ISSN 1239-6095 (print),   ISSN 1797-2469 (online)
© Boreal Environment Research 2011

Contents of Volume 16 Number 2

Schletterer, M., Schönhuber, M. & Füreder, L. 2011: Biodiversity of diatoms and macroinvertebrates in an east European lowland river, the Tudovka River (Tver Region, Russia). Boreal Env. Res. 16: 79–90.
Abstract
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Rautiainen, M., Stenberg, P., Mõttus, M. & Manninen, T. 2011: Radiative transfer simulations link boreal forest structure and shortwave albedo. Boreal Env. Res. 16: 91–100.
Abstract
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Drouin, A., Archambault, P. & Sirois, P. 2011: Distinction of nektonic and benthic communities between fish-present (Salvelinus fontinalis) and natural fishless lakes. Boreal Env. Res. 16: 101–114.
Abstract
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Thorstad, E. B., Uglem, I., Arechavala-Lopez, P., Økland, F. & Finstad B. 2011: Low survival of hatchery-released Atlantic salmon smolts during initial river and fjord migration. Boreal Env. Res. 16: 115–120.
Abstract
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Hällfors, H., Hajdu, S., Kuosa, H. & Larsson, U. 2011: Vertical and temporal distribution of the dinoflagellates Dinophysis acuminata and D. norvegica in the Baltic Sea. Boreal Env. Res. 16: 121–135.
Abstract
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Juutinen, R. & Kotiaho, J. S. 2011: Finnish Forest Act as a conservation tool in protecting boreal springs and associated bryophyte flora. Boreal Env. Res. 16: 136–148.
Abstract
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Hesthagen, T., Austigard, A. & Holmedal, K. 2011: Diurnal and seasonal resource partitioning in young brown trout (Salmo trutta), Arctic charr (Salvelinus alpinus) and Alpine bullhead (Cottus poecilopus) in a subalpine lake in southeastern Norway. Boreal Env. Res. 16: 149–157.
Abstract
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Roivainen, P., Makkonen, S., Holopainen, T. & Juutilainen, J. 2011: Soil-to-plant transfer of uranium and its distribution between plant parts in four boreal forest species. Boreal Env. Res. 16: 158–166.
Abstract
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Schletterer, M., Schönhuber, M. & Füreder, L. 2011: Biodiversity of diatoms and macroinvertebrates in an east European lowland river, the Tudovka River (Tver Region, Russia). Boreal Env. Res. 16: 79–90.

Knowledge about river ecosystems in the east European lowlands is scattered, however it is strongly needed for water management and conservation issues. The aim of the present study was to provide information on biotic key elements and their responses to major environmental gradients in a European lowland river. During the summers of 2006 and 2007, 124 diatom and 128 macroinvertebrate species were recorded in a pristine brownwater river, the Tudovka, a tributary of the Volga River. The canonical correspondence analysis showed that conductivity, pH and colour were significant environmental variables in explaining diatom data, while macroinvertebrate distribution was most related to distance from source (rkm). The eigenvalues of the first two CCA axes were significant (p < 0.05) for diatoms and invertebrates. However, the diatom analysis explained more of the taxonomic variation (41.7% vs. 34.6%). Overall, invertebrates responded more to physical factors, while diatoms depended on water chemistry, thus both components are needed for assessing river health. We suggest the use of a combination of diatom (Austrian saprobic and trophic indices, TDI and IBD) and macroinvertebrate (Austrian saprobic index, the SPEARpesticides index and ITC) indices for further monitoring programmes in the Tver Region. With this study we provide important information on the riverine biocenosis in this ecosystem, as this river type is elsewhere affected by human activities.
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Rautiainen, M., Stenberg, P., Mõttus, M. & Manninen, T. 2011: Radiative transfer simulations link boreal forest structure and shortwave albedo. Boreal Env. Res. 16: 91–100.

Vegetation cover and land-use changes induced by human activities have changed the global surface albedo, or the extent to which incoming solar radiation is reflected back to the atmosphere. Forest albedo is a critical variable affecting the Earth's climate, and is still among the main uncertainties of the radiation budget in climate modelling. A synthesis of current research results clearly indicates a need for more reliable quantitative predictions of the effect of forest structure on the global albedo. This paper reports a case study on the application of a forest radiative transfer model in shortwave albedo simulations: we simulate the blue-sky and black-sky albedos of coniferous stands in Finland, and link forest albedo to stand structure and management practices. Our results indicate that boreal forest albedo decreases as the stands become older and as their standing stock increases, and that regular thinning procedures reduce stand summer albedo of coniferous forests.
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Drouin, A., Archambault, P. & Sirois, P. 2011: Distinction of nektonic and benthic communities between fish-present (Salvelinus fontinalis) and natural fishless lakes. Boreal Env. Res. 16: 101–114.

Natural geographic barriers and escarpments inhibited the post-glacial colonisation of numerous lakes by fish on the eastern Canadian Boreal Shield. The aim of this study was to assess how different top-down control in lakes containing a single fish population of brook trout (Salvelinus fontinalis) and naturally fishless lakes affects the characteristics and structure of littoral macroinvertebrate communities throughout the ice-free season. Nektonic and zoobenthic communities were examined through univariate community characteristics [abundance, species density, species richness (D), evenness (J'), diversity, H')] and multivariate species assemblages. The total abundance of nektonic and zoobenthic communities and their univariate diversity indices were similar between fish-present and fishless lakes over the entire sampling period. However, species assemblages for both types of macroinvertebrate communities were significantly different between fish-present and fishless lakes throughout the season. Typically, the same invertebrate species occurred in the two lake types; but their relative abundance was different. The results of our study show that the top-down control in fish-present and fishless lakes leads to different littoral community structures, which were not perceptible through the studied univariate community characteristics. This study highlights the importance of selecting appropriate indicators for the assessment of invertebrate communities in lakes of the eastern Canadian Boreal Shield.
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Thorstad, E. B., Uglem, I., Arechavala-Lopez, P., Økland, F. & Finstad B. 2011: Low survival of hatchery-released Atlantic salmon smolts during initial river and fjord migration. Boreal Env. Res. 16: 115–120.

Even though release strategies have been improved, recapture rates of hatchery-reared Atlantic salmon as adults have been low in the River Eira, Norway. To evaluate whether loss of fish occurs in the river immediately after release, in the early marine phase in the fjord, or during the subsequent feeding migration at sea, 20 smolts were equipped with acoustic transmitters. The survival and movement pattern of the smolts were monitored along the 9-km-long river and during the first 37 km of the fjord migration. Only 25% of the smolts survived from release in the upper part of the river and until passing the fjord site 37 km from the river mouth. The within-river loss (15%, 3 of 20 smolts) was smaller than the marine mortality (71%, 12 of 17 smolts). The marine mortality was largest in the inner part of the fjord, with 41% mortality during the first 3.6 km, 40% mortality during the next 6.0 km, and only 17% mortality during the last 27.5 km (i.e., 11.4%, 6.7% and 0.6% mortality per km, respectively). The data suggested that at least 9 of the 12 smolts lost in the fjord were eaten by predatory fish (i.e. 45% of the fish released in the river were lost to fish predators). Hence, our results indicate that a considerable proportion of hatchery-reared smolts released in rivers might be lost due to predation before they actually leave the fjords.
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Hällfors, H., Hajdu, S., Kuosa, H. & Larsson, U. 2011: Vertical and temporal distribution of the dinoflagellates Dinophysis acuminata and D. norvegica in the Baltic Sea. Boreal Env. Res. 16: 121–135.

We investigated the distributions of the toxic dinoflagellates Dinophysis acuminata and D. norvegica in the brackish Baltic Sea, and found them to differ both regarding their seasonality and their vertical distribution. Dinophysis acuminata was considerably more abundant, especially in the Gulf of Finland, where we observed an August peak of 14300 cells l–1. It occurred in elevated abundances during or after periods of high phytoplankton biomass in early and late summer. Dinophysis norvegica was abundant during a shorter period, peaking one month after the first D. acuminata maximum. While D. norvegica probably is restricted by both salinity and temperature in the northern Baltic Sea, the more tolerant D. acuminata thrives. The results presented here expand the wide range of scenarios in which D. acuminata may bloom worldwide. Both species mainly formed population maxima either in the mixed surface waters or near the thermocline. Dinophysis acuminata usually occurred in the illuminated and nutrient-poor mixed surface layer, but in the presence of light and a nutricline it formed distinct subsurface peaks. Dinophysis norvegica was not as sensitive to darkness and predominantly formed subsurface peaks, even below the euphotic zone. These occurrences were promoted by shallow stratification, and the combination of a deep mixed layer and cool surface waters drew the D. norvegica population closer to the surface. When D. acuminata and D. norvegica co-occurred, their abundances peaked at different depths; this was observed even when both species formed maxima in the surface layer.
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Juutinen, R. & Kotiaho, J. S. 2011: Finnish Forest Act as a conservation tool in protecting boreal springs and associated bryophyte flora. Boreal Env. Res. 16: 136–148.

To halt the loss of biodiversity, serious conservation measures are needed. Recently, key habitat approach has been adopted in all Nordic and Baltic countries. In Finland, conservation of Forest Act Habitats (FAHs) is the main instrument. We assessed whether FAHs have the potential to conserve the unique bryoflora of springs by studying 58 spring complexes, 8 of which included a predetermined FAH. FAHs had more pool surface and colder water than other springs. Our results suggest that a clear bias towards protecting certain types of springs exists, and that a significant number of FAHs have not yet been found. Moreover, our species data did not support the assumption that FAHs are of special importance: richness of bryophytes, specialists or red-listed species were not higher in FAHs. We conclude that the high demand of naturalness and the bias towards aesthetically appealing springs can lead to an ecologically crippled network of protected areas.
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Hesthagen, T., Austigard, A. & Holmedal, K. 2011: Diurnal and seasonal resource partitioning in young brown trout (Salmo trutta), Arctic charr (Salvelinus alpinus) and Alpine bullhead (Cottus poecilopus) in a subalpine lake in southeastern Norway. Boreal Env. Res. 16: 149–157.

Diurnal habitat and food segregation in young Arctic charr (Salvelinus alpinus), brown trout (Salmo trutta) and Alpine bullhead (Cottus poecilopus) were studied in Atnsø, a lake in southeastern Norway. The mean lengths ± SD of the three species were 118 ± 20 mm (n = 872), 112 ± 14 mm (n = 109), and 66 ± 8 mm (n = 70), respectively. Epibenthic gillnet catches of all three species were much higher at night (21.00–05.00 GMT) than during the day (09.00–17.00 GMT). In general, there was segregation by depth zone between these three species, which were caught at night at mean depths of 17.3 ± 6.2 m, 7.9 ± 3.3 m, 13.6 ± 5.0 m, respectively. During the hours of darkness in spring and late summer, Alpine bullhead were more likely to be associated with the bottom than Arctic charr and brown trout. Artic charr fed almost exclusively on zooplankton, while brown trout and Alpine bullhead fed largely on insect larvae and Eurycercus lamellatus. Although selective differences are partly responsible for resource partitioning between the two salmonid species and Alpine bullhead, interactive segregation may also occur.
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Roivainen, P., Makkonen, S., Holopainen, T. & Juutilainen, J. 2011: Soil-to-plant transfer of uranium and its distribution between plant parts in four boreal forest species. Boreal Env. Res. 16: 158–166.

Uranium (U) can be released to the environment through the entire nuclear fuel cycle. U uptake by plants is an important process for possible adverse effects in ecosystems. The soil-to-plant transfer of natural U and its distribution across plant parts were investigated in May lily (Maianthemum bifolium), narrow buckler fern (Dryopteris carthusiana), rowan (Sorbus aucuparia) and Norway spruce (Picea abies). Concentration ratios (CR) between plant and soil were calculated. The CRs for roots were higher than those for the above-ground parts of the plants. Soil pH was the only soil parameter showing an effect on CRs. No significant differences were noticed between species. The CRs observed were consistent with those reported previously in other forest types. The pooled values of 0.06 for roots and 0.005 for stems/petioles and leaves/needles can be considered as good estimates of CR values to be used in modelling the U uptake in boreal forest species.
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