Natural Resources Institute Finland Luke
Natural Resources Institute Finland Luke
Riikonen J.,Natural Resources Institute Finland Luke
Forest Ecology and Management | Year: 2017
Light quality affects the morphological development of a plant. The aim of the experiment was to examine the effect of far-red radiation (FR, 700–800 nm) on growth, morphology, and root growth capacity (RGC) in Scots pine seedlings originating from latitudes 61°N and 67°N, and on gas exchange and subsequent field growth in seedlings originating from 61°N. The seedlings were grown in a greenhouse under natural daylight, receiving either FR-rich (+FR) or FR-deficient (−FR) supplemental light for 20 h per day, provided using light-emitting diodes (LEDs). The seedlings were outplanted and grown in the field for two growing seasons. Growth under +FR hastened terminal bud formation in seedings originating from 61°N, and delayed it in seedlings from 67°N. At the end of the growth period under the LEDs, +FR seedlings were dominated by secondary needles and had a higher needle mass than −FR seedlings, whose foliage comprised mainly primary needles. −FR improved root growth capacity in the seedlings originating from 61°N, but not in seedlings originating from 67°N. In seedlings from 61°N, photosynthesis (Pn) at the needle area level was higher and stomatal conductance lower under −FR, resulting in higher water use efficiency than under +FR. Due to the greater amount of photosynthetic tissue under +FR, the whole-seedling-level Pn was higher under +FR. Height and diameter growth were greater in −FR seedlings than in +FR seedlings during the second growing season. Growth habit and growth rate of Scots pine seedlings can be manipulated by controlling the FR content in the supplemental light, enabling production of seedlings targeted for outplanting on sites with specific characteristics. © 2017 Elsevier B.V.
Hyvaluoma J.,Natural Resources Institute Finland Luke
International Journal of Geographical Information Science | Year: 2017
Topographical parameters derived from digital elevation models by employing flow routing algorithms may depend on the orientation of the square grid. Grid orientation dependence results from the insufficient isotropy of square grid and affects the flow directions and subsequent calculations based on flow routing. In this article, a systematic approach for analysing the rotational invariance of flow accumulation calculations is presented and applied. Computed flow accumulation maps are found to depend strongly on the grid orientation, especially if flow routing methods with low dispersion are used. It is also shown that isotropy of flow routing algorithms can be significantly improved by introducing a numerical parameter resulting in adjustable weighting for cardinal and diagonal directions in flow routing. The actual value of this parameter depends on the used flow routing method. © 2017 Informa UK Limited, trading as Taylor & Francis Group
Kuisma M.,Natural Resources Institute Finland Luke |
Kahiluoto H.,Lappeenranta University of Technology
Resources, Conservation and Recycling | Year: 2017
Enhancing the efficiency of biotic resource use by avoiding losses and boosting circular economy is one key in agrifood systems to ensuring food security and the functioning of the Earth system. The aims of this study were to first identify the greatest prospects for improving the biotic resource use efficiency and, second, to design methods to assess this efficiency. We assessed biotic resource use efficiencies (outputs/inputs) and biotic residue ratios (residues/inputs) in terms of dry matter, energy (LHVd), nitrogen and phosphorus for two Finnish case regions. We identified the greatest biotic resource use inefficiency as occurring in animal production, followed by crop production. The resource use efficiency in animal production is unavoidably low, but in crop production, the utilization of recycled nutrients, i.e., animal and green manures, and the rejection of the use of spare mineral fertiliser can enhance efficiency. In addition, the agrifood system efficiency was 3.4–21% higher according to the circular use of biotic resources compared to the exclusion of these. The losses from the agrifood system represent 52–76% of the current biotic inputs of the studied elements in crop production, which highlights the importance of efficient resource use in terms of food security. We conclude that substituting the external resources in favour of the circular use of biotic resources as well as the avoidance of losses are the keys to enhancing the system's efficiency. The determination of the biotic resource use efficiency and biotic residue ratio applying the introduced generic assessments serves boosting of circular economy. © 2017 Elsevier B.V.
Nevalainen S.,Natural Resources Institute Finland Luke
Silva Fennica | Year: 2017
The literature on the most prominent forest damage related to even-aged and uneven-aged forest management regimes was reviewed. A questionnaire to expert researchers was conducted to estimate risks in even-aged and uneven-aged forest management chains in Finland. There are only a few empirical comparisons of damage risks in even-and uneven-aged stands in the literature. The results from the expert survey showed that the damage risks were higher in even-aged management in Norway spruce and Scots pine. However, the variation in the risks between individual chains and between individual causes was high. The highest risks in Scots pine were caused by moose (in even-aged chains) and harvesting damage (in uneven-aged chains). In Norway spruce, root rot caused the highest risks in both even-aged and uneven-aged chains. The higher risks in even-aged forestry are largely due to the many associated practices which favour various types of damage. However, there are some important exceptions: the damage risks may be higher in some uneven-aged stands, especially in Norway spruce stands infected with root rot where the utilization of undergrowth or natural regeneration can be risky. Moreover, the repeated thinnings in uneven-aged stands may lead to increased mechanical damage. © 2017, Finnish Society of Forest Science. All rights reserved.
van Overbeek L.S.,Wageningen University |
Saikkonen K.,Natural Resources Institute Finland Luke
Trends in Plant Science | Year: 2016
Research on different endophyte taxa and the related scientific disciplines have largely developed separately, and comprehensive community-level studies on bacterial and fungal interactions and their importance are lacking. Here, we discuss the transmission modes of bacteria and fungi and the nature of their interactions in the endosphere at both the molecular and physiological level. Mixed-community biofilms in the endosphere may have a role in protecting endophytes against encountered stresses, such as from plant defense systems. However, transmission from static (in biofilms) to free-living (planktonic) forms may be crucial for the exploration of new habitable spaces in plants. Important features previously recognized as plant-microbe interactions or antagonism in endophyte genomes and metagenomes are proposed to have essential roles in the modulation of endophyte communities. © 2016 Elsevier Ltd.
Riikonen J.,Natural Resources Institute Finland Luke
New Forests | Year: 2016
Forest nurseries use different greenhouse light sources including new light technologies to produce conifer seedlings without knowing their real impact on subsequent field performance. The aim of the experiment was to investigate whether different growth light spectra during pre-cultivation of Scots pine and Norway spruce seedlings under controlled conditions affect growth and morphology of seedlings, and whether the possible differences between the treatments will be maintained after outplanting to a field site. The seedlings were pre-cultivated for 5.5–6.5 weeks in a darkened greenhouse under four light spectra consisting of different proportions of blue (B, 400–500 nm), red (R, 600–700 nm), and far-red (FR, 700–800 nm), with high-pressure sodium lamps (HPS) serving as controls. The light treatments (250 µmol m−2 s−1 photosynthetically active radiation) were provided using light-emitting diodes, and the treatments included the following: (1) 25 % B + 70 % R + 5 % FR; (2) 25 % B + 75 % R; (3) 55 % B + 45 % R; and (4) HPS: 6 % B + 44 % green (500–600 nm) + 41 % R + 9 % FR (control). Growth and morphology were studied at the time of transplanting in spring, and again, at the time of outplanting the seedlings in the field site in autumn. Growth, survival and phenology of the seedlings were followed in the field for 1 year. Growth and morphology of the seedlings were modified by the different growth light spectra during pre-cultivation, but by the time of outplanting, these differences between the treatments had disappeared. In conclusion: Growth and morphology of seedlings can be modified by adjusting the spectral composition of growth light during pre-cultivation, but the modifications may not be long-lasting. © 2016, Springer Science+Business Media Dordrecht.
Lehtonen A.,Natural Resources Institute Finland Luke |
Heikkinen J.,Natural Resources Institute Finland Luke
Canadian Journal of Forest Research | Year: 2016
Changes in the soil carbon stock of Finnish upland soils were quantified using forest inventory data, forest statistics, biomass models, litter turnover rates, and the Yasso07 soil model. Uncertainty in the estimated stock changes was assessed by combining model and sampling errors associated with the various data sources into variance-covariance matrices that allowed computationally efficient error propagation in the context of Yasso07 simulations. In sensitivity analysis, we found that the uncertainty increased drastically as a result of adding random year-to-year variation to the litter input. Such variation is smoothed out when using periodic inventory data with constant biomass models and turnover rates. Model errors (biomass, litter, understorey vegetation) and the systematic error of total drain had a marginal effect on the uncertainty regarding soil carbon stock change. Most of the uncertainty appears to be related to uncaptured annual variation in litter amounts. This is due to fact that variation in the slopes of litter input trends dictates the uncertainty of soil carbon stock change. If we assume that there is annual variation only in foliage and fine root litter rates and that this variation is less than 10% from year to year, then we can claim that Finnish upland forest soils have accumulated carbon during the first Kyoto period (2008-2012). © 2016 National Research Council of Canada, All rights reserved.
Uusivuori J.,Natural Resources Institute Finland Luke
Forest Science | Year: 2016
One of the most fundamental questions in forest economics is how to divide forestland between productive and conserved land. In this study, voluntary land conservation by private forest owners is analyzed in two cases: first, in a case in which access to conserved forest is closed; and second, in a case in which there is an open access to the recreational amenities of conserved forest. It is demonstrated that, under private ownership of forestland, recreational open access gives rise to a competitive equilibrium solution in which less forestland is designated to conservation than with the closed-access solution. Essentially this tragedy-of-commons type of result is based on a free-rider behavior. Optimal conservation policies are also studied in the two regimes. When conservation policies are imposed in a closed-access regime, optimal policies become dependent on income distribution and wealth differentials between land-owning and nonlandowning members of society. © 2016 Society of American Foresters.
Huuskonen A.,Natural Resources Institute Finland Luke
Journal of Applied Animal Research | Year: 2016
The aim of this study was to provide information concerning calf performance when dairy calves are fed milk replacers (MR) in which skim milk powder is partly or completely replaced by whey products and wheat protein. A feeding experiment comprised 30 dairy bull calves. During the pre-weaning the calves received three different MRs. The main ingredients of MR1 were skim milk powder (418 g/kg dry matter), whey powder (409) and vegetable oil (163). MR2 included less skim milk powder (300) compared to MR1 including whey powder (283), vegetable oil (190), whey fractions (100), hydrolysed wheat protein (65) and wheat starch (50). MR3 did not include skim milk powder while the main ingredients were whey powder (448), whey fractions (300) vegetable oil (160) and hydrolysed wheat protein (70). Live weight gain of the MR2 calves was 14% higher compared to the MR3 calves during the pre-weaning but there were no differences when compared MR1 calves to other treatments. No treatment differences were observed in gain during post-weaning or average during the experiment. There were no differences in feed conversion among treatments. The results indicated that both skim milk powder and whey-based products were suitable energy sources in MR. © 2016 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group
Laitila J.,Natural Resources Institute Finland Luke |
Nuutinen Y.,Natural Resources Institute Finland Luke
Croatian Journal of Forest Engineering | Year: 2015
Impurities in harvested stumps are a quality problem because high levels of mineral contaminants decrease the effective heating value of the stump wood, and can also affect ash melting behaviour during combustion, leading to sintering and drift problems. The aim of this case study was to clarify the productivity and screening efficiency of the Kompetech Crambo 6000 low-speed double-shaft grinder equipped with a Komptech star screen, in the integrated grinding and screening of Norway spruce and Scots pine stumps for fuel at a roadside landing, when using two different sieve sizes (250 x 320 mm and 180 x 180 mm screen baskets). Furthermore, we studied the fuel consumption of the Crambo 6000 grinder, ash content and particle size distribution of ground stump wood, and ash content and particle size distribution of the screening reject. In addition, the heating value of the produced hog fuel and screening reject were analysed. During the time of the studies, both the grinder and star screen were operating well and there were no delays due to machine breakdowns. The mobile Crambo 6000 grinder was also capable of operating well in constricted roadside landings. The quality of the produced hog fuel was high, due to low ash content (0.4–2.3%), and this highlights the significance of screening to guarantee sufficient quality when processing stump fuel. The ash content of the screening reject was 32.4–74.7%, and the effective heating value was 5.2–13.4 MJ/kg. The effective heating value of the produced hog fuel was 17.9–19.9 MJ/kg. The average grinding productivity, when using the 250 x 320 mm screen basket, was 162 loose m3 per effective hour, and the fuel consumption of the grinder was 0.44 litres per loose m3. With a narrower screen, the average grinding productivity was 101 loose m3 per effective hour, and the fuel consumption of the grinder was 0.75 litres per loose m3. © 2015, University of Zagreb. All rights reserved.