Hansen, J. P., Wikström, S. A. & Kautsky, L. 2012: Taxon composition and food-web structure in a morphometric gradient of Baltic Sea land-uplift bays. Boreal Env. Res. 17: 1–20.
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Räsänen, J. V., Yli-Pirilä, P., Holopainen, T., Joutsensaari, J., Pasanen, P. & Kivimäenpää, M. 2012: Soil drought increases atmospheric fine particle capture efficiency of Norway spruce. Boreal Env. Res. 17: 21–30.
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Laapas, M., Jylhä, K. & Tuomenvirta, H. 2012: Climate change and future overwintering conditions of horticultural woody-plants in Finland. Boreal Env. Res. 17: 31–45.
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Hui, N., Liu, X. X., Kurola, J., Mikola, J. & Romantschuk, M. 2012: Lead (Pb) contamination alters richness and diversity of the fungal, but not the bacterial community in pine forest soil. Boreal Env. Res. 17: 46–58.
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Muukkonen, P., Angervuori, A., Virtanen, T., Kuparinen, A. & Merilä, J. 2012: Loss and fragmentation of Siberian jay (Perisoreus infaustus) habitats. Boreal Env. Res. 17: 59–71.
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Rautiainen, M., Heiskanen, J. & Korhonen, L. 2012: Seasonal changes in canopy leaf area index and MODIS vegetation products for a boreal forest site in central Finland. Boreal Env. Res. 17: 72–84.
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Hansen, J. P., Wikström, S. A. & Kautsky, L. 2012: Taxon composition and food-web structure in a morphometric gradient of Baltic Sea land-uplift bays. Boreal Env. Res. 17: 1–20.

Shallow Baltic Sea bays undergo a process of morphometric isolation from the sea due to post-glacial land uplift. Recent studies have documented that both flora and fauna communities change along this gradient. Changes in taxon composition may in turn alter feeding ecology and trophic relationships. In addition, the relative importance of energy from terrestrial sources may increase with bay isolation. In accordance with previous studies, we found a change in the community composition of both flora and fauna with bay isolation. Results of a stable-isotope analysis (δ¹³C, δ¹⁵N) suggested that epiphytes and periphyton are the major carbon sources for most benthic primary consumers, but that their importance in relation to angiosperms and charophytes decreased with bay isolation. The results also indicated that filter feeders utilize terrestrially-derived carbon, but its importance could not be critically related to bay isolation. Trophic positions of the consumers were similar across the bay isolation gradient.

Räsänen, J. V., Yli-Pirilä, P., Holopainen, T., Joutsensaari, J., Pasanen, P. & Kivimäenpää, M. 2012: Soil drought increases atmospheric fine particle capture efficiency of Norway spruce. Boreal Env. Res. 17: 21–30.

Atmospheric fine particles from natural and anthropogenic sources reduce air quality and thus cause undesirable health and climate effects. Trees can act as obstacles to dispersal of particle pollution and thus remove a significant amount of particulate matter from the atmosphere. However, the significance of environmental factors in this context is not well understood. The effect of drought on fine particle capture efficiency (Cp) of Norway spruce (Picea abies) saplings was studied in controlled wind-tunnel experiments. The results showed that Cp of Norway spruce saplings with low soil water availability was 0.065% and well watered saplings 0.051%. Particle deposition onto all parts of the canopy was equally efficient with no difference in Cp between current- and previous-year needle generations. The results suggest that water availability significantly affects Cp of Norway spruce, which may be partly due to altered stomatal function.

Laapas, M., Jylhä, K. & Tuomenvirta, H. 2012: Climate change and future overwintering conditions of horticultural woody-plants in Finland. Boreal Env. Res. 17: 31–45.

Climate in Finland offers challenging conditions for commercial horticulture. The short and insufficient growing season together with risky overwintering strongly limits species suitable for cultivation. The aim of this study was to examine the climatic conditions around Finland in the aspect of horticulture, focusing on processes relevant to woody plants and species with photoperiod controlled growth cessation, and how these conditions may be expected to change due to the projected global warming. For this, a set of temperature-related indices and threshold events were used. These indices represent the severity of coldness during winter, wintertime thaws, and frost events close to the onset and ending of the growing season. The combined results of 19 GCMs (General Circulation Model) from the CMIP3 (Coupled Model Intercomparison Project 3) multi-model data set under SRES-B1 and SRES-A2 (Special Report on Emission Scenarios) emission scenarios were used to produce the future projections. By mid-century our results suggest wintertime conditions with reduced cold stress, caused by less frequent and shorter periods of severe frost together with a rise in the extreme minimum temperature. Conversely, an increase in the number and intensity of wintertime thaw events leads to a higher risk in overwintering. Also the risk of spring frost damage is projected to decrease slightly, and the conditions for cold hardening process to improve, as the first autumnal frosts occur later.

Hui, N., Liu, X. X., Kurola, J., Mikola, J. & Romantschuk, M. 2012: Lead (Pb) contamination alters richness and diversity of the fungal, but not the bacterial community in pine forest soil. Boreal Env. Res. 17: 46–58.

The aim of the study was to gain a more detailed view of the changes in microbial community structure in boreal forest soil due to lead contamination. The Hälvälä shooting range in southern Finland is heavily polluted by lead. The humus soil microbial community was examined using DNA based methods. To examine the bacterial community a 400 bp section of the 16S rRNA gene was amplified, cloned, and sequenced. For fungi, the internal transcribed spacer (ITS) area was examined. The 917 bacterial sequences grouped into 398 operational taxonomic units (OTUs) at ≤ 97% similarity, while 649 fungal sequences grouped into 155 OTUs at ≤ 99% similarity. No effect of lead was found on bacterial richness or diversity, while fungal richness and diversity were significantly altered. Some OTUs assigned to Basidiomycota were much rarer in the lead contaminated areas while the genus Thelephora was enriched in the lead contaminated soil. This difference between bacterial and fungal responses to lead suggests a difference in the strategy to avoid the contaminant. The analyses performed here do not, however, allow for conclusions regarding mechanisms.

Muukkonen, P., Angervuori, A., Virtanen, T., Kuparinen, A. & Merilä, J. 2012: Loss and fragmentation of Siberian jay (Perisoreus infaustus) habitats. Boreal Env. Res. 17: 59–71.

We analyzed forest landscape changes in a western Finnish breeding area of Siberian jays utilizing Landsat MSS and TM satellite images taken during a 29-year period (1976–2005). We found that Siberian jays appeared to favour closed spruce-dominated forest patches, possibly because they provide better visual protection against predators. Such spruce-dominated forest patches became smaller and increasingly fragmented during the study period. According to a 25-m pixel analysis, the total area of spruce-dominated habitats decreased from 14.7% to 11.0% and the mean patch size from 2.0 ha to 1.4 ha during 1987–2005. This was mainly due to intense loggings of spruce forests and a special form of land ownership, which has induced narrow forest estates measuring few dozens of metres in width. The parallel decline in potential breeding habitats as well as Siberian jay population size suggests that loss and fragmentation of key habitats, and possibly related changes in predator community, are the most probable causes for the decline of Siberian jay population in the study area.

Rautiainen, M., Heiskanen, J. & Korhonen, L. 2012: Seasonal changes in canopy leaf area index and MODIS vegetation products for a boreal forest site in central Finland. Boreal Env. Res. 17: 72–84.

Seasonal change in leaf area index (LAI) is highly important in remote sensing of land surface phenology because LAI is a main driving factor of forest reflectance. We present a time series of in situ measurements of boreal forest LAI expanding throughout the growing period from budburst to senescence. We measured the LAI of 20 stands at approximately two-week intervals between mid-May and mid-September in 2009 in southern Finland using hemispherical photography. We compared our field reference data with landscape-level MODIS surface reflectance trajectories, vegetation indices and LAI products. Our results showed that the timing of maximum LAI varies in different forest types. In general, the MODIS-based vegetation indices followed the general trend of spring–summer canopy LAI well. The MODIS LAI product, on the other hand, portrayed well the spring build-up of canopy-level foliage of broadleaved stands but began to decrease earlier in the fall than the ground reference LAI.