| 1. |
- Adler, Anneli, et al.
(författare)
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Variation of growth and phenology traits in poplars planted in clonal trials in Northern Europe-implications for breeding
- 2021
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Ingår i: BioEnergy Research. - : Springer Science and Business Media LLC. - 1939-1234 .- 1939-1242. ; 14, s. 426-444
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Tidskriftsartikel (refereegranskat)abstract
- The increased demand for wood to replace oil-based products with renewable products has lifted focus to the Baltic Sea region where the environment is favorable for woody biomass growth. The aim of this study was to estimate broad-sense heritabilities and genotype-by-environment (GxE) interactions in growth and phenology traits in six climatically different regions in Sweden and the Baltics. We tested the hypothesis that both bud burst and bud set have a significant effect on the early growth of selected poplar clones in Northern Europe. Provenance hybrids of Populus trichocarpa adapted to the Northern European climate were compared to reference clones with adaptation to the Central European climate. The volume index of stemwood was under low to medium genetic control with heritabilities from 0.22 to 0.75. Heritabilities for phenology traits varied between 0.31 and 0.91. Locally chosen elite clones were identified. GxE interactions were analyzed using pairwise comparisons of the trials. Three different breeding zones for poplars between the latitudes of 55 degrees N and 60 degrees N in the Baltic Sea Region were outlined. The studied provenance hybrids with origin from North America offer a great possibility to broaden the area with commercial poplar plantations in Northern Europe and further improve the collection of commercial clones to match local climates. We conclude that phenology is an important selection criterion after growth.
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| 2. |
- Aronsson, Pär, et al.
(författare)
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Impact of nitrogen fertilization to short-rotation willow coppice plantations grown in Sweden on yield and economy
- 2014
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Ingår i: BioEnergy Research. - : Springer Science and Business Media LLC. - 1939-1234 .- 1939-1242. ; 7, s. 993-1001
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Tidskriftsartikel (refereegranskat)abstract
- A fertilization trial was carried out in established short-rotation willow coppice (SRWC) plantations of two bred varieties of willow (Salix spp.; "Tora" and "Jorr") at five sites in central Sweden between 2008 and 2010. Mineral nitrogen was applied at four different rates: No fertilization (Control), 160 kg nitrogen ha(-1) as a single dose after harvest (Economy), 60-100-60 kg nitrogen ha(-1) in year 1-2-3 (Normal), and 160 kg nitrogen ha(-1) year(-1) in years 1-3 (Intensive), using a randomized block design with four replicates. The yield response (biomass increase per kg fertilizer nitrogen) was 65, 67 and 46 kg kg(-1) in the Economy, Normal and Intensive treatments, respectively. The results from the fertilization trial were used for economic calculations of different fertilization strategies given varying costs for fertilization and marginal value of the increased yield (price received for wood chips minus the costs for harvest and transportation of wood chips to a district heating plant). Comparative calculations were made based on data from a previous fertilization trial during the first cutting cycle of old, non-bred varieties. The calculations showed positive net present values of fertilizing bred willow varieties given a realistic fertilization response and a price for wood chips close to the market price for forestry-based wood chips in Sweden.
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| 3. |
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| 4. |
- Dimitriou, Ioannis, et al.
(författare)
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Impact of Populus plantations on water and soil quality
- 2017
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Ingår i: BioEnergy Research. - : Springer Science and Business Media LLC. - 1939-1234 .- 1939-1242. ; 10, s. 750-759
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Tidskriftsartikel (refereegranskat)abstract
- Trees of genus Populus (in our context primarily poplars) are predominantly grown in Sweden in small plantations on arable land in southern and central parts of the country to produce biomass for energy and other purposes. This study evaluated the effects (i) of poplar plantations on groundwater quality, by determining differences in leaching of nitrogen and phosphorus to groundwater, and (ii) of poplar and hybrid aspen plantations on soil quality in terms of carbon in the top- and subsoil. The study was conducted comparing Populus plantations in Sweden with adjacent fields with cereals and grasslands. The experiment concerning the groundwater leaching was conducted in eight poplar plantations along three growing seasons (2012-2015). For the soil carbon experiments, 19 poplar and two hybrid aspen plantations and the respective reference fields were sampled. NO3-N leaching from poplar plantations was significantly lower than that from reference fields with cereals, but not when compared with grasslands. Spring NO3-N leaching was significantly lower in poplars than in the reference fields, whereas leaching of NO3-N in autumn did not differ. Concentrations of PO4-P in the groundwater of poplar plantations were lower compared to the respective ones of the reference fields. There were no clear trends observed when comparing carbon concentrations in the topsoil of the poplar and hybrid aspen plantations compared to the respective adjacent reference fields. For the subsoil, the average carbon concentrations in the poplar and hybrid aspen plantations were equal to the respective ones of cereals, but were higher when compared to grassland.
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| 5. |
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| 6. |
- Edelfeldt, Stina, et al.
(författare)
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Effects of Cutting Length, Orientation and Planting Depth on Early Willow Shoot Establishment
- 2015
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Ingår i: BioEnergy Research. - : Springer Science and Business Media LLC. - 1939-1234 .- 1939-1242. ; 8, s. 796-806
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Tidskriftsartikel (refereegranskat)abstract
- To assess the effects of different planting systems on early performance (survival, shoot emergence time, number of shoots, maximum shoot height and biomass shoot production) of willow, cuttings of varying lengths were planted horizontally at different depths and compared with vertically planted cuttings. Cutting lengths of (i) 25-200 cm and (ii) 7-21 cm were studied in a field experiment and in a box experiment, respectively. Shorter cuttings planted deeper had a lower survival rate and emerged a few days later compared to longer cuttings planted shallower. The performance was considerably higher at the apical part of the cuttings, regardless of cutting length. Longer cuttings planted shallow had a higher performance. Vertically planted cuttings produced more biomass and shoots per length unit than horizontally planted cuttings. We conclude that planting systems based on the use of longer horizontally planted cuttings would probably lead to an uneven establishment and gaps in the stand caused by apical dominance. Also, to achieve the same performance, the need of planting material would be considerably higher compared to systems with vertically planted cuttings. To obtain a fast and more even early establishment of willows, we recommend the use of vertically planted cuttings with a length of at least 20 cm. If cuttings are planted horizontally, they should not be planted deeper than 5 cm.
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| 7. |
- Edelfeldt, Stina, et al.
(författare)
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Establishment and Early Growth of Willow at Different Levels of Weed Competition and Nitrogen Fertilization
- 2016
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Ingår i: BioEnergy Research. - : Springer Science and Business Media LLC. - 1939-1234 .- 1939-1242. ; 9, s. 763–772-
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Tidskriftsartikel (refereegranskat)abstract
- To evaluate the effects of weed competition and nitrogen fertilization on the early growth performance of willow, cuttings of the clone Tora (Salix schwerinii x S. viminalis) were planted in buckets together with model weeds (spring barley or white mustard) sown 15, 26, and 30 days after willow planting. The buckets were fertilized with 30 or 90 kg N ha(-1). Willow with weeds sown after 15 days produced less biomass and smaller leaf area and had a lower maximum shoot height compared to willow planted without weeds and willow with weeds sown after 26 or 30 days. Fertilization with 90 kg N ha(-1) gave higher willow biomass production in willow with weeds sown after 26 or 30 days. Type of model weed had no effect on willow performance. Weed biomass and maximum shoot height were higher in weeds planted without willows compared to the willow-weed mixtures. A high nitrogen level gave more weed biomass when planted without willows and in the willow-weed mixture with weeds sown after 15 days. We conclude that for the given high density of willow, competition from weeds emerging soon after willow planting had strong effect on early production. Furthermore, if there is a risk of weed infestation, fertilization should be delayed.
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| 8. |
- Englund, Oskar, 1982, et al.
(författare)
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Meeting Sustainability Requirements for SRC Bioenergy: Usefulness of Existing Tools, Responsibilities of Involved Stakeholders, and Recommendations for Further Developments
- 2012
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Ingår i: Bioenergy Research. - : Springer Science and Business Media LLC. - 1939-1234 .- 1939-1242. ; 5:3, s. 606-620
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Tidskriftsartikel (refereegranskat)abstract
- Short rotation coppice (SRC) is considered an important biomass supply option for meeting the European renewable energy targets. This paper presents an overview of existing and prospective sustainability requirements, Member State reporting obligations and parts of the methodology for calculating GHG emissions savings within the EU Renewable Energy Directive (RED), and shows how these RED-associated sustainability criteria may affect different stakeholders along SRC bioenergy supply chains. Existing and prospective tools are assessed on their usefulness in ensuring that SRC bioenergy is produced with sufficient consideration given to the RED-associated criteria. A sustainability framework is outlined that aims at (1) facilitating the development of SRC production systems that are attractive from the perspectives of all stakeholders, and (2) ensuring that the SRC production is RED eligible. Producer manuals, EIAs, and voluntary certification schemes can all be useful for ensuring RED eligibility. However, they are currently not sufficiently comprehensive, neither individually nor combined, and suggestions for how they can be more complementary are given. Geographical information systems offer opportunities for administrative authorities to provide stakeholders with maps or databases over areas/fields suitable for RED-eligible SRC cultivation. However, proper consideration of all relevant aspects requires that all stakeholders in the SRC supply chain become engaged in the development of SRC production systems and that a landscape perspective is used.
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| 9. |
- Hammar, Torun, et al.
(författare)
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Climate Impact of Willow Grown for Bioenergy in Sweden
- 2014
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Ingår i: Bioenergy Research. - : Springer-Verlag New York. - 1939-1234 .- 1939-1242. ; 7:4, s. 1529-1540
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Tidskriftsartikel (refereegranskat)abstract
- Short-rotation coppice willow (SRCW) is a fast-growing and potentially high-yielding energy crop. Transition to bioenergy has been identified in Sweden as one strategy to mitigate climate change and decrease the current dependency on fossil fuel. In this study, life cycle assessment was used to evaluate and compare the climate impacts of SRCW systems, for the purpose of evaluating key factors influencing the climate change mitigation potential of SRCW grown on agricultural land in Sweden. Seven different scenarios were defined and analysed to identify the factors with the most influence on the climate. A carbon balance model was used to model carbon fluxes between soil, biomass and atmosphere under Swedish growing conditions. The results indicated that SRCW can act as a temporary carbon sink and therefore has a mitigating effect on climate change. The most important factor in obtaining a high climate change-mitigating effect was shown to be high yield. Low yield gave the worst mitigating effect of the seven scenarios, but it was still better than the effect of the reference systems, district heating produced from coal or natural gas.
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| 10. |
- Hammar, Torun, et al.
(författare)
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Time-Dynamic Effects on the Global Temperature When Harvesting Logging Residues for Bioenergy
- 2015
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Ingår i: BioEnergy Research. - : Springer Science and Business Media LLC. - 1939-1234 .- 1939-1242. ; 8, s. 1912-1924
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Tidskriftsartikel (refereegranskat)abstract
- The climate mitigation potential of using logging residues (tree tops and branches) for bioenergy has been debated. In this study, a time-dependent life cycle assessment (LCA) was performed using a single-stand perspective. Three forest stands located in different Swedish climate zones were studied in order to assess the global temperature change when using logging residues for producing district heating. These systems were compared with two fossil reference systems in which the logging residues were assumed to remain in the forest to decompose over time, while coal or natural gas was used for energy. The results showed that replacing coal with logging residues gave a direct climate benefit from a single-stand perspective, while replacing natural gas gave a delayed climate benefit of around 8-12 years depending on climate zone. A sensitivity analysis showed that the time was strongly dependent on the assumptions for extraction and combustion of natural gas. The LCA showed that from a single-stand perspective, harvesting logging residues for bioenergy in the south of Sweden would give the highest temperature change mitigation potential per energy unit. However, the differences between the three climate zones studied per energy unit were relatively small. On a hectare basis, the southern forest stand would generate more biomass compared to the central and northern locations, which thereby could replace more fossil fuel and give larger climate benefits.
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