Nitrogen dynamics of organic farming in a crop rotation based on red clover (Trifolium pratense) leys

In agricultural systems which rely on organic sources of nitrogen (N), of which the primary source is biological N fixation (BNF), it is extremely important to use N as efficiently as possible with minimal losses to the environment. The amount of N through BNF should be maximised and the availability of the residual N after legumes should be synchronised to the subsequent plant needs in the crop rotation. Six field experiments in three locations in Finland were conducted in 1994-2006 to determine the productivity and amount of BNF in red clover-grass leys of different ages. The residual effects of the leys for subsequent cereals as well as the N leaching risk were studied by field measurements and by simulation using the CoupModel. N use efficiency (NUE) and N balances were also calculated. The yields of red clover-grass leys were highest in the two-year-old leys (6 700 kg ha-1) under study, but the differences between 2- and 3-year old leys were not high in most cases. BNF (90 kg ha-1 in harvested biomass) correlated strongly with red clover dry matter yield, as the proportion of red clover N derived from the atmosphere (> 85%) was high in our conditions of organically farmed field with low soil mineral N. A red clover content of over 40% in dry matter is targeted to avoid negative N-balances and to gain N for the subsequent crop. Surprisingly, the leys had no significant effect on the yields and N uptake of the two subsequent cereals (winter rye or spring wheat, followed by spring oats). On the other hand, yield and C:N of leys, as well as BNF-N and total-N incorporated into the soil influenced on subsequent cereal yields. NUE of cereals from incorporated ley crop residues was rather high, varying from 30% to 80% (mean 48%). The mineral N content of soil in the profile of 0-90 cm was low, mainly 15-30 kg ha-1. Simulation of N dynamics by CoupModel functioned satisfactorily and is considered a useful tool to estimate N flows in cropping systems relying on organic N sources. Understanding the long-term influence of cultivation history and soil properties on N dynamics remains to be a challenge to further research.

Sianlihan tuotantoon vaikuttavat tekijät vuosina 1995-2006

Ennen Suomen EU-jäsenyyttä kansallisen maatalouspolitiikan yksi päätavoitteista oli elintarvikeomavaraisuus. Tavoitteen saavuttamiseksi Suomessa oli maatalouspolitiikan osalta käytössä hintatukijärjestelmä, jossa yksi pääasiallisista tuotannon ohjauskeinoista oli tavoitehinnat, joilla valtiovalta pyrki vaikuttamaan tuottajahintoihin. Tavoitehintojen avulla tuottajat pystyivät ennakoimaan tulevan hintatason ja näin siirtämään tuotantoaan taloudellisesti kannattavimpaan suuntaan. Tästä oli kuitenkin seurauksena kotimaisen elintarvikeomavaraisuuden ylittyminen varsinkin eläinkunnan tuotteiden osalta. Vuonna 1994 lihatuotteiden yhteenlaskettu omavaisuus oli 110 prosenttia. Sianlihan osalta omavaisuus oli hieman tätä suurempi, 114 prosenttia. Suomen liityttyä EU:n jäsenmaaksi vuonna 1995 tavoitehinnoista luovuttiin ja samalla tuottajahinnat putosivat. Korvaukseksi tuottajahintojen pudotuksesta tuottajille alettiin maksaa suoria tulotukia. Tutkimuksen tarkoituksena oli selvittää mitkä tekijät vaikuttivat sianlihan tuotantopäätöksiin maatalouden muuttuneessa toimintaympäristössä ja miten yhteisen maatalouspolitiikan uudistukset vaikuttivat sianlihan tarjontaan. Tutkimuksen tarkasteluaikavälinä olivat vuodet 1995 2006. Tutkimuksen tavoitteena oli myös tuotantoon vaikuttavien tekijöiden pohjalta ennustaa sianlihan tuotantoa vuoteen 2013. Tuotantopäätöksiin vaikuttavia tekijöitä tarkasteltiin regressio-analyysin avulla, jotta saataisiin selville sianlihan tuotantoa parhaiten selittävät tekijät. Tutkimuksen aikasarja-aineisto poimittiin maa- ja metsätalousministeriön tietopalvelukeskuksen (Tike:n) ja tilastokeskuksen julkaisemista ja ylläpitämistä tilastoista. Sianlihan tuotantoon vaikuttavien tekijöiden ennusteisiin tutkimuksessa käytettiin sekä kansainvälisten että kotimaisten taloustutkimuslaitosten ja organisaatioiden ennusteita. Tutkimuksen teoreettinen viitekehys muodostui yrityksen teoriasta, tarjontateoriasta ja aikavälin merkityksestä tarjontaan. Tuotantomallin estimoinnin tuloksena sianlihan tuotantoon vaikuttivat vuosien 1996 2006 aikana sianlihan tuotannon tuottavuuden kasvua kuvaava teknologiamuuttuja, neljällä neljänneksellä viivästetty sianlihan tuottajahinta ja tuotantotuet yhteenlaskettuna, kolmella neljänneksellä viivästetty vehnän tuottajahinta, kahdeksalla neljänneksellä viivästetty sianlihan tuotanto, kahdella neljänneksellä viivästetty porsaan välityshinta ja kuudella neljänneksellä viivästetty investointituet. Sianlihan tuotantomallin selitysasteeksi saatiin 0,91. Estimoidulla tuotantomallilla ennustettiin sianlihan tuotannon kehitystä vuosina 2007 2013. Perusskenaariossa tuotannon ennustettiin muuttuvan vuodesta 2007 eteenpäin samalla tavalla kuin vuosina 1995 2006 keskimäärin. Perusskenaarion lisäksi tuotantomallilla simuloitiin tuotantotukien ja investointitukien dekoplauksen vaikutusta sianlihan tuotantoon. Tuotantotukien dekoplauksen myötä sianlihan tuotanto laskisi 177 milj. kiloon vuonna 2009, mutta nousisi 193 milj. kiloon vuonna 2013. Investointitukien dekoplauksen myötä tuotanto laskisi 176 milj. kiloon vuonna 2009 ja nousisi vuoteen 2013 mennessä 191 milj. kiloon. Suurimman pudotuksen aiheutti kuitenkin vehnän tuottajahinnan nousu vuosien 2006 ja 2007 aikana, jonka seurauksena sianlihan tuotanto laskisi jo vuonna 2008 180 milj. kiloon.

Kemian ylioppilaskokeen tehtävät summatiivisen arvioinnin välineenä

The main purpose of the research was to illustrate chemistry matriculation examination questions as a summative assessment tool, and represent how the questions have evolved over the years. Summative assessment and its various test item classifications, Finnish goal-oriented curriculum model, and Bloom’s Revised Taxonomy of Cognitive Objectives formed the theoretical framework for the research. The research data consisted of 257 chemistry questions from 28 matriculation examinations between 1996 and 2009. The analysed test questions were formulated according to the national upper secondary school chemistry curricula 1994, and 2003. Qualitative approach and theory-driven content analysis method were employed in the research. Peer review was used to guarantee the reliability of the results. The research was guided by the following questions: (a) What kinds of test item formats are used in chemistry matriculation examinations? (b) How the fundamentals of chemistry are included in the chemistry matriculation examination questions? (c) What kinds of cognitive knowledge and skills do the chemistry matriculation examination questions require? The research indicates that summative assessment was used diversely in chemistry matriculation examinations. The tests included various test item formats, and their combinations. The majority of the test questions were constructed-response items that were either verbal, quantitative, or experimental questions, symbol questions, or combinations of the aforementioned. The studied chemistry matriculation examinations seldom included selected-response items that can be either multiple-choice, alternate choice, or matching items. The relative emphasis of the test item formats differed slightly depending on whether the test was a part of an extensive general studies battery of tests in sciences and humanities, or a subject-specific test. The classification framework developed in the research can be applied in chemistry and science education, and also in educational research. Chemistry matriculation examinations are based on the goal-oriented curriculum model, and cover relatively well the fundamentals of chemistry included in the national curriculum. Most of the test questions related to the symbolism of chemical equation, inorganic and organic reaction types and applications, the bonding and spatial structure in organic compounds, and stoichiometry problems. Only a few questions related to electrolysis, polymers, or buffer solutions. None of the test questions related to composites. There were not any significant differences in the emphasis between the tests formulated according to the national curriculum 1994 or 2003. Chemistry matriculation examinations are cognitively demanding. The research shows that the majority of the test questions require higher-order cognitive skills. Most of the questions required analysis of procedural knowledge. The questions that only required remembering or processing metacognitive knowledge, were not included in the research data. The required knowledge and skill level varied slightly between the test questions in the extensive general studies battery of tests in sciences and humanities, and subject-specific tests administered since 2006. The proportion of the Finnish chemistry matriculation examination questions requiring higher-order cognitive knowledge and skills is very large compared to what is discussed in the research literature.

Reconstructions of past climates from documentary and natural sources in Finland since the 18th century

In this paper both documentary and natural proxy data have been used to improve the accuracy of palaeoclimatic knowledge in Finland since the 18th century. Early meteorological observations from Turku (1748-1800) were analyzed first as a potential source of climate variability. The reliability of the calculated mean temperatures was evaluated by comparing them with those of contemporary temperature records from Stockholm, St. Petersburg and Uppsala. The resulting monthly, seasonal and yearly mean temperatures from 1748 to 1800 were compared with the present day mean values (1961-1990): the comparison suggests that the winters of the period 1749-1800 were 0.8 ºC colder than today, while the summers were 0.4 ºC warmer. Over the same period, springs were 0.9 ºC and autumns 0.1 ºC colder than today. Despite their uncertainties when compared with modern meteorological data, early temperature measurements offer direct and daily information about the weather for all months of the year, in contrast with other proxies. Secondly, early meteorological observations from Tornio (1737-1749) and Ylitornio (1792-1838) were used to study the temporal behaviour of the climate-tree growth relationship during the past three centuries in northern Finland. Analyses showed that the correlations between ring widths and mid-summer (July) temperatures did not vary significantly as a function of time. Early (June) and late summer (August) mean temperatures were secondary to mid-summer temperatures in controlling the radial growth. According the dataset used, there was no clear signature of temporally reduced sensitivity of Scots pine ring widths to mid-summer temperatures over the periods of early and modern meteorological observations. Thirdly, plant phenological data with tree-rings from south-west Finland since 1750 were examined as a palaeoclimate indicator. The information from the fragmentary, partly overlapping, partly nonsystematically biased plant phenological records of 14 different phenomena were combined into one continuous time series of phenological indices. The indices were found to be reliable indicators of the February to June temperature variations. In contrast, there was no correlation between the phenological indices and the precipitation data. Moreover, the correlations between the studied tree-rings and spring temperatures varied as a function of time and hence, their use in palaeoclimate reconstruction is questionable. The use of present tree-ring datasets for palaeoclimate purposes may become possible after the application of more sophisticated calibration methods. Climate variability since the 18th century is perhaps best seen in the fourth paper study of the multiproxy spring temperature reconstruction of south-west Finland. With the help of transfer functions, an attempt has been made to utilize both documentary and natural proxies. The reconstruction was verified with statistics showing a high degree of validity between the reconstructed and observed temperatures. According to the proxies and modern meteorological observations from Turku, springs have become warmer and have featured a warming trend since around the 1850s. Over the period of 1750 to around 1850, springs featured larger multidecadal low-frequency variability, as well as a smaller range of annual temperature variations. The coldest springtimes occurred around the 1840s and 1850s and the first decade of the 19th century. Particularly warm periods occurred in the 1760s, 1790s, 1820s, 1930s, 1970s and from 1987 onwards, although in this period cold springs occurred, such as the springs of 1994 and 1996. On the basis of the available material, long-term temperature changes have been related to changes in the atmospheric circulation, such as the North Atlantic Oscillation (February-June).

Avioliiton teologia Englannin kirkossa ja Suomen evankelis-luterilaisessa kirkossa vuosina 1963-2006

The theology of marriage in the Church of England(CofE) and in the Evangelical Lutheran Church of Finland(ELCF)1963–2006 The method of the study is a systematic analysis of the sources. In the CofE marriage stems from creation, but it is also sacramental, grounded in the theology of love and redemption. Man and woman have a connection between them that is a mystical union in character because of the one between Christ and the Church; therefore every marriage is sacramental. The purposes of marriage have been expressed in a different order than earlier. A caring relationship and sexuality are set before childbirth as the causes of marriage. The remedial cause of marriage is also moved to the background and it cannot be found in the recent wedding formulas. A personal relationship and marriage as a school of faith and love have a central place in the theology of marriage. The theology of love unites the love of God and marriage. In the CofE the understanding of divorce and co-habiting has changed, too. Co-habiting can now be understood as a stage towards marriage. Divorce has been understood as a phenomenon that must be taken as a fact after an irretrievable breakdown of marriage. Thus the church must concentrate on pastoral care after divorce. Similarly, the ELCF also maintains that the order of creation is the origin of marriage as a lifelong institution. This is also an argument for the solemnization of marriage in the church. Faith and grace are not needed for real marriage because marriage is the culmination of reason and natural law. The society defines marriage and the church gives its blessing to the married couples if so requested. Luther’s view of marriage is different from this because he saw marriage as a school of love and faith, similar to CofE. He saw faith as essential to enable the fullfillment of natural law. Marriage in the ELCF is mostly a matter of natural ethics. An ideal form of life is sought through the Golden Rule. This interpretation of marriage means that it does not presuppose Christian education for children to follow. The doctrine of the two kingdoms is definitely essential as background. It has been impugned by scholars, however, as a permanent foundation of marriage. There is a difference between the marriage formulas and the other sources concerning the purposes of marriage in the ELCF. The formulas do not include sexuality, childbirth or children and their education as purposes of marriage. The formulas include less theological vocabulary than in the CofE. The liturgy indicates the doctrine in CofE. In the Lutheran churches there is not any need to express the doctrine in the wedding formulas. This has resulted in less theology of marriage in the formulas. The theology of Luther is no longer any ruling principle in the theology of marriage. The process of continuing change in society refines the terms for marriage more than the theological arguments do.

Ihanteena vapaaehtoisuus : Diakoniatyö Porvoon hiippakunnan seurakunnissa, erityisesti Iitin ja Tampereen rovastikunnissa vuosina 1897-1923

The Ideal of Volunteerism. An institutional approach to social welfare work in the parishes of the Diocese of Porvoo especially in the deaneries of Iitti and Tampere, Finland, in the years 1897-1923 Social welfare work (also known as diakonia) has achieved a high status in the Evangelical Lutheran Church of Finland. Since 1944, provisions of the Finnish Church Act have obliged each parish to employ at least one deacon or deaconess. This study sets out to examine the background and development of social welfare work in the Evangelical Lutheran Church of Finland from the 1890s to the 1920s, by which time social welfare work had become an established practice in the Church. The study investigates the development of social welfare work on the level of parishes. The main source material was collected from sixteen parishes in the Diocese of Porvoo especially in the deaneries of Iitti and Tampere. In the 1890s, two approaches were used in church social work in Finland. The dioceses of Kuopio, Savonlinna and Turku pursued a congregational approach to social work, while the Diocese of Porvoo employed an institutional approach, mainly because of the influence of Bishop Herman Råbergh. This study charts the formation of church social work in Finnish parishes, which took place during a period of tension between the two approaches. The institutional approach to church social work adopted by the Diocese of Porvoo was based on the German system of Asisters= houses@, in which deaconess institutes sent parish sisters to serve congregations. The parish or, in many cases, a separate association dedicated to church social work paid an annual fee to the deaconess institute, which took care of the parish sisters in old age. In the institutional approach, volunteers were recruited to carry out church social work. It was considered as inappropriate to use tax revenue or other public funding for church social work, which was supposed to be based on Christian love for one=s fellow humans and the needy, and for which only voluntary financial contributions were supposed to be used. In the congregational approach, church social work was directly based on the efforts of the parish. The approach relied on the administrative bodies of parishes and the Church, and tax revenue collected by the parishes, as well as other forms of public funding, could be used to carry out the social welfare work. The parishes employed deacons and deaconesses and paid their salaries. The approaches described above were not pursued in their ideal forms; instead, many variations existed. However, in principle, the social welfare work undertaken by the parishes of the Diocese of Porvoo was based on the institutional approach, while the congregational approach was largely employed elsewhere in Finland. Both of the approaches were viable. Parishes began to employ deacons and deaconesses as of the 1890s. The number of parishes which had hired a deacon or deaconess increased particularly in the 1910s, by which time 60% of parishes had employed one. This level was maintained until 1944 when each parish in the Evangelical Lutheran Church of Finland was obliged to employ a deacon or deaconess. Deaconesses usually worked as travelling nurses. The autonomous status of Finland as part of the Russian Empire did not give Finns the right to develop legislation on social affairs and health care. Consequently, the legislation process did not begin until Finland gained its independence in 1917. The social welfare work carried out by parishes and a number of voluntary organisations satisfied the emerging need for medical treatment in Finnish society. Neither the government nor the municipalities had sufficient resources to provide this treatment. Based on the ideal of volunteerism, the institutional social work practiced in the Diocese of Porvoo ran into serious difficulties at the end of the First World War. Because of severe inflation, prices began to rise as of 1915 and tripled in 1917-1918. During the same period, Finnish society went through a deep crisis which escalated into Civil War in spring 1918. This period of economic and social turmoil marked a turning-point which led to a weakening of the status of institutional social work in parishes. Voluntary efforts were no longer sufficient to maintain the practice. In contrast, congregational social work, which was based on public funding, was able to cope with the changes and survived the crisis. The approach to social work adopted by the Diocese of Porvoo turned out to be no more than a brief detour in the history of social work in the Evangelical Lutheran Church of Finland. At the start of the 1920s, the two approaches were integrated into a common vision for establishing church social work as a statutory practice in parishes.

Sanan vai rakkauden palveluksessa? : Diakonian viralle esitetyt teologiset perusteet Suomen evankelis-luterilaisessa kirkossa vuosina 1997-2006

Tämän tutkielman tehtävänä on selvittää diakonian viralle esitettyjä teologisia perusteita kirkon viralliseen päätöksentekoon liittyvissä asiakirjoissa Suomen evankelis-luterilaisessa kirkossa vuosina 1997-2006. Diakonaatti tarkoittaa kirkon hengelliseen virkaan kuuluvaa papin virasta erillistä palveluvirkaa. Tässä tutkielmassa diakonaattia tarkastellaan kirkkolaissa ilmaistun karitatiivisen diakonian viran näkökulmasta suhteessa kirkon erityiseen virkaan. Systemaattisessa analyysissa on pyritty kuvaamaan aineistosta esiin nouseva diakonian viran keskeinen teologia ja keskeisimmät virkakeskustelussa esiin tulleet ongelmakohdat. Diakonian viran teologisia perusteita ei tässä tutkielmassa pidetä yhtenä kokonaisuutena, vaan siinä tapahtuvat muutokset on pyritty nostamaan esiin historiallisessa viitekehyksessä. Dispositio on tämän vuoksi rakennettu kronologisesti eteneväksi. Suomen evankelis-luterilaisessa kirkossa käytävä keskustelu diakonian viran uudistamisesta on käytännöllisten uudistamistarpeiden lisäksi lähtökohdiltaan yhteydessä kansainväliseen ja ekumeeniseen virkateologiseen kehitykseen, jossa kirkot ovat arvioineet omaa olemustaan ja tehtäväänsä. Virkarakenneuudistuksen pani vireille piispainkokouksen esitys 1/1994 diakonian viran kehittämisestä. Tutkielman keskiössä ovat siihen liittyen komiteamietinnöt Yhdessä kirkon virassa (1997) ja Palvelijoiksi vihityt (2002). Tarkasteltuna ajanjaksona lähdeaineistossa on havaittavissa kirkon viran ja diakonian viran määrittelyä koskeva terminologian ja ordinaatiokäsityksen muutos. Linjausten argumentoinnissa on havaittavissa joitakin epäselvyyksiä, koska esiin otettiin uusia käsitteitä. Kaikki analysoidut asiakirjat katsoivat kirkon viran perustuvan jumalalliseen asetukseen. Sekä kaksisäikeisessä että kolmisäikeisessä virkamallissa diakonian virka ymmärrettiin osaksi Jumalan asettamaa kirkon virkaa. Yksi ministerium ecclesiasticum aukeaa useampaan tehtävään. Kristus asetti kirkolle viran kutsuessaan ja lähettäessään apostolit. Viran muodot ja jakautuminen esimerkiksi piispan, papin ja diakonian virkoihin on nähty periaatteessa inhimillisenä järjestelykysymyksenä, sillä viran jumalallinen asetus ei koske viran muotoja. Asiakirjoissa tukeuduttiin kirkon viran määrittelyssä yhteisen pappeuden perustaan. Kristityt muodostavat uskon ja rakkauden yhteisön, jossa koko seurakunnalla on vastuu tietyistä tehtävistä. Kirkon erityinen palveluvirka rakentuu tälle pohjalle. Aineistosta vahvasti nouseva teema on Lutherin teologiaan perustuva näkemys uskon ja rakkauden sisäkkäisyydestä sekä uskossa läsnäolevasta Kristuksesta rakkauden perustana. Lutherin teologiaan liittyy myös diakonian viran argumentointi sakramentaalisen sanakäsityksen pohjalta. Sanakäsitys on nähty laajasti myös ekumeenisessa dialogissa. Diakonian virkaa tarkasteltiin aineistossa suhteessa seurakuntaan. Yhteisöllisyyden korostus diakonian viran edellytyksenä ja myös sen seurauksena nousi esiin. Yhteisöllisyyden ja siten myös diakonian lähteeksi hahmottui jumalanpalvelus ja ehtoollinen. Ajatus koinoniasta toi mukanaan myös vahvan pneumatologisen perustelun diakonian viralle. Voidaankin sanoa, että diakonian virka tulkittiin lähteissä ankkuroituneeksi Kristukseen. Kristuksen ja kristittyjen yhteyden vuoksi Kristus on sekä diakonian lähde että sen kohde. Aineiston pohjalta on hahmotettavissa diakonian viran teologisena lähtökohtana yhteinen pappeus sekä yhteys sanaan ja sakramentteihin. Viran edellytyksenä on erityinen kutsu, valtuutuksena ordinaatio ja palveluviran sisältönä apostolisen esikuvan mukainen palvelu. Palveluvirka kirkossa perustuu yleiseen pappeuteen siten, että vain yleisen pappeuden omaava kastettu ja uskova kirkon jäsen voi saada erityisen kutsun ja valtuutuksen erityiseen virkaan. Yleinen pappeus ei kuitenkaan yksin riitä virkaan eikä sitä ole mahdollista johtaa yleisestä pappeudesta. Erityinen kirkon virka edellyttää lisäksi erityisen Jumalan kutsun, jonka kirkko hyväksyy ja vahvistaa. Jumalan kutsun julkinen vahvistaminen ja tunnustaminen tapahtuu ordinaatiossa. Diakonian virkaa koskevassa suomalaisessa keskustelussa on oltu yksimielisiä siitä, että diakonian virkaan sisältyvät karitatiivinen, katekeettinen ja liturginen funktio. Käytännössä diakonian viralla on kuitenkin vahvasti karitatiivinen luonne Suomen evankelis-luterilaisessa kirkossa.

The ecology of the mountain hare (Lepus timidus L.) in managed boreal forests: habitat associations at different forest scales

Aims of this thesis This study is part of a larger hare project in Finland, which provides answers to basic ecological questions regarding the mountain hare. This study of the ecology of the mountain hare focuses in particular on different levels of managed boreal forest. The feeding habits and intensity of mountain hares in winter are explored, and the connections between mountain hares versus the forest structure are also studied (e.g. habitat use and the importance of different forest layers for hares). The use of the environment by hares at the landscape level was examined (forest patch structures), and the home ranges of mountain hares were studied. Finally, the productivity and survival rate of mountain hare populations were also studied (discussion e.g. predator effects on hare populations). Conclusions Feeding intensity seemed to be highest in the spring-winter, when home ranges were also largest. Favourable food species are covered by snow in winter and the mobility of hares is highest during late winter. A shortage of suitable food species may be problematic for hares, especially during the winter period. In this study mountain hares preferred a dense shrub layer at local level and deciduous and mixed tree forest over coniferous forest at the landscape level. Food and shelter are vital for hares and the preference for particular habitats may also affect the population dynamics of the mountain hare. It would be possible to improve the quality of food and shelter or at least prevent the most negative habitat changes through forest management. At a local level it is also possible to add supplementary food for hares through the winter period. The intensive clearing of young sapling stands and especially the removal of deciduous shrubs and trees reduces the quality of habitats for the mountain hare. Mountain hares primarily live in forest habitat and it is possible that changes in the forest structure play a crucial role in mountain hare habitat preference. Ecological knowledge of the mountain hare is vital to create habitat structure more suitable for the species. More deciduous trees should be saved in managing forests and the mechanical clearing of the shrub layer should be done carefully.

Invertebrate predation and trophic cascades in a pelagic food web : The multiple roles of Chaoborus flavicans (Meigen) in a clay-turbid lake

In lake ecosystems, both fish and invertebrate predators have dramatic effects on their prey communities. Fish predation selects large cladocerans while invertebrate predators prefer prey of smaller size. Since invertebrate predators are the preferred food items for fish, their occurrence at high densities is often connected with the absence or low number of fish. It is generally believed that invertebrate predators can play a significant role only if the density of planktivorous fish is low. However, in eutrophic clay-turbid Lake Hiidenvesi (southern Finland), a dense population of predatory Chaoborus flavicans larvae coexists with an abundant fish population. The population covers the stratifying area of the lake and attains a maximum population density of 23000 ind. m-2. This thesis aims to clarify the effects of Chaoborus flavicans on the zooplankton community and the environmental factors facilitating the coexistence of fish and invertebrate predators. In the stratifying area of Lake Hiidenvesi, the seasonal succession of cladocerans was exceptional. The spring biomass peak of cladocerans was missing and the highest biomass occurred in midsummer. In early summer, the consumption rate by chaoborids clearly exceeded the production rate of cladocerans and each year the biomass peak of cladocerans coincided with the minimum chaoborid density. In contrast, consumption by fish was very low and each study year cladocerans attained maximum biomass simultaneously with the highest consumption by smelt (Osmerus eperlanus). The results indicated that Chaoborus flavicans was the main predator of cladocerans in the stratifying area of Lake Hiidenvesi. The clay turbidity strongly contributed to the coexistence of chaoborids and smelt at high densities. Turbidity exceeding 30 NTU combined with light intensity below 0.1 μE m-2 s-1provides an efficient daytime refuge for chaoborids, but turbidity alone is not an adequate refuge unless combined with low light intensity. In the non-stratifying shallow basins of Lake Hiidenvesi, light intensity exceeds this level during summer days at the bottom of the lake, preventing Chaoborus forming a dense population in the shallow parts of the lake. Chaoborus can be successful particularly in deep, clay-turbid lakes where they can remain high in the water column close to their epilimnetic prey. Suspended clay alters the trophic interactions by weakening the link between fish and Chaoborus, which in turn strengthens the effect of Chaoborus predation on crustacean zooplankton. Since food web management largely relies on manipulations of fish stocks and the cascading effects of such actions, the validity of the method in deep clay-turbid lakes may be questioned.

Phytoplankton ecology of subarctic lakes in Finnish Lapland

Climate is warming and it is especially seen in arctic areas, where the warming trend is expected to be greatest. Arctic freshwater ecosystems, which are a very characteristic feature of the arctic landscape, are especially sensitive to climate change. They could be used as early warning systems, but more information about the ecosystem functioning and responses are needed for proper interpretation of the observations. Phytoplankton species and assemblages could be especially suitable for climate-related studies, since they have short generation times and react rapidly to changes in the environment. In addition, phytoplankton provides a good tool for lake classifications, since different species have different requirements and tolerance ranges for various environmental factors. The use of biological indicators is especially useful in arctic areas, were many of the chemical factors commonly fall under the detection limit and therefore do not provide much information about the environment. This work brings new information about species distribution and dynamics of arctic freshwater phytoplankton in relation to environmental factors. The phytoplankton of lakes in Finnish Lapland and other European high-altitude or high-latitude areas were compared. Most lakes were oligotrophic and dominated by flagellated species belonging to chrysophytes, cryptophytes and dinoflagellates. In Finnish Lapland cryptophytes were of less importance, whereas desmids had high species richness in many of the lakes. In Pan-European scale, geographical and catchment-related factors were explaining most of the differences in species distributions between different districts, whereas lake water chemistry (especially conductivity, SiO2 and pH) was most important regionally. Seasonal and interannual variation of phytoplankton was studied in subarctic Lake Saanajärvi. Characteristic phytoplankton species in this oligotrophic, dimictic lake belonged mainly to chrysophytes and diatoms. The maximum phytoplankton biomass in Lake Saanajärvi occurs during autumn, while spring biomass is very low. During years with heavy snow cover the lake suffers from pH drop caused by melt waters, but the effects of this acid pulse are restricted to surface layers and last for a relatively short period. In addition to some chemical parameters (mainly Ca and nutrients), length of the mixing cycle and physical factors such as lake water temperature and thermal stability of water column had major impact on phytoplankton dynamics. During a year with long and strong thermal stability, the phytoplankton community developed towards an equilibrium state, with heavy dominance of only a few taxa for a longer period of time. During a year with higher windiness and less thermal stability, the species composition was more diverse and species with different functional strategies were able to occur simultaneously. The results of this work indicate that although arctic lakes in general share many common features concerning their catchment and water chemistry, large differences in biological features can be found even in a relatively small area. Most likely the lakes with very different algal flora do not respond in a similar way to differences in the environmental factors, and more information about specific arctic lake types is needed. The results also show considerable year to year differences in phytoplankton species distribution and dynamics, and these changes are most likely linked to climatic factors.

Evaluation and modelling of the spatial and temporal variability of particulate matter in urban areas

This thesis contains three subject areas concerning particulate matter in urban area air quality: 1) Analysis of the measured concentrations of particulate matter mass concentrations in the Helsinki Metropolitan Area (HMA) in different locations in relation to traffic sources, and at different times of year and day. 2) The evolution of traffic exhaust originated particulate matter number concentrations and sizes in local street scale are studied by a combination of a dispersion model and an aerosol process model. 3) Some situations of high particulate matter concentrations are analysed with regard to their meteorological origins, especially temperature inversion situations, in the HMA and three other European cities. The prediction of the occurrence of meteorological conditions conducive to elevated particulate matter concentrations in the studied cities is examined. The performance of current numerical weather forecasting models in the case of air pollution episode situations is considered. The study of the ambient measurements revealed clear diurnal variation of the PM10 concentrations in the HMA measurement sites, irrespective of the year and the season of the year. The diurnal variation of local vehicular traffic flows seemed to have no substantial correlation with the PM2.5 concentrations, indicating that the PM10 concentrations were originated mainly from local vehicular traffic (direct emissions and suspension), while the PM2.5 concentrations were mostly of regionally and long-range transported origin. The modelling study of traffic exhaust dispersion and transformation showed that the number concentrations of particles originating from street traffic exhaust undergo a substantial change during the first tens of seconds after being emitted from the vehicle tailpipe. The dilution process was shown to dominate total number concentrations. Minimal effect of both condensation and coagulation was seen in the Aitken mode number concentrations. The included air pollution episodes were chosen on the basis of occurrence in either winter or spring, and having at least partly local origin. In the HMA, air pollution episodes were shown to be linked to predominantly stable atmospheric conditions with high atmospheric pressure and low wind speeds in conjunction with relatively low ambient temperatures. For the other European cities studied, the best meteorological predictors for the elevated concentrations of PM10 were shown to be temporal (hourly) evolutions of temperature inversions, stable atmospheric stability and in some cases, wind speed. Concerning the weather prediction during particulate matter related air pollution episodes, the use of the studied models were found to overpredict pollutant dispersion, leading to underprediction of pollutant concentration levels.

Yliopisto-opetuksen yhteistoiminnallinen kehittäminen

The main aim of this work is to study the possibility of applying the cooperative learning approach to develop academic learning and teaching culture. In this work cooperative learning refers to a pedagogical approach that applies social psychological knowledge of group dynamics and small group teaching. Furthermore, theories of collaborative learning and organization development have been applied. Based on these theories a model of developing learning and teaching culture was developed. The model was tested in the development project that was carried out in the Faculty of Agriculture and Forestry of Helsinki University. The research questions were: How were the theories of cooperative and collaborative learning and organization development applied in the project? What kind of effects did the development project have on the learning and teaching culture? Through which kind of mechanisms did the project influence this culture? How should the development model be revised after the empirical test? The project lasted five years and the major part of the project consisted of a one-year pedagogical training course. Altogether 145 people (teachers, researchers, library staff, and students) participated in the training, two to three departments at a time. In the pedagogical training cooperative learning methods were widely used. A questionnaire was used to study effects of the development project. The questionnaire was sent to 87 people and 65.5 % answered it. Both the answers to the questionnaire and a sample of learning diaries (n=61) were used to study the mechanism of the project. A sample of the learning diaries consisted of two pedagogical training group members diaries. The frequency distributions were calculated as extrapolations from the answers to the structured questions. Furthermore the answers were classified by the main background variables. The analysis of the open answers to the questionnaire and the learning diaries were data-based. According to the answers to the questionnaire, the effects of the pedagogical training were as follows: The participants consider learning more as an active process of constructing knowledge. Furthermore they considered the individual learning styles and strategies, cooperation and motivation as more important part of the learning process than before the pedagogical training. The role of the teacher was viewed more challenging than before. Additionally the cooperation between teachers, other staff members and students had projected to increase. After the project had ended the teaching methods in the whole faculty were viewed to become varied and the teaching was considered to be more valued than before. According to the answers to the questionnaire, the project influenced through the following ways: the project stimulated the change process, provided new methods for learning and teaching, had an effect on conceptions of learning and teaching and facilitated meaningful communication with others (staff and students). The analysis of the learning diaries supported these findings. In addition, the analysis of the learning diaries deepened the understanding of how the cooperative learning methods supported positive learning atmosphere and reduced the negative effect of the status differences between the members of the group. The critical comments in the learning diaries could be interpreted as collision between cooperative and traditional teaching culture. Cooperative learning gives theory-based methods to develop academic learning and teaching culture. The approach helps the developer to create positive collaborative learning environment and gives ways to support learning in small groups, which can promote cultural change. On the other hand, to understand the whole process of organization development and promote change the theories of organizations and more sosioconstructivist theory of learning are needed. Cooperative learning, collaborative learning, higher education, group dynamics, social constructionism, organisational culture, organisation development

Lapsuusiän kantasolusiirrot HUS:ssa vuosina 1993-2006

Tutkielma kuvaa lapsuusiän kantasolusiirtojen merkittävimmät tulokset ja komplikaatiot keskeisissä tautiryhmissä modernin hoidon aikakaudella HUS:ssä. Aineistona on HUS:n Lasten ja nuorten sairaalan veri- ja syöpätautien sekä kantasolusiirtoyksikön potilaista kerätty, vuonna 1993 perustetun ProLapsi-rekisterin sisältämä kliininen kantasolusiirtoaineisto vuosilta 1993-2006. Aineisto sisältää runsaat 90% Suomessa tehdyistä lasten allogeenisista kantasolusiirroista (n=233) sekä kaikki HUS:in autologiset siirrot (n=117) ko. aikajaksolla. Tutkielma on toteutettu kvantitatiivisia tutkimusmenetelmiä käyttäen. Suurin allogeenisen kantasolusiirron saaneiden potilaiden diagnoosiryhmä oli akuutti lymfoblastileukemia, ja suurin autologisen kantasolusiirron saaneiden ryhmä neuroblastoomapotilaat. Allogeenisista kantasolusiirroista 38% tehtiin HLA-identtiseltä sukulaisluovuttajalta ja 53% rekisteriluovuttajan soluilla. Kumulatiivinen kokonaisselviytyminen oli merkitsevästi parempaa sukulaisluovuttajan soluilla tehdyissä siirroissa kuin rekisteriluovuttajan (p=0,003). Allogeenisen kantasolusiirron saaneista potilaista 71% sai jonkin asteisen akuutin ja 42% kroonisen käänteishyljinnän (GVHD). Sekä akuutin että kroonisen GVHD:n vaikeus puolestaan korreloi kuolleisuuteen. Allogeenisen kantasolusiirron pitkäaikaisvaikutusta arvioitiin seurantatietojen perusteella. 58%:lla elämänlaatu arvioitiin normaaliksi, 35%:lla hieman rajoittuneeksi ja 7%:lla heikoksi.