| 1. |
|
|
| 2. |
|
|
| 3. |
- Salomon, Björn, et al.
(author)
-
Evolutionary process of Hordeum brachyantherum 6x and related tetraploid species revealed by nuclear DNA sequences
- 2009
-
In: Breeding Science. - : Japanese Society of Breeding. - 1344-7610 .- 1347-3735. ; 59, s. 611-616
-
Journal article (peer-reviewed)abstract
- A hexaploid form of Hordeum brachlyantherum ssp. brachyantherum was discovered in California in 1980, and its origin has since been studied over the past three decades. We applied EF-G, a nuclear DNA sequence, to infer the parents of the hexaploid form. In polyploid taxa, amplified DNAs were cloned into a vector, and EF-G copies were amplified from the colonies by PCR and digested with restriction enzymes to separate different types. Phylogenetic analysis was performed based on the DNA sequences. The result showed that H. brachyantherum ssp. brachyantherum 6x and 4x carried one identical DNA sequence of 910 bp, and had closely related DNA sequences of 931 bp. H. brachyantherum ssp. brachyantherum 6x and H. marinum ssp. gussoneanum 2x shared one identical DNA sequence of 915 bp. From these results we hypothesized that H. brachyantherum ssp. brachyantherum 6x has evolved by an outcrossing between H. marinum ssp. gussoneanum 2x and H. brachyantherum ssp. brachyantherum 4x, followed by a chromosome doubling. Our results also indicate that H. marinum was involved in the polyploidization of H. secalinum, H. capense, and H. marinum. The origins of H. jubatum and H. depressum are discussed.
|
|
| 4. |
- Carlsson, Anders
(author)
-
Plant oils as feedstock alternatives to petroleum - A short survey of potential oil crop platforms
- 2009
-
In: Plant Breeding. - : Elsevier BV. - 0179-9541 .- 1439-0523. ; 91, s. 665-670
-
Research review (peer-reviewed)abstract
- Our society is highly depending on petroleum for its activities. About 90% is used as an energy source for transportation and for generation of heat and electricity and the remaining as feedstocks in the chemical industry. However, petroleum is a finite source as well as causing several environmental problems such as rising carbon dioxide levels in the atmosphere. Petroleum therefore needs to be replaced by alternative and sustainable sources. Plant oils and oleochemicals derived from them represent such alternative sources, which can deliver a substantial part of what is needed to replace the petroleum used as feedstocks.Plant derived feedstock oils can be provided by two types of oil qualities, multi-purpose and technical oils. Multi-purpose oils represent oil qualities that contain common fatty acids and that can be used for both food and feedstock applications. Technical oil qualities contain unusual fatty acids with special properties gained from their unique molecular structure and these types of oils should only be used for feedstock applications. As a risk mitigation strategy in the selection of crops, technical oil qualities should therefore preferably be produced by oil crop platforms dedicated for industrial usage. This review presents a short survey of oil crop platforms to be considered for either multi-purpose or technical oils production. Included among the former platforms are some of the major oil crops in cultivation such as oil palm, soybean and rapeseed. Among the later are those that could be developed into dedicated industrial platforms such as crambe, flax, cotton and Brassica carinata. The survey finishes off by highlighting the potential of substantial increase in plant oil production by developing metabolic flux platforms, which are starch crops converted into oil crops. (c) 2009 Elsevier Masson SAS. All rights reserved.
|
|
| 5. |
|
|
| 6. |
- Ranius, Thomas, et al.
(author)
-
Development of tree hollows in pedunculate oak (Quercus robur)
- 2009
-
In: Forest Ecology and Management. - : Elsevier BV. - 0378-1127 .- 1872-7042. ; 257, s. 303-310
-
Journal article (peer-reviewed)abstract
- Many invertebrates, birds and mammals are dependent on hollow trees. For landscape planning that aims at persistence of species inhabiting hollow trees it is crucial to understand the development of such trees. In this study we constructed an individual-based simulation model to predict diameter distribution and formation of hollows in oak tree populations. Based on tree ring data from individual trees, we estimated the ages when hollow formation commences for pedunculate oak (Quercus robur) in southeast Sweden. At ages of about 200-300 years, 50% of the trees had hollows. Among trees < 100 years old, less than 1% had hollows, while all > 400-year-old trees had hollows. Hollows formed at earlier ages in fast-growing trees than in slow-growing trees, which may be because hollows are formed when big branches shed, and branches are thicker on fast-growing trees in comparison to slow-growing trees of the same age. The simulation model was evaluated by predicting the frequency of presence of hollows in relation to tree size in seven oak stands in the study area. The evaluation suggested that future studies should focus on tree mortality at different conditions. Tree ring methods on individual trees are useful in studies on development of hollow trees as they allow analysis of the variability in time for hollow formation among trees. (C) 2008 Elsevier B.V. All rights reserved.
|
|
| 7. |
- Sriskandarajah, Sridevy, et al.
(author)
-
High frequency shoot organogenesis and somatic embryogenesis in juvenile and adult tissues of seabuckthorn (Hippophae rhamnoides L.)
- 2009
-
In: Plant Cell, Tissue and Organ Culture. - : Springer Science and Business Media LLC. - 0167-6857 .- 1573-5044. ; 99, s. 259–268-
-
Journal article (peer-reviewed)abstract
- Seabuckthorn (Hippophae rhamnoides) is a multipurpose small tree with unique berries of high nutritional and pharmaceutical values. A clonally propagated plant originating from a 20-year-old tree of H. r. rhamno- ides 9 mongolica hybrid cultivar Julia and seedling offspring of this cultivar were investigated regarding induction of shoot organogenesis in leaf explants and in roots of intact seedlings, and induction of direct somatic embryogenesis in explants from shoot tissue. The highest percentage of leaf explants showing shoot organogenesis was achieved (juvenile explants, 65%; adult explants, 75%) when incubated in Mu- rashige and Skoog (MS) medium supplemented with either 4.5 lM of the phenylurea cytokinin thidiazuron (TDZ) or 2.25 lM TDZ plus 2.2 lM 6-benzyladenine (BA), for juve- nile and adult explants, respectively, both supplemented with 0.53 lM a-naphthaleneacetic acid (NAA). Juvenile explants developed on average 18 shoots per explant in the MS med- ium supplemented with 4.5 lM TDZ, a four fold increase over those incubated on the medium supplemented with 2.25 lM TDZ and 2.2 lM BA. Adult leaf explants grown on medium containing 2.25 lM TDZ and 2.2 lM BA medium produced 12 shoots per explant, while those grown on med- ium containing 4.5 lM TDZ produced 5 shoots per explant. Shoot organogenesis was observed in roots of intact seedlings pre-cultured on plain medium lacking nutrients (PM) or woody plant medium (WPM) salts and then grown on WPM salts supplemented with 4.4 lM BA, 0.29 lM gibberrelic acid (GA3), and 57.0 lM indoleacetic acid (IAA). The number of shoots formed on each seedling root system was ten fold higher when the pre-culture was in WPM medium indi- cating a promoting effect of mineral nutrients in the pre-cul- ture medium. Somatic embryogenesis was induced in both juvenile and adult leaf explants in 65 and 78% of the explants, respectively, in MS-based medium supplemented with 2.0 lM N-(2-Chloro-4-pyridyl)-N1-phenylurea (CPPU), 0.53 lM NAA and varying concentrations of BA. There was an interaction effect between MS salt strength and BA con- centration. The most effective medium for inducing somatic embryogenesis in juvenile explants contained half strength MS salts and 2.2 lM BA and full strength MS salts and 13.2 lM BA for adult explants
|
|
| 8. |
|
|
| 9. |
|
|
| 10. |
- Åkerström, Andreas, et al.
(author)
-
Effects of Sampling Time and Nitrogen Fertilization on Anthocyanidin Levels in Vaccinium myrtillus Fruits
- 2009
-
In: Journal of Agricultural and Food Chemistry. - : American Chemical Society (ACS). - 0021-8561 .- 1520-5118. ; 57, s. 3340-3345
-
Journal article (peer-reviewed)abstract
- Vaccinium myrtillus berries (bilberries) contain antioxidants, in particular anthocyanins, which are secondary metabolites that have proven health-promoting effects. Bilberries were collected at the Svartberget research forest in northern Sweden from plots with no, low, and high applications of NH(4)NO(3) on three replicated dates in each year from 2005-2007, and their anthocyanidin contents were analyzed by high performance liquid chromatography. Their mean total anthocyanidin contents Were 9.0, 6.2, and 22.7 mg/g DW in 2005, 2006, and 2007, respectively. The values were significantly higher in 2005 than in 2006 and significantly higher in 2007 than in both previous years, across all three sampling dates. In addition, anthocyanidin contents were significantly affected by sampling date in all years (P < 0.001); they were linearly correlated with the thermal sum in 2005 and 2007 but rose between the first and second sampling occasions and subsequently declined in 2006. No significant effect of nitrogen fertilization on total anthocyanidin levels was detected in any of the studied years. The results indicate that climatic factors and yearly fluctuations influence anthocyanidin biosynthesis and degradation more strongly than nitrogen availability. To our knowledge, this is the first time this effect of sampling time on anthocyanins in mature bilberries has been shown.
|
|
| 11. |
|
|
| 12. |
|
|
| 13. |
|
|
| 14. |
|
|
| 15. |
- Torimaru, Takeshi, et al.
(author)
-
Evaluation of pollen contamination in an advanced Scots pine seed orchard in Sweden
- 2009
-
In: Silvae Genetica. - : J.D. Sauerländer's Verlag. - 0037-5349 .- 2509-8934. ; 58:5-6, s. 262-269
-
Journal article (peer-reviewed)abstract
- The pollination pattern in a Scots pine (Pinus sylvestris L.) seed orchard consisting of 28 clones was studied using nine microsatellite (SSR) loci. The nine SSR loci produced unique multilocus genotypes for each of the orchard's 28 clones and allowed paternal assignment of the studied 305 seed using paternity exclusion probability of 99.9%. Fifty two percent of the studied seeds were sired by outside the orchard pollen sources (i.e., pollen contamination) and as expected, low selfing (2.3%) was detected. These results are valuable for the evaluation of the seed orchard function and the impact of contamination on the expected genetic gain.
|
|
| 16. |
- Berg, Björn, et al.
(author)
-
Sequestration of carbon in the humus layer of Swedish forests - direct measurements
- 2009
-
In: Canadian Journal of Forest Research. - 0045-5067 .- 1208-6037. ; 39:5, s. 962-975
-
Journal article (peer-reviewed)abstract
- To determine sequestration rates of carbon dioxide (CO2) we calculated the carbon (C) storage rate in humus layers of Swedish forests with Podsolic soils, which account for 14.2 x 106 ha of the 22.7 x 106 ha of forested land in Sweden. Our data set covered 41 years of humus inventories and mean humus layer thickness in 82513 plots. We analysed three forest types: (i) all combinations of tree species, (ii) forests dominated (>70%) by Norway spruce (Picea abies (L.) Karst.), and (Ui) forests dominated (>70%) by Scots pine (Pinus sylvestris L.). To relate changes in humus layer thickness to land area we used the intersections in 25 km x 25 km grids and used kriging interpolation, permitting calculations for each forest type. For each intersection mean humus thickness for each year was calculated and regressed against time to obtain the rate of change. This rate, humus bulk density, and humus C concentration were used, to calculate sequestration rates. The mean sequestration rate was 251 kg C-ha-1'year1, which is higher than theoretical values. The sequestration rate was positively related to temperature sum, albeit including effects of forest management. The pine-dominated forest type had a mean rate of 283 kgCha⁁year-1, and. the spruce-dominated had a mean rate of 239 kg Cha-1-year1. Under similar site conditions, pine sequestered more C than spruce (difference of 71 kg Cha-1'year-1; p < 0.0001), showing the importance of this type of ecosystem for C sequestration.
|
|
| 17. |
|
|
| 18. |
- Blennow, Kristina, et al.
(author)
-
Climate change: Motivation for taking measure to adapt
- 2009
-
In: Global Environmental Change. - : Elsevier BV. - 1872-9495 .- 0959-3780. ; 19, s. 100-104
-
Journal article (peer-reviewed)abstract
- We tested two consequences of a currently influential theory based on the notion of seeing adaptations to climate change as local adjustments to deal with changing conditions within the constraints of the broader economic-social-political arrangements. The notion leaves no explicit role for the strength of personal beliefs in climate change and adaptive capacity. The consequences were: (i) adaptive action to climate change taken by an individual who is exposed to and sensitive to climate change is not influenced to a considerable degree by their strength of belief in climate change and (ii) adaptive action to climate change taken by an individual who is exposed to and sensitive to climate change is not influenced to a considerable degree by their strength of belief in an adaptive capacity. Data from a 2004 questionnaire of 1950 Swedish private individual forest owners, who were assumed exposed to and sensitive to climate change, were used. Strength of belief in climate change and adaptive capacities were found to be crucial factors for explaining observed differences in adaptation among Swedish forest owners. (C) 2008 Elsevier Ltd. All rights reserved.
|
|
| 19. |
|
|
| 20. |
|
|
| 21. |
|
|
| 22. |
- Drobyshev, Igor
(author)
-
Tree mortality in a mixed deciduous forest in Northwestern Russia over 22 years
- 2009
-
In: Annals of Forest Science. - : Springer Science and Business Media LLC. - 1286-4560 .- 1297-966X. ; 66
-
Journal article (peer-reviewed)abstract
- We studied mortality rates of birch, small-leaved linden, pedunculate oak, Norway maple, black alder, common ash and Norway spruce, assessed through two inventories of 12 664 trees in the unmanaged mixed deciduous forests of Oranienbaum Park, northwestern Russia, in 1981 and 2003.Our objectives were to evaluate if (a) long-term mortality rates vary among species, and if (b) crown condition, age and tree size affect the probability of mortality.Over this period, tree mortality rates in the park varied annually from 1 to 3% for healthy and moderately healthy trees, and from 3.9 to 9.3% for declining trees. The lowest mortality rates were observed for small-leaved linden and oak (0.8 and 1.0%, respectively), and the highest rate for birch (2.7%). We found (1) a significant and consistent association between tree condition and the probability of mortality, and (2) significantly higher mortality rates in smaller trees of ash, maple and oak.The effect of species-specific biology on mortality rates in the Oranienbaum Park was largely overridden by the "health status" and environmental conditions of the trees (e.g. degree of crown shading). The observed rates were similar to the estimates from natural temperate deciduous forests in both Europe and North America, indicating similar intensity of mortality in these ecosystems under natural conditions.
|
|
| 23. |
- Eriksson, Leif, 1970, et al.
(author)
-
Radar data
- 2008
-
In: Advances in Photogrammetry, Remote Sensing and Spatial Information Sciences: 2008 ISPRS Congress Book, Editors: Zhilin Li, Jun Chen and Emmanuel Baltsavias, Taylor & Francis Group, London, UK. - 9780415478052 ; , s. 447-449
-
Book chapter (other academic/artistic)
|
|
| 24. |
- Eriksson, Leif, 1970, et al.
(author)
-
Stem volume estimation for boreal forest using ALOS PALSAR
- 2007
-
In: 5th International Symposium on Retrieval of Bio- and Geophysical Parameters from SAR Data for Land Applications, Bari, Italy, September 25-28, 2007, ESA, Istituto di Studi sui Sistemi Intelligenti per l´Automazione. ; , s. CD-
-
Conference paper (other academic/artistic)abstract
- An evaluation of ALOS PALSAR data for standwise forest stem volume estimation has been performed at a Swedish test site. The site is dominated by coniferous tree species. SAR data from three operational PALSAR modes, including single, dual and quad polarization, have been analyzed. In total, images from 18 different dates were included. Altogether, 56 forest stands with stem volume in the range of 45-650 m3 ha-1 (average 325 m3 ha-1) were analyzed by relating backscatter intensity to field data. The estimation accuracy of stem volume at stand level was calculated in terms of root mean square error (RMSE). For the best case investigated an RMSE of 30% was obtained for one of the single polarization images acquired in the winter season. In this case no saturation was observed for high stem volumes. The corresponding RMSEs for the dual and quad polarization images were between 62%, and 81%. The better results for single polarization might be explained by particularly favourable weather conditions at image acquisition. An extended evaluation will be performed to verify the cause.
|
|
| 25. |
- Folkesson, Klas, 1976
(author)
-
Model-Based Stem Volume Retrieval and Windthrow Detection using CARABAS and P-band SAR
- 2008
-
Doctoral thesis (other academic/artistic)abstract
- Radar remote sensing is an efficient method for monitoring forests over large areas. Radar waves transmitted from a system carried by a satellite or an aircraft interact with trees on the ground, and the reflected waves are used to form images which are independent of weather and light conditions. Information in the images is then used to retrieve forest parameters.CARABAS is an airborne synthetic aperture radar (SAR) system. Due to the long wavelengths of the system (3-15 m), the radar signal is able to penetrate the forest canopies and for boreal forests the main backscattering component is the ground-trunk double-bounce. The scattering strength is directly related to the stem volume and hence stem volume retrieval with CARABAS has higher accuracy than SAR systems using shorter wavelengths. However, the ground-trunk double-bounce is very sensitive to ground slope and if not corrected for, ground slope will cause the stem volume to be underestimated.By using multiple images acquired with different flight headings and combining the image information with ground topography data in a model-based inversion method, most of the ground topography influence on the retrieved stem volume is removed. With four CARABAS images and a coarse digital elevation model with 50 m horizontal grid, the stem volume can be retrieved with a root mean square error(RMSE) of 48 m3/ha for stem volumes in the range 80-700 m3/ha. The proposed retrieval method gives better accuracy and is more robust than existing heuristic methods. By using this method, the retrieval accuracy in areas with ground topography is similar to that of similar forests standing on flat and horizontal ground.Another forestry application where CARABAS and other airborne SAR systems with long-wavelengths and high resolution can provide timely and useful information is in the detection of windthrown trees. A method for detecting windthrows in CARABAS images and a discussion about when windthrows can be detected is presented in this thesis.
|
|
