Southeastern Finland Research Articles

A decision framework for possible remediation of contaminated sediments in the River Kymijoki, Finland

The paper describes the spatial contamination of the River Kymijoki, South-Eastern Finland, and the coastal region of the Gulf of Finland with PCDD/Fs and mercury. The findings of ecotoxicologial and human health studies are also reported, including environmental and human risk assessments. Sediments from the River Kymijoki, draining into the Gulf of Finland, have been heavily polluted by the pulp and paper industry and by chemical industries. A wood preservative, known as Ky-5, was manufactured in the upper reaches of the river between 1940 and 1984 causing severe pollution of river sediments with polychlorinated dibenzo-p-dioxins (PCDD) and dibenzofurans (PCDF). Moreover, the sediments have been polluted with mercury (Hg) from chlor-alkali production and the use of Hg as a slimicide in pulp and paper manufacturing. An extensive sediment survey was conducted as well as sediment transport modeling, toxicity screening of sediment invertebrates, and a survey of contaminant bioaccumulation in invertebrates and fish. Studies on human exposure to PCDD/Fs and the possible effects on hypermineralization of teeth as well as an epidemiological study to reveal increased cancer risk were also conducted. An assessment of the ecological and human health risks with a null hypothesis (no remediation) was undertaken. The sediment survey revealed severe contamination of river and coastal sediments with PCDD/Fs and Hg. The total volume of contaminated sediments was estimated to reach 5x10(6) m3 and hot spots with extremely high concentrations (max 292,000 ng g(-1) or 1,060 ng I-TEQ g(-1) d.w.) were located immediately downstream from the pollution source (approximately 90,000 m3). Sediment contamination was accompanied by changes in benthic assemblages, but direct effects were masked by many factors. The fish showed only slightly elevated PCDD/F levels in muscle, but orders of magnitude higher in the liver compared with reference freshwater sites and the Baltic Sea. The concentrations in human fat did not reveal high human exposure in the Kymijoki area in general and was lower than in sea fishermen. The relative risk for total cancer among farmers was marginally higher (RR=1.13) among those living close to the river, compared with farmers living further away, and the possibility of increased cancer risk cannot be ruled out. A conservative risk assessment revealed that the present probability of exceeding the WHO upper exposure limit of 4 pg WHO-TEQ kg(-1) d(-1) for PCDD/Fs and DL-PCBs was 6%. The probability of exceeding the WHO limit value of 0.23 mug kg(-1) d(-1) for methyl mercury was estimated to be notably higher at 62%. Based on these studies and the estimated risks connected with different remediation techniques a general remediation plan with cost benefit analysis was generated for several sub-regions in the river. Dredging, on-site treatment, and a close disposal of the most contaminated sediments (90,000 m3) was suggested as the first phase of the remediation. The decision regarding the start of remediation will be made during autumn 2008. The sediments in the River Kymijoki are heavily polluted with PCDD/Fs and mercury from earlier chlorophenol, chlor-alkali, and pulp and paper manufacturing. A continuous transport of contaminants is taking place to the Gulf of Finland in the Baltic Sea. The highly increased PCDD/F and Hg levels in river sediments pose an ecotoxicological risk to benthic fauna, to fish-eating predators and probably to human health. The risks posed by mercury exceed those from PCDD/Fs and need to be evaluated for (former) chlor-alkali sites and other mercury releasing industries as one basis for remediation decision making. The studies form the basis of a risk management strategy and a plan for possible remediation of contaminated sediments currently under consideration in the Southeast Finland Regional Environment Centre. It is recommended that a detailed restoration plan for the most seriously contaminated areas should be undertaken. Based on current knowledge, the restoration of the whole river is not feasible, considering the current risk caused by the contaminated sediment in the river and the costs of an extensive restoration project. The experiences gained in the present case should be utilized in the evaluation of PCDD/F- and mercury-contaminated sites in other countries. The case demonstrates that the historic reservoirs are of contemporary relevance and should be addressed, e.g., in the national implementation plans of the Stockholm Convention.

Effects of thinning and fertilization on wood properties and economic returns for Norway spruce

The effects of silviculture on wood and tracheid properties, and economic returns of Norway spruce ( Picea abies (L.) Karst.) were investigated in two case studies, one comparing different thinning intensity in southeastern Finland and the other considering the effects of optimal nutrient addition in northern Sweden. Models for predicting the wood and tracheid properties of Norway spruce were integrated into a distance-independent process-based growth and yield model. Increasing the thinning intensity resulted in a lower mean wood density, tracheid length, and latewood proportion in harvested wood. Wood density and tracheid length of harvested pulpwood slightly decreased in later thinnings and final cuts. Thinning regimes with high early growing stock and decreasing later growing stock were most profitable. Nutrient addition accelerated volume growth and increased the value growth. The increase in volume growth due to nutrient addition more than offset the economic influence of the loss in wood density and tracheid length.

Impact of the open biomass fires in spring and summer of 2006 on the chemical composition of background air in south-eastern Finland

In the spring and summer of 2006 the air quality in southern Finland was affected by two major biomass fire smoke episodes. At the Virolahti background station, closest to the eastern fire areas, the episodes lasted altogether several weeks. The high point in spring was 25 April and in summer 13 August. In spring the aerosol detected at Virolahti originated at distances of even hundreds of kilometres to the south and south-east, and consequently was a mixture of material from biomass burning and from other sources (both LRT and local), all of which contributed to the detected elevation of PM 10 concentrations. The elevated concentrations of trace elements (Cd, Pb, Zn) during the most intense biomass fire episode were associated with other anthropogenic emissions. In contrast, during August 2006, the PM 10 at Virolahti was quite exclusively impacted by close (ca. 50–100 km) biomass fire sources. The presumably organic component comprised, at its highest, as much as 90% of the total PM 10. In addition to record high PM 10 and PM 2.5 concentrations, the concentrations of polycyclic aromatic hydrocarbons were considerably elevated, even reaching values more typical of wintertime urban environments. During the peaks of the episodes in August, the total gaseous mercury concentration in the air was more than double its background value. In general, the trace elements did not exceed their background values.

Population exposure to fine particles and estimated excess mortality in Finland from an East European wildfire episode

Long-range transported particulate matter (PM) air pollution episodes associated with wildfires in the Eastern Europe are relatively common in Southern and Southeastern Finland. In severe cases such as in August-September 2002, the reduced visibility and smell of the smoke, and symptoms such as irritation of eyes and airways experienced by the population raise the issue into the headlines. Because PM air pollution, in general, has been identified as a major health risk, and the exposures are of repeating nature, the issue warrants a risk assessment to estimate the magnitude of the problem. The current work uses the available air quality data in Finland to estimate population exposures caused by one of the worst episodes experienced in this decade. This episode originated from wildfires in Russia, Belarus, Ukraine, and the Baltic countries. The populations of 11 Southern Finnish provinces were exposed between 26 August and 8 September 2002, for 2 weeks to an additional population-weighted average PM(2.5) level of 15.7 microg/m(3). Assuming similar effect on mortality for these particles as observed in epidemiological time series studies on urban particles (0.5%-2% increase in mortality per 10 microg/m(3), central estimate 1%), this exposure level would be associated with 9-34 cases (17 cases central estimate) of additional mortality. Epidemiological evidence specific to particles from biomass combustion is scarce, affecting also the reliability of the current risk assessment. Do the wildfire aerosols exhibit the same level of toxicity as the urban particles? To shed light on this question, it is interesting to look at the exposure data in relationship to the observed daily mortality in Finland, even though the limited duration of the episode allows only for a weak statistical power. The percentage increases observed (0.8%-2.1% per 10 microg/m(3) of fine PM) are in line with the more general estimates for urban PM and those used in the current risk assessment.

SOKO PROJECT: DEVELOPING DETAILED OIL COMBATING PLAN FOR MANAGING ON-SHORE CLEAN-UP PROCEDURES IN FINLAND

ABSTRACT Shipping on the Baltic Sea, especially the transportation of oil, has grown significantly over the past few years. One of the most accident risky areas for Finland is situated in the Eastern Gulf of Finland (lat. 60° 11’ long. 027° 45’ E). The Baltic Sea has officially been classified by the International Maritime Organization as Particularly Sensitive Sea Area in 2005. In Finland the Regional Rescue Services (RRS) are responsible for organising on-shore clean-up with the assistance of the Regional Environmental Centres (REC). These oil combating authorities of Kymenlaakso region in south-eastern Finland have developed a thorough preparedness for oil incidents with the help of SOKO – Management of on-shore oil combating - project (SOKO). SOKO, innovated and administrated by the Kymenlaakso University of Applied Sciences (KyAMK), produced a detailed guidebook for oil combating authorities and the response commander (RC). The scope of the guidebook was achieved as an interdisciplinary effort between educational institutes, rescue services, environmental centres, authorities, civic organisations and businesses. The guidebook provides detailed information on how to conduct oil combating in the case of a major oil incident where the oil reaches the shores. The guidebook is used as an action plan, as a manual for the response commander (RC) as well as for training both authorities and volunteers. It is an extensive collection of studies undertaken by further education students and specialists under the supervision of the project steering committee, formed by local oil combating authorities and KyAMK SOKO project personnel. The guidebook discusses the oil combating organisation and the management, the human resources, the communication and the financing issues. The guidebook also covers the arranging cleaning operations, the oil combating equipment and the temporary storage sites in the mainland and the archipelago and the construction specifications for the temporary storages. Transportation of oily wastes was also examined including the methods for loading and discharging oily wastes, as well as the sea, road and railway transportation methods using a database for estimating the best and most economic routes from the archipelago to the mainland. In addition, detailed operative charts were produced, with indications of the cleaning sectors and the oil waste transportation spots. The SOKO contingency plan differs from the governmental plans by focusing only on the on-shore response excluding the at-sea response. The role of the oil combating authorities in the project was to identify unresolved issues in preparedness, provide practical information, supervise and accept the outcome. The main financier of SOKO in 2003–2007 was the Finnish Ministry of Education. The SOKO concept is currently expanding to cover more coastal area in the Gulf of Finland (SOKO II -project 2007–2011).

Differences in fibre properties in cloned Norway spruce (Picea abies)

In forest breeding programmes, growth has typically been used as a selection trait of prime importance in Norway spruce ( Picea abies (L.) Karst.), whereas less attention has been given to the wood and fibre characteristics. In the above context, we investigated phenotypic relationships between different fibre properties and growth and wood density traits in 20 cloned Norway spruce based on a clonal trial established in the 1970s in southeastern Finland. We found that fibre width showed, on average (2.9%), the lowest phenotypic variation followed by fibre wall thickness (3.4%), coarseness (5.5%), and fibre length (8.1%). All of the phenotypic correlations between the fibre properties were also positive (p < 0.05), ranging from moderate to strong, suggesting that selection for one trait could simultaneously affect the other traits. The phenotypic correlations, on average, were quite weak but positive between growth and fibre properties and slightly negative or weak positive between wood density and different fibre properties (p < 0.05). Individually, some of the clones showed negative correlation between growth traits and fibre length. As a result, selection for fibre properties alone could also reduce overall stem volume (or stem mass) and would not directly indicate wood density traits and vice versa.

The role of cultural models in local perceptions of SFM – Differences and similarities of interest groups from three boreal regions

Differences in the way local and regional interest groups perceive Sustainable Forest Management in regions with different forest use histories were studied using Southeastern Finland, the Mauricie in Quebec and Central Labrador in Canada as examples of regions with high, medium and low importance of commercial forestry. We present a conceptual model illustrating the cyclic interaction between the forest, cultural models about forests and forest management. We hypothesized that peoples' perceptions would be influenced by their cultural models about forests and would thus vary amongst regions with different forest use histories and among different interest groups. The weightings of the environmental, economic and social components of sustainability as well as themes important for each of the interest groups were elicited using individual listing of SFM indicators and group work aimed at developing a consensus opinion on a common indicator list. In Southeastern Finland the views of the different groups were polarized along the environment–economy axis, whereas in Central Labrador all groups were environmentally oriented. The social dimension was low overall except among the Metis and the Innu in Labrador. Only environmental groups were similar in all three research regions, the largest differences between regions were found among the forestry professionals in their weightings concerning economy and nature. As the importance of commercial forestry increased, a greater importance of economic issues was expressed whereas the opposite trend was observed for issues regarding nature. Also inter-group differences grew as the importance of commercial forestry increased in the region. Forest management and forest use can be seen as factors strongly influencing peoples' cultural models on forests.

Chromosomal polymorphism and racial evolution of Sorex uruneus L. in Finland

Halkka, L., Soderlund, V., Skaren, U. and Heikkila, J. 1987. Chromosomal polymorphism and racial evolution of Sorex araneus L. in Finland. —Hereditas 106: 257–275. Lund, Sweden. ISSN 0018–0661. Received October 2, 1986 Karyotypes of 197 Sorex araneus specimens from 26 populations throughout Finland were studied. Six chromosomal races with different combinations of arms, g, h, k, m, n, o, q and r were found to form chromosomes nos 3,5,7 and 8. The races may have evolved from a common ancestral karyotype through a series of reciprocal translocations. Postglacial geological development and distribution routes of Sorex support this hypothesis. Ancestor 3=qg, 5=nh, 7=rk, 8=om (Northern Russia)—race II 3=mg, 5=nh, 7=rk, 8=qo easternmost Finland) — race I 3=mg, 5=nh, 7=qk, 8=ro (Northern Finland and Lapland). Ancestor —race IV 3=qg, 5=nh, 7=ok, 8=rm (Central and Southern Finland, via Salpausselka ridge) — race V13, 5, 7, 8 =g, h, k, m, n, o, q, r (Aland Islands), race IV — race V3=k, g, 5=nh, 7=rm, 8=qo(Rauma, new centric fusion or hybrid). Ancestor — race III 3=qg, 5=kh, 7=om, 8=rn (Southeastern Finland, via Karlelian Isthmus). Chromosomes 3, 5, 7, 8, 4=li and 6=pi form an internal chromosomal polymorphism with two arms being combined to one metacentric chromosome (m) or being separated into two telocentric arms (t). The lowest frequencies of telocentrics were found in Central Finland and the highest, in Southwestern Finland and Aland. The chromosomal phenotypes mm, mt and tt seem to stay in Hardy-Weinberg equilibrium inside populations. The possible role of transposable elements in chromosomal evolution of Sorex araneus is discussed.

Wood density within Norway spruce stems

We studied the variation in average wood density of annual rings, earlywood density, and latewood density in addition to ring width and latewood percentage within Norway spruce (Picea abies (L.) Karst.) stems from the pith to the bark, and from the stem base towards the stem apex. Moreover, the variation in wood density within annual rings was studied at the different heights and radial positions in the stem. The material consisted of 85 trees from central and south-eastern Finland. Variation between the annual rings accounted for 11–27% of the total variation in wood density. Only small differences (3–6%) in wood density were found between different heights in the stem. The largest (49–80%) variation in wood density was found within the annual rings. The difference in wood density between earlywood and latewood was smaller in the rings near the pith than in the outer rings. The increasing wood density from the pith outwards was related to increasing latewood density and latewood percentage, whereas the earlywood density increased only slightly from the pith outwards. In a given cambial age (i.e., given rings from the pith), the average wood density of annual rings increased with increasing stem height. In contrast, in the rings formed in the same calendar years (i.e., given rings from the bark), the average wood density of annual rings decreased with increasing stem height. The results of this study verify our knowledge of wood density variation and can further contribute to creating models to predict wood density.

Surface weathering of rapakivi granite outcrops – implications for natural stone exploration and quality evaluation

Implications of surface weathering of rapakivi granite outcrops for natural stone evaluation were studied in the Wiborg rapakivi granite batholith in southeastern Finland. The study was performed as field mapping, comprising the whole batholith and as detailed investigations on selected outcrops. The Wiborg batholith is composed of wiborgite, pyterlite, even-grained rapakivi granite, porphyritic rapakivi granite, porphyry aplite, and gabbro-anorthosite. Wiborgite is the main rapakivi granite type. Weathering affects coarse-grained rapakivi varieties: wiborgite, pyterlite, and porphyritic rapakivi granite. Weathering occurs as surficial weathering of outcrops and randomly along subhorizontal and subvertical fractures, and varies in intensity. In the weathered upper parts of the outcrops the colour of the stone is altered and soundness of the stone diminished, which has a significant impact on the natural stone evaluation. In rapakivi granite areas, subsurface evaluation methods, by which the weathered surface part of the outcrops can be recognized, should always be used. Development of subsurface methods is required in order to make them more applicable in the evaluation of natural stone in areas with weathered rock.

Differences in growth and wood property traits in cloned Norway spruce (Picea abies)

Volume growth has typically been used as a selection trait of prime importance in forest tree breeding. Less attention has been given to the genetic or phenotypic relationships between the growth or yield and wood density traits. In the above context, we aimed to investigate the phenotypic relationships among different growth, yield, and wood density traits of 20 Norway spruce ( Picea abies (L.) Karst.) clones grown in southeastern Finland, in order to identify whether a high growth rate was associated with low wood density in any of the clones. Compared with growth or yield traits, the wood density traits showed lower phenotypic variations. The phenotypic correlations between growth, yield, and wood density traits were, on average, from moderate to high, suggesting that selection for one trait would simultaneously affect the other traits. Compared with volume production, selection based on stem mass could be more profitable if a clonal stand is managed for pulpwood rather than mechanical wood processing and vice versa; whereas selection for overall wood density alone would reduce both the stem volume and stem mass. However, by compromising the gain or loss in wood density and stem volume, clones with high stem volume and a relatively high wood density could be found.

Interactive effects of elevated ozone and springtime frost on growth and physiology of birch (Betula pendula) in field conditions

We studied the impact of ozone enrichment and late frost, singly and interactively, on four birch (Betula pendula Roth) families selected from a naturally regenerated birch stand in southeastern Finland. Seedlings were exposed to 1.5× ambient ozone over one and a half growing seasons using free-air ozone enrichment system. Simulated springtime frost was implemented at the beginning of the second study year, 4 weeks after the bud burst. Plants were measured for timing of bud burst, visible ozone injuries, chlorophyll fluorescence, net photosynthesis and concentrations of photosynthetic pigments, as well as for growth and carbon allocation. Frost treatment caused a rapid 60% decline in net photosynthesis. The recovery of net photosynthesis from acute frost treatment was not complete during the subsequent 3 weeks, which led to significant growth reductions, decreased shoot/root ratio and accumulation of excess nitrogen in the leaves. Photosynthetic responses to ozone were very variable and family-specific. Concentrations of photosynthetic pigments were sensitive to both stress factors, while the maximum quantum yield of PSII was unaffected. Ozone exacerbated the effect of frost only on diameter increment. However, ozone and frost affected different seedling characters, e.g., ozone reduced pigments and frost collapsed net photosynthesis, and these effect combined appear to damage birch seedlings more than a single stress situation.

Fatal Road Accidents among Finnish Military Conscripts: Fatigue-Impaired Driving

The aims of the present study were to determine the current prevalence of personal car usage for holiday trips among Finnish conscripts and to analyze conscripts' fatal road accidents. The data included questionnaire data collected from 259 young conscripts at a garrison in southeastern Finland and data on 46 fatal road accidents caused by conscripts during the years 1991-2004, extracted from the national database of fatal road accidents studied in depth. The questionnaire data showed that one-third (35.9%) of young Finnish conscripts had used personal cars to travel to or from the garrison in the preceding 2 months. More than one-half of them reported driving while fatigued (a majority reported several occasions of such driving). In addition to those driving themselves, 41.6% of the conscripts rode at least occasionally as a passenger in a car driven by a fellow conscript. Analysis of the fatality data showed that one-half of the conscripts' fatal accidents occurred on the way to or from the garrison or while on duty. Falling asleep was the main cause of all conscripts' accidents (34.8%), with the largest proportion occurring when departing for leave (42.9%). Haste (including speeding) was the second greatest factor contributing to accidents occurring on the way to or from the garrison (26.1%), whereas drunk driving (22.7%) and suspected suicides (18.2%) were typical of accidents occurring on leave.

Timing of Palaeoproterozoic intra-orogenic sedimentation in the central Fennoscandian Shield; evidence from detrital zircon in metasandstone

Detrital zircon U–Pb SIMS data on quartz-rich metasandstone units presumed to belong to the upper part of the Svecofennian stratigraphy in southeastern Finland and east-central Sweden suggest the existence of clastic sedimentary basins between the two main orogenic phases at 1.89–1.86 Ga and 1.83–1.79 Ga, during a period referred to as the intra-orogenic phase (1.86–1.83 Ga). Stratigraphically below the metasandstone at Hamrånge, east-central Sweden, is a metadacite with an U–Pb zircon TIMS age of 1888 ± 6 Ma, which indicates the maximum age of sedimentation. It also indicates that an earlier proposed correlation of Hamrånge metavolcanic rocks and 1.86 Ga equivalents at Los to the northwest must be rejected. Instead, there is a temporal affinity to the metavolcanic rocks in the Bergslagen Province to the south or Southern Finland to the east. Quartz-rich metasandstone samples from four localities, Luukkola, Pyhäntaka and Tiirismaa in Finland and Hamrånge in Sweden, yield multimodal detrital zircon age distributions with main populations at 2.95–2.60 Ga, 2.10–1.95 Ga and 1.92–1.85 Ga. The groups are similar in all four samples, and they are comparable to previously reported detrital ages in this part of the Fennoscandian Shield. The oldest zircon analysed gave an age of 3.32 Ga (Tiirismaa). The maximum ages of sedimentation (and of subsequent deformation and metamorphism), indicated by the youngest detrital zircon , from the four localities are 1842 ± 10 Ma (Luukkola), 1865 ± 11 Ma (Pyhäntaka), 1848 ± 13 Ma (Tiirismaa), and 1855 ± 10 Ma (Hamrånge), respectively. Possible source rocks for these zircon grains are found within and around the vast Ljusdal Batholith in Sweden, and in the Arc Complexes of Western and Southern Finland. It is concluded that several intra-orogenic sedimentary basins existed during the time interval 1.86–1.83 Ga ago, between two major orogenic events in the Fennoscandian Shield.

The 2003 earthquake swarm in Anjalankoski, south-eastern Finland

During May 2003 a swarm of 16 earthquakes ( M L = 0.6–2.1) occurred at Anjalankoski, south-eastern Finland. The activity lasted for three weeks, but additional two events were observed at the same location in October 2004. A comparison of the waveforms indicated that the source mechanisms and the hypocentres of the events were nearly identical. A relative earthquake location method was applied to better define the geometry of the cluster and to identify the fault plane associated with the earthquakes. The relocated earthquakes aligned along an ENE–WSW trending zone, with a lateral extent of about 1.0 km by 0.8 km. The relative location and the waveform-modelling of depth sensitive surface wave (Rg) and S-to-P converted body wave (sP) phases indicated that the events were unusually shallow, most likely occurring within the first 2 km of the surface. The revised historical earthquake data confirm that shallow swarm-type seismicity is characteristic to the area. The focal mechanism obtained as a composite solution of the five strongest events corresponds to dip-slip motion along a nearly vertical fault plane (strike = 250°, dip = 80°, rake = 90°). The dip and strike of this nodal plane as well as the relocated hypocentres coincide with an internal intrusion boundary of the Vyborg rapakivi batholith. The events occur under a compressive local stress field, which is explained by large gravitational potential energy differences and ridge-push forces. Pore-pressure changes caused by intrusion of ground water and/or radon gas into the fracture zones are suggested to govern the swarm-type earthquake activity.

ELMOD2 Is a Candidate Gene for Familial Idiopathic Pulmonary Fibrosis

We performed a genomewide scan in six multiplex families with familial idiopathic pulmonary fibrosis (IPF) who originated from southeastern Finland. The majority of the Finnish multiplex families were clustered in the region, and the population history suggested that the clustering might be explained by an ancestor shared among the patients. The genomewide scan identified five loci of interest. The hierarchical fine mapping in an extended data set with 24 families originating from the same geographic region revealed a shared 110 kb to 13 Mb haplotype on chromosome 4q31, which was significantly more frequent among the patients than in population-based controls (odds ratio 6.3; 95% CI 2.5-15.9; P = .0001). The shared haplotype harbored two functionally uncharacterized genes, ELMOD2 and LOC152586, of which only ELMOD2 was expressed in lung and showed significantly decreased messenger-RNA expression in IPF lung (n = 6) when compared with that of healthy lung (n = 7; P = .05). Our results suggest ELMOD2 as a novel candidate gene for susceptibility in familial IPF.

Satellite‐based mapping of the growing season and bioclimatic zones in Fennoscandia

ABSTRACTAim To test whether satellite‐derived NDVI values obtained during the growing season as delimited by the onset of phenological phases can be used to map bioclimatically a large region such as Fennoscandia.Location Fennoscandia north of about 58° N and neighbouring parts of NW Russia.Methods Phenology data on birch from 15 research stations and the half‐monthly GIMMS‐NDVI data set with 8 × 8 km2 resolution from the period 1982–2002 were used to characterize the growing season. To link surface phenology with NDVI data, new algorithms on a pixel‐by‐pixel basis that show high correlation with phenophases on birch were developed. Then, time‐integrated values (TI NDVI) during the phenologically defined growing season were computed to produce a bioclimatological map of Fennoscandia, which was tested and correlated with growing degree days (GDD) obtained from 20 meteorological stations. The map was also compared vs. traditional bioclimatic maps, and analysed for error factors distorting NDVI values.Results The correlation between GDD and TI NDVI data during the phenologically defined growing season was very high. Therefore, the TI NDVI map could be presented as a bioclimatic map reflecting GDD. However, several major areas have interfering factors distorting NDVI values, such as the pixel heterogeneity caused by the altitudinal mosaic in western Norway, the mosaic of lakes in southeastern Finland, and the agriculture‐dominated areas in southern Fennoscandia.Main conclusions TI NDVI data from the phenologically defined growing season during 1982–2002 in Fennoscandia can be processed as a bioclimatic map reflecting GDD, except for the areas distorting NDVI values by their strong ground‐cover heterogeneity.

Two metamorphic stages in the Svecofennian domain: Evidence from the isotopic geochronological study of the Ladoga and Sulkava metamorphic complexes

The Ladoga, Russia, and adjacent Sulkava, southeastern Finland, metamorphic complexes are the two largest “granulite” provinces of the Svecofennian domain. In this area, the domain is composed of outer and inner zones. Sulkava is situated in the inner zone, which principally can be compared to the accretionary arc complex of Southern Finland. Ladoga is situated in the outer zone, which is correlated with the accretionary arc complexes of central and Western Finland. The complexes contain different metamorphic assemblages, which are caused by the different composition of the sedimentary protoliths: the rocks of the Sulkava metamorphic complex are higher in Al and K than those of the Ladoga Complex. Pb-Pb step leaching dating was used to determine the age of prograde sillimanite from both complexes. The dates thus obtained constrain metamorphic peaks for the Sulkava and Ladoga complexes at 1799 ± 19 Ma and 1878 ± 7 Ma, respectively, which is consistent with the U-Pb monazite ages of gneisses from both of the complexes. The differences in the ages of the metamorphic minerals from these complexes reflect the Early Svecofennian (1.89–1.86 Ga) and Late Svecofennian (1.83–1.79 Ga) metamorphic stages in the Fennoscandian Svecofennides.

Thinning intensity and growth of mixed spruce-birch stands on drained peatlands in Finland

The impacts of thinning at various intensities on the growth and mortality of mixed spruce-birch stands were investigated in thinning experiments on spruce swamps in northern and south-eastern Finland. At the time of establishment, three of the stands had recently reached the first commercial thinning stage and four were more advanced. The monitoring period was mainly 15 years, and the thinning intensity varied from heavy thinning (ca. 46 per cent of the basal area removed) to no thinning. Basal area removals of light and moderate thinning were ca. 22% and 39%, respectively. Unthinned plots had the highest volume increment. Light and moderate thinning slightly decreased the 15-year volume increment by, on an average, 1% and 8%, respectively. Heavy thinning led to a greater reduction (22%) in volume increment. The growth response to thinning intensity was evident as a higher relative volume and mean diameter increment of the living trees with decreasing stand density. Part of the volume increment on the unthinned plots was lost through natural mortality. Even light thinning significantly decreased natural mortality.

Does thinning intensity affect the tracheid dimensions of Norway spruce?

The effect of thinning intensity on the growth rate and tracheid dimensions of Norway spruce (Picea abies (L.) Karst) was studied in two long-term thinning experiments (Heinola and Punkaharju) in southeastern Finland. The stand age was 86 and 67 years in Heinola and Punkaharju, respectively. Thinning intensities in this study were lower and higher than recommended in the 1960s for forestry practice in Finland. An increase in tree growth rate (31% in Heinola and 37% in Punkaharju) caused by the high thinning intensity resulted in slightly shorter tracheids (9% in Heinola and 4% in Punkaharju) than with the low thinning intensity. Increased growth rate had no pronounced effect on tracheid cell wall thickness and lumen diameter. A faster growth rate slightly decreased the average cell wall thickness of an annual ring, but the changes in average lumen diameter were small. The effect of thinning intensity was similar in earlywood and latewood. Variation in fiber properties between and within individual trees and annual rings was large. In conclusion, the current thinning intensities used in Finnish forestry practice enhance growth rate but have a rather small effect on tracheid dimensions.