Northern Parts Of Finland Research Articles

Climate Change Effect on Freeze-thaw Load in Finland

Freeze-thaw damage is one of the major degradation mechanisms of climate exposed porous rock-based building materials in existing Finnish building stock. In recent studies, it has been shown that not only the amount of freeze-thaw cycles but especially the amount of wind-driven rain (WDR) before freeze-thaw cycles has a major effect on the rate of freeze-thaw damage in concrete structures. In this study, freeze-thaw cycles after a rain event, the average annual amount of WDR before freeze-thaw cycles and the average amount of WDR before each cycle is calculated in different locations in Finland. The calculations are made for present and projected 2050 and 2080 climates with three greenhouse gas scenarios: RCP2.6, RCP4,5 and RCP8.5. Based on the results, the freeze-thaw load is decreasing in coastal and southern areas and staying at current level or increasing in northern parts of Finland. In addition, the level of freeze-thaw load is getting less direction or geographically dependent. The results strongly indicate that the exposure level might be decreasing in coastal area and southern parts of Finland because both the freeze-thaw cycles and the annual amount of WDR before cycles are decreasing. However, an average amount of WDR before a freeze-thaw cycle is actually increasing and so, the intensity of freeze-thaw attack is not decreasing. Thus, for the future climates freeze-thaw durability of porous rock-based structures should be still emphasised.

Bioclimate change across the protected area network of Finland

Protected areas (PAs) are crucial in conserving biodiversity under climate change. In boreal regions, trends of biologically relevant climate variables (i.e., bioclimate) in PAs have remained unquantified. We investigated the changes and variability of 11 key bioclimatic variables across Finland during the period 1961–2020 based on gridded climatology. Our results suggest significant changes in annual mean and growing season temperatures over the entire study area, whereas, e.g., annual precipitation sum and April–September water balance have increased especially in the central and northern parts of Finland. We found substantial variation in bioclimatic changes over the 631 studied PAs; in the northern boreal zone (NB) the number of snow-covered days has decreased on average by 5.9 days between 1961–1990 and 1991–2020, while in the southern boreal zone (SB) the corresponding decrease has been 16.1 days. The number of frost days in spring with absent snow cover has decreased in the NB (on average −0.9 days) while increasing in the SB (0.5 days), reflecting the changing exposure of biota to frost. The observed increases in accumulation of heat in the SB and more frequent rain-on-snow events in the NB can affect drought tolerance and winter survival of species, respectively. Principal component analysis suggested that the main dimensions of bioclimate change in PAs vary across vegetation zones; for example, in the SB the changes are related to annual and growing season temperatures, whereas in the middle boreal zone the changes are linked to altered moisture and snow conditions. Our results highlight the substantial spatial variation in bioclimatic trends and climate vulnerability across the PAs and vegetation zones. These findings provide a basis for the understanding of the multifaceted changes the boreal PA network is facing and help to develop and direct conservation and management.

Manipulating overstory density and mineral soil exposure for optimal natural regeneration of Scots pine

In northern boreal region the growth of forests is slow, and yield and profit are low, which is why low reforestation costs are important for profitable forestry. If natural regeneration is successful, expensive artificial forest regeneration (planting or direct seeding) can be avoided. In this study, we look at the impact of overstory density and site preparation on natural regeneration and seedling growth of Scots pine. Study stands were established in different parts of Northern Finland and in each stand following treatments: 50, 150 and 250 trees ha−1 or unthinned control, where the stand density was ≥ 250 trees ha−1, were randomly allocated to experimental plots. In addition, site preparation (disc trenching, 4000–5000 m ha−1) was carried out on two experimental plots in which tree density was either 50 or 150 trees ha−1. In the experimental stands seedling number, age and growth were monitored for 11 years. Monitoring revealed that the number of seedlings increased with decreasing tree density. Average seedling height growth was very low or even non-existent in the unthinned control and in the densest (250 trees ha−1) treatment, but increased when the density of trees decreased. The highest seedling number and the highest growth were achieved when the tree density was 50 trees ha−1 and the soil was prepared to expose mineral soil. Achieving e.g. 2000 seedlings ha−1, would need about 40% exposition of mineral soil. The required low tree density implies that not only seed supply from seed trees and site preparation is important for regeneration success in northern boreal Scots pine forests but also the reduction of competition by mature trees.

Understanding inclusive entrepreneurship

A recent OECD report recognises that the limited scope for immigrant women to integrate into mainstream Finnish society has kept them out of the labour market. In fact, a woman with migrant background faces several challenges to get access to the Finnish labour force and this has prompted them to become self-employed in small business, particularly in the northern part of Finland. However, establishing a small business and its operation induces diverse problems in this remote, mainly rural region. An inclusive entrepreneurship policy may support improving their condition in entrepreneurship. The study explores the main factors hindering the financial and socio-cultural inclusion of women immigrants in Northern Finland. A thematic analysis of cultural and economic inclusivity, based on descriptive phenomenology, helps understand and reconstruct a policy of inclusive societies in the context of rural entrepreneurship.

Shaping employability for immigrants through social entrepreneurship in Lapland

ABSTRACT Many immigrants are either underemployed or unemployed in Lapland, and indeed many of them are long-term unemployed. This unemployment rate among immigrants varies from region to region in Finland. As a disadvantaged group in the labour market, sometimes they are pushed into establishing a business; however, their motivation to do so is weak, due to a lack of market understanding along with other socio-cultural factors. As an alternative way of doing business and gaining access to the labour market, social enterprise could be another instrument for employment. We studied whether Social Entrepreneurship (SE) represents an exceptional mindset among the group. SE invention for this group of people is a less-studied area of research in Finland compared to many other European countries such as Sweden and Scotland. Our research examines whether SE could be a way to facilitate the integration of immigrants, particularly immigrant women, who are at risk of marginalisation, into the Finnish labour market in the near future, with Lapland as a case study. We analyse the factors that can be taken into account to enable immigrants to conduct their business under the guidance of a social enterprise in the northern part of Finland, thereby shaping their employability for the future.

Kwenowie – (nie)zapomniana mniejszość

The Kven People have lived in the North Cape area since ancient times. The first account of the Cwenas is to be found in Ohthere’s of Hålogaland account, which dates back to 890 C.E., and describes the existence of peoples living in Cwena land in the north of Sweden. Kven people are said to be descendants of Finnish peasants and fishermen who emigrated from the northern parts of Finland and Sweden to Northern Norway. The tax books from the sixteenth century indicate clearly that the Kven people lived permanently in the area of the Gulf of Bothnia. The Kvens were well integrated, and perceived as a valuable workforce. Still, tempestuous Russian history combined with Finnish dependency on the Russian Empire backfired on the perception of the Kvens in Norway, as they were seen as a menace to national security. As a result, they were made to go through a very strict assimilation process from the nineteenth century onwards. After WWII, their situation became somewhat better, but it still left much to be desired, since they were thought to collaborate with the USSR. The wind of change started to blow in 1996, when the Kvens were granted minority status in Norway, and in 2005 the Kven language was recognized as a minority language in Norway.

The road weather model RoadSurf (v6.60b) driven by the regional climate model HCLIM38: evaluation over Finland

Abstract. In this paper, we evaluate the skill of the road weather model RoadSurf to reproduce present-day road weather conditions in Finland. RoadSurf was driven by meteorological input data from cycle 38 of the high-resolution regional climate model (RCM) HARMONIE-Climate (HCLIM38) with ALARO physics (HCLIM38-ALARO) and ERA-Interim forcing in the lateral boundaries. Simulated road surface temperatures and road surface conditions were compared to observations between 2002 and 2014 at 25 road weather stations located in different parts of Finland. The main characteristics of road weather conditions were accurately captured by RoadSurf in the study area. For example, the model simulated road surface temperatures with a mean monthly bias of −0.3 ∘C and mean absolute error of 0.9 ∘C. The RoadSurf's output bias most probably stemmed from the absence of road maintenance operations in the model, such as snow plowing and salting, and the biases in the input meteorological data. The biases in the input data were most evident in northern parts of Finland, where the regional climate model HCLIM38-ALARO overestimated precipitation and had a warm bias in near-surface air temperatures during the winter season. Moreover, the variability in the biases of air temperature was found to explain on average 57 % of the variability in the biases of road surface temperature. On the other hand, the absence of road maintenance operations in the model might have affected RoadSurf's ability to simulate road surface conditions: the model tended to overestimate icy and snowy road surfaces and underestimate the occurrence of water on the road. However, the overall good performance of RoadSurf implies that this approach can be used to study the impacts of climate change on road weather conditions in Finland by forcing RoadSurf with future climate projections from RCMs, such as HCLIM.

Monitoring changes in forestry and seasonal snow using surface albedo during 1982–2016 as an indicator

Abstract. The surface albedo time series, CLARA-A2 SAL, was used to study trends in the snowmelt start and end dates, the melting season length and the albedo value preceding the melt onset in Finland during 1982–2016. In addition, the melt onset from the JSBACH land surface model was compared with the timing of green-up estimated from Moderate Resolution Imaging Spectroradiometer (MODIS) data. Moreover, the melt onset was compared with the timing of the greening up based on MODIS data. Similarly, the end of snowmelt timing predicted by JSBACH was compared with the melt-off dates based on the Finnish Meteorological Institute (FMI) operational in situ measurements and the Fractional Snow Cover (FSC) time-series product provided by the EU FP7 CryoLand project. It was found that the snowmelt date estimated using the 20 % threshold of the albedo range during the melting period corresponded well to the melt estimate of the permanent snow layer. The longest period, during which the ground is continuously half or more covered by snow, defines the permanent snow layer (Solantie et al., 1996). The greening up followed within 5–13 days the date when the albedo reached the 1 % threshold of the albedo dynamic range during the melting period. The time difference between greening up and complete snowmelt was smaller in mountainous areas than in coastal areas. In two northern vegetation map areas (Northern Karelia–Kainuu and Southwestern Lapland), a clear trend towards earlier snowmelt onset (5–6 days per decade) and increasing melting season length (6–7 days per decade) was observed. In the forested part of northern Finland, a clear decreasing trend in albedo (2 %–3 % per decade in absolute albedo percentage) before the start of the melt onset was observed. The decreasing albedo trend was found to be due to the increased stem volume.

The Evolution of Sleep Apnea Six Months After Acute Ischemic Stroke and Thrombolysis.

Our goal was to investigate the evolution of prevalence, severity, and type of sleep apnea among patients who had an ischemic stroke, with or without treatment with thrombolysis after 6 months. We prospectively studied 204 patients who had an ischemic stroke (110 in the thrombolysis and 94 in the non-thrombolysis group). After follow-up, 177 patients were eligible for a final analysis (98 in the thrombolysis group and 79 in the non-thrombolysis group). An unattended sleep study with a three-channel portable device was performed both on admission and after the 6-month follow-up. The patients receiving thrombolysis were younger than those in the non-thrombolysis group (mean 65.5 versus 69.6 years P = .039). Sleep apnea, defined as a respiratory event index (REI) ≥ 5 events/h, was diagnosed in 92.7% patients, 93.9% versus 91.1% (P = .488) in the thrombolysis and non-thrombolysis groups, respectively. The prevalence remained unchanged during follow-up. Mild sleep apnea progressed to moderate or severe sleep apnea in 69.2% of the patients. Globally, mean central apneas per hour increased by 2.2% (P = .002), whereas obstructive apneas declined by 1.7% (P = .014). The mean change of oxygen desaturation index was -6.1% (P < .001) in the thrombolysis group, -1.8% (P = .327) in the non-thrombolysis group, and 4.2% (P = .001) in the whole group. In the non-thrombolysis group, the risk for new sleep apnea incidence increased by 6.1-fold (P = .024) at follow-up when compared to the thrombolysis group. Sleep apnea prevalence remained high in patients who had an ischemic stroke at 6 months post-stroke. The risk for developing sleep apnea after stroke was significantly lower among patients undergoing thrombolysis. Registry: ClinicalTrials.gov; Title: Ischaemic Stroke and Sleep Apnea in Northern Part of Finland; Identifier: NCT01861275; URL: https://clinicaltrials.gov/ct2/show/NCT01861275.

Spatiotemporal Variability and Trends in Extreme Temperature Events in Finland over the Recent Decades: Influence of Northern Hemisphere Teleconnection Patterns

Fifteen temperature indices recommended by the ETCCDI (Expert Team on Climate Change Detection and Indices) were applied to evaluate spatiotemporal variability and trends in annual intensity, frequency, and duration of extreme temperature statistics in Finland during 1961–2011. Statistically significant relationships between these high-resolution (10 km) temperature indices and seven influential Northern Hemisphere teleconnection patterns (NHTPs) for the interannual climate variability were also identified. During the study period (1961–2011), warming trends in extreme temperatures were generally manifested by statistically significant increases in cold temperature extremes rather than in the warm temperature extremes. As expected, warm days and nights became more frequent, while fewer cold days and nights occurred. The frequency of frost and icing days also decreased. Finland experienced more (less) frequent warm (cold) temperature extremes over the past few decades. Interestingly, significant lengthening in cold spells was observed over the upper part of northern Finland, while no clear changes are found in warm spells. Interannual variations in the temperature indices were significantly associated with a number of NHTPs. In general, warm temperature extremes show significant correlations with the East Atlantic and the Scandinavia patterns and cold temperature extremes with the Arctic Oscillation and the North Atlantic Oscillation patterns.

Distribution and habitat preference of Bombus (Kallobombus) soroeensis (Fabricius, 1777) on the territory of Arkhangelsk Region

In this paper, we summarise material pertaining to the distribution and habitat preference of Bombus (Kallobombus) soroeensis (Fabricius, 1777) on the territory of Arkhangelsk Region. B.soroeensis is widely represented on the territory as nominative subspecies B.soroeensisssp.soroeensis, which is common mainly in Fennoscandia, the British Isles and Eastern Europe. The northern border of the species range in the Arkhangelsk Region is the lower reaches of the Mezen River, located in the transition zone between the northern taiga and the forest-tundra. This locality is probably one of the most northern records of this species in the northern part of the Russian Plain. In Eastern Fennoscandia, B.soroeensis is distributed far to the north, i.e., in the northern parts of Finland and Norway. In relation to the habitat preference, B.soroeensis in the study region belongs to the category of meadow species. This species is typical of different types of meadows and ruderal habitats. B.soroeensis is not typical with regards to the native taiga habitats, in most cases. This is similar to the situation on the territory of Finland, where this species is associated with open meadow habitats. Individuals of B.soroeensis have been recorded on a wide range of entomophilous plants, and the main examples are Rhinanthusminor, Epilobiumangustifolium, Cirsiumarvense, Scorzoneroidesautumnalis, Lotuscorniculatus.

Calibration of nationwide airborne laser scanning based stem volume models

In-situ field measurements of sample plots are a major cost component in airborne laser scanning (ALS) based forest inventories. Field measurements on new inventory areas can be reduced by utilizing existing stand attribute models from former inventory areas. We constructed a nationwide model for stem volume, and examined seven different calibration scenarios using 22 inventory areas distributed evenly throughout Finland. These scenarios can be divided into three main categories: 1) calibration with additional predictor variables, 2) calibration with 200 geographically nearest sample plots, and 3) calibration with MS-NFI (Multi-source National Forest Inventory of Finland) volume at the target inventory area. Calibration with degree days, precipitation, and proportion of birch resulted in the greatest decrease in error rate of stem volume predictions. The mean of the root mean square errors (RMSE) among the 22 inventory areas decreased from 28.6% to 25.9%, and the standard deviation of RMSEs from 4.3% to 3.9% using three additional predictor variables. Correspondingly, the mean and standard deviation of absolute values of mean differences (|MD|) decreased from 8.3% to 5.6% and from 5.6% to 4.4%, respectively. All calibration scenarios decreased the error rate, especially the high |MDs| observed in the northern part of Finland. Calibration with sample plots from geographically nearest inventory areas was useful when there were sample plots that offered a good representation of the target area. MS-NFI based calibration was also a reasonable option if loggings and other inconsistencies between datasets could be detected and accounted for.

State sport policy for indigenous sport: inclusive ambitions and exclusive coalitions

ABSTRACTWith the policy aim ‘Sport for all’ as a backdrop, this paper investigates sport policies for Sami sport in Sweden and Norway (the Sami is the indigenous people residing in the northern parts of Finland, Norway, Russia and Sweden). By applying an Advocacy Coalition Framework, the purpose of the paper is to explore how the organisation of and possibilities to exercise Sami sport are affected by political coalitions, social structures and institutions. Drawing on data from policy documents and interviews with government and Sami Parliament representatives, results show how institutionalised relationships affect the general ambitions to provide sport for all and the more specific ambitions to reach under-represented groups. In both countries, dominant coalitions are made up by the institutionalised cooperation between the states’ Ministry of Culture and the umbrella sport organisations. Alternative and emerging coalitions are made up by the Sami sport organisations, the Sami Parliaments and the Sami policy units of the states. While the dominant coalition is stronger in Sweden, the alternative coalition is stronger in Norway. These differences are interpreted as being results of policy elements outside the policy subsystem of sport – the two countries’ different relationships to legal adoptions of indigenous rights. These findings suggest that approaching sport organisations outside dominant coalitions can be conducive in reaching sport for all ambitions.

Heavy snow loads in Finnish forests respond regionally asymmetrically to projected climate change

Abstract. This study examined the impacts of projected climate change on heavy snow loads on Finnish forests, where snow-induced forest damage occurs frequently. For snow-load calculations, we used daily data from five global climate models under representative concentration pathway (RCP) scenarios RCP4.5 and RCP8.5, statistically downscaled onto a high-resolution grid using a quantile-mapping method. Our results suggest that projected climate warming results in regionally asymmetric response on heavy snow loads in Finnish forests. In eastern and northern Finland, the annual maximum snow loads on tree crowns were projected to increase during the present century, as opposed to southern and western parts of the country. The change was rather similar both for heavy rime loads and wet snow loads, as well as for frozen snow loads. Only the heaviest dry snow loads were projected to decrease over almost the whole of Finland. Our results are aligned with previous snowfall projections, typically indicating increasing heavy snowfalls over the areas with mean temperature below −8 °C. In spite of some uncertainties related to our results, we conclude that the risk for snow-induced forest damage is likely to increase in the future in the eastern and northern parts of Finland, i.e. in the areas experiencing the coldest winters in the country. The increase is partly due to the increase in wet snow hazards but also due to more favourable conditions for rime accumulation in a future climate that is more humid but still cold enough.

Late Iron Age transculturalism in the northern “periphery”: understanding the long-term prehistoric occupational area of Viinivaara E, Finland

ABSTRACTThe Late Iron Age of northern Finland is often approached through an ethnic perspective. Archaeological sites are defined as local or foreign and, accordingly, linked to either Sámi or non-Sámi groups. In recent decades, the concept of transculturalism and mixing of cultural traits has been discussed by several researchers, and their work has shown that such categorizations can be questioned. Correspondingly, certain sites and artifacts found in the northern parts of Finland seem to relate to interactions and contacts instead of ethnic backgrounds. One such site was excavated at Viinivaara E in 2013 and 2014. Based on the fieldwork, the site can be linked to encounters and cultural exchange between local groups and visitors. The entangled nature of the site is understood by taking into consideration its location and landscape, but also by examining the archaeological and historical conception of Late Iron Age northern Finland in general. Further, transcultural dynamics present at the site are also tied to social development on a broader temporal and spatial scale.

Evidence of post‐glacial secondary contact and subsequent anthropogenic influence on the genetic composition of Fennoscandian moose (Alces alces)

AbstractAimTo determine whether a contemporary population of the moose (Alces alces), a large northern ungulate, retains genetic signatures of post‐glacial recolonization and/or the effects of anthropogenic factors. We focused on investigating spatial genetic structure and the distribution of genetic diversity of this species to clarify its still obscure history.LocationEastern Fennoscandia, Northern Europe.MethodsIn total, 574 Finnish and Russian Karelian moose were genotyped at 16 microsatellite loci, and the mitochondrial control region was sequenced from 224 individuals. Spatially explicit Bayesian clustering, multivariate and spatial autocorrelation methods were applied alongside traditional F‐statistics to study the effects of landscape on genetic structure. The demographic history of our study populations was explored with coalescent analysis and Bayesian skyline plots.ResultsA major mitochondrial divergence of moose was discovered between northern parts of Finland and the rest of the studied area. Landscape genetic analyses on the microsatellite data identified three genetic clusters connected by clines, with coalescent analysis indicating the division to be of ancient origin. Additionally, recent population bottlenecks were detected using Bayesian skyline plots.Main conclusionsOur results indicate a post‐glacial secondary contact between two distinct moose mitochondrial lineages that diverged during the Pleistocene, whereas admixture of three diverged genetic subpopulations was detected using microsatellites. The emergence of these subpopulations was estimated to have occurred after the post‐glacial recolonization of Fennoscandia. The observed genetic bottlenecks coincide with recorded historical population declines in the 18th century. We conclude that the contemporary genetic composition of the moose population in eastern Fennoscandia has been affected by both ancient and recent factors.

EARLY COPPER USE IN NEOLITHIC NORTH-EASTERN EUROPE: AN OVERVIEW

Introduction Copper was known and used in different parts of Eurasia several millennia before the beginning of the Bronze Age. The earliest evidence derives from the Near East and Anatolia, where copper was first used between the 11th and 7th millennia BC, whereas copper use in Europe, specifically in the Balkans and the South-East, began by the mid-6th millennium BC (Roberts et al. 2009, 1013). Copper use spread from south-eastern Europe to the steppes of southern Russia (Chernykh 1992, 41 f.) and was introduced farther to the forested regions of East European (or Russian) Plain along the rivers Volga and Kama in the 4th millennium BC (Krajnov 1987, 14 f.; Nagovitsyn 1987, 32). The use of copper was introduced in central, western and northern Europe through different processes at different times (Roberts et al. 2009, 1015 f.); copper smelting was known in the eastern Alps in the 5th millennium BC (Hoppner et al. 2005), at a time when large-scale metal production in the Balkans had begun (Bailey 2000, 209), whereas signs of metal use are few in north-western Europe before 2500 BC (Roberts 2009, 467). In north-eastern Europe the use of native copper began soon after 4000 BC in what is today the Republic of Karelia (Russian Federation), when copper artefacts appear in find assemblages. While a number of early copper finds are also known from central and northern parts of Finland, they are very rare on the Scandinavian Peninsula and in the Baltic countries. The early appearance of copper in eastern Fennoscandia is common knowledge among Russian and Finnish archaeologists, but the general picture of this early copper use is patchy and its wider context elusive, which has to do with the limited research material, different academic traditions as well as linguistic and national boundaries. As the relevant publications are mainly in Russian and Finnish, the early copper finds from northeastern Europe have often been omitted from the surveys and studies on the beginning of metal use in Europe. Even the early metal finds have been subject to some research and scientific analyses in Russia and Finland, very little has been said about why copper was adopted and how early copper use relates to broader cultural developments. This paper provides an overview and discussion of the early copper finds and metal use in north-eastern Europe. More specifically, the geographical research area stretches from the shores of Lake Onega in the east to the Baltic Sea in the west and from the Baltic countries in the south to the Arctic Ocean in the north (Fig. 1). Early metal use in this region is put in a broader context, with a special reference to the northern European Russia. The period of interest here is 4000-2000 BC (all dates are given in calibrated radiocarbon years, i.e. calBC). A large part of this time frame is commonly referred to as the Eneolithic in Russia but is called the (Sub-)Neolithic in Finland (Fig. 2). In this paper the term Neolithic is preferred, although we acknowledge that it contradicts especially the Russian periodisation. Without going deeper into the reasoning behind the definitions it suffices to say that recent research (e.g. Vaneeckhout 2009; Mokkonen 2011; Herva et al. n.d.) has increasingly indicated that the cultures in the research area between 4000-2000 BC can be described as Neolithic in a more real sense that has been traditionally thought. It is against this 'Neolithic proper' background the early copper use in the north must be considered. [FIGURE 1 OMITTED] [FIGURE 2 OMITTED] Cultural context and dating of early copper use in Karelia and Finland Before turning to a closer examination of the copper finds, it is necessary to provide a general outline of the cultural phases and development in the research area in 4000-2000 BC. Ceramic chronology is of special interest here, although the absolute dating of pottery types is far from complete. Nevertheless, the relative chronology based on pottery provides the only available framework for dating copper finds from particular sites--a detailed discussion on this topic will be provided in another article (Nordqvist et al. …

Organization of the Reindeer Husbandry in Finland

Reindeer husbandry is practised in the northern parts of Finland in a region that comprises almost all of the Province of Lapland and parts of the Province of Oulu and covers a good third of the Finnish surface. It is governed by the herding co-operative system. Each reindeer owner is a member of a herding co-operative, and the member's respective rights and responsibilities are determined on the basis of the number of reindeer owned by him. The 56 reindeer herding co-operatives have defined borders as well as different surfaces and reindeer volumes. All herding co-operatives are members of the Association of Herding Co-operatives

Prevalence of single crowns and fixed partial dentures in elderly citizens in the southern and northern parts of Finland

The epidemiology of oral rehabilitation using fixed prosthodontics has received little attention. The aim of this study was to evaluate the prevalence of single crowns, fixed partial dentures (FPDs), resin-bonded FPDs and implants in elderly Finnish patients and to identify factors that might be associated with the findings. The survey was carried out in the southern and northern parts of Finland. The target population consisted of all persons born in 1919, 1922, 1925, 1928, 1931, 1934 and 1937, who lived in Kirkkonummi and in Lakeus (n=1733) in 1996. The age range of the subjects was 60-78years. In addition to a clinical examination, panoramic radiograph was taken. Data on background factors were obtained using questionnaires and/or interviews. The presence of single crowns, FPDs, resin-bonded FPDs and implants were determined from the panoramic radiographs. Overall, 12·4% of men and 12·1% of women had single crowns, while 4·8% of men and 8·0% of women had FPDs. A logistic regression analysis showed that the presence of crowns and FPDs was significantly associated with a southern place of residence, high and middle levels of education and high frequency of dental visits.

Radial and peripheral clines in northern polymorphic populations of Philaenus spumarius.

Geographic variability in the colour polymorphism of Philaenus spumarius (Homoptera) was investigated in the northern parts of Finland, Norway and Sweden. The investigation was directed mainly at peripheral populations south of the Baltic—Arctic divide. The colour phenotypes were found to differ in their “north tolerance”. The phenotypes typ (pt/pt) and lat (pt/pt) were the most, and the phenotype tri (pt/pT) the least tolerant to marginal conditions. Differences in “north tolerance” between the phenotypes cause radial clines to be present in allele frequencies. The radial clines may be caused by the combined effect of several different factors. These include shortness of the thermal growth period, random genetic drift, decreasing diversity of the food plant flora, and decreasing diversity of predators. These different explanations are discussed in the light of the ecology of Philaenus. Very clear clines perpendicular to the radial clines were observed in the frequencies of the phenotypes Ice (pt/pT) and lop (pt/pO). Both were found to increase in frequency in the west—east direction. These peripheral clines may be caused by increasing humidity from west to east. The frequency of typ (pt/pt) also seems to be a sensitive index of humidity conditions, or other factors parallelling humidity in distribution.