Browsing by Subject "typpi"

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  • Västilä, Kaisa; Väisänen, Sari; Koskiaho, Jari; Lehtoranta, Virpi; Karttunen, Krister; Kuussaari, Mikko; Järvelä, Juha; Koikkalainen, Kauko (MDPI, 2021)
    Sustainability 13, 16
    Conventional dredging of ditches and streams to ensure agricultural drainage and flood mitigation can have severe environmental impacts. The aim of this paper is to investigate the potential benefits of an alternative, nature-based two-stage channel (TSC) design with floodplains excavated along the main channel. Through a literature survey, investigations at Finnish field sites and expert interviews, we assessed the performance, costs, and monetary environmental benefits of TSCs in comparison to conventional dredging, as well as the bottlenecks in their financing and governance. We found evidence supporting the expected longer-term functioning of drainage as well as larger plant and fish biodiversity in TSCs compared to conventional dredging. The TSC design likely improves water quality since the floodplains retain suspended sediment and phosphorus and remove nitrogen. In the investigated case, the additional value of phosphorus retention and conservation of protected species through the TSC design was 2.4 times higher than the total costs. We demonstrate how TSCs can be made eligible for the obligatory vegetated riparian buffer of the European Union agri-environmental subsidy scheme (CAP-AES) by optimising their spatial application with respect to other buffer measures, and recommend to publicly finance their additional costs compared to conventional dredging at priority sites. Further studies on biodiversity impacts and long-term performance of two-stage channels are required.
  • Forsius, Martin; Posch, Maximilian; Holmberg, Maria; Vuorenmaa, Jussi; Kleemola, Sirpa; Augustaitis, Algirdas; Beudert, Burkhard; Bochenek, Witold; Clarke, Nicholas; de Wit, Heleen A.; Dirnböck, Thomas; Frey, Jane; Grandin, Ulf; Hakola, Hannele; Kobler, Johannes; Krám, Pavel; Lindroos, Antti-Jussi; Löfgren, Stefan; Pecka, Tomasz; Rönnback, Pernilla; Skotak, Krzysztof; Szpikowski, Józef; Ukonmaanaho, Liisa; Valinia, Salar; Váňa, Milan (Elsevier, 2021)
    Science of The Total Environment 753 (2021), 141791
    Anthropogenic emissions of nitrogen (N) and sulphur (S) compounds and their long-range transport have caused widespread negative impacts on different ecosystems. Critical loads (CLs) are deposition thresholds used to describe the sensitivity of ecosystems to atmospheric deposition. The CL methodology has been a key science-based tool for assessing the environmental consequences of air pollution. We computed CLs for eutrophication and acidification using a European long-term dataset of intensively studied forested ecosystem sites (n = 17) in northern and central Europe. The sites belong to the ICP IM and eLTER networks. The link between the site-specific calculations and time-series of CL exceedances and measured site data was evaluated using long-term measurements (1990–2017) for bulk deposition, throughfall and runoff water chemistry. Novel techniques for presenting exceedances of CLs and their temporal development were also developed. Concentrations and fluxes of sulphate, total inorganic nitrogen (TIN) and acidity in deposition substantially decreased at the sites. Decreases in S deposition resulted in statistically significant decreased concentrations and fluxes of sulphate in runoff and decreasing trends of TIN in runoff were more common than increasing trends. The temporal developments of the exceedance of the CLs indicated the more effective reductions of S deposition compared to N at the sites. There was a relation between calculated exceedance of the CLs and measured runoff water concentrations and fluxes, and most sites with higher CL exceedances showed larger decreases in both TIN and H+ concentrations and fluxes. Sites with higher cumulative exceedance of eutrophication CLs (averaged over 3 and 30 years) generally showed higher TIN concentrations in runoff. The results provided evidence on the link between CL exceedances and empirical impacts, increasing confidence in the methodology used for the European-scale CL calculations. The results also confirm that emission abatement actions are having their intended effects on CL exceedances and ecosystem impacts.
  • Rekolainen, Seppo (National Board of Waters and the Environment. Vesi- ja ympäristöhallitus, 1993)
    Publications of the Water and Environment Research Institute 12
    Yhteenveto: Maatalouden aiheuttama vesistönkuormitus ja sen vähentäminen
  • Metsärinne, Vilma (Helsingfors universitet, 2017)
    Biokaasulaitos tuottaa biokaasua energiakäyttöön ja mädätettä lannoitteeksi kasvintuotantoon. Biokaasulaitos on täten monipuolinen tuotanto- ja kierrätyslaitos. Tavanomainen energian- ja lannoitteiden tuotanto on hyvin energiaintensiivistä ja uusiutumattomia energianlähteitä käyttävää. Biokaasulaitos mahdollistaa hajautetun energiantuotannon ja lannoitteiden tuottamisen uusiutuvista raaka-aineista, monesti raaka-aineista jotka olisivat muuten jätteeksi luokiteltavaa. Tutkimuksen tarkoitus oli selvittää, mitä Suomessa toimivissa biokasulaitoksissa käytetään syötteinä, kuinka paljon biokaasua saadaan tuotettua, millaisia ovat mädätteen ravinnepitoisuudet ja kuinka viljelijät käyttävät mädätettä pelloilla. Tutkimuksessa selvitettiin myös, millainen olisi ideaali biokaasulaitoksen toiminta kaasuntuoton, mädätteen jatkokäytön ja laitoksen toiminnan kannalta. Kuinka biokaasuntuotantoa voitaisiin Suomessa lisätä ja parantaa energia- ja ravinneomavaraisuutta? Tarkoitus oli kerätä tietoa sekä keskitetysti toimivilta biokaasulaitoksilta että maatilojen omilta biokaasulaitoksilta. Tavoitteena oli vertailla eri laitosten antamia tietoja ja selvittää millaisia eroja laitoksista löytyy. Tutkimus toteutettiin internetpohjaisena kyselynä. Kyselypohjia oli kaksi: toinen biokaasulaitoksille ja toinen maatiloille, joilla joko oli oma biokaasulaitos tai tilalla oli joskus käytetty mädätettä lannoitteena. Yhteensä vastaajia kertyi 14 kappaletta. Mädätteiden pääravinnepitoisuuksissa oli eroja, vaihteluväli oli 2,8-16 ja keskiarvo 6,47 kokonaistypen osalta. Niissä mädätteissä, joissa oli korkea kokonaistyppipitoisuus, oli myös korkea kokonaisfosforipitoisuus (R2=0,56; p=0,013). Tuloksista ei voi tehdä selkeitä johtopäätöksiä sen suhteen, mikä tai mitkä olisivat parhaita syöteaineita. Syöteaineet olivat vaihtelevia, ja samanlaatuisilla syöteaineilla kaasuntuotanto ja mädätteen laatu erosivat kahdella eri laitoksella.
  • Grönroos, Juha; Munther, Joonas; Luostarinen, Sari (Finnish Environment Institute, 2017)
    Reports of the Finnish Environment Institute 37/2017
    Agricultural gaseous nitrogen emissions are mostly related to manure management, grazing and fertilisation. These emissions include ammonia (NH3), nitrous oxide (N2O), nitric oxide (NO) and di-nitrogen (N2). Most of the non-methane volatile organic compounds (NMVOC) emissions originate from livestock farming, but also from cultivated crops. All these emissions are inventoried and reported for the UN Convention on Long-range Transboundary Air Pollution (CLRTAP), EU National Emission Ceilings Directive (2001/81/EC) and the UN Framework on Climate Change (UNFCC). In Finland, a specific national model for gaseous nitrogen emissions from agriculture has been used for the inventory since 1998. The revised calculation model documented here is tied to the Finnish Normative Manure System, which provides data on manure quality and quantity for various livestock categories. The emission calculation follows the flow of total ammoniacal nitrogen (TAN) and total nitrogen (N) through the manure management systems, starting from excretion and ending at manure spreading. The main manure management phases considered in the calculation are livestock housing, manure storing and manure field application. The calculation also embeds estimations on emissions from grazing and outdoor yards, as well as emissions from the use of mineral fertilisers. The nitrogen calculation model provides data for the calculation of agricultural NMVOC emissions. All calculations are constructed in compliance with the Tier 2 method of the EMEP/EEA emission inventory guidebook (2016).
  • Valve, Matti (Vesihallitus. National Board of Waters, 1985)
    Vesientutkimuslaitoksen julkaisuja 58, 28-54
    Yhdistetty typen ja fosforin poisto jätevesistä
  • Grönroos, Juha; Mattila, Pasi; Regina, Kristiina; Nousiainen, Jouni; Perälä, Paula; Saarinen, Kristina; Mikkola-Pusa, Johanna (Finnish Environment Institute, 2009)
    The Finnish Environment 8/2009
    Agriculture is the main source of ammonia (NH3) emissions in Finland comprising ca. 90% of the total emissions annually. Agriculture is also an important source of nitrous oxide (N2O), a greenhouse gas for which agriculture is responsible for ca. 50% of emissions. The main source for ammonia is livestock manure whereas for N2O its importance is much smaller. However, the same activity data are needed to assess both NH3 and direct N2O emissions from animal husbandry. In addition to this, indirect emissions of N2O are calculated based on NH3 and NO emissions. NH3 and N2O emissions are annually reported according to international reporting classifications. The aims of the study were 1) to construct a calculation model for gaseous agricultural nitrogen emissions thereby developing and updating the emission calculation procedure to better reflect the development of these emissions in Finland, and 2) to improve correspondence of the emission inventory reporting with the reporting classifications. In 2007, the Finnish emissions of ammonia from agricultural sources totalled 30,686 tonnes, of which more than 60% originated from cattle manure. Time series for ammonia emissions from agriculture show that there have been no large changes in the total emissions during the last two decades. Despite the decreased number of cattle during that period the emissions have remained near the present level, mainly because of the increased nitrogen excretion of cattle. Emission projections for the years 2008–2050 show no significant changes in emissions in the future. As for ammonia, no significant changes for nitrous oxide emissions from animal husbandry have taken place, and no big changes can be expected in the future as long as there are no drastic alterations in animal production. Despite the development of emission modelling, the emission estimates still include significant sources of uncertainty, which is mainly related to information on the distribution of manure management systems and the use of different manure application methods as well as to information on ammonia evaporation in different manure management phases in Finland.
  • Kauppi, Lea (Vesihallitus, 1979)
    Vesientutkimuslaitoksen julkaisuja 30, 21-41
    Tiivistelmä: Valuma-alueen vaikutus fosforin ja typen hajakuormitukseen.
  • Kauppi, Lea; Kenttämies, Kaarle; Puomio, Eeva-Riitta (Vesi- ja ympäristöhallitus. National Board of Waters and Environment, 1986)
    Publications of the Water Research Institute 69, 70-87
    Asumajätevesien fosforin ja typen poiston vaikutus järvien rehevöitymiseen
  • Mäkipää, Raisa (The Finnish Society of Forest Science and The Finnish Forest Research Institute, 1994)
    Forest ecosystems may accumulate large amounts of nitrogen in the biomass and in the soil organic matter. However, there is increasing concern that deposition of inorganic nitrogen compounds from the atmosphere will lead to nitrogen saturation; excess nitrogen input does not increase production. The aim of this study was to determine the long-term changes caused by nitrogen input on accumulation of nitrogen in forest soils and in ground vegetation. The fertilization experiments used in this study were established during 1958–1962. They were situated on 36- to 63-year old Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies (L.) Karsten) stands of different levels of fertility. The experiments received nitrogen fertilization 5–7 times over a 30-year period, and the total input of nitrogen was 596–926 kg/ha. Nitrogen input increased the amount of organic matter in the humus layer and the nitrogen concentration in the organic matter. Furthermore, the total amounts of nutrients (N, P, K, Ca and Mg) bound by the humus layer increased due to the increase in the amount of organic matter. However, nitrogen input decreased the biomass of ground vegetation. The nitrogen concentration of the plant material on the nitrogen-fertilized plots was higher than that on the control plots, but the amount of nutrients bound by ground vegetation decreased owing to the drastic decrease in the biomass of mosses. Ground vegetation does not have the potential to accumulate nitrogen, because vegetation is dominated by slow-growing mosses and dwarf shrubs, which do not benefit from nitrogen input.
  • Nurmi, Elina (Helsingin yliopisto, 2015)
    Agriculture and other human activity has considerably affected the nitrogen cycle, which initially doubled the amount of nitrogen on the planet. The most well-known consequence of this phenomenon is eutrophication. The objective of this thesis was to study nutrient balances and their usefulness in evaluating the nitrogen usage in beef cattle farms, the nitrogen load and nitrogen use efficiency in those farms as well as how well the farms utilize their inputs. This study based on three organic beef cattle farms which took part in BERAS Implementation –project in 2010-2013. All farms specialized in suckler cow production. The data was collected in July-August 2013 when the farmers were interviewed about their inputs and outputs during the years 2010-2012. On the basis of this information different type of nitrogen balances were calculated. The farm gate nitrogen balances were 27, 36 and 70 kg/ha. Except for the last one, the feed self-sufficiency of the farms was very high, more than 90 %. The farm with the largest nitrogen surplus utilized a considerable amount of input from outside the farm which reflected in low feed self-sufficiency (64 %). The other two with smaller surpluses received excellent primary nutrient ratios (1,38 and 1,40) which indicates active nutrient recycling. However, despite of these results, it is important to remember that nutrient balances should be viewed with a critical eye. The uncertainties primarily concern the amount of biologically fixated nitrogen and the amount of yields of cultivated plants. These variables were taken into consideration in sensitivity analysis. Instead of nutrient balances, it would more useful to draw attention to other indicators such as feed self-sufficiency or animal unit density when evaluating nitrogen load of farms. The efficiency of beef cattle production depends also on how the production is actually implemented. It is especially important to acknowledge the importance of feeding and manure handling. The feed conversion ratio is always low in beef production since it is less than 10 %. Nevertheless, there are other benefits in cattle breeding such as utilization of natural pastures and cultivation of perennial grasses which not only are excellent for soil fertility, but also decrease nutrient leaching.
  • Bäcklund, Kirsi (Helsingfors universitet, 2013)
    Boreal forest soil contains large nitrogen resources. Most of the nitrogen is bound to humified material and proteins. However, plants can directly utilize only simple nitrogen compounds as ammonium, nitrate and simple amino acids. The amount of these simple nitrogen compounds is very small in forest soil. Trees form ectomycorrhizal symbiosis with a large number of fungi. Ectomycorrhizal fungi receive carbon compounds from host trees and trees receive nutrients from fungi. Some ectomycorrhizal fungi produce proteases which are enzymes that hydrolyze proteins. This symbiosis might be important in utilizing the large nitrogen resources in forest soils and supplying nitrogen to host plants. The main aim of this study was to measure if ectomycorrhizas produce proteases in the field and to find out if the mycorrhizal protease activities change during the year. The aim was also to find out if proteolytic activity is found in the soil fluid and to see if the activities in soil fluid are related to mycorrhizal activities. Mycorrhizal fungi were isolated to form pure cultures and their protease activities were measured and species were identified. As background information mycorrhizal, nonmycorrhizal and dead root tips were calculated to see how their amounts change during the year. Also different kinds of protease producing mycorrhizal morphotypes were calculated. Samples were taken in Hyytiälä Forestry Field Station in Central Finland monthly from March to October. Fifteen soil cores were collected each month. If possible, eight ectomycorrhizas were randomly picked from the pine roots in the humus layer of each soil core. Protease activities were measured from the ectomycorrhizas and from the soil solution obtained from the homogenized humus layer using Protease Fluorescent Detection Kit (PF0100-1KT, SIGMA). Detection limit of the kit was enzyme activity that is equivalent to 5 ng of trypsin control activity. Results were read from the trypsin standard curve so the protease activities of the samples are equivalent to fluorescence of certain amount of trypsin control. Pure cultures were isolated to Hagem’s agar plates and species were identified by doing PCR from the ITS gene region and sequencing. Root tip and morphotype calculations were done by using a microscope. 12 % of all ectomycorrhizal root tips produced proteases. The smallest activities couldn’t be detected because of the detection limit of the kit. Ectomycorrhizal protease production varied between 0–12 ?g/m2 of soil. Statistically non-significant protease production peaks were observed in spring and autumn. The protease activity of the soil fluid varied mainly between 0–200 ?g/m2 of soil. The highest activity was detected in the frozen soil in March, when the variation was large and an average of 800 ?g of protease was measured per m2 of soil. The protease activities in the soil fluids were not related to the protease activities of the ectomycorrhizas. 17 pure cultures were achieved. Some of them couldn’t be identified to species level. Part of the pure cultures produced proteases. Number of mycorrhizal root tips was large in spring, decreasing in early summer and increasing again towards autumn. About half of the mycorrhizal morphotypes produced proteases. The most important conclusions are that ectomycorrhizal fungi produce proteases in the field and a lot of protease activity is also found in the soil fluid. The used method is sensitive and suitable for measuring protease activities directly from mycorrhizal root tips and soil fluid. Seasonal variation in the protease activities may occur both in mycorrhizas and in soil fluid.
  • Mattsson, Tuija (Finnish Environment Institute, 2010)
    Monographs of the Boreal Environment Research 36
    The terrestrial export of dissolved organic matter (DOM) is associated with climate, vegetation and land use, and thus is under the influence of climatic variability and human interference with terrestrial ecosystems, their soils and hydrological cycles. The present study provides an assessment of spatial variation of DOM concentrations and export, and interactions between DOM, catchment characteristics, land use and climatic factors in boreal catchments. The influence of catchment characteristics, land use and climatic drivers on the concentrations and export of total organic carbon (TOC), total organic nitrogen (TON) and dissolved organic phosphorus (DOP) was estimated using stream water quality, forest inventory and climatic data from 42 Finnish pristine forested headwater catchments, and water quality monitoring, GIS land use, forest inventory and climatic data from the 36 main Finnish rivers (and their sub-catchments) flowing to the Baltic Sea. Moreover, the export of DOM in relation to land use along a European climatic gradient was studied using river water quality and land use data from four European areas. Additionally, the role of organic and minerogenic acidity in controlling pH levels in Finnish rivers and pristine streams was studied by measuring organic anion, sulphate (SO4) and base cation (Ca, Mg, K and Na) concentrations. In all study catchments, TOC was a major fraction of DOM, with much lower proportions of TON and DOP. Moreover, most of TOC and TON was in a dissolved form. The correlation between TOC and TON concentrations was strong and TOC concentrations explained 78% of the variation in TON concentrations in pristine headwater streams. In a subgroup of 20 headwater catchments with similar climatic conditions and low N deposition in eastern Finland, the proportion of peatlands in the catchment and the proportion of Norway spruce (Picea abies Karsten) of the tree stand had the strongest correlation with the TOC and TON concentrations and export. In Finnish river basins, TOC export increased with the increasing proportion of peatland in the catchment, whereas TON export increased with increasing extent of agricultural land. The highest DOP concentrations and export were recorded in river basins with a high extent of agricultural land and urban areas, reflecting the influence of human impact on DOP loads. However, the most important predictor for TOC, TON and DOP export in Finnish rivers was the proportion of upstream lakes in the catchment. The higher the upstream lake percentage, the lower the export, indicating organic matter retention in lakes. Molar TOC:TON ratio decreased from headwater catchments covered by forests and peatlands to the large river basins with mixed land use, emphasising the effect of the land use gradient on the stoichiometry of rivers. This study also demonstrated that the land use of the catchments is related to both organic and minerogenic acidity in rivers and pristine headwater streams. Organic anion dominated in rivers and streams situated in northern Finland, reflecting the higher extent of peatlands in these areas, whereas SO4 dominated in southern Finland and on western coastal areas, where the extent of fertile areas, agricultural land, urban areas, acid sulphate soils, and sulphate deposition is highest. High TOC concentrations decreased pH values in the stream and river water, whereas no correlation between SO4 concentrations and pH was observed. This underlines the importance of organic acids in controlling pH levels in Finnish pristine headwater streams and main rivers. High SO4 concentrations were associated with high base cation concentrations and fertile areas, which buffered the effects of SO4 on pH.
  • Raitanen, Henna (Helsingin yliopisto, 2020)
    In this study, the goal was to determine which nutrient, phosphorus or nitrogen, limits the phytoplankton growth at the Vanajavesi freshwater site. The aims were to detect spatial and temporal changes and find out if the wastewater treatment plant (hereafter, WWTP) located by the study site affects the nutrient concentrations and the limiting nutrient. The reliability of determining limiting nutrient by bioassays and measuring the phytoplankton response to different treatments as fluorescence was also evaluated. The study was conducted because knowledge of nutrient limitation is essential when allocating resources to reduce nutrient loading and planning other remediation practices in eutrophicated waterbodies. According to the EU Water Framework Directive, all waterbodies in the EU must be in a good ecological status by the year 2027. This goal is yet to be achieved in Vanajavesi; the ecological status of the river Vanajanreitti is poor and that of lake Vanajanselkä is moderate. The samples for bioassays were taken from five different locations. Three sampling sites were in the river and two by the lake. Based on the direction which the water flows, one of the sampling sites was before the outlet from the WWTP and the rest after it. The bioassays were carried out with the water and natural phytoplankton community taken from the study site. The experiment was conducted five times: in November, March, May, July and August. The temperature and light conditions in the incubation room were set to mimic those in Vanajavesi at each given time. Part of the preparations was to filter out the zooplankton using 50 μm plankton net. There were four different treatments: control without nutrient additions, nitrogen addition, phosphorus addition and nitrogen and phosphorus additions. Fluorescence from the 2 litre incubation bottles was measured every 1-3 days during each experiment. Chlorophyll a was determined in laboratory before and after the experiments. Nutrient concentrations were also determined before each experiment. Small seasonal and temporal changes were observed in the nutrient concentrations and the limiting nutrient. These changes were most likely due to changing seasons, effluent from the WWTP and denitrification at lake Vanajanselkä. Phosphorus limited phytoplankton growth year around at all places. At the end of the summer also nitrogen was limiting. In July co-limitation was detected in all sampling sites. In situations of co-limitation there was either no secondary limiting nutrient, or it was phosphorus. Only once, in August at the sampling point before the outlet from the WWTP, was the secondary limiting nutrient nitrogen. On average the nutrient concentrations were higher in the river than in the lake. Chlorophyll a concentrations and some nutrient concentrations were higher after the WWTP. However, no significant negative impact due to WWTP could be detected, especially at lake Vanajanselkä and the WWTP did not result in a change from phosphorus limitation to nitrogen limitation. Bioassays and the phytoplankton yield measured with a fluorometer was a reliable way of determining the limiting nutrient. Chlorophyll a concentrations verified the fluorescence results. The probe used in this study measured only the fluorescence of chlorophyll a. Even more accurate result of the phytoplankton biomass would have been obtained with a probe that measures also the fluorescence of phycocyanin, the photosynthetic pigment in cyanobacteria, because cyanobacteria has less chlorophyll a than other phytoplankton groups. As Vanajavesi is phosphorus limited or co-limited by phosphorus and nitrogen year around, reductions in phosphorus loading will likely improve the water quality. The main source of phosphorus to Vanajavesi is the nutrient loading from agricultural practises on the drainage basin. Efficient management of this diffuse loading will cause the phytoplankton biomass, especially the biomass of harmful cyanobacteria, to decrease. Nitrogen-fixing cyanobacteria is not dependent on the nitrogen concentrations in the water column, but the concentration of phosphorus. Significantly reducing the phosphorus loading is a prerequisite for the Vanajanreitti and Vanajavesi to be in a good ecological status by the year 2027.
  • Marttinen, Eeva (Helsingfors universitet, 2010)
    Nitrogen is usually the growth limiting nutrient in boreal forest soils. Most of the nitrogen is bound to organic fraction, and low bioavailability of nitrogen delimits plant growth in boreal forest soils. Amino acids are easily available nitrogen compounds and thus they are important nitrogen sources for soil microorganisms. Almost all boreal forest trees form mycorrhizal assoociations with fungi. Mycorrhizal fungi produce wide variety of enzymes which break down organic nitrogen compounds. So far there is little knowledge of amino acid mineralization mechanisms of ectomycorrhizal fungi. L-amino acid oxidase (LAO) catalyses the mineralization of amino acids to ammonium. The ectomycorrhizal fungi Hebeloma spp. and Laccaria spp. have been shown to possess LAO enzyme activities. It has been proposed that LAO is one of the nitrogen mineralization mechanisms in ectomycorrhizal fungi, but so far no LAO genes have been described from basidiomycete fungi. In this study the first LAO gene sequences from the basidiomycete fungus Hebeloma cylindrosporum was described. The RACE-PCR -method was used to determine the 3´ and 5´ end sequences of the cDNA of the LAO1 gene. Based on the obtained sequences, primers to isolate the genomic DNA and cDNA sequences of the LAO1 gene were designed. The structure of the LAO1 gene, which is composed of five exons and four introns, was determined. Binding site of nitrogen regulating protein was found from upstream region of LAO1-gene. The partial genomic DNA sequence of gene adjacent to LAO1-gene was also measured. In the L. bicolor genome the gene preceding the LAO1 gene has been annotated as a putative pyruvate decarboxylase. In this study the partial cDNA sequence of another LAO-homolog of H. cylindrosporum was also determined. The LAO gene from another basidiomycete fungus, Laccaria bicolor, was also recognised. The gene model of LAO gene of L. bicolor was unannotated in the NCBI database. Based on the phylogenetic tree of LAO-related protein sequences, the ancestral form of LAO gene has been duplicated. This study provides molecular biological information on the catabolic mechanisms of amino acids in ectomycorrhizal fungi. Ammonium ions, produced by ectomycorrhizal fungi, might be a significant source of nitrogen for plants and other soil microbes. It is possible that LAO is an important factor of nitrogen cycle in soils of boreal forests.
  • Jaale, Marko (Helsingfors universitet, 2007)
    Saaristomeren pinnanalaisen ravintoverkon rakennetta sekä ravinteiden alkuperää ja kulkeutumista tutkittiin hiilen ja typen pysyviä isotooppeja hyväksi käyttäen. Tutkimuksen kohteena olivat suspendoitunut partikkeliaines (SPM), sedimentin pintakerros, pohjaeläimet, kalat ja makrolevät. Näytteitä otettiin toukokuussa, kesäkuussa ja lokakuussa. Ravinnelähteiden arvioinnin ohella tutkittiin voiko sisäsaariston kalankasvatuksen vaikutusta määritellä analysoimalla kalanrehupellettejä. Lisäksi arvioitiin joidenkin lajikohtaisten tai lajien välisten ominaisuuksien erojen vaikutusta (esimerkiksi eläimen koko ja kudosten C:N –suhde rasvapitoisuuden kuvaajana) δ-arvojen määräytymiseen. Myös joitain tarkennuksia tehtiin lajien ravinnonkäyttöluokituksiin. Sisäsaaristossa toukokuussa pian lumien sulamisen aiheuttaman kasvaneen jokivirtaaman jälkeen SPM:stä havaittiin korkeita δ13C- ja δ15N-arvoja (keskimäärin -16 ‰ ja 9 ‰, vastaavasti). Ulkosaariston asemilta saatiin paljon alempia arvoja (-24 ‰ ja 4 ‰, vastaavasti). Sisäsaaristossakin arvot laskivat kesäkuuhun mennessä (-26 ‰ ja 5 ‰, vastaavasti) ollen kuitenkin hieman korkeampia kuin samaan aikaan tutkituilla ulommilla välisaariston asemilla. Kasviplanktonin lajistokoostumusta tutkittiin touko- ja kesäkuussa, mutta suuria eroja ei ajankohtien välillä havaittu. Lokakuussa sateisen loppukesän jälkeen δ13C oli tasainen (-23 ‰ - -24 ‰) koko tutkimusalueella, mutta δ15N oli taas huomattavasti korkeampi sisäsaaristossa (8 ‰) kuin ulkosaaristossa (4 ‰). Päinvastoin kuin yleensä tutkimuksissa on esitetty, tässä tutkimuksessa korkeat δ13C ja/tai δ15N-arvot kuvannevat lisääntynyttä jokien tuomaa terrestristä alkuperää olevaa ravinnekuormaa. Lisäksi kauden aikana suuresti vaihtelevat, mutta silti voimakkaasti korreloivat δ13C ja δ15N indikoivat hiilen ja typen olevan pääosin samaista alkuperää. Kirjallisuudessa ravinnepulssien yhtäaikaisesti korkeat δ13C ja δ15N katsotaan alkuperältään ihmis- tai eläinperäisiksi ja yleensä liitetään karjanlannan käyttöön lannoitteena. Tätä ei kuitenkaan voitu Saaristomerellä osoittaa, koska terrestrisiä ravinnelähteitä ei tutkittu. Kuitenkin muista tunnetuista SPM:n δ-arvoja voimakkaasti muokkaavista tekijöistä voitiin poissulkea ravinnerajoitteisuudesta johtuva fraktionaation muutos sekä synteettisten lannoitteiden käyttö ja kalankasvatus ravinnelähteinä. Pintasedimentistä saatiin paljon tasaisempia δ13C- ja δ15N-arvoja kaikilla näytteenotoilla (keskimäärin -24 ‰ ja 4 ‰, vastaavasti), jotka kuvannevat sedimentoituvan aineksen pitkäaikaisia keskiarvoja. Havaittavissa oli hienoinen laskeva suuntaus kohti ulompia asemia ja monista pohjan lähellä tai sedimentissä elävistä eläimistä saatiin samaan tapaan laskevia arvoja. SPM:n vaihtelevat ja eläinten δ-arvot korreloivat heikosti lukuunottamatta joitakin suspensionsyöjiä (Balanus improvisus ja Mytilus edulis). δ13C ja C:N korreloivat negatiivisesti joillakin lajeilla (Macoma balthica, Monoporeia affinis ja Mytilus edulis), joka johtunee muuttuvasta rasvojen osuudesta kudoksissa. Ainakin näiden lajien käyttöön ravinnelähteiden arvioinnissa kannattaa suhtautua varauksella. Makrolevien δ15N oli n. 4 ‰ korkeampi sisäsaaristossa kuin ulommilla asemilla, joka myöskin heijastanee jokien tuoman terrestristä alkuperää olevien ravinteiden vaikutusta. Fucus vesiculosus, tutkimuksen ainut varsinainen monivuotinen levä, sai 6 ‰ korkeampia δ13C-arvoja kuin muut levät keskimäärin. Gammarus sp:n Idothea baltican δ15N seurasi makrolevien δ15N:n vaihtelua, mutta δ13C:n perusteella arvioituna ne suosivat rehevöitymisen seurauksena runsastuvia rihmaleviä sisäsaaristossa, kun taas F. vesiculosus näytti kasvattavan tärkeyttä ravintona ulkosaaristossa. Hiilen ja typen pysyvät isotoopit osoittautuivat tehokkaiksi työkaluiksi ravinteiden lähteiden ja kulkeutumisen tarkasteluissa erityisesti sisäsaaristossa, vaikkakin joitakin lajikohtaisia piirteitä on otettava huomioon ja joidenkin biologisten prosessien, kuten denitrifikaation osuus fraktionaation aiheuttajana pitäisi määrittää ennen kuin luotettavia arvioita ravinnelähteistä voidaan tehdä.
  • Lepistö, Ahti (Finnish Environment Institute, 1996)
    Monographs of the Boreal Environment Research 1
  • Rautio, Mikko (Etelä-Savon ympäristökeskus, 2007)
    ESAra 1/2007
    Julkaisu sisältää tietoa Etelä-Savon ympäristökeskuksen toiminta-alueella (Etelä-Savon maakunta) aiheutuvasta ympäristökuormituksesta. Tiedot on koottu Ympäristöhallinnon ylläpitämästä Valvonta- ja kuormitustietojärjestelmästä (VAHTI), jonne ympäristölupavelvolliset vuosittain ilmoittavat tiedot mm. ilma- ja vesipäästöistä sekä jätemääristä. Raportti keskittyy vuoden 2005 tietoihin, mutta osa tiedoista on aikaisemmilta vuosilta, jos vuoden 2005 tietoja ei ole ollut saatavilla. Raporttiin on koottu tietoa myös aikaisempien vuosien kuormituksesta, jotta voidaan seurata kuormituksen kehittymistä. Ihmisen aiheuttama ympäristökuormitus Etelä-Savossa on erittäin vähäistä verrattuna muuhun Suomeen. Etelä- Savosta puuttuu lähes kokonaan suuret teollisuuslaitokset, jotka ovat suuria piste-kuormittajia. Maakunnan asukasmäärä ja –tiheys ovat pieniä verrattuna keskimäärin muuhun Suomeen, jolloin yhdyskuntien pistekuormittajat (esim. voimalaitokset ja jätevedenpuhdistamot) ovat kooltaan melko pieniä ja kuormitus vähäistä.
  • Wartiovaara, Jyrki (Vesihallitus, 1975)
    Vesientutkimuslaitoksen julkaisuja 13
    Engl. summary: Amounts of substances discharged by rivers off the coast of Finland