Northernmost Finland Research Articles

Water Chemistry and Bacterioplankton in Two Subalpine Rivers in Finnish Lapland

Water chemistry and bacterioplankton were analysed for two subalpine rivers, River Kidisjoki and River Utsjoki, in northernmost Finland. The data set is based on continuous runoff measurements and weekly chemical and biological samples. The data were collected during the open water period, from May to October, in year 2000. The runoff patterns during the summer were similar in the two rivers at though the size of the catchments is very different (the catchment of River Utsjoki 1,520 km2 and of River Kidisjoki 22 km2). For both rivers, variations in runoff were followed by variations in the water quality and bacterial densities. The measured chemical concentrations were usually the highest in the headwaters of river Kidisjoki, while in the lower Kidisjoki they were clearly lower than in Utsjoki. Bacterial densities were on average highest in Utsjoki and the strongest relationships between water chemistry and bacteria were found in Kidisjoki. Both the chemical concentrations and bacterial densities were low in the two rivers when compared to other studied rivers in northern Finland.

<i>Kikimora palustris</i> Eskov, 1988 (Araneae: Linyphiidae) found in Europe

Kikimora palustris Eskov, an erigonine spider known hitherto from Siberia only, was found in northernmost Finland. Males and females were trapped in a palsa mire in Enontekiö, 1999. Redescription with diagnostic figures is given, and taxonomy, distribution and ecology briefly discussed. Slit sense organs were found on basal part of male cymbium

Relief control of summer wind direction and velocity: A case study from Finnish Lapland

The nature of local wind observations is demonstrated with hourly round-the-clock wind recordings June-September 1975, in a hilly environment in northernmost Finland. The observations are compared with the official wind recordings 10 km away in a main valley with different orientation. The main valley (Utsjoki) is oriented S-N and the synoptic meteorological station is located at 107 m a.s.l. The local observation site is in a valley c . 300 m a.s.l. and oriented NE-SW. Wind velocities and directions were plotted and evaluated on frequency isopleth diagrams to compare the characteristics of these two sites. The wind patterns differed considerably. The valleys strongly guided the winds. Only the pattern of the strong NW winds (>7 m/s) came out similarly at both sites. The importance of local wind recording for aeolian geomorphological studies in hilly and mountainous regions is emphasized.

Evacuation Rates of Coded Wire Tags Implanted in Prey of Northern Pike

Abstract In 2001–2003, all of the 400,000 juvenile brown trout Salmo trutta to be stocked into the watercourse of Lake Inari, in northernmost Finland, will be coded-wire-tagged to indicate rearing hatchery, genetic strain, site of stocking, and age of fish. One of our future objectives will be studying the relative predation by northern pike Esox lucius on stocked brown trout with respect to the different groups, as identified by coded wire tags. However, successful sampling of northern pike and the subsequent diet analysis will require answers for the following questions: Do coded wire tags injected into the snouts of juvenile brown trout accumulate in the intestine of a northern pike? If not, what is the evacuation time of the tags? Does evacuation time depend on the size of northern pike and brown trout? In experimental feeding trials, we found that coded wire tags implanted into snouts of juvenile brown trout (weight range, 28–260 g) did not accumulate in the intestine of northern pike (weight range, ...

Status of Zoobenthos and Fish Populations in Subarctic Rivers of the Northernmost Finland: Possible Effects of Acid Emissions from Russian Kola Peninsula

In 1990, a monitoring programme was initiated to survey the status of benthic invertebrate communities and fish populations over a wide range of subarctic rivers in northernmost Finnish Lapland (68°15′–70°N). A special emphasis was placed on detecting possible effects of acidification through sulfur emissions from Russian Kola Peninsula. Sampling in 13 rivers within four major river systems covered watercourses from small brooks to large 7th order rivers, and watersheds with different distances from the emission sources. The community structure of zoobenthos and the occurrence of acid-sensitive indicator species were assessed in 90 sampling sites. Sensitive fluvial fish species, including Atlantic salmon (Salmo salar), brown trout (Salmo trutta), European minnow (Phoxinus phoxinus) and burbot (Lota lota), were monitored by studying their occurrence, abundance and juvenile recruitment. No signs of acid-induced failure in juvenile recruitment were detected in salmonid populations. The occurrence of minnow and burbot covered all the systems studied. In parallell, the structure of benthic communities with relatively high species diversity and wide distribution of a highly acid-sensitive caddisfly indicated no effects of acidification.

Perceiving the Environment in Finnish Lapland

We contrast two understandings of traditional knowledge: as enframed in the discourse of modernity (MTK), and as generated in the practices of locality (LTK). Where `indigenous knowledge' is opposed to science, it always appears in the guise of MTK. This modernist understanding rests on a genealogical model of transmission that separates the acquisition of knowledge from environmentally situated practice. For local people, by contrast, traditional knowledge is inseparable from the practices of inhabiting the land that both bring places into being and constitute persons as of those places. To illustrate the meaning of LTK, we describe how Saami people in northernmost Finland perceive their environment, focusing on their experiences of the weather. These are shown to be embedded in life-histories, dependent on tasks of travel, multisensory, crucial to spatial orientation and the co-ordination of activities, and seasonally periodic. To regard people's knowledge of the weather as an aspect of tradition means thinking of tradition as process rather than substance, as part of a way of life conceived not as the enactment of a received script but as the continual negotiation of a path through the world. Here there is no contradiction between continuity and change. LTK, we show, is tantamount to skill: a property of the whole organism-person, having emerged through a history of involvement in an environment. From the perspective of LTK, there is no opposition between traditional knowledge and science. For science is itself a form of LTK, differing from other forms in the practices through which it is generated, rather than in the epistemological status of the knowledge itself.

Performance of moth larvae on birch in relation to altitude, climate, host quality and parasitoids.

We studied topographical and year-to-year variation in the performance (pupal weights, survival) and larval parasitism of Epirrita autumnata larvae feeding on mountain birch in northernmost Finland in 1993-1996. We found differences in both food plant quality and parasitism between sites ranging from 80 m to 320 m above sea level. Variation in food plant quality had particularly marked effects on larval survival. The advanced phenology of the birches in relation to the start of the larval period reduced pupal weights. Parasitism rates were different between years and between sites. The clearest site differences were in the proportions of different parasitoid species: Eulophus larvarum was most abundant at the lowest-altitude sites, and Cotesia jucunda at the highest. Differences in the performance of E. autumnata were related to temperature conditions: at higher temperatures, survival and the egg production index were lower, and larval parasitism was higher than at lower temperatures. The higher parasitism at higher temperatures was probably due to greater parasitoid activity during warmer days. In the comparison of different sources of spatial and annual variation in the performance of E. autumnata, the most important factor appeared to be egg mortality related to minimum winter temperature, followed by parasitism and, finally, the variation in food plant quality. If, as predicted, the climate gradually warms up, the effects of warmer summers on the outbreaks of E. autumnata suggest a decrease in outbreak intensity.

Fast‐flowing areas affect the feeding activity of migrating Altantic salmon smolts in tributaries of a subarctic river

Feeding activity of migrating wild Atlantic salmon smolts was investigated in different types of tributaries of the River Teno, northernmost Finland. General feeding activity and the amount of surface prey in the stomachs were correlated inversely with proportion of habitats with high water velocity in the tributaries.

Detecting Phenophases of Subarctic Shrub Canopies by Using Automated Reflectance Measurements

Boreal and subarctic plant phenophases are advantageous indicators of climatic change on a global scale. Remote sensing is a promising technique for assessing such changes over extended areas. An automated field measuring system collected seasonal reflectances of natural shrubs in visible, near-, and mid-infrared wavelength ranges. A boom-mounted four-band spectroradiometer was installed on a 4-m-high tower to measure seasonal radiances in green (520–600 nm), red (630–690 nm), near-infrared (765–900 nm), and mid-infrared (1570–1730 nm) spectral bands from undisturbed subarctic shrub vegetation during the 1994 and 1995 growing seasons (mid-June to mid-September) in northernmost Finland (69°45′N, 27°00′E, 105 m above sea level). The radiometer was vertically looking down on four fixed ground plots and a weatherproof reference panel continuously during all the daylight hours. The reflectance factor calculations, using the reference panel and solarimeter readings, included corrections for the reference panel degradation and non-Lambertian characteristics. Daily averages of visible and near-infrared band reflectance factors offered smooth seasonal trends in spite of the variation in solar irradiance at the times of data collection. The turning point dates in the trends of seasonal near-infrared (765–900 nm) and red (630–690 nm) reflectance factors might indicate the end of growth and the beginning of autumn changes, respectively. The normalized difference vegetation index and ratio of green (520–600 nm) to red (630–690 nm) band reflectance factors, however, seemed to be more accurate in monitoring them.

Differences in the physiological status of Atlantic salmon smolts in three tributaries of the River Teno

Physiological characteristics of wild Atlantic salmon smolts at the beginning of their migration were compared between three tributaries of the River Teno in northernmost Finland. Samples were collected during or just prior to the peak of smolt migration. Two of the tributaries are not spawning rivers but juveniles ascend into them from the main stem. The smolts in these tributaries were significantly larger when compared to those in a spawning tributary. Though smolts of all the tributaries survived a salt water challenge test, significant differences were found in the physiological smolting indices of the smolts between the rivers. The energy stores of smolts were significantly smaller in the spawning river than in the two other tributaries. The smolts sampled at the beginning of the main migration showed high concentrations of plasma glucose and protein and a low one for chloride ion, all reflecting an early state of smolting. The size differences of the smolts between the tributaries did not explain the physiological differences of the smolts, but the physiological status of the smolts was dependent on the tributary.

Modelling topoclimatic patterns of egg mortality of Epirrita autumnata (Lepidoptera: Geometridae) with a Geographical Information System: predictions for current climate and warmer climate scenarios

1. Our aim was to quantify the effects of a warmer winter climate on the egg mortality (and, consequently, the risk of an outbreak) of Epirrita autumnata, a serious defoliator of mountain birch. 2. The egg survival of E. autumnata was studied in northernmost Finland from 1993 to 1996, when minimum temperatures were also recorded. Utilizing a digital elevation map with a GIS (Geographical Information System), models were developed for egg survival and minimum temperature, taking into account altitude, local topography and temperatures at a meteorological station in the study area. 3. Areas of high egg mortality of E. autumnata can be modelled in the GIS with reasonable accuracy by the model describing areal distribution of minimum winter temperatures, taking account of the fact that the critical limit for egg survival of E. autumnata in midwinter is about −35·5°C. The approach can be applied in short‐term forecasting of outbreak areas when previous year population densities and minimum winter temperatures at meteorological stations are known. 4. In our study area, from 1961 to 1991 more than one‐third of the years were egg‐killing winters in the mixed birch‐pine forests zone, and 15% of years in the birch forest zone. In order for an outbreak to take place, at least three consecutive seasons with a high population growth rate are needed; in the mixed birch‐pine forests the possibilities of an E. autumnata outbreak during the period 1961–91 were very rare, while in the birch forest zone outbreak possibilities were also noticeably restricted by winter minimum temperatures. 5. If winter warming takes place according to the scenarios presented, by the middle of the next century the birch‐growing areas in our study area protected by low temperatures from outbreaks of E. autumnata will be only one‐third as great as those of today, and by the end of the next century only one‐tenth of those of today. 6. The models and methods described in this paper can be applied to other ecological processes. The modelling strategies and techniques described here serve as intermediate tools for linking large scale climate models (general circulation models, GCMs) and ecological processes happening at a smaller scale.

Feeding of Atlantic salmon,Salmo salarL., parr in the subarctic River Teno and three tributaries in northernmost Finland

Abstract—Available food and feeding of Atlantic salmon parr were studied in different parts of a subarctic river in northernmost Finland, the River Teno: in the large main stem, in a major tributary influenced by lakes, and in two minor tributaries. The highest density of benthic organisms was found in an outlet of a lake, but drifting organisms were the most abundant in the small tributaries. Migrant parr that move to the small tributaries from the main stem have better food resources in their new habitat. Plecoptera nymphs were the most important prey for salmon parr early in the spring. Later in the summer dipterans were usually the dominant prey group. In September the importance of Plecoptera was emphasized in the small tributaries and the lake outlet, and that of Trichoptera in other sites. Drifting prey was used more by large than by small parr. The utilization of drifting food appeared to be related to the water temperature rather than to the availability of the drift.

Delayed Inducible Resistance in Mountain Birch in Response to Fertilization and Shade

Delayed inducible resistance (DIR) is triggered by artificial or herbivore—caused foliar damage and is manifested as decreased performance of herbivore generation(s) feeding on the trees subsequent to the generation during which the damage took place. DIR is associated with increase in concentrations of foliage phenolics and decrease in nitrogen. The growth—differentiation balance hypothesis, and the carbon—nutrient balance (CNB) hypothesis contained in it, claim that DIR is caused by nutritional stress after defoliation of trees growing on nutrient—poor soils. In these environments, nutrient uptake limits plant growth more strongly than does photosynthesis; that is, carbon—based secondary metabolites (e.g., phenolics) are prone to accumulate. According to the CNB hypothesis, an excess of limiting nutrient(s) or reduced photosynthetic rate should lead to elimination of DIR. We tested this using same—aged Betula pubescens ssp. tortuosa trees of five open—pollinated families growing in a common arboretum in northernmost Finland. In addition to unmanipulated control trees, we had three nutritional treatments during three successive growth seasons: N—fertilization, PK—fertilization adding all nutrients except N, and shading to decrease carbon assimilation. Half of the trees in each treatment were artificially defoliated (50% leaf area) in the second study year, one year before the growth trial with geometrid (Epirrita autumnata) larvae. Tree growth measurements showed that N is the growth—limiting nutrient in our study area. N—fertilization and shading of the trees affected foliage chemistry generally as proposed by the CNB hypothesis. For example, they reduced foliar concentrations of total phenolics and condensed tannins. The birch families differed significantly in foliage chemistry, suggesting genetic differences, but the differences were not associated with fertilizations, shading, or defoliation of the trees. Contrary to fertilizing—shade treatments, changes in leaf chemistry and E. autumnata performance caused by defoliation were not consistent with the CNB hypothesis. For example, defoliation caused significant DIR irrespective of N—fertilization or shading. There were no significant differences among the birch families in performance of the moth larvae or in effects of fertilization, shade, or defoliation on larval performance. These responses to defoliation contrast with those of some other studies, especially those on the Betula resinifera—Rheumaptera hastata system in Alaska, which provide clear support for the CNB as an explanation of DIR. We find methodological differences to be an unlikely explanation for the different results but are unable to propose any single mechanism that will explain the diverse plant responses.

The breeding biology of the RedstartPhoenicurus phoenicurusin a marginal area of Finland

The breeding biology of the Redstart was studied in its marginal breeding area in northernmost Finland during the years 1982–1994. The mean clutch size was higher than in more southern populations. Losses during the egg and nestling stages were negligible: hatching success (hatchlings per egg) and fledging success (fledglings per hatchling) were 0.91 and 0.89, respectively. Only heavy rainfall decreased nestling survival. Our results show that population size is stable and breeding success is good in this marginal breeding area compared to other breeding grounds. The population size fluctuated in parallel with the vole cycle as expected if small (mammal) predators switch to taking birds when vole numbers are low.

Seasonal occurrence of arthropods as a source of food for birds in Finnish Lapland

The seasonal occurrence in arthropod abundance was studied in Utsjoki, northernmost Finland, from the viewpoint that arthropods form an important food resource for birds. On ground surfaces, Araneae was the most abundant taxon. The abundance peak of spiders occurred in June. Diptera, which was the dominant taxon in samples collected from dwarf shrubs, had their dominance peak in July. In birch foliage, Homoptera and Coleoptera were most common in June, but lepidopteran and symphytan larvae dominated in late summer. The larvae in pines (Symphyta; Diprionidae and Pamphiliidae) also had their abundance peak in autumn. The role of predation in the seasonality is discussed from the point-of-view of both birds and arthropods.

High serum alpha‐tocopherol, albumin, selenium and cholesterol, and low mortality from coronary heart disease in northern Finland*

The mortality from coronary heart disease (CHD) is exceptionally low in northernmost Finland, the Sámi (formerly known as Lapp) area. To clarify the reasons for this, the levels of serum cholesterol, other classic risk factors, and major antioxidants, alpha-tocopherol, retinol, albumin and selenium were determined in males living in the low-mortality area and in a reference area. A health survey amongst reindeer herdsmen living in the three northernmost communes of Finland (the Sámi area) and in the six neighbouring communities to the south (the reference area). The mortality from CHD in the two areas was determined from death certificates issued during the period 1981-1990. A total of 350 participants of the health survey, mean age 46 (SD 14) years. The mortality from CHD was 17% lower in the Sámi area than in the reference area [95% confidence interval (CI) for the difference: 4-29]. Subjects living in the low-mortality area showed higher serum-lipid-adjusted alpha-tocopherol (18.4 vs. 16.1 mumol L-1; 95% CI for difference: 0.7-3.9; P < 0.001), albumin (46.9 vs. 46.2 g L-1; 0.2-1.3; P < 0.02), selenium (1.59 vs. 1.47 mumol L-1; 0.02-0.22; P < 0.02), cholesterol (6.76 vs. 6.34 mmol L-1; 0.12-0.72; P < 0.001) and LDL cholesterol (4.76 vs. 4.45 mmol L-1; 0.05-0.57; P < 0.02) than those in the reference area. The HDL cholesterol:cholesterol ratio was lower in the Sámi area than in the reference area (0.20 vs. 0.21; -0.02-0.00; P < 0.04). The Sámis showed higher serum selenium than the Finns. Serum alpha-tocopherol increased with the consumption of reindeer meat and serum selenium increased with fish consumption. Alpha-tocopherol, albumin and selenium may play a role in the low mortality from CHD observed in northernmost Finland. The favourable serum antioxidant status in northerners may be credited to the local diet.

Evidence on climatic variability and prehistoric human activities between 165 B.C. and A.D. 1400 derived from subfossil Scots pines (Pinus sylvestris L.) found in a lake in Utsjoki, northernmost Finland

Evidence on climatic variability and prehistoric human activities between 165 B.C. and A.D. 1400 derived from subfossil Scots pines (Pinus sylvestris L.) found in a lake in Utsjoki, northernmost Finland

Birch pollen production, transport and deposition for the period 1984–1993 at Kevo, northernmost Finland

Betula pollen production and flowering, pollen transport and pollen deposition are considered for the mountain birch region of northern Finland for the ten-year period 1984–1993. The most abundant flowering year was 1989 and, after that, 1985. In these years the highest values were also recorded for pollen in the air. There is a significant correlation between the amount of pollen released and the thermal sum of the previous year. In terms of pollen deposition the peak years were 1989 and 1986. The correlation between the amount of pollen in the air and that being deposited on the ground is also statisticaly significant. It is evident that some birch pollen is already present in the air before local flowering begins and that, in some years, this non-local pollen can account for more than 20% of the yearly total. This preflowering proportion was highest in 1985 and 1993, the latter being a prolific flowering year in the south of the country. There is a clear relationship between the proportion of the non-local pollen in the air and the proportion ofBetula pubescens/pendula type pollen deposited on the ground and, conversely, there is a significant correlation between the amount of local pollen in the air and the amount ofBetula tortuosa plusB. nana type pollen being deposited on the ground. The questions both of the viability of this long-distance pollen and of its ability to cause allergic reactions are considered. An assessment is also made of the degree to which fossil birch pollen assemblages can be realistically interpreted in terms of local vegetation if a varying proportion of the same pollen type is non-local.

Pollen evidence of localized impact on the vegetation of northernmost Finland by hunter-gatherers

Pollen data are presented for the pine forest region around Lake Inari in eastern Finnish Lapland. The region has traditionally been the home of the Saami people who, until the 19th century, followed a seasonally nomadic way of life with an economy based on hunting, fishing and gathering. Although the Saami had no permanent centres of settlement, they did gather together at specific sites every winter, revisiting them year after year over several decades. A pollen diagram is presented from a peat area adjacent to one such winter village, Einehlammet. This shows a clear interference phase characterized by a peak in Ericales followed by a small but distinct peak in Poaceae and the slight, sporadic occurrence of pollen types that can be shown to be connected with human presence. At the same time Pinus values fall and, at the end of the phase, there is a strong increase in Betula pollen. This evidence is compared with that from actually within a dwelling (kota) at another winter village, Nukkumajoki, and is seen to follow exactly the same pattern. Such changes in forest composition in this situation could not be attributed to climatic change. The results demonstrate that, peoples pursuing a purely hunting and gathering economy and moving in the forests in a manner designed to preserve rather than destroy their environment can, nevertheless, cause vegetation changes that are discernable by pollen analysis within a distance of 50 m.

Among-Tree Variation in Leaf Phenology and Morphology and Its Correlation with Insect Performance in the Mountain Birch

We studied variation in leaf morphology and phenology in a population of the mountain birch (Betula pubescens ssp. tortuosa) in northernmost Finland over two summers. We tested tree quality with bioassay using several leaf-eating insect species to study the impact of plant variation on herbivore performance. Leaf size and phenology varied considerably between years. Differences among trees were significant, but undividual trees retained their leaf-character-ranking within and between seasons. Positive correlations between tree height and leaf size and differences in bud growth patterns indicate that the mountain is genetically related to the dwarf birch, B. nana (...)