Articles containing the keyword 'biomass production'.

• Hytönen, Natural Resources Institute Finland, Silmäjärventie 2, FI-69100 Kannus, Finland ORCID ID: – E-mail: jyrki.hytonen@luke.fi
• Saarsalmi, Natural Resources Institute Finland, P.O. Box 18, FI-01301 Vantaa, Finland ORCID ID: – E-mail: anna.saarsalmi@luke.fi

• Hytönen, Finnish Forest Research Institute, Kannus, Finland ORCID ID: – E-mail: jyrki.hytonen@metla.fi
• Aro, Finnish Forest Research Institute, Kannus, Finland ORCID ID: – E-mail: lasse.aro@metla.fi

• Johansson, Swedish University of Agricultural Sciences, Department of Forest Management and Products, P.O. Box 7060, S-750 07 Uppsala, Sweden ORCID ID: – E-mail: tord.johansson@sh.slu.se

• Backlund, Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Skogsmarksgränd, SE-901 83 Umeå, Sweden ORCID ID: – E-mail: ingegerd.backlund@slu.se
• Bergsten, Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Skogsmarksgränd, SE-901 83 Umeå, Sweden ORCID ID: – E-mail: urban.bergsten@slu.se

The biomass production and nutrient uptake of silver birch (Betula pendula Roth), downy birch (Betula pubescens Erhr.), grey alder (Alnus incana (L.) Moench), native willows Salix triandra L. and S. phylicifolia L. and exotic willows S. x dasyclados and S. ’Aquatica’ growing on a clay mineral soil field (Sukeva) and on two cut-away peatland areas (Piipsanneva, Valkeasuo) were investigated.

Biomass production of downy birch was greater than that of silver birch, and the biomass production of the native willows greater than that of the exotic ones. The performance of S. phylicifolia was the best of the studied willow species. Exotic willows were susceptible to frost damage and their winter hardiness was poor. The production of all species was lower on the clay mineral soil field than on the cut-away peatland areas. Fertilization of birches and alder – on the double dose given to the willows – increased biomass production. After 6 growing seasons the leafless biomass production of fertilized silver birch at Piipsanneca was 21 t ha^-1 (at Valkeasuo 34 t ha^-1) and of grey alder 24 t ha^-1, and that of S. triandra after five growing seasons 31 t ha^-1, S. phylicifolia 38 t ha^-1 and of S. x dasyclados 16 t ha^-1.

6-year-old stands of silver birch bound more nutrients per unit biomass than downy birch stands. Grey alder bound more N, Ca and Co but less Mn and Zn per unit biomass than silver and downy birch. On the field more P was bound in grey alder per unit biomass compared to downy birch. The willows had more K per unit biomass than the other tree species, and the exotic willow species more N than the native ones. Less N, K and Mg were bound per unit biomass of S. phylicifolia compared to the other tree species.

• Hytönen, ORCID ID: – E-mail: –
• Rossi, ORCID ID: – E-mail: –
• Saarsalmi, ORCID ID: – E-mail: –

The effects of repeated fertilizer treatment on biomass production and nutrient status of willow (Salix ’Aquatica’) plantations established on two cut-away peatland areas in western Finland were studied over a rotation period of three years. Comparisons were made between single fertilizer applications and repeated annual fertilization.

The annually repeated fertilizer application increased the amounts of acid ammonium acetate extractable phosphorus and potassium in the soil as well as the concentrations of foliar nitrogen, phosphorus and potassium compared to single application. Depending on the fertilizer treatment and application rate, annual fertilizer application resulted in over two times higher biomass production when compared to single fertilizer application over a three-year rotation period. The effect of phosphorus fertilizer application lasted longer than that of nitrogen. The optimum fertilization regime for biomass production requires that nitrogen fertilizer should be applied annually, but the effect of phosphorus can last at least over a rotation of three years. Potassium fertilizer treatment did not increase the yield in any of the experiments during the first three years. The leafless, above-ground yield of three-year-old, annually NP-fertilized willow plantations was 9.5 t ha^-1 and the total biomass, including stems, leaves, roots and the stump, averaged 17 t ha^-1.

• Hytönen, ORCID ID: – E-mail: –

The effects of fertilized treatment on the soil nutrient concentrations, biomass production and nutrient consumption of Salix x dasyclados and Salix ’Aquatica’ were studied in five experiments on three cut-away peatland sites in western and eastern Finland during three years. Factorial experiments with all combinations of N (100 kg ha^-1 a-¹⁾, P (30 kg ha^-1 a^-1) and K (80 kg ha^-1 a^-1) were conducted.

The application of P and K fertilizers increased the concentrations of corresponding extractable nutrients in the soil as well as in willow foliage. N-fertilization increased foliar nitrogen concentration. An increase in age usually led to decreases in bark and wood N, P and K concentrations and increases in bark Ca concentrations. N-fertilization increased the three-year biomass yield 1.5–2.7 times when compared to control plots. P-fertilization increased the yield only in those experimental fields whose substrates had the lowest phosphorus concentration. K-fertilization did not increase the yield in any of the experimental fields. The highest total biomass yield of NPK-fertilized willow after three growing seasons, 23 t ha^-1, was distributed in the following way: wood 42%, bark 19%, foliage 17%, stumps 6% and roots 16%. As the yield and stand age increased, more biomass was allocated in above-ground wood. Three-year-old stands (above-ground biomass 18 t ha^-1) contained as much as 196 kg N ha^-1, 26 kg P ha^-1, 101 kg K ha^-1, 74 kg Ca ha^-1 and 37 kg Mg ha ^-1. By far the highest proportion of nutrients accumulated in the foliage. The bark and wood contained relatively high proportions of calcium and phosphorus. With an increase in age and size, the amount of nitrogen and potassium bound in one dry-mass ton of willow biomass decreased while that of phosphorus remained unchanged.

• Hytönen, ORCID ID: – E-mail: –

Crown characteristics and the distribution of three years’ (1986–88) biomass production of 20 pendulous Norway spruce (Picea abies f. pendula (Lawson) Sylvén) trees with heritable narrow crown and 15 normal-growned spruces (Picea abies (L.) H. Karst.) were studied in a 19-year-old mixed stand.

The form of the crown is conical in normal-crowned trees, columnar and narrow in pendulous trees. The partitioning of aboveground biomass to stems during the studied 3-year period was significantly higher in pendulous (0.281) than in normal-crowned trees (0.255) and also the ratio between growth of stemwood and growth of needle biomass during three years was higher in pendulous trees (0.67 g g^-1) than in normal-crowned trees (0.52 g g^-1). The needle biomass was distributed higher in the crown in pendula than in normal-crowned trees and they had a higher needle biomass/branchwood biomass ratio than normal trees. The difference in harvest increment between the two crown types are mostly due to the significantly lower branchwood biomass values in pendulous than in normal-crowned trees. The higher needle ’efficiency’ in pendulous trees is probably connected with high partitioning of needle biomass to the upper part of the crown in pendulous trees.

The PDF includes an abstract in Finnish.

• Pulkkinen, ORCID ID: – E-mail: –

The development of shoot number and shoot properties was examined in successive shoot cohorts of young widely-spaced Scots pine trees (Pinus sylvestris L.) growing in a progeny trial. This was accomplished by reconstructing the branching process of the trees over a period of five years, from tree age 4 to 8. During this time the number of shoots in successive shoot cohorts increased rapidly, while at the same time the mean shoot length decreased. The decrease in shoot lengths from older to younger shoots was accompanied by a decline in the bifuraction frequency of the shoots. In general, rapid changes occurred in the branching characteristics during the yearly development of the trees. The variation in the branching characteristics was reflected in the development of the architecture and biomass production of the trees.

The PDF includes an abstract in Finnish.

• Kuuluvainen, ORCID ID: – E-mail: –

The architecture of Scots pine (Pinus sylvestris L.) was studied in an eight-year-old progeny test. The measurements included characteristics of crown structure, spatial distribution of shoots and yield components. The spatial distribution of shoots showed striking between-tree differences, and two extreme distribution patterns were detected. One represented a non-layered structure with a vertically relative even shoot distribution, and the other a layered structure with a vertically highly uneven shoot distribution.

Close correlations existed between several components of tree architecture and it is suggested that changes in the phenotypic architecture in Scots pine follow an epigenetic pattern, which enables the prediction of adaptational changes in structural components. The structural characteristics related to high above-ground biomass were a long crown, high total shoot length, high number of branches per whorl and big shoots of low needle density occupying a big share of the crown volume.

The PDF includes a summary in Finnish.

• Kuuluvainen, ORCID ID: – E-mail: –
• Kanninen, ORCID ID: – E-mail: –
• Salmi, ORCID ID: – E-mail: –

Possibilities of developing suitable willow (Salix spp.) clones for short-rotation forestry on mined peatlands in the north-western area of Finland were studied in a field experiment in which 300 willow clones were tested during 1985–87. Most of the tested clones started to grow from cuttings on limed and fertilized peat soil. Salix viminalis L. clones of southern origin had a higher leafless above ground biomass production than the well adapted control clone and the local Finnish willows, but their winter hardiness was not satisfactory. The growth habit of some southern willows was also better than that of the control clone. It was also possible to select clones with good sprouting capacity. There were few Salix myrsinifolia Calisb. clones of Finnish origin, which had better cold tolerance than all other willows tested and higher biomass production than that of the control clone. The most critical factor to be selected for this is the optimal combination of winter hardiness and biomass production. This is attempted by selecting clones on the basis of this experiment for a breeding program.

The PDF includes a summary in Finnish.

• Lumme, ORCID ID: – E-mail: –
• Törmälä, ORCID ID: – E-mail: –

Willow (Salix sp.) species and clones have been selected in Finland, originally for basket willow husbandry, since 1910's. Screening for biomass willows started in 1973 by the Foundation for Forest Tree Breeding. Biomass willow research for energy started in 1978. The objective of the study was, based on theoretical background, on historical record of Finnish willow research between 1910–80 and on analysis of the Finnish biomass willow research of the 1980s, a further selection of exotic and indigenous willows for energy and chemicals.

Swedish selection of 63 exotics, mainly of Salix viminalis L. and S. burjatica Nazarov, was screened in Kompparnäs willow research site in the southern coast of Finland in 1983–89. S. viminalis showed both high yield potential and good crop certainty. The yield variation in S. burjatica were big due to rust (Melampsora sp.) infection followed by lowered winter hardiness. Three recommendable S. viminalis clones for Southern Finland were found.

Finnish indigenous species were screened based on collection (375 clones) in 1974–74 of the Foundation for Forest Tree Breeding, and the Finnish 4H-organization (566 clones) in 1978–79 in test sites in Suomusjärvi, Nurmijärvi, Kannus and Haapavesi. Salix myrsinifolia Salisb. was most productive of the indigenous willows. Five recommendable clones were selected. The second most productive indigenous was S. phylicifolia, with three recommendable clones. Based on willow hybridization studies in the Finnish Forest Research Institute, a considerable additional selection effect, boosted by heterosis, was found from the progenies. Further intraspecific crossings of geographically distant clones of S. myrsinifolia are recommended.

Based on the results, S. viminalis is recommended for practical biomass forestry application in the southernmost agroclimatic zone of Finland. S. myrsinifolia is recommended for further research and development in the other zones.

The PDF includes a summary in Finnish.

• Pohjonen, ORCID ID: – E-mail: –