Environmental factors affecting the occurrence of periglacial landforms in Finnish Lapland: a numerical approach

Determination of the environmental factors controlling earth surface processes and landform patterns is one of the central themes in physical geography. However, the identification of the main drivers of the geomorphological phenomena is often challenging. Novel spatial analysis and modelling methods could provide new insights into the process-environment relationships. The objective of this research was to map and quantitatively analyse the occurrence of cryogenic phenomena in subarctic Finland. More precisely, utilising a grid-based approach the distribution and abundance of periglacial landforms were modelled to identify important landscape scale environmental factors. The study was performed using a comprehensive empirical data set of periglacial landforms from an area of 600 km2 at a 25-ha resolution. The utilised statistical methods were generalized linear modelling (GLM) and hierarchical partitioning (HP). GLMs were used to produce distribution and abundance models and HP to reveal independently the most likely causal variables. The GLM models were assessed utilising statistical evaluation measures, prediction maps, field observations and the results of HP analyses. A total of 40 different landform types and subtypes were identified. Topographical, soil property and vegetation variables were the primary correlates for the occurrence and cover of active periglacial landforms on the landscape scale. In the model evaluation, most of the GLMs were shown to be robust although the explanation power, prediction ability as well as the selected explanatory variables varied between the models. The great potential of the combination of a spatial grid system, terrain data and novel statistical techniques to map the occurrence of periglacial landforms was demonstrated in this study. GLM proved to be a useful modelling framework for testing the shapes of the response functions and significances of the environmental variables and the HP method helped to make better deductions of the important factors of earth surface processes. Hence, the numerical approach presented in this study can be a useful addition to the current range of techniques available to researchers to map and monitor different geographical phenomena.

Helsingin Östersundomin pienvesien kartoitus

The area of Östersundom (29,1 square kilometers) was attached to Helsinki in the beginning of the year 2009. Östersundom is formed mostly from the municipality of Sipoo, and partly from the city of Vantaa. Nowadays Östersundom is still quite rural, but city planning has already started, and there are plans to develop Östersundom into a district with 45 000 inhabitants. In this study, the headwaters, streams and small lakes of Östersundom were studied to produce information as a basis for city planning. There are six main streams and five small lakes in Östersundom. The main methodology used in this study was the examination of the physical and the chemical quality of the water. The hygienic quality of the water was also studied. It was also examined whether the waters are in their natural state, or have they been treated and transformed by man. In addition, other factors affecting the waters were examined. Geographical information data was produced as a result of this work. Östersundom is the main area looked at in this study, some factors are examined in the scope of the catchment areas. Water samples were collected in three sampling periods: 31.8 4.9.2009, 3. 4.2.2010, and 10. 14.4.2010. There were 20 sampling points in Östersundom (5 in small lakes, 15 in streams). In the winter sampling period, only six samples were collected, from which one was taken from a small lake. Field measurements associated with water sampling included water temperature, oxygen concentration, pH and electoral conductivity. Water samples were analyzed in the Laboratories of Physical Geography in the University of Helsinki for the following properties: total suspended solids (TSS), total dissolved substances (TDS), organic matter, alkalinity, colour, principal anions and cations and trace elements. Metropolilab analyzed the amount of faecal coliform bacteria in the samples. The waters in Östersundom can be divided to three classes according to water quality and other characteristics: the upper course of the streams, the lower course of the streams and the small lakes. The streams in their upper course are in general acidic, and their acid neutralization capacity is low. The proportion of the organic matter is high. Also the concentrations of aluminium and iron tend to be high. The streams in the lower course have acidity closer to neutral, and the buffering capacity is good. The amounts of TSS and TDS are high, and as a result, the concentrations of many ions and trace elements are high as well. Bacteria were detected at times in the streams of the lower course. Four of the five small lakes in Östersundom are humic and acidic. TSS and TDS concentrations tend to be low, but the proportion of organic matter is often high. There were no bacteria in the small lakes. The fifth small lake (Landbonlampi) differs from the others by its water colour, which is very clear. This lake is very acidic, and its buffering capacity is extremely low. Compared to the headwaters in Finland in general, the concentrations of many ions and trace elements are higher in Östersundom. On the other hand, the characteristics of water were different according to the classification upper course streams, lower course streams, and small lakes. Generally, the best water quality was observed in the stream of Gumbölenpuro and in the lakes Storträsk, Genaträsk, Hältingträsk and Landbonlampi. Several valuable waters in their natural state were discovered from the area. The most representative example is the stream of Östersundominpuro in its lower course, where the stream flows through a broad-leaf forest area. The small lakes of Östersundom, and the biggest stream Krapuoja, with its meandering channel, are also valuable in their natural state.

Aktiiviseen kansalaisuuteen kasvattaminen yläkoulun maantieteen opetuksessa

Tutkielmassa tarkasteltiin aktiivista kansalaisuutta perusopetuksen yläkoulun (luokat 7–9) maantieteen opetuksessa. Tutkielman taustana olivat aktiiviseen kansalaisuuteen liittyvät viralliset ja epäviralliset diskurssit: opetussuunnitelman perusteiden aihekokonaisuudet, kouluun kohdistuvat kansalaiskasvatushankkeet sekä nuoriin, kansalaisuuteen ja kansalaisyhteiskuntaan liittyvät keskustelut. Maantieteen opetuksen osalta taustana olivat opetussuunnitelman velvoitteet huomioida aktiivinen kansalaisuus yläkoulun maantieteen opetuksessa sekä (pääasiassa brittiläinen) kirjallisuus, jossa maantieteen ja kansalaiskasvatuksen/aktiivisen kansalaisuuden välillä nähdään yhtäläisyyksiä. Tutkielmassa pyrittiin selvittämään, mitä aktiivinen kansalaisuus on yläkoulun maantieteen opetuksessa ja miten maantieteen opettajat suhtautuvat tehtäviinsä nuorten kansalaisten kasvattajina ja yhteiskunnallisina vaikuttajina. Tutkielmaa varten kerättiin teemahaastatteluaineisto kuudelta yläkoulun maantieteen opettajalta. Haastatteluihin pyrittiin löytämään mahdollisimman aktiivisia maantieteen opettajia. Haastatteluaineiston analyysissa käytettiin sisällönanalyysia, ja aineiston avulla pyrittiin kuvaamaan ilmiötä. Haastateltujen opettajien mukaan yläkoulun maantieteen opetuksessa luonnonmaantieteelliset sisällöt painottuvat enemmän kuin kulttuurimaantieteelliset. Aktiivisen kansalaisuuden kannalta keskeisiä sisältöjä, kuten vaikutusmahdollisuuksia oman ympäristön suunnitteluun ja kehittymiseen sekä kotikunnan ja lähiympäristön tutkimista käsitellään opetuksessa vain vähän, jos ollenkaan. Aktiivinen kansalaisuus on yläkoulun maantieteen opetuksessa eniten tiedon jakamista, ajattelun taitojen ja mielipiteen muodostamisen harjoittelua sekä ympäristövastuullisuuteen kansalaisuuteen kasvattamista. Opetuksessa käytetään myös aktiivisen kansalaisuuden kannalta keskeisiä työtapoja, mutta työtapojen käyttö vaihtelee. Haastatellut opettajat eivät koe opetussuunnitelman aihekokonaisuuksia juurikaan omakseen. Opettajat eivät myöskään määrittele kansalaisvaikuttamiseen kasvattamista koulun tärkeimpien tehtävien joukkoon. Osa opettajista kokee kuitenkin olevansa yhteiskunnallinen vaikuttaja opettajana. Opettajien puheessa koulun kansalaiskasvatuksen tavoite, kunnon kansalainen, ei määrity kovin aktiivisena tai poliittisena. Opettajien puhe sisältää kuitenkin monenlaisia näkemyksiä suhteessa nuoriin kansalaisina ja aktiivisuuteen: toisaalta nuoret eivät ole kiinnostuneita yhteiskunnallisista asioista eikä heiltä vaaditakaan sitä, toisaalta maaperä nuorten kasvattamiseen aktiivisiksi kansalaisiksi on hyvä ja aktiivisuus on pieniä asioita lähiympäristössä sekä yhdessä tekemiseen uskomista. Haastattelujen pohjalta todettiin, että lukuun ottamatta joidenkin opettajien ympäristökasvatuksellista otetta, aktiivinen kansalaisuus ei ole täysin tiedostettu tavoite yläkoulun maantieteen opetuksessa.

Kaupunkipurot Helsingissä - Veden laatu vuonna 2004

In recent years urban hydrology and individual urban streams have been in focus and subjects to research also in Helsinki. However, until now there has been lack of research covering simultaneously the whole area of the city of Helsinki. The aim of this study was to find out the general state of water quality in small urban streams in the city of Helsinki. 21 streams were studied: Mätäjoki, Korppaanoja, Mätäpuro, Näsinoja-Tuomarinkylänoja, Tuomarinkartanonpuro, Kumpulanpuro, Tapaninkylänpuro, Tapaninvainionpuro, Puistolanpuro, Longinoja, Säynäslahdenpuro, Viikinoja, Porolahdenpuro, Mustapuro, Marjaniemenpuro, Mellunkylänpuro, Vuosaarenpuro, Rastilanpuro, Ramsinkannaksenpuro, Skatanpuro and Yliskylänpuro. Water samples were collected from 48 sampling points, each stream having at least one point. Four water samples were collected from each point, sampling periods being 9.-11.2., 26.-28.4., 29.6.-1.7. and 25.-27.10.2004. Field measurements associated with water sampling included water temperature, oxygen concentration, pH and electrical conductivity. Water samples were analysed in the Laboratory of Physical Geography in the University of Helsinki and in the Environmental Laboratory of the City of Helsinki Environment Centre for following properties: suspended solids, dissolved substances, alkalinity, principal anions and cations (Na+, K+, Mg2+, Ca2+, F-, Cl-, NO3-, PO43- and SO42-), colour, turbidity, biological and chemical oxygen demand (BOD7 and CODMn-values), nutrient concentrations and bacterial indicators of hygienic quality. The main water quality issues found in this study were low oxygen levels in many streams and poor hygienic quality at least occasionally. E.g. in summer oxygen levels were under 60 % in every stream. Amount of total dissolved substances and nutrients were high in some of the streams studied. Compared to other Finnish streams the values of alkalinity and pH were higher. Although these problems were common, the variation between different streams and sampling points was significant. This was probably due to local conditions. Best overall water quality was found in Mätäpuro and Tuomarinkartanonpuro streams. Seasonal variation was evident in almost all water quality properties. For example the total amount of dissolved substances was largest in winter and decreased during the year. Colour and turbidity were smallest in winter and increased towards the end of the year. The same was true for suspended solids, which had smallest concentration in winter and greatest in autumn. It must be kept in mind that the spring samples were collected after the spring flood otherwise the largest suspended solid concentrations would have been expected in spring. Finnish general water quality classification was used to assess the quality of urban stream waters. Its suitability for small urban streams is not, however, completely trouble-free. This classification does not take into account the quick changes in such small streams but evaluates only the yearly mean values. This can oversimplify the picture of the water quality situation in the streams. Also in order to better reflect the urban environment the analysed water quality properties should also include total dissolved substances and e.g. concentrations of chloride and sodium.

Investigating physical properties of solid dosage forms during pharmaceutical processing : Process analytical applications of vibrational spectroscopy

In order to improve and continuously develop the quality of pharmaceutical products, the process analytical technology (PAT) framework has been adopted by the US Food and Drug Administration. One of the aims of PAT is to identify critical process parameters and their effect on the quality of the final product. Real time analysis of the process data enables better control of the processes to obtain a high quality product. The main purpose of this work was to monitor crucial pharmaceutical unit operations (from blending to coating) and to examine the effect of processing on solid-state transformations and physical properties. The tools used were near-infrared (NIR) and Raman spectroscopy combined with multivariate data analysis, as well as X-ray powder diffraction (XRPD) and terahertz pulsed imaging (TPI). To detect process-induced transformations in active pharmaceutical ingredients (APIs), samples were taken after blending, granulation, extrusion, spheronisation, and drying. These samples were monitored by XRPD, Raman, and NIR spectroscopy showing hydrate formation in the case of theophylline and nitrofurantoin. For erythromycin dihydrate formation of the isomorphic dehydrate was critical. Thus, the main focus was on the drying process. NIR spectroscopy was applied in-line during a fluid-bed drying process. Multivariate data analysis (principal component analysis) enabled detection of the dehydrate formation at temperatures above 45°C. Furthermore, a small-scale rotating plate device was tested to provide an insight into film coating. The process was monitored using NIR spectroscopy. A calibration model, using partial least squares regression, was set up and applied to data obtained by in-line NIR measurements of a coating drum process. The predicted coating thickness agreed with the measured coating thickness. For investigating the quality of film coatings TPI was used to create a 3-D image of a coated tablet. With this technique it was possible to determine coating layer thickness, distribution, reproducibility, and uniformity. In addition, it was possible to localise defects of either the coating or the tablet. It can be concluded from this work that the applied techniques increased the understanding of physico-chemical properties of drugs and drug products during and after processing. They additionally provided useful information to improve and verify the quality of pharmaceutical dosage forms

Arkeologia, historialliset kartat ja paikkatieto

This licentiate thesis is composed of three parts, of which the parts 2 and 3 have been published elsewhere. Part 1 deals with the research history of large-scaled historical maps in Finland. The research done in four disciplines – archaeology, history, art history and geography – is summarized. Compared to the other disciplines, archaeology is characterized by its deep engagement with the location. Because archaeology studies different aspects of the past through material culture, it is the only discipline in which the concrete remains portrayed on the maps are “dug up”. For the archaeologist, historical maps are not merely historical documents with written information and drawings in scale, but actual maps which can be connected with the physical features they were made to illustrate in the first place. This aspect of historical maps is discussed in the work by looking at the early (17th and 18th century) urban cartographic material of two Finnish towns, Savonlinna and Vehkalahti-Hamina. In both cases, the GIS-based relocating of the historical maps highlights new aspects in the early development of the towns. Part 1 ends with a section in which the contents of the entire licentiate thesis are summarized. Part 2 is a peer reviewed article published in English. This article deals with the role of historical maps converted into GIS in archaeological surveys made in Finnish post-medieval towns (16th and 17th centuries). It is based on the surveys made by the author between 2000 and 2003 and introduces a new method for the archaeological surveying of post-medieval towns with wooden houses. The role of archaeology in the sphere of urban research is discussed. The article emphasizes that the methods used in studying the development of southern European towns with stone houses cannot be adequately applied to the wooden towns of the north. Part 3 is a monograph written in Finnish. It discusses large-scaled historical maps and the methods for producing digital spatial information based on historical maps. Since the late 1990’s, archaeological research in Finland has been increasingly directed towards the historical period. As a result, historical cartography has emerged as one of the central sources of information for the archaeologist, too. The main theme of this work is the need for using historical maps as real maps which, surprisingly, has been uncommon in the historical sciences. Projecting historical maps to the very place they were made to illustrate is essential to understanding the maps. This is self-evident for the archaeologist, who is accustomed to studying the material past, but less so to researchers in other historical disciplines that concentrate on written and visual sources of information. With the help of GIS, the historical maps can be concretely linked to the places they were originally made to illustrate. In doing so, and equipped with a cartographic comprehension, new observations can be made and questions asked, which supplement and occasionally challenge the prevailing views.

Social-class inequalities in ill health - the contribution of physical workload

Tutkimuksen aiheita olivat yhteiskuntaluokkien väliset erot sairastavuudessa ja alentuneessa toimintakyvyssä, sekä fyysisen työkuormituksen ja joidenkin muiden työolojen vaikutus sairastavuuteen. Empiirisestä työstä on raportoitu myös neljässä kansainvälisissä tieteellisissä aikakauskirjoissa julkaistussa artikkelissa. Tässä julkaistu yhteenveto sisältää tulosten yhteenvedon lisäksi myös tutkimusta koskevien käsitteellisten ja teoreettisten kysymysten sekä tutkimustradition kriittisen katsauksen. Työn päätavoitteita olivat 1) tutkia fyysisesti kuormittavan työn, ja jossain määrin muiden työolojen osuutta yhteiskuntaluokkien välisiin eroihin sairaudessa ja toimintakyvyn alentuneisuudessa; 2) tutkia työn fyysisen kuormittavuuden, työhön liittyvien vaikutusmahdollisuuksien ja hallinnan (decision latitude), luokka-aseman, iän ja sukupuolen yhteisvaikutuksia heikentyneeseen terveydentilaan; sekä 3) tutkia missä määrin mekaanisten työaltisteiden ja tuki- ja liikuntaelinsairastavuuden välinen yhteys voi selittää yhteiskuntaluokkien välisiä eroja heikentyneessä yleisessä terveydentilassa. Tutkittavat olivat keski-ikäisiä Helsingin kaupungin työntekijöitä. Analyysit perustuivat poikittaisasetelmaan, ja käytetty aineisto oli Helsinki Health Studyn vuosien 2000 ja 2002 välillä kerättyä aineistoa. Analyyseihin käytetyssä aineistossa oli 3740:stä 8002:een tutkittavaa. Tulosten perusteella fyysisillä (sekä fysikaalisilla) työoloilla on merkittävä vaikutus yhteiskuntaluokkien välisiin eroihin yleisessä sairastavuudessa, toimintakyvyn heikentymisessä, tuki- ja liikuntaelinsairastavuudessa sekä itsearvioidussa terveydentilassa. Naisilla lähes puolet heikentyneen toimintakyvyn ja koetun terveydentilan luokkaeroista vaikutti olevan selitettävissä fyysisellä työkuormituksella. Hallintamahdollisuuksien ei havaittu merkittävästi muuttavan fyysisen kuormituksen vaikutusta toimintakykyyn. Fyysisen kuormittavuuden terveysvaikutus voimistui kasvavan iän mukaan enemmän naisilla kuin miehillä. Osa, mutta ei koko fyysisen kuormituksen vaikutus yhteiskuntaluokkien eroihin heikentyneessä terveydessä vaikutti välittyvän tuki- ja liikuntaelinsairastavuuden kautta. Terveys ja sairaus eivät ole yhtenäisiä tiloja, ja siksi monet eri sosiaalisesti ja rakenteellisesti määräytyvät olosuhteet todennäköisesti vaikuttavat yhteiskunnallisten terveyserojen syntymiseen. Fyysis-materiaalisten olojen vaikutusta terveyserojen syntyyn nyky-yhteiskunnassa on mahdollisesti aliarvioitu. Yhteiskuntaluokkien väliset erot fyysis-materiaalisissa olosuhteissa eivät ole kadonneet, ja nämä erot todennäköisesti vaikuttavat terveyserojen syntyyn.

Trends and Explanations for Socioeconomic Differences in Physical Activity

Very limited scientific knowledge exists on the trends and explanations of socioeconomic differences in physical activity among adults. There is a paucity of studies examining whether determinants vary across socioeconomic position and different life stages. This study examines a) how socioeconomic differences in leisure-time and commuting physical activity have changed in Finland from 1978 to 2002 and b) the contribution of childhood socioeconomic position, adolescence sports and exercise, adulthood socioeconomic position, working conditions and other adulthood health behaviours to socioeconomic differences in leisure-time physical activity. This study utilised three population-based datasets collected by the National Institute for Health and Welfare (THL, formerly National Institute for Public Health): the Health Behaviour and Health among the Finnish Adult Population Study from 1978 to 2002 (N=96 105), the National FINRISK Study 2002 and its physical activity sub-study (N= 9 179), and the Health 2000 Study (N=8 028). Survey information was collected by self-administered questionnaires, interviews at home, and measurements made at the study site. The response rates varied from 69 to 89 per cent. Several socioeconomic measures were linked from the national population registers. Based on the results, those with low income were physically inactive during leisure-time and while commuting from 1978 to 2002. Manual worker women, however, were more physically active commuters compared to their counterparts. Parental socioeconomic position contributed directly to adulthood educational differences in leisure-time physical inactivity but also indirectly through adulthood socioeconomic position (occupation, household income) and other unhealthy behaviours (mainly smoking). Among those with low education participation in competitive sports in youth and among those with high education exercise in late adolescence contributed to leisure-time physical activity in adulthood. Long exposure to physically strenuous working conditions in men and current job strain in women contributed to occupational class differences in leisure-time physical activity. Socioeconomic differences in physical activity have remained similar for twenty years in Finland. Educational career seems to have a strong contribution to physical activity. To adopt a lifelong physically active life-style, one should participate in a range of different sports and exercise in adolescence and in youth, have a low exposure to physically and mentally strenuous working conditions in later life and have other healthy behaviours in later life.

Physical activity, fitness, abdominal obesity, and cardiovascular risk factors in Finnish men and women : The National FINRISK 2002 Study

Physical inactivity, low cardiorespiratory fitness, and abdominal obesity are direct and mediating risk factors for cardiovascular disease (CVD). The results of recent studies suggest that individuals with higher levels of physical activity or cardiorespiratory fitness have lower CVD and all-cause mortality than those with lower activity or fitness levels regardless of their level of obesity. The interrelationships of physical activity, fitness, and abdominal obesity with cardiovascular risk factors have not been studied in detail. The aim of this study was to investigate the associations of different types of leisure time physical activity and aerobic fitness with cardiovascular risk factors in a large population of Finnish adults. In addition, a novel aerobic fitness test was implemented and the distribution of aerobic fitness was explored in men and women across age groups. The interrelationships of physical activity, aerobic fitness and abdominal obesity were examined in relation to cardiovascular risk factors. This study was part of the National FINRISK Study 2002, which monitors cardiovascular risk factors in a Finnish adult population. The sample comprised 13 437 men and women aged 25 to 74 years and was drawn from the Population Register as a stratified random sample according to 10-year age groups, gender and area. A separate physical activity study included 9179 subjects, of whom 5 980 participated (65%) in the study. At the study site, weight, height, waist and hip circumferences, and blood pressure were measured, a blood sample was drawn, and an aerobic fitness test was performed. The fitness test estimated maximal oxygen uptake (VO2max) and was based on a non-exercise method by using a heart rate monitor at rest. Waist-to-hip ratio (WHR) was calculated by dividing waist circumference with hip circumference and was used as a measure of abdominal obesity. Participants filled in a questionnaire on health behavior, a history of diseases, and current health status, and a detailed 12-month leisure time physical activity recall. Based on the recall data, relative energy expenditure was calculated using metabolic equivalents, and physical activity was divided into conditioning, non-conditioning, and commuting physical activity. Participants aged 45 to 74 years were later invited to take part in a 2-hour oral glucose tolerance test with fasting insulin and glucose measurements. Based on the oral glucose tolerance test, undiagnosed impaired glucose tolerance and type 2 diabetes were defined. The estimated aerobic fitness was lower among women and decreased with age. A higher estimated aerobic fitness and a lower WHR were independently associated with lower systolic and diastolic blood pressure, lower total cholesterol and triglyceride levels, and with higher high-density lipoprotein (HDL) cholesterol and HDL to total cholesterol ratio. The associations of the estimated aerobic fitness with diastolic blood pressure, triglycerides, and HDL to total cholesterol ratio were stronger in men with a higher WHR. High levels of conditioning and non-conditioning physical activity were associated with lower high-sensitivity C-reactive protein (CRP) levels. High levels of conditioning and overall physical activities were associated with lower insulin and glucose levels. The associations were stronger among women than men. A better self-rated physical fitness was associated with a higher estimated aerobic fitness, lower CRP levels, and lower insulin and glucose levels in men and women. In each WHR third, the risk of impaired glucose tolerance and type 2 diabetes was higher among physically inactive individuals who did not undertake at least 30 minutes of moderate-intensity physical activity on five days per week. These cross-sectional data show that higher levels of estimated aerobic fitness and regular leisure time physical activity are associated with a favorable cardiovascular risk factor profile and that these associations are present at all levels of abdominal obesity. Most of the associations followed a dose-response manner, suggesting that already low levels of physical activity or fitness are beneficial to health and that larger improvements in risk factor levels may be gained from higher activity and fitness levels. The present findings support the recommendation to engage regularly in leisure time physical activity, to pursue a high level of aerobic fitness, and to prevent abdominal obesity.

Physical characterization of plastic surfaces in wearing and cleanability research

Plastic surfaces are a group of materials used for many purposes. The present study was focused on methods for investigation of surface topography, wearing and cleanability of polyvinyl chloride (PVC) model surfaces and industrial plastic surfaces. Contact profilometry, scanning electron microscopy (SEM) and atomic force microscopy (AFM) are powerful methods for studying the topography of plastic surfaces. Although they have their own limitations, they are together an effective tool providing useful information on surface topography, especially when studying laboratory-made PVC model surfaces with known chemical compositions and structures. All examined laboratory-made PVC plastic surfaces examined in this work could be considered as smooth according to both AFM and profilometer measurements because height differences are in the nanoscale on every surface. Industrial plastic surfaces are a complex group of materials because of their chemical and topographical heterogeneity, but they are nevertheless important reference materials when developing cleaning and wearing methods. According to the results of this study the Soiling and Wearing Drum and the Frick-Taber methods are very useful when simulating three-body wearing of plastic surfaces. Both the investigated wearing methods can be used to compare the wearing of different plastic materials using appropriate evaluation methods of wearing and industrial use. In this study, physical methods were developed and adapted from other fields of material research to cleanability studies. The thesis focuses on the methodology for investigating the cleanability of plastic surfaces under realistic conditions, where surface topography and the effect of wear cleanability were among the major topics. A colorimetric method proved to be suitable for examining the cleanability of the industrial plastic surfaces. The results were utilized to evaluate the relationship between cleanability and the surface properties of plastic surfaces. The devices and methods used in the work can be utilized both in material research and product development.

Spatial and temporal variability in midge (Nematocera) assemblages in shallow Finnish lakes (60−70 °N) : community-based modelling of past environmental change

Multi- and intralake datasets of fossil midge assemblages in surface sediments of small shallow lakes in Finland were studied to determine the most important environmental factors explaining trends in midge distribution and abundance. The aim was to develop palaeoenvironmental calibration models for the most important environmental variables for the purpose of reconstructing past environmental conditions. The developed models were applied to three high-resolution fossil midge stratigraphies from southern and eastern Finland to interpret environmental variability over the past 2000 years, with special focus on the Medieval Climate Anomaly (MCA), the Little Ice Age (LIA) and recent anthropogenic changes. The midge-based results were compared with physical properties of the sediment, historical evidence and environmental reconstructions based on diatoms (Bacillariophyta), cladocerans (Crustacea: Cladocera) and tree rings. The results showed that the most important environmental factor controlling midge distribution and abundance along a latitudinal gradient in Finland was the mean July air temperature (TJul). However, when the dataset was environmentally screened to include only pristine lakes, water depth at the sampling site became more important. Furthermore, when the dataset was geographically scaled to southern Finland, hypolimnetic oxygen conditions became the dominant environmental factor. The results from an intralake dataset from eastern Finland showed that the most important environmental factors controlling midge distribution within a lake basin were river contribution, water depth and submerged vegetation patterns. In addition, the results of the intralake dataset showed that the fossil midge assemblages represent fauna that lived in close proximity to the sampling sites, thus enabling the exploration of within-lake gradients in midge assemblages. Importantly, this within-lake heterogeneity in midge assemblages may have effects on midge-based temperature estimations, because samples taken from the deepest point of a lake basin may infer considerably colder temperatures than expected, as shown by the present test results. Therefore, it is suggested here that the samples in fossil midge studies involving shallow boreal lakes should be taken from the sublittoral, where the assemblages are most representative of the whole lake fauna. Transfer functions between midge assemblages and the environmental forcing factors that were significantly related with the assemblages, including mean air TJul, water depth, hypolimnetic oxygen, stream flow and distance to littoral vegetation, were developed using weighted averaging (WA) and weighted averaging-partial least squares (WA-PLS) techniques, which outperformed all the other tested numerical approaches. Application of the models in downcore studies showed mostly consistent trends. Based on the present results, which agreed with previous studies and historical evidence, the Medieval Climate Anomaly between ca. 800 and 1300 AD in eastern Finland was characterized by warm temperature conditions and dry summers, but probably humid winters. The Little Ice Age (LIA) prevailed in southern Finland from ca. 1550 to 1850 AD, with the coldest conditions occurring at ca. 1700 AD, whereas in eastern Finland the cold conditions prevailed over a longer time period, from ca. 1300 until 1900 AD. The recent climatic warming was clearly represented in all of the temperature reconstructions. In the terms of long-term climatology, the present results provide support for the concept that the North Atlantic Oscillation (NAO) index has a positive correlation with winter precipitation and annual temperature and a negative correlation with summer precipitation in eastern Finland. In general, the results indicate a relatively warm climate with dry summers but snowy winters during the MCA and a cool climate with rainy summers and dry winters during the LIA. The results of the present reconstructions and the forthcoming applications of the models can be used in assessments of long-term environmental dynamics to refine the understanding of past environmental reference conditions and natural variability required by environmental scientists, ecologists and policy makers to make decisions concerning the presently occurring global, regional and local changes. The developed midge-based models for temperature, hypolimnetic oxygen, water depth, littoral vegetation shift and stream flow, presented in this thesis, are open for scientific use on request.

Spatial variation of climate and the impact of disturbances on local climate and forest recovery in northern Finland

The structure and function of northern ecosystems are strongly influenced by climate change and variability and by human-induced disturbances. The projected global change is likely to have a pronounced effect on the distribution and productivity of different species, generating large changes in the equilibrium at the tree-line. In turn, movement of the tree-line and the redistribution of species produce feedback to both the local and the regional climate. This research was initiated with the objective of examining the influence of natural conditions on the small-scale spatial variation of climate in Finnish Lapland, and to study the interaction and feedback mechanisms in the climate-disturbances-vegetation system near the climatological border of boreal forest. The high (1 km) resolution spatial variation of climate parameters over northern Finland was determined by applying the Kriging interpolation method that takes into account the effect of external forcing variables, i.e., geographical coordinates, elevation, sea and lake coverage. Of all the natural factors shaping the climate, the geographical position, local topography and altitude proved to be the determining ones. Spatial analyses of temperature- and precipitation-derived parameters based on a 30-year dataset (1971-2000) provide a detailed description of the local climate. Maps of the mean, maximum and minimum temperatures, the frost-free period and the growing season indicate that the most favourable thermal conditions exist in the south-western part of Lapland, around large water bodies and in the Kemijoki basin, while the coldest regions are in highland and fell Lapland. The distribution of precipitation is predominantly longitudinally dependent but with the definite influence of local features. The impact of human-induced disturbances, i.e., forest fires, on local climate and its implication for forest recovery near the northern timberline was evaluated in the Tuntsa area of eastern Lapland, damaged by a widespread forest fire in 1960 and suffering repeatedly-failed vegetation recovery since that. Direct measurements of the local climate and simulated heat and water fluxes indicated the development of a more severe climate and physical conditions on the fire-disturbed site. Removal of the original, predominantly Norway spruce and downy birch vegetation and its substitution by tundra vegetation has generated increased wind velocity and reduced snow accumulation, associated with a large variation in soil temperature and moisture and deep soil frost. The changed structural parameters of the canopy have determined changes in energy fluxes by reducing the latter over the tundra vegetation. The altered surface and soil conditions, as well as the evolved severe local climate, have negatively affected seedling growth and survival, leading to more unfavourable conditions for the reproduction of boreal vegetation and thereby causing deviations in the regional position of the timberline. However it should be noted that other factors, such as an inadequate seed source or seedbed, the poor quality of the soil and the intensive logging of damaged trees could also exacerbate the poor tree regeneration. In spite of the failed forest recovery at Tunsta, the position and composition of the timberline and tree-line in Finnish Lapland may also benefit from present and future changes in climate. The already-observed and the projected increase in temperature, the prolonged growing season, as well as changes in the precipitation regime foster tree growth and new regeneration, resulting in an advance of the timberline and tree-line northward and upward. This shift in the distribution of vegetation might be decelerated or even halted by local topoclimatic conditions and by the expected increase in the frequency of disturbances.

Traditionally Protected Forests and Sacred Forests of Zigua and Gweno Ethnic Groups in Tanzania

In Tanzania, indigenous forests can still be found whose existence is based on the management systems of precolonial society. This study covers material from over 900 forests. There are similar types of forests elsewhere in Africa, and similar forests can also be found in indigenous cultures on every continent. In this study they are called traditionally protected forests (TPFs). They have a high level of endemism and a rich biodiversity. The field study was carried out during the years 1997-2003 using participatory methods. An active debate is going on concerning the capacity of local communities to manage their environment. The role of indigenous people and their institutions in the development of the physical environment is a central issue in the debate. This study discusses the opportunities that the local people have had to decide on how to conserve, maintain, utilise, and manage their environment during different political periods. The study explains what kinds of changes have taken place in these forests and institutions in northeastern Tanzania among the matrilinear Zigua and patrilinear Gweno ethnic groups. About 2% of the land area of the communities was still protected by the precolonial structures. The communities have established their protection systems for different reasons, not only because of their beliefs but also because of different secular and clearly environmentally motivated reasons. There are different TPF types. Less than half of them are directly related to spirituality, and more than half are not. In earlier research elsewhere, it has been commonly understood that spiritual reasons played the main role in the protection of these environments. This study is also part of the postcolonial geographical discussion on the precolonial landscape and environmental management which was started by Carl Sauer. In the Zigua case study villages, only two out of five first comer clans have performed rain rituals in the past 30 years. Many of the most respected sacred sites do not have a ritual maker or even a person who knows how to perform rituals any longer. The same is happening with male initiation rites. In all case study villages there have been illegal cuts in the TPFs, but variations can be seen between the communities. The number of those who neither respect indigenous regulations nor accept indigenous penalties is growing. Positive developments have also taken place. Nowadays, the Forest Act of 2002 is in effect, which works as a cornerstone of community-based land ownership and also allows elders to protect TPFs, and by-laws are created with the support of different projects. Moreover, during the field study it was found that many young people are ignorant about their village's TPF sites, but interested in learning about their history and values.

Postglacial climate changes and vegetation responses in northern Europe

Postglacial climate changes and vegetation responses were studied using a combination of biological and physical indicators preserved in lake sediments. Low-frequency trends, high-frequency events and rapid shifts in temperature and moisture balance were probed using pollen-based quantitative temperature reconstructions and oxygen-isotopes from authigenic carbonate and aquatic cellulose, respectively. Pollen and plant macrofossils were employed to shed light on the presence and response rates of plant populations in response to climate changes, particularly focusing on common boreal and temperate tree species. Additional geochemical and isotopic tracers facilitated the interpretation of pollen- and oxygen-isotope data. The results show that the common boreal trees were present in the Baltic region (~55°N) during the Lateglacial, which contrasts with the traditional view of species refuge locations in the south-European peninsulas during the glacial/interglacial cycles. The findings of this work are in agreement with recent paleoecological and genetic evidence suggesting that scattered populations of tree species persisted at higher latitudes, and that these taxa were likely limited to boreal trees. Moreover, the results demonstrate that stepwise changes in plant communities took place in concert with major climate fluctuations of the glacial/interglacial transition. Postglacial climate trends in northern Europe were characterized by rise, maxima and fall in temperatures and related changes in moisture balance. Following the deglaciation of the Northern Hemisphere and the early Holocene reorganization of the ice-ocean-atmosphere system, the long-term temperature trends followed gradually decreasing summer insolation. The early Holocene (~11,700-8000 cal yr BP) was overall cool, moist and oceanic, although the earliest Holocene effective humidity may have been low particularly in the eastern part of northern Europe. The gradual warming trend was interrupted by a cold event ~8200 cal yr BP. The maximum temperatures, ~1.5-3.0°C above modern values, were attained ~8000-4000 cal yr BP. This mid-Holocene peak warmth was coupled with low lake levels, low effective humidity and summertime drought. The late Holocene (~4000 cal yr BP-present) was characterized by gradually decreasing temperatures, higher lake levels and higher effective humidity. Moreover, the gradual trends of the late Holocene were probably superimposed by higher-frequency variability. The spatial variability of the Holocene temperature and moisture balance patterns were tentatively attributed to the differing heat capacities of continents and oceans, changes in atmospheric circulation modes and position of sites and subregions with respect to large water bodies and topographic barriers. The combination of physical and biological proxy archives is a pivotal aspect of this work, because non-climatic factors, such as postglacial migration, disturbances and competitive interactions, can influence reshuffling of vegetation and hence, pollen-based climate reconstructions. The oxygen-isotope records and other physical proxies presented in this work manifest that postglacial climate changes were the main driver of the establishment and expansion of temperate and boreal tree populations, and hence, large-scale and long-term vegetation patterns were in dynamic equilibrium with climate. A notable exception to this pattern may be the postglacial invasion of Norway spruce and the related suppression of mid-Holocene temperate forest. This salient step in north-European vegetation history, the development of the modern boreal ecosystem, cannot be unambiguously explained by current evidence of postglacial climate changes. The results of this work highlight that plant populations, including long-lived trees, may be able to respond strikingly rapidly to changes in climate. Moreover, interannual and seasonal variation and extreme events can exert an important influence on vegetation reshuffling. Importantly, the studies imply that the presence of diffuse refuge populations or local stands among the prevailing vegetation may have provided the means for extraordinarily rapid vegetation responses. Hence, if scattered populations are not provided and tree populations are to migrate long distances, their capacity to keep up with predicted rates of future climate change may be lower than previously thought.