Browsing by Subject "turve"

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  • Heiskanen, Juha; Laitinen, Jukka (Suomen metsätieteellinen seura, 1992)
  • Yli-Halla, Markku; Lumme, Ilari (Suomen metsätieteellinen seura, 1987)
  • Seppälä, Jyri; Grönroos, Juha; Koskela, Sirkka; Holma, Anne; Leskinen, Pekka Juhani; Liski, Jari; Tuovinen, Juha-Pekka; Laurila, Tuomas; Turunen, Jukka; Lind, Saara; Maljanen, Marja; Matikainen, Pertti; Kilpeläinen, Antti (Finnish Environment Institute, 2010)
    The Finnish Environment 16/2010
    In recent years there has been a lively debate in Finland and Sweden on the climate impact of peat fuel utilization. The aim of this study was to clarify the contradictions between the Finnish and Swedish studies and provide a better basis for energy policy decision-making by summarizing the recent scientific knowledge about the climate impacts of peat fuel utilization chains based on the life cycle assessment (LCA) methodology. A starting point for this study was to carry out a critical review of Finnish and Swedish life cycle studies of the climate impacts of peat fuel utilization chains. The critical review was conducted according to the recommendations of international standards and its aim was to ensure that the methods, data and interpretation of results were carried out in a scientifically and technically valid way. During the review the available data (mostly published) on the greenhouse gas (GHG) balances and the radiative forcing impacts of GHGs were gathered and updated.  The re-calculations showed that the climate impact of "Pristine mire – afforestation" utilization chain is similar to the climate impact of coal utilization, whereas the result of the peat utilization chain "Pristine mire – restoration" is slightly worse than for the coal utilization chain. The results were similar in the reviewed studies. The peat utilization chain "Forestry-drained peatlands – afforestration" causes a slightly higher climate impact on average than the coal utilization chain does. From the viewpoint of peat utilization the result was similar to the result of Finnish study. According to the reviewed studies the use of cultivated peatlands causes the lowest climate impact compared to the climate impacts of the other peatlands. However, cultivated peatlands do not play important role as an extraction area for peat utilization. From the viewpoint of peat utilization the result of cultivated peatland was worse compared to the result produced by the Finnish and Swedish studies. The climate impacts of peat fuel utilization chains are mostly caused by the carbon dioxide released by peat combustion. These emissions are known quite  well. However, the emission assessments of different peat types include large uncertainty before, during and after peat extraction. In spite of that it can be said that land change options related to peat extraction and after-treatments have very limited effects on the climate impacts of peat utilization chain.
  • Starr, Michael; Westman, Carl Johan (Suomen metsätieteellinen seura, 1978)
  • Mannerkoski, Hannu (Suomen metsätieteellinen seura, 1973)
  • 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.
  • Westman, Carl Johan (Suomen metsätieteellinen seura, 1981)
  • Westman, Carl Johan (Suomen metsätieteellinen seura, 1976)
  • Heikurainen, Leo; Päivänen, Juhani; Sarasto, Juhani (Suomen metsätieteellinen seura, 1964)
  • Päivänen, Juhani (Suomen metsätieteellinen seura, 1973)
  • Mäensivu, Anniina (Helsingfors universitet, 2017)
    Primary peat formation, infilling (terrestrialization) and paludification are the three main kinds of peatland formation processes. A peatland can develop over previously drier mineral soil if water table level rises or previously formed mire grows or expands. In Finland, the expansion of mires has been occasionally fast and in major part of ombrotrophic raised bogs it has occured while the mire has been in the minerotrophic fen stage. However, based on previous studies there have been different speculations whether the paludification still continues. Paludification study site at the edge of peatland and forested mineral soil was established in Häädetkeidas Strict Nature Reserve in year 1931. The study site, with a set of 4 transects, was studied in 1931, 1945, 1957 and 1997. Vegetation analysis on these permanent transects was repeated in 2016 as a part of this thesis. The aim of this study was to describe the variation of vegetation at the edge of the mire and forested mineral soil and study how the vegetation and plant species assemblies have changed between the years 1931–2016. A long-term vegetation study can reveal whether the species have changed from forest-dominated species to peatland-dominated species and does the paludification process still continue. The paludification process was studied by estimating the canopy-cover of ground layer and field layer vegetation and litter cover, measuring peat thickness, the thickness of aerated peat layer and anoxic peat layer and forest cover in four transects, consisting of 180 subplots. Non-metric multidimensional scaling (NMDS) was used to describe the data. Ground and field layer vegetation were examined by comparing the species’ average cover and frequencies. Environmental variables were studied by correlation analysis. Differences in peat thickness and in the coverage of Sphagnum-mosses between the examination years were studied with oneway variance analysis and t-test. In all four transects the coverage of Sphagnum-mosses had increased between the years 1931 and 2016. The coverage of forest mosses had decreased in two out of four transects. Succession related changes in species were observed in both vegetation layers. There was variation in the vegetation development between the transects and they seemed to be in different stages of the succession and paludification processes. In 93 percent of the study plots the thickness of peat layer had increased during the last 19 years. The changes in vegetation between the years 1931 and 2016 as well as the growth of the peat layer suggests that the paludification process still continues.
  • Kärppä, Mai (Helsingin yliopisto, 2020)
    Arctic peatlands are globally extensive and long-lasting storages of carbon and are therefore important ecosystems controlling global carbon cycling. Changes in climate affect peatlands’ ability to accumulate carbon through changes in hydrology and water table level, vegetation, soil temperature and permafrost thaw. As climate warming is projected mostly to northern and arctic regions, it may change the peatlands’ capacity to sequester and release carbon as carbon dioxide and methane. In this Master’s Thesis I studied how the past climate changes are reflected in carbon accumulation rates over the past millennia. Known climate anomalies, such as the Medieval Climate Anomaly, Little Ice Age and the last rapid warming starting from 1980, and their impact on average long-term apparent rate of carbon accumulation were studied from the peat proxies. 15 peat cores were collected from northern subarctic Swedish Lapland and from North-East European Russia. Cores were collected from the active peat layer above permafrost that is known to be sensitive to climate warming. Cores were dated with radiocarbon (14C) and lead (210Pb) methods and peat properties and accumulation patterns were calculated for one centimeter thick subsamples based on chronologies. The Little Ice Age and the last rapid warming affected the carbon accumulation rate considerably whereas for Medieval Climate Anomaly period the peat records did not show very distinctive response. During the Little Ice Age the carbon accumulation rates were low (median 10,5 g m-2v-1) but during the post-Little Ice Age and especially during the last warm decades after 1980 carbon accumulation rates have been high (median 48,5 g m-2v-1). Medieval Climate Anomaly had only a minor positive effect on accumulation rates. On average, the long-term apparent rate of carbon accumulation during the past millennia was 43,3 g m-2v-1 which is distinctly higher than the previously studied rate of 22,9 g m-2v-1 for northern peatlands (p-value 0,0003). Based on results it can be concluded that warm climate periods accelerated the carbon accumulation rate whereas during cold periods accumulation decelerated. Warm climate prolongs the growth period and accelerates the decomposition of peat; cold climate shortens the period of plant growth and thickens the permafrost layer in peatlands, respectively. However, peat layers that are formed after the Little Ice Age are incompletely decomposed which amplifies the carbon accumulation rate partly. Nevertheless, permafrost thawing has been shown to increase accumulation rates, as well. Studying past carbon accumulation rates helps to understand the peatland and carbon cycling dynamics better. Even though accumulation rates reveal a lot about carbon sequestration capabilities of peat, it does not indicate whether a peatland has been a carbon sink or a source.
  • Laatikainen, Pertti (Suomen metsätieteellinen seura, 1973)
  • Munsterhjelm, Klaus (Vesihallitus, 1972)
    Vesihallitus. Tiedotus 38
    English summary: On the efficiency of peat infiltration of sewage during various seasons and on its improvement
  • Kämppi, Armas (Vesihallitus, 1971)
    Vesihallitus. Tiedotus A4
  • Kuisma, Eero (Helsingfors universitet, 2013)
    The use of peat as a growing-medium has raised concerns globally, because it is not ecologically sustainable. Coir is an ecologically friendly alternative, but it is transported very long way to Finland. Therefore, a substitute for peat and coir as a growing-medium in soilless culture is needed. The aim of this research was to find out, whether Finnish plant fibre medium can replace peat or coir in greenhouse production of strawberry. In the experiments four substrates were compared: coir, peat, plant fibre and peat/plant fibre mix. Water holding capacity, pH-buffer capacity and mineralisation of nitrogen were determined, and vegetative and generative growth of strawberries on different substrates were measured. In strawberry cultivation experiment the pH of plant fibre (6,5-7,7) was very close to that of peat (6,4-7,6). Coir and plant fibre had considerably lower pH-buffer capacity than the media that contained peat. The water holding capacity (613 % per dw) of plant fibre was considerably lower than in other media. Plant fibre medium´s water content (32-42 % v/v) was however closest to strawberry´s optimum (25-34 % v/v) during almost the whole experiment. Plant fibre (23:1) and peat/plant fibre mix (29:1) had optimal C/N- ratios in this experiment. The amount of soluble nitrogen was highest in plant fibre medium in the beginning of the experiment. The EC of plant fibre medium was very low in the beginning (0,5 mS/cm), but it increased quickly being 1,2-2,1 mS/cm, so it was second closest to the optimum during the rest of the experiment. The vegetative growth of strawberry plants was more vigorous in peat compared to other substrates. The growth of the root system was weakest in peat. Medium had no significant influence on the amount of yield, and had only minor influence on the quality of the yield. In conclusion, the plant fibre medium could replace peat or coir in the soilless cultivation of strawberry.
  • Karesniemi, Kalevi (Vesihallitus, 1975)
    Vesihallitus. Tiedotus 86
    English summary: Investigation of peat and peatland in the Kemihaara reservoir area.
  • Heikurainen, Leo; Seppälä, Kustaa (Suomen metsätieteellinen seura, 1963)
  • Elina, Galina A.; Lukashov, Anatoly D.; Yurkovskaya, Tatyana K. (Finnish Environment Institute, 2010)
    The Finnish Environment 4/2010
    The monograph is a generalization based on the analysis and synthesis of the voluminous scope of data on the dynamics of palaeovegetation and its mapping, along with aspects of palaeogeography of the Kola Peninsula and Karelia. All the elements of past landscapes are considered against the background of the present state of environments: geology, geomorphology and vegetation. The interval under consideration embraces the Late Glacial Time (12 000-10 300 years BP) and the Holocene (from 10 300 years BP up to the present). The book discusses the methodical and theoretical treatments of the last decade. As a result, the dynamics of past landscapes are shown in the unity of all their components (i.e., relief, hydrology and vegetation), and in comparison with their present-day parameters. Cartographic and textual materials on geology and modern vegetation as well as palaeovegetation maps of model territories used in this book are entirely original. The model territories are rather evenly distributed throughout the Kola Peninsula and Karelia. Seven of them are represented in this work; for each of model territory, a series of maps (for 10 500, 9 500, 8 500, 5 500, 3 000, and 1 000 years BP) are provided, correlated with relief and present-day vegetation. The second stage of data generalization is a comparison of maps related to the same temporal sections. The sequence of the maps from ‘older’ to ‘younger’ characterizes the dynamics of chorological palaeovegetation units. These dynamics readily illustrate shifts of geographical zones in space and time.