Högström, U., Sahlée, E., Drennan, W. M., Kahma, K. K., Smedman, A.-S., Johansson, C., Pettersson, H., Rutgersson, A., Tuomi, L., Zhang, F. & Johansson, M. 2008: Momentum fluxes and wind gradients in the marine boundary layer — a multi-platform study. Boreal Env. Res. 13: 475–502.

During five autumn weeks, measurements of turbulent fluxes were obtained in the Baltic Sea at three levels on a 30-m tower and two levels on an ASIS buoy 4 km from the tower together with profiles of wind and temperature. Wave data and SST were obtained from ASIS. In the mean, momentum fluxes measured on the tower and on ASIS during onshore winds agree closely. Dimensionless wind gradients [phi]_m(z/L) for (i) stable conditions are linear in z/L (L is the Obukhov length); (ii) unstable, growing sea conditions are much smaller than predicted by `standard' equations, due to an indirect effect of the boundary layer height. Individual wind profiles extrapolated from ASIS to tower by integration of [phi]_m(z/L) deviate by about 0.5 m s^–1 from measured values, but corresponding mean profiles agree well for all levels from 1.18 m to 30 m. This random variation in the wind field is shown to be related to inherent dynamics of the atmospheric surface layer.

Ilus, E. & Keskitalo, J. 2008: The response of phytoplankton to increased temperature in the Loviisa archipelago, Gulf of Finland. Boreal Env. Res. 13: 503–516.

Phytoplankton was studied in the Loviisa archipelago (south coast of Finland) in 1971–1994. Since 1977, thermal effluents from the Loviisa nuclear power plant have been discharged into the sea there. A general increase of nutrients in the Gulf of Finland contributed to an increase in phytoplankton biomass and primary production in the Loviisa archipelago during the late 1970s and 1980s, though biomass seemed to decrease again in the 1990s. The rise in temperature was, however, a more important factor than nutrients stimulating the production and biomass in the area close to the cooling water outlet. The thermal discharges increased especially the biomass of Aphanizomenon spp., which is the most abundant cyanoprocaryote (blue-green alga) and one of the most common phytoplankton taxa in the study area. At the intake area, total amounts of phosphorus best explained the changes in total biomass. The results indicate that increased temperature can lengthen the growing season, advance eutrophication and somewhat change species dominances in the circumstances prevailing in the northern Baltic Sea.

Komulaynen, S. F. 2008: Phytoperiphyton community structure and distribution in the Teno River and its tributaries (Finnish Lapland). Boreal Env. Res. 13: 517–524.

Communiuties of attached algae (phytoperiphyton) from the Teno River and its tributaries were studied and their floristic composition and spatial distribution were analysed. A total of 215 taxa from 49 locations were identified. Attached algae communities, characteristic of oligotrophic waters, prevailed in the studied streams. Diatoms, dominated by typical attached forms such as Tabellaria flocculosa, Synedra ulna, Achnanthes minutissima, Eunotia pectinalis and Cymbella affinis, were most common and abundant. However, the bulk of biomass (0.8–42.9 g m^–2) was formed mainly by the filamentous green algae Zygnema, Bulbochaete and Oedogonium.

Hernesmaa, A., Björklöf, K., Jørgensen, K. S., Haahtela, K. & Romantschuk, M. 2008: Potential impacts of clear-felling on microbial activities in boreal humus and mineral soil layers. Boreal Env. Res. 13: 525–538.

Changes affecting the microbial activity in boreal coniferous forest humus and mineral soil layers after clear-felling were investigated by studying exoenzyme activities, microbial colony counts and community level physiological profiles, CLPPs. A recently clear-felled site and an old clear-felled site were compared with a standing forest site. The activities of exoenzymes in the humus layer increased 12 months after clear-felling. During this period, the amount of fungi increased in the humus layer as compared with that in the standing forest soil. The utilization potential of carbohydrates increased more than the utilization potential of amino acids and carboxylic acids in the humus layer of the new felled site. Immediate effects in the humus layer were followed by a 1-year delay of minor effects in the mineral layer. We showed that instant structural polymer degradation is initiated by a burst of exoenzymes in the humus layer. This effect was still observed in the old felled site seven years after felling.

Lopatin, E., Kolström, T. & Spiecker, H. 2008: Long-term trends in radial growth of Siberian spruce and Scots pine in Komi Republic (northwestern Russia). Boreal Env. Res. 13: 539–552.

Komi is situated on the eastern boundary of the European part of Russia, in the boreal region where large areas of natural forest still exist. Using radial growth measurements it was possible to attain positive long-term trends of growth in Scots pine (Pinus sylvestris) and Siberian spruce (Picea obovata) in the Komi Republic. Increases in the radial growth of Siberian spruce in the forest–tundra were 134% and in the northern taiga zone 35% over successive 50-year periods from 1901 to 1950 and from 1951 to 2000. Respectively, in the middle taiga zone a 76% increase in radial growth was found (over 100 years), whilst in the southern taiga zone the changes were not statistically significant. The increase in radial growth of Scots pine in the northern taiga zone was 32%. In the middle taiga zone the radial growth increase in Scots pine was 55% and in the southern taiga zone the changes were not statistically significant. The long-term growth trends of Komi were compared with those in other parts of Europe.

Väänänen, R., Hristov, J., Tanskanen, N., Hartikainen, H., Nieminen, M. & Ilvesniemi, H. 2008: Phosphorus sorption properties in podzolic forest soils and soil solution phosphorus concentration in undisturbed and disturbed soil profiles. Boreal Env. Res. 13: 553–567.

Podzol horizons (O, E, B1, B2 and C) from three undisturbed sites were analyzed for phosphorus (P) sorption, P saturation, P fractions, and P concentrations in soil solutions, and three disturbed Podzols for P in soil solution. The threshold concentrations for net sorption were 8000 µg l^–1 and 700 µg l^–1 for the O and E horizons, respectively, and 3–6 µg l^–1 for the B1, B2 and C horizons. Consequently, if water percolates through the B horizon the risk of P leaching is low. Phosphorus saturation degree was 0.2%–25%. Fe-P dominated in the O, E, B1 and B2 horizons, and Ca-P in the C horizon. P was depleted from the E horizon (24 µg g^–1) and enriched in the B1 and B2 horizons (500 and 250 µg g^–1) as compared with that in the C horizon (160 µg g^–1). P in soil solution increased in the topmost 3 cm of the disturbed B horizons.