; Proposal for Conservation Programme) and environmental legislation as central data. Our results show how the representation of nature reflected the purpose of the documents and consensus of participants' values. The representation of nature changed from skewed use of ecosystem services to detailed ecological knowledge. However, simultaneously, political power changed and the planned supplementation programme for peatland conservation was not implemented. The Environment Protection Act was reformulated so that it prohibited the use of the most valuable peatlands. Landowners did not have the chance to fully participate in the policy process. Overall, the conservation policy instruments changed to emphasize voluntariness but without an adequate budget to ensure sufficient conservation.
  • Hillgén, Oona (Helsingin yliopisto, 2022)
    Fungi play an important role, especially in boreal coniferous forests and peatlands. For example, they are responsible for the circulation of nutrients, and are an important part of forest vegetation, such as tree function and nutrient uptake. Drainage of peatlands for silvicultural purposes has increased over the years and forest management has been found to change the structure of fungal communities. In addition to clear-cutting (CC) as one of the forest management methods, the method of continuous cover forestry (CCF) has been proposed as one of the possible forest management methods, but its effects on the soil fungal community have not been extensively studied. The aims of this master's thesis were to study how the active soil fungal community and its structure vary between the different forest management methods (CC, CCF and uncut control forest) of the peatland forest in Janakkala and between the seasons (spring, summer and autumn). The active community was studied by taking RNA samples from the area in May, July, and September 2021. In addition, the goal was to examine how potential environmental factors such as soil temperature and groundwater variations affect the active fungal community. Overall, diversity was higher in the autumn in all samples. The most stable area was the control forest, where active community members varied between seasons, but where biodiversity was similar between samples in both spring and autumn. The results of the CCF site followed in many ways the uncut forest, but in the autumn, there were large differences in the biodiversity and community structure of the samples in the forest of the CCF site. The biodiversity of the CC area was high. This may be explained by the deforestation of young trees already formed at the time of sampling, which contributes to the return of for instance, mycorrhizal fungi to the area. It should also be noted that the full number of parallel samples from the CC site in the spring and the autumn were not successful. In addition, the summer samples failed completely and no results could be obtained from them. The failure of the samples may be explained by the long hot and dry period in the area in the summer of 2021.