Articles containing the keyword 'chemistry'

Gravimetrically expressed nutrient concentrations of soil analysis were converted to volumetric values using dry bulk densities measured in the natural state and in the laboratory after air-drying and sieving the samples. The aim was to examine, using volumetric samples representing different soil classes, exactly how the converted nutrient values calculated by this laboratory method describe volumetric nutrient contents in undisturbed soil. In the fine soil classes undisturbed bulk density was higher than laboratory bulk density and converted nutrient concentrations were too small. In coarser soil classes the reverse was true, and the values were too high.

The PDF includes an abstract in English.

• Niska, E-mail: kn@mm.unknown

The heating values of wood, inner and outer bark, and foliage components of seven small-size tree species (Pinus sylvestris L., Picea abies (L.) H. Karst., Betula pubescens Erhr., B. pendula Roth, Alnus incana (L.) Moench, A. glutinosa (L.) Gaertn., Populus tremula L.) were studied. Significant differences were found between species within each component. However, the differences between species for weighted stem, crown and whole-tree biomass are very small. The weighted heating value of the crown mass is slightly higher than that of the stem in all species. The heating value of stem, crown and whole-tree material was found to increase with increasing latitude.

The effective heating value of wood correlated best with the lignin content, inner bark with carbohydrate, and outer bark with carbohydrates and the extractives soluble in alkalic solvents. It is suggested that the determination of the heating value might be used as an indicator of the cellulose content of coniferous wood.

The PDF includes a summary in Finnish.

• Nurmi, E-mail: jn@mm.unknown

There is evidence that moose are attracted to fertile growth habitats apparently due to better quality and larger quantities of food. The nutrients in mineral soils originate from the weathering of bedrock and the composition of parental bedrock affects the fertility of produced mineral soil, thus affecting also the import of nutrients into the whole food web. We surveyed the connection between moose damage in forest plantations and the composition of bedrock and surficial deposits in Finnish Lapland. We used a database of compensated moose damage in private forests in years 1997−2010. Undamaged stands in National Forest Inventories (NFI) from years 1986–2008 served as a control data and moose-damaged NFI-stands as a reference data. Bedrock and surficial depositions and the location of studied stands in relation to ancient shorelines were explored by using the digital databases of the Geological Survey of Finland. Moose-damaged stands were concentrated in southwestern and east Lapland in the areas of the Peräpohja Schist Belt and Lapland’s Greenstone Belt that are both composed of nutrient-rich rocks. The bedrock of damaged stands contained a higher proportion of mafic and alkaline rocks than did the control stands. Moose-damaged stands were pine-dominated and grew in more fertile forest sites than did control stands. Part of pine stands probably located in soils formerly occupied by spruce, which may increase the stands’ vulnerability to biotic threats. Especially, there were relatively more moose damage in pine plantations regenerated on fine-grained mineral soils derived from nutrient rich rocks than in less fertile soils.

• Ruuhola, Natural Resources Institute Finland (Luke), Natural Resources and Bioproduction, Yliopistokatu 6, FI-80101 Joensuu, Finland; University of Eastern Finland, Faculty of Science and Forestry, P.O. Box 111, FI-80101 Joensuu, Finland E-mail: teija.ruuhola@uef.fi
• Nikula, Natural Resources Institute Finland (Luke), Economics and Society, Eteläranta 55, FI-96300 Rovaniemi, Finland E-mail: ari.nikula@luke.fi
• Vesa, Natural Resources Institute Finland (Luke), Economics and Society, Eteläranta 55, FI-96300 Rovaniemi, Finland E-mail: vesa.nivala@luke.fi
• Nevalainen, Natural Resources Institute Finland (Luke), Natural Resources and Bioproduction, Yliopistokatu 6, FI-80101 Joensuu, Finland E-mail: seppo.nevalainen@luke.fi
• Matala, Natural Resources Institute Finland (Luke), Natural Resources and Bioproduction, Yliopistokatu 6, FI-80101 Joensuu, Finland E-mail: juho.matala@luke.fi

• Nieminen, Finnish Forest Research Institute, Vantaa Research Unit, P.O. Box 18, FI-01301 Vantaa, Finland E-mail: mika.nieminen@metla.fi
• Ahti, Finnish Forest Research Institute, Vantaa Research Unit, P.O. Box 18, FI-01301 Vantaa, Finland E-mail: ea@nn.fi
• Koivusalo, Department of Civil and Environmental Engineering, Aalto University School of Science and Technology, P.O. Box 15200, FI-00076 Aalto, Finland E-mail: hk@nn.fi
• Mattsson, Finnish Environment Institute, P.O. Box 140, FI-00251 Helsinki, Finland E-mail: tm@nn.fi
• Sarkkola, Finnish Forest Research Institute, Vantaa Research Unit, P.O. Box 18, FI-01301 Vantaa, Finland E-mail: ss@nn.fi
• Laurén, Finnish Forest Research Institute, Joensuu Research Unit, P.O. Box 68, FI-80101 Joensuu, Finland E-mail: al@nn.fi

• Tamminen, Finnish Forest Research Institute, Vantaa Research Centre, P.O. Box 18, FI-01301 Vantaa, Finland E-mail: pekka.tamminen@metla.fi
• Derome, Finnish Forest Research Institute, Rovaniemi Research Station, P.O. Box 16, FI-96301 Rovaniemi, Finland E-mail: jd@nn.fi

• Rosenberg, Skogforsk – The Forestry Research Institute of Sweden, Uppsala Science Park, SE-751 83 Uppsala, Sweden E-mail: olle.rosenberg@skogforsk.se
• Jacobson, Skogforsk – The Forestry Research Institute of Sweden, Uppsala Science Park, SE-751 83 Uppsala, Sweden E-mail: sj@nn.se

• Nieminen, Finnish Forest Research Institute, Vantaa Research Centre, P.O. Box 18, FIN-01301 Vantaa, Finland E-mail: mika.nieminen@metla.fi

Mechanical site preparation (MSP) is deliberate soil disturbance which is undertaken to improve the conditions for forest regeneration. Disc trenching and mounding are the dominant MSP practices currently used in Sweden and Finland. In this paper, the impacts of MSP on the soil, water quality, greenhouse gas (GHG) emissions and ground vegetation of mineral soil sites in Sweden and Finland are reviewed. The practices considered are patch scarification, mounding, inverting, disc trenching, and ploughing, which together represent a wide range of soil disturbance intensity. The environmental effects of MSP in this region have not been studied extensively. The environmental impact of MSP derives from the process of creating microsites which involves horizontal and/or vertical redistribution of soil and soil mixing. This typically affects decomposition, element circulation and leaching, vegetation coverage and uptake of nutrients and water, and possibly erosion and sediment exports. Following disc trenching or mounding the effects on GHG emissions appear to be minor over the first two years. For a few years after disc trenching concentrations in soil water collected below ridges are higher than that below furrows for some elements (e.g., NO₃^-, NH₄⁺, Mg²⁺, and total or dissolved organic C). The physical and chemical effects of ploughing remain detectable for several decades. There is little evidence about how the effects of forestry activities in upland areas on soil-water chemistry are transferred to adjacent surface water bodies, including what role streamside discharge areas play. MSP increases the tree biomass C store and may increase the total ecosystem C store. The impact of MSP on the cover and abundance of ground vegetation species depends on the composition of the original plant community, MSP intensity, and the establishment rate of different species. Species cover generally seems to decline for late succession understory species, while pioneer and ruderal species can benefit from the microsites created. Areas containing lichens which are used for reindeer forage require special consideration. More research is needed on the environmental effects of MSP, particularly regarding its long-term effects. Further efforts should be made to develop efficient site-preparation practices which better balance the disturbance intensity with what is needed for successful regeneration.

• Ring, Skogforsk (The Forestry Research Institute of Sweden), Uppsala Science Park, 751 83, Uppsala, Sweden https://orcid.org/0000-0002-8962-9811 E-mail: eva.ring@skogforsk.se
• Sikström, Skogforsk (The Forestry Research Institute of Sweden), Uppsala Science Park, 751 83, Uppsala, Sweden E-mail: ulf.sikstrom@skogforsk.se