Zettler, M. L., Röhner, M. & Frankowski, J. 2006: Long term changes of macrozoobenthos in the Arkona Basin (Baltic Sea). Boreal Env. Res. 11: 247–260.

In 2001–2004 extensive studies of the macrozoobenthos community within the German Arkona Basin were undertaken. The results with consideration of the habitat conditions prevailing in different depth zones are presented. By multidimensional scaling we distinguished two separate macrozoobenthos communities (global r = 0.758, p = 0.1), one predominant in a habitat with sandy sediment or gravel and stones at water depths < 35 m (8–11 psu) and the other preferring a muddy habitat with higher salinity (11–23 psu) at water depths > 35 m. Additionally, long-term changes in selected benthic species of the Arkona Basin are described by comparing the recent macrozoobenthic data with data sets of the last 80 years. Special emphasis was placed on the use of historical data as a tool of assessment of changes of macrozoobenthic communities with respect to different habitat conditions. While the distribution patterns of several species under investigation have changed between the different time periods, nevertheless, with few exceptions no consistent changes from the past to present days were observed. The species composition of the macrozoobenthic community in the shallower area was very similar during all time periods. Only in deeper waters did we find differences, which may be explained by past changes in hydrography (e.g. salinity, oxygen). In both depth ranges a 3–10-fold increase of abundance from the past to the present has been observed that might have been caused by eutrophication.

Nordmyr, L., Boman, A., Åström, M. & Österholm, P. 2006: Estimation of leakage of chemical elements from boreal acid sulphate soils. Boreal Env. Res. 11: 261–273.

The amount of element leakage from young Finnish (boreal) acid sulphate soils was investigated using hydrochemical and geochemical approaches. These approaches gave similar results for S, Na, Mg, Al, Mn, Zn, Sr, Ni and Co, while Ca, La, Cd, U and Fe displayed higher leakage figures when using the hydrochemical approach and K, Cu, Ba, Ga, Sc, Ti, Pb, Th and Tl higher ones when using the geochemical approach. Total reducible sulphur (TRS) was the dominant sulphur species in the parent sediment and in the transition zone, while in the upper oxidised zone it had to a substantial extent been oxidised into sulphuric acid and subsequently leached, giving rise to typical AS soils and waters. However, also in this zone there was a reservoir of TRS left, which shows that the soils still have a great oxidation and acidification potential. The combination of the two approaches gave a clear picture of the qualitative and quantitative leaching of chemical elements from the soils with more reliable results than if only one approach would have been used. The method applied here can therefore be recommended for future studies and environmental monitoring in areas affected by acid sulphate soils.

Sundström, R. & Åström, M. 2006: Characterization of the metal leakage from Finnish agricultural acid sulphate soils in the light of the European Water Framework Directive. Boreal Env. Res. 11: 275–281.

On the coastal plains of Finland, widespread acid sulphate soils have developed as a result of agricultural drainage activities and constitute a massive supplier of metals and acidic compounds to the aquatic environment. As a consequence, the aquatic life (fish, etc.) is seriously damaged in many water courses. The EU Water Framework Directive (WFD) which came into force in December 2000, sets new goals for the condition of Europe's waters. For surface waters the overall objective is `good chemical and ecological status', which shall be achieved by December 2015. Furthermore, there is a list of `priority substances' in the WFD, for which discharges, emissions and losses have to be reduced or phased out. The existing environmental data concerning the Finnish AS soils show that the current management of these soils results in aquatic impacts which clearly conflicts with the provisions of the WFD.

Tissari, J. M., Yli-Tuomi, T., Raunemaa, T. M., Tiitta, P. T., Nuutinen, J. P., Willman, P. K., Lehtinen, K. E. J. & Jokiniemi, J. K. 2006: Fine particle emissions from milled peat production. Boreal Env. Res. 11: 283–293.

Peat dust emissions and particle concentrations at different distances from a milled peat production field were studied for two different harvesting methods. The dust emissions were found to be sporadic. The momentary PM_2.5 concentrations, which varied up to 5 mg m^–3 near the operation area, depended on the operation and weather conditions as well as peat composition. By using the Fugitive Dust Model, PM_2.5 emission rates were estimated to range from 0.3 to 43 g s^–1. Wind erosion increased the PM_2.5 concentrations remarkably at wind speeds over 4 m s^–1. Using time activity data of the different operational phases the lowest fine particle emissions were observed from the milling phase and the highest in the harvesting phases, respectively. As compared with the present EU daily limit value, the concentrations further from the peat production field were estimated to be low. However, short term negative influences on living conditions in the neighbourhood of peat production areas may be possible under certain environmental conditions.

Pakkanen, T. A., Mäkelä, T., Hillamo, R. E., Virtanen, A., Rönkkö, T., Keskinen, J., Pirjola, L., Parviainen, H., Hussein, T. & Hämeri, K. 2006: Monitoring of black carbon and size-segregated particle number concentrations at 9-m and 65-m distances from a major road in Helsinki. Boreal Env. Res. 11: 295–309.

In February and August 2003, black carbon (BC) and size-segregated particle number concentrations were monitored simultaneously at 9-m and 65-m distances from a major road in Helsinki, Finland, using aethalometers and electrical low-pressure impactors, respectively. During weekdays in winter, the average total particle number concentrations in the diameter range 0.007–1 ?m increased during morning rush hours from the nighttime values of 17000 and 12000 cm^–3 to 190000 and 130000 cm^–3 at the 9-m and 65-m stations, respectively. The corresponding BC concentrations increased from 730 and 430 ng m^–3 to 2800 and 1550 ng m^–3. Compared with those in winter, the average rush-hour particle number concentrations were much lower in summer, the likely reason being enhanced nucleation in cold winter conditions. BC concentrations were slightly higher during summer than during winter. Number size distributions measured at the 9-m and 65-m distances and at a background site had similar modal characteristics with the highest peak occurring below 0.03 ?m. Despite the different wind conditions in winter and summer, concentrations of total particle number and BC decreased similarly between the 9-m and 65-m stations, the likely principal mechanism being mixing with background air. The strong diurnal variation in concentrations during the weekdays, together with the large concentration difference between the 9-m and 65-m distances, suggests that local traffic was the main source of the measured pollutants, especially during rush hours at the 9-m site. In winter, the decrease in the particle number concentrations from the 9-m site to the 65-m site was most pronounced for the smallest exhaust particles. During an episodic pollution event in winter there were indications of condensational growth of 0.007–0.03 ?m particles, which increased the number concentration of 0.03–0.06 ?m particles at the 65-m site.

Arneth, A., Lloyd, J., Shibistova, O., Sogachev, A. & Kolle, O. 2006: Spring in the boreal environment: observations on pre- and post-melt energy and CO₂ fluxes in two central Siberian ecosystems. Boreal Env. Res. 11: 311–328.

A range of observations points towards earlier onset of spring in northern high latitudes. However, despite the profound effects this may have on vegetation–atmosphere exchange of carbon (NEE), vegetation–atmosphere physical coupling, or the location of the tundra–taiga interface, the number of studies that investigate winter–spring transition fluxes in contrasting northern vegetation types is limited. Here, we examine spring ecosystem–atmosphere energy and carbon exchange in a Siberian pine forest and mire. Divergent surface albedo before and during snow-melt resulted in daytime net radiation (R_n) above the forest exceeding R_n above the mire by up to 10 MJ m^–2. Until stomata could open, absorbed radiation by the green pine canopy caused substantial daytime sensible heat fluxes (H > 10MJ m^–2). H above the mire was very low, even negative (< –2 MJ m^–2), during that same period. Physiological activity in both ecosystems responded rapidly to warming temperatures and snow-melt, which is essential for survival in Siberia with its very short summers. On days with above-zero temperatures, before melt was complete, low rates of forest photosynthesis (1–2 umol m^–2 s^–1) were discernible. Forest and mire NEE became negative the same day, or shortly after, photosynthesis commenced. The mire lagged by about two weeks behind the forest and regained its full carbon uptake capacity at a slower rate. Our data provide empirical evidence for the importance the timing of spring and the relative proportion of forest vs. mire has for late winter/spring boundary-layer growth, and production and surface–atmosphere mixing of trace gases. Models that seek to investigate effects of increasingly earlier spring in high latitudes must correctly account for contrasting physical and biogeochemical ecosystem–atmosphere exchange in heterogeneous landscapes.