Puuston hakkuiden tai palamisen aiheuttamat typen ja fosforin ravinnehuuhtoumat

Tiivistelmä. Tässä työssä tarkasteltiin avohakkuiden vaikutuksia typen ja fosforin huuhtoumiin. Työssä pyrittiin selvittämään huuhtoumia aiheuttavia mekanismeja ja niitä lieventäviä metsänhoidon käytäntöjä. Lisäksi verrattiin avohakkuiden aiheuttamia huuhtoumia maastopalojen aiheuttamiin huuhtoumiin. Tutkimusmenetelmänä käytettiin kirjallisuuskatsausta boreaalisella alueella toteutetuista alan tutkimuksista sekä viranomaisten tuottamista tutkimusraporteista. Ennen tutkimuskysymyksen vastausta työssä käytiin läpi typen ja fosforin kiertokulkua metsäekosysteemissä sekä metsien hydrologiaa. Sen jälkeen kerrottiin avohakkuiden vaikutuksista metsän hydrologiaan ja tarkasteltavien ravinteiden kulkuun. Yleisesti ravinnehuuhtoumien kasvua selittävä tekijä oli ravinteita sitovan ja vettä haihduttavan puuston poisto, joka lisäsi paikallista valumaa. Pohjaveden pinnan nousun todettiin mahdollisesti aiheuttavan fosforin lisääntynyttä huuhtoumaa hapettomien olosuhteiden lisätessä redox-herkkien rauta-fosforiyhdisteiden liukoisuutta. Vesiliukoista nitraattia muodostavan nitrifikaation havaittiin kohonneen maaperässä, mikä saattaa lisätä typen huuhtoumaa. Ravinteikkailla turvemailla tehtyjen avohakkuiden arveltiin joissain tutkimuksissa aiheuttavan enemmän typpihuuhtoumaa kuin köyhemmillä turvemailla toteutettujen hakkuiden. Fosforihuuhtoumien taas on tutkimuksissa havaittu olevan mahdollisesti suurempia köyhistä kuin rikkaista turvemaista johtuen köyhien maiden alhaisista fosforia sitovien alkuaineiden pitoisuuksista. Jatkuvapeitteisen metsänkasvatuksen hyödystä fosforihuuhtoumien lieventämisessä on hieman tutkimusnäyttöä. Typen suhteen tutkimusnäyttö ei ole selkeää. Avohakkuissa syntyvien hakkuujätteiden korjaamisen vaikutukset ravinnehuuhtoumiin eivät ole selkeitä tarkastellun kirjallisuuden perusteella. Suojavyöhykkeiden havaittiin joissain tutkimuksissa alentavan hakkuiden jälkeisiä ravinnehuuhtoumia tehokkaasti, pintavalutuskenttien käytön tehosta sen sijaan on ristiriitaisia tuloksia. Maastopalojen vaikutuksien ravinnehuuhtoumaan havaittiin tutkimuksissa olevan tarkasteltujen ravinteiden kohdalla avohakkuihin rinnastettavia.Leaching of nitrogen and phosphorus caused by clear-cutting or wildfires. Abstract. This thesis examined eutrophication causing leaching of nitrogen and phosphorus caused by clear-cutting. The thesis aimed to find mechanisms which cause leaching and forestry practices to alleviate it, and compared leaching caused by clear-cutting to that caused by wildfires. The research method utilized was literature review of research done in the boreal region and research reports produced by governmental agencies. Before answering the research question, topics such as the cycle of nitrogen and phosphorus in forests, the hydrology of forests and the effects of clear-cutting on the cycles and hydrology were examined. Clear-cuts were found in many studies to cause increase in runoff from forested areas in response to the disappearance of processes which cause trees to evaporate water. The nutrient take-up of trees also disappeared, and these two factors explained the cause of universal nutrient leaching. The rise of groundwater table level and subsequent creation of anoxic conditions was discovered to possibly cause increased leaching of phosphorus in studies with anoxic conditions increasing the solubility of redox-sensitive iron-phosphorus compounds. Nitrification, which forms water-soluble nitrate, was found to increase in soil after clear-cutting, possibly increasing the leaching of nitrogen. Clear-cutting on rich peat soils was thought in some studies to cause more nitrogen leaching than similar logging on poorer peat soils. Phosphate leaching, on the other hand, was found to be greater on poorer than richer peat soils, because of the low amount of strongly phosphorus-binding elements in poor peat soils. Based on studies there is some evidence of continuous coverage of forests to slightly alleviate phosphorus leaching. The evidence is not clear on the effects on nitrogen leaching. The collection of logging waste after clear-cutting did not have any clear effects on nutrient leaching based on the research studied. Buffer zones were found in some studies to effectively lower nutrient leaching from areas of clear-cutting, whereas the studies on overland-flow fields discovered mixed results. The leaching of nitrogen and phosphorus caused by wildfires was found to be similar as that of clear-cutting

Helsinki Harvest: Proceedings of the 11th Nordic Conference on the Application of Scientific Methods in Archaeology

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Research on the Mesolithic of North Karelia in 2003–2017 - Implications for the early postglacial archaeology of Northern Europe

In this paper we describe the results of small-scale archaeological fieldwork projects carried out i North Karelia, Finland, in 2003–2014, which ended up having a far greater research impact than anyone could have anticipated. The projects yielded a multitude of new and relevant information, especially on the Early Mesolithic, including the earliest radiocarbon dates for human occupation in Eastern Fennoscandia. Results of this research have been published in a variety of venues. We use this opportunity to present the first summary of these results and to emphasize that even with discontinuous short-term funding it is possible to carry out ambitious and influential research. Over the years, Karelia has been one of the main focus areas of Mika Lavento’s research. We want to honour Mika’s 60th birthday by providing an overview of the results of our studies conducted in the northern parts of this large geographical and administrative area.Peer reviewe

Research on the Mesolithic of North Karelia in 2003–2017 - Implications for the early postglacial archaeology of Northern Europe

In this paper we describe the results of small-scale archaeological fieldwork projects carried out i North Karelia, Finland, in 2003–2014, which ended up having a far greater research impact than anyone could have anticipated. The projects yielded a multitude of new and relevant information, especially on the Early Mesolithic, including the earliest radiocarbon dates for human occupation in Eastern Fennoscandia. Results of this research have been published in a variety of venues. We use this opportunity to present the first summary of these results and to emphasize that even with discontinuous short-term funding it is possible to carry out ambitious and influential research. Over the years, Karelia has been one of the main focus areas of Mika Lavento’s research. We want to honour Mika’s 60th birthday by providing an overview of the results of our studies conducted in the northern parts of this large geographical and administrative area.Peer reviewe

The dIANA database - Resource for isotopic paleodietary research in the Baltic Sea area

Paleodietary research is a complex field, which requires large sets of background information. Owing to increasing interest and activity in the field, a substantial amount of archaeological isotope baseline data exist for Northern Europe, consisting mainly of animal bone collagen delta C-13, delta N-15, and delta S-34 values. However, the data are scattered into dozens of publications written in multiple languages and less-accessible formats, making the data laborious to use. This article presents the first compilation work of this data, the open access dIANA database (Dietary Isotopic baseline for the Ancient North; https://www.oasisnorth.org/diana.html), aimed to support (paleo)dietary research in the Baltic Sea area. The database work is complemented with new analyses of archaeological and (pre-)modern domestic and wild fauna from Finland and Russia broadening the selection of analysed species in the database. We present and discuss data examples, which on one hand show existing spatiotemporal isotope patterns related to diet and differences in the environmental carbon sources and on the other, also visualize the current status of baseline research and the need for further analyses in the circum-Baltic area

Efflux Protein Expression in Human Stem Cell-Derived Retinal Pigment Epithelial Cells

Retinal pigment epithelial (RPE) cells in the back of the eye nourish photoreceptor cells and form a selective barrier that influences drug transport from the blood to the photoreceptor cells. At the molecular level, ATP-dependent efflux transporters have a major role in drug delivery in human RPE. In this study, we assessed the relative expression of several ATP-dependent efflux transporter genes (MRP1, -2, -3, -4, -5, -6, p-gp, and BCRP), the protein expression and localization of MRP1, MRP4, and MRP5, and the functionality of MRP1 efflux pumps at different maturation stages of undifferentiated human embryonic stem cells (hESC) and RPE derived from the hESC (hESC-RPE). Our findings revealed that the gene expression of ATP-dependent efflux transporters MRP1, -3, -4, -5, and p-gp fluctuated during hESC-RPE maturation from undifferentiated hESC to fusiform, epithelioid, and finally to cobblestone hESC-RPE. Epithelioid hESC-RPE had the highest expression of MRP1, -3, -4, and P-gp, whereas the most mature cobblestone hESC-RPE had the highest expression of MRP5 and MRP6. These findings indicate that a similar efflux protein profile is shared between hESC-RPE and the human RPE cell line, ARPE-19, and suggest that hESC-RPE cells are suitable in vitro RPE models for drug transport studies. Embryonic stem cell model might provide a novel tool to study retinal cell differentiation, mechanisms of RPE -derived diseases, drug testing and targeted drug therapy