Current issue: 53(2)

Under compilation: 53(3)

Impact factor 1.683
5-year impact factor 1.950
Silva Fennica 1926-1997
1990-1997
1980-1989
1970-1979
1960-1969
Acta Forestalia Fennica
1953-1968
1933-1952
1913-1932

Articles by Per C. Odén

Category: Research article

article id 9996, category Research article
Mulualem Tigabu, Mostafa Farhadi, Lars-Göran Stener, Per C. Odén. (2018). Visible + Near Infrared Spectroscopy as taxonomic tool for identifying birch species. Silva Fennica vol. 52 no. 4 article id 9996. https://doi.org/10.14214/sf.9996
Highlights: Multivariate modelling of visible + near infrared (NIR) reflectance spectra of single seeds distinguished Betula pubescens and B. pendula with 100% and 99% accuracy, respectively; The results demonstrate the feasibility of NIR spectroscopy as taxonomic tool for classification of species that have morphological resemblance.

The genus Betula L. is composed of several species, which are difficult to distinguish in the field on the basis of morphological traits. The aim of this study was to evaluate the taxonomic importance of using visible + near infrared (Vis + NIR) spectra of single seeds for differentiating Betula pendula Roth and Betula pubescens Ehrh. Seeds from several families (controlled crossings of known parent trees) of each species were used and Vis + NIR reflectance spectra were obtained from single seeds. Multivariate discriminant models were developed by Orthogonal Projections to Latent Structures – Discriminant Analysis (OPLS-DA). The OPLS-DA model fitted on Vis + NIR spectra recognized B. pubescens with 100% classification accuracy while the prediction accuracy of class membership for B. pendula was 99%. However, the discriminant models fitted on NIR spectra alone resulted in 100% classification accuracies for both species. Absorption bands accounted for distinguishing between birch species were attributed to differences in color and chemical composition, presumably polysaccharides, proteins and fatty acids, of the seeds. In conclusion, the results demonstrate the feasibility of NIR spectroscopy as taxonomic tool for classification of species that have morphological resemblance.

  • Tigabu, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, Box 49, SE-230 52 Alnarp, Sweden ORCID ID:E-mail: mulualem.tigabu@slu.se (email)
  • Farhadi, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, Box 49, SE-230 52 Alnarp, Sweden ORCID ID:E-mail: mostafa.farhadi@gmail.com
  • Stener, The Forestry Research Institute of Sweden, Ekebo 2250, SE-268 90 Svalöv, Sweden ORCID ID:E-mail: lars-goran.stener@skogforsk.se
  • Odén, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, Box 49, SE-230 52 Alnarp, Sweden ORCID ID:E-mail: per.christer.oden@slu.se
article id 1340, category Research article
Mostafa Farhadi, Mulualem Tigabu, Per Christer Odén. (2015). Near Infrared Spectroscopy as non-destructive method for sorting viable, petrified and empty seeds of Larix sibirica. Silva Fennica vol. 49 no. 5 article id 1340. https://doi.org/10.14214/sf.1340
Highlights: Near Infrared spectroscopy discriminates filled-viable, empty and petrified seeds of Larix sibirica with 98%, 82% and 87% accuracy, respectively based on spectral differences attributed to moisture and storage reserves; The classification accuracy reached 100% when sorting seeds into viable and non-viable class; The results demonstrate that NIR spectroscopy has great potential as non-destructive sorting technique to upgrade seed lot quality.

Larix sibirica Ledeb. is one of the promising timber species for planting in the boreal ecosystem; but poor seed lot quality is the major hurdle for production of sufficient quantity of planting stocks. Here, we evaluated the potential of Near Infrared (NIR) Spectroscopy for sorting viable and non-viable seeds, as the conventional sorting technique is inefficient. NIR reflectance spectra were collected from single seeds, and discriminant models were developed with Orthogonal Projections to Latent Structure – Discriminant Analysis (OPLS-DA). The computed model predicted the class membership of filled-viable, empty and petrified seeds in the test set with 98%, 82% and 87% accuracy, respectively. When two-class OPLS-DA model was fitted to discriminate viable and non-viable (empty and petrified seeds combined), the predicted class membership of test set samples was 100% for both classes. The origins of spectral differences between non-viable (petrified and empty) and viable seeds were attributed to differences in seed moisture content and storage reserves. In conclusion, the result provides evidence that NIR spectroscopy is a powerful non-destructive method for sorting non-viable seeds of Larix sibirica; thus efforts should be made to develop on-line sorting system for large-scale seed handling.

  • Farhadi, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 49, SE-230 53 Alnarp, Sweden ORCID ID:E-mail: mostafa.farhadi@slu.se
  • Tigabu, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 49, SE-230 53 Alnarp, Sweden ORCID ID:E-mail: mulualem.tigabu@slu.se (email)
  • Odén, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 49, SE-230 53 Alnarp, Sweden ORCID ID:E-mail: per.oden@slu.se
article id 1334, category Research article
Abolfazl Daneshvar, Mulualem Tigabu, Asaddollah Karimidoost, Per Christer Oden. (2015). Single seed Near Infrared Spectroscopy discriminates viable and non-viable seeds of Juniperus polycarpos. Silva Fennica vol. 49 no. 5 article id 1334. https://doi.org/10.14214/sf.1334
Highlights: Near Infrared (NIR) Spectroscopy discriminates viable and non-viable (empty, insect-attacked and shriveled) seeds of J. polycarpos with 98% and 100% accuracy, respectively; The origins of spectral differences between non-viable and viable seeds were attributed to differences in seed coat chemical composition and storage reserves; The results demonstrate that NIR spectroscopy has great potential as seed sorting technology to ensure precision sowing.

A large quantity of non-viable (empty, insect-attacked and shriveled) seeds of Juniperus polycarpos (K. Koch) is often encountered during seed collection, which should be removed from the seed lots to ensure precision sowing in the nursery or out in the field. The aims of this study were to evaluate different modelling approaches and to examine the sensitivity of the change in detection system (Silicon-detector in the shorter vis-a-vis InGsAs-detector in the longer NIR regions) for discriminating non-viable seeds from viable seeds by Near Infrared (NIR) spectroscopy. NIR reflectance spectra were collected from single seeds, and discriminant models were developed by Partial Least Squares – Discriminant Analysis (PLS-DA) and Orthogonal Projection to Latent Structures – Discriminant Analysis (OPLS-DA) using the entire or selected NIR regions. Both modelling approaches resulted in 98% and 100% classification accuracy for viable and non-viable seeds in the test set, respectively. However, OPLS-DA models were superb in terms of model parsimony and information quality. Modelling in the shorter and longer wavelength region also resulted in similar classification accuracy, suggesting that prediction of class membership is insensitive to change in the detection system. The origins of spectral differences between non-viable and viable seeds were attributed to differences in seed coat chemical composition, mainly terpenoids that were dominant in non-viable seeds and storage reserves in viable seeds. In conclusion, the results demonstrate that NIR spectroscopy has great potential as seed sorting technology to upgrade seed lot quality that ensures precision sowing.

  • Daneshvar, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 49, SE-230 53, Alnarp, Sweden; (permanent address) Department of Natural Resources, Gonbad Kavous University, Shahid Fallahi Street, P.O. Box 163, Gonbad, Iran ORCID ID:E-mail: abolfazl.daneshvar@slu.se
  • Tigabu, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 49, SE-230 53, Alnarp, Sweden ORCID ID:E-mail: mulualem.tigabu@slu.se (email)
  • Karimidoost, Agriculture and Natural Resources Research Center of Golestan Province, Beheshti Ave. P.O. Box 4915677555, Gorgan, Iran ORCID ID:E-mail: karimidoost@yahoo.com
  • Oden, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 49, SE-230 53, Alnarp, Sweden ORCID ID:E-mail: per.oden@slu.se
article id 444, category Research article
Sovu, Mulualem Tigabu, Patrice Savadogo, Per Christer Odén. (2012). Facilitation of forest landscape restoration on abandoned swidden fallows in Laos using mixed-species planting and biochar application. Silva Fennica vol. 46 no. 1 article id 444. https://doi.org/10.14214/sf.444
The cessation of swidden cultivation and the increasing trend of abandonment of swidden fallows have created an opportunity for forest landscape restoration. However, ways need to be found to improve the poor soil fertility at these sites with affordable materials and to generate short-term socio-economic benefits for small-scale swidden fallow holders. This study assessed the feasibility of using mixed-planting of eight native species and application of rice husk biochar as soil amendment measure at a site in Laos. The effect of biochar application was compared against addition of inorganic (NPK) fertilizer and the control. The establishment and growth of the planted seedlings was then monitored for four years. The addition of rice husk biochar and NPK fertilizer did not significantly (p = 0.578) improve the survival rate of planted seedlings, which ranged from 72% to 91% (depending on the species) compared to the control. No significant growth responses to the soil amendments were observed for most of the species during the first year after planting compared to the control. The biochar effect was, however, more evident at the fourth year for diameter (p < 0.01) and height (p < 0.01) of sapling for all species; particularly its effect was more vivid on the diameter of slow-growing species. The results indicate that the species tested in the mixed-planting showed marked growth variation while application of rice husk biochar boosted their growth. Thus, planting mixed-species in swidden fallows has potential to provide continuous supplies of wood from different species to diversify the livelihood of swidden field owners, while maintaining ecosystem services.
  • -, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, Alnarp, Sweden ORCID ID:E-mail:
  • Tigabu, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, Alnarp, Sweden ORCID ID:E-mail: mulualem.tigabu@slu.se (email)
  • Savadogo, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, Alnarp, Sweden ORCID ID:E-mail:
  • Odén, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, Alnarp, Sweden ORCID ID:E-mail:
article id 452, category Research article
Catherine Ky-Dembele, Mulualem Tigabu, Jules Bayala, Patrice Savadogo, Issaka Joseph Boussim, Per Christer Odén. (2010). Clonal propagation of Detarium microcarpum from root cuttings. Silva Fennica vol. 44 no. 5 article id 452. https://doi.org/10.14214/sf.452
Detarium microcarpum is a valuable tree species for fuelwood, timber, food and medicine in sub-Saharan Africa. However, its population is dwindling due to overexploitation, its seedlings’ low survival rate and slow growth. Vegetative propagation might enhance both survival and growth, but to date a successful clonal method does not exist for D. microcarpum. We conducted four experiments to examine the effects of propagation environment (high versus low humidity), cutting length and diameter, alignment of root segments (horizontal versus vertical) and distance from the root collar of donors on the regeneration ability of root segments collected from field-grown D. microcarpum trees in Burkina Faso. The size of root segments significantly affected their regeneration ability, while alignment had no effect. Sprouting was possible from 10 and 20-cm long segments of 15–60 mm diameter with 7–43% sprouting efficiency and multiple shoots while 5 cm long segments were unsuitable with 0–3% sprouting efficiency. Cuttings maintained at low humidity produced larger diameter sprouts than those in greenhouse. All cuttings showed strong polarity with most of the shoots developing at the proximal end. Rootlings from 20 cm root segments produced more new roots (0.62 ± 0.08 g) than those from 10 cm segments (0.34 ± 0.09 g), but they were similar for sprout and leaf growth. We conclude that lateral roots of field-grown mature trees can be used to produce rootlings in a nursery. Since this study is the first attempt to propagate D. microcarpum from root cuttings, further investigations are required to optimize the technique.
  • Ky-Dembele, Département Productions Forestières, Institut de l’Environnement et de Recherches Agricoles, 03 BP 7047 Ouagadougou 03, Burkina Faso & Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 101, SE-230 53 Alnarp, Sweden (catherine.dembele@ess.slu.se) ORCID ID:E-mail: kydembele@hotmail.com (email)
  • Tigabu, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 101, SE-230 53, Alnarp, Sweden ORCID ID:E-mail:
  • Bayala, World Agroforestry Centre, West Africa and Centre Regional Office, Sahel Node, BP E5118 Bamako, Mali ORCID ID:E-mail:
  • Savadogo, Département Productions Forestières, Institut de l’Environnement et de Recherches Agricoles, 03 BP 7047 Ouagadougou 03, Burkina Faso & Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 101, SE-230 53 Alnarp, Sweden ORCID ID:E-mail:
  • Boussim, Université de Ouagadougou, Unité de Formation et Recherche en Sciences de la Vie et de la Terre, 03 BP 7021, Ouagadougou 03, Burkina Faso ORCID ID:E-mail:
  • Odén, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 101, SE-230 53, Alnarp, Sweden ORCID ID:E-mail:
article id 121, category Research article
Catherine Ky-Dembele, Jules Bayala, Patrice Savadogo, Mulualem Tigabu, Per Christer Odén, Issaka Joseph Boussim. (2010). Comparison of growth responses of Khaya senegalensis seedlings and stecklings to four irrigation regimes. Silva Fennica vol. 44 no. 5 article id 121. https://doi.org/10.14214/sf.121
Khaya senegalensis is an important tree species for timber production, native to West Africa, but mahogany shoot borer attacks prevent successful plantations. This research was aimed at comparing the growth of two propagule types, seedlings and stecklings, of Khaya senegalensis subjected to four irrigation regimes, 25, 50, 75 and 100% field capacity in Burkina Faso. The relative growth rate, biomass allocation and intrinsic water use efficiency of the propagules were assessed in a full-factorial pot experiment in block design. Except the relative growth rate of stem basal diameter and specific leaf area, for which mean values were significantly higher for seedlings than stecklings, the two propagule types had similar growth patterns regarding relative growth rates of stem length, leaf, stem, root and the total plant biomass. There was no significant difference between propagule types concerning biomass fraction to total plant biomass of leaf, stem and root, root to stem ratio, leaf area productivity and carbon isotope ratio (δ13C). However, the irrigation regimes significantly affected all parameters. In contrast to 75 and 100% field capacity irrigation regimes, the low water supply of 25 and 50% field capacity resulted in plant stress, which was evident from the significant reduction in plant growth and biomass production and an increase in the root biomass to total plant biomass ratio and δ13C. It can be concluded that seedlings and stecklings have comparable growth patterns, while water stress is a major growth-limiting factor highlighting the need for selecting drought and borer resistant genotypes for successful plantations.
  • Ky-Dembele, Département Productions Forestières, Institut de l’Environnement et de Recherches Agricoles, 03 BP 7047 Ouagadougou 03, Burkina Faso & Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 101, SE-230 53 Alnarp, Sweden (catherine.dembele@slu.se) ORCID ID:E-mail: kydembele@hotmail.com (email)
  • Bayala, World Agroforestry Centre, West Africa and Centre Regional Office, Sahel Node, BP E5118 Bamako, Mali ORCID ID:E-mail:
  • Savadogo, Département Productions Forestières, Institut de l’Environnement et de Recherches Agricoles, 03 BP 7047 Ouagadougou 03, Burkina Faso & Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 101, SE-230 53 Alnarp, Sweden ORCID ID:E-mail:
  • Tigabu, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 101, SE-230 53, Alnarp, Sweden ORCID ID:E-mail:
  • Odén, Swedish University of Agricultural Sciences, Southern Swedish Forest Research Centre, P.O. Box 101, SE-230 53, Alnarp, Sweden ORCID ID:E-mail:
  • Boussim, Université de Ouagadougou, Unité de Formation et Recherche en Sciences de la Vie et de la Terre, 03 BP 7021, Ouagadougou 03, Burkina Faso ORCID ID:E-mail:

Register
Click this link to register for Silva Fennica submission and tracking system.
Log in
If you are a registered user, log in to save your selected articles for later access.
Contents alert
Sign up to receive alerts of new content
Your selected articles

Committee on Publication Ethics A Trusted Community-Governed Archive