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- Menkis, A, et al.
(författare)
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Afforestation of abandoned farmland with conifer seedlings inoculated with three ectomycorrhizal fungi - impact on plant performance and ectomycorrhizal community.
- 2007
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Ingår i: Mycorrhiza. - : Springer Science and Business Media LLC. - 0940-6360 .- 1432-1890. ; 17:4, s. 337-348
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Tidskriftsartikel (refereegranskat)abstract
- The aim of a 3-year study was to investigate whether inoculation of Pinus sylvestris L. and Picea abies (L.) Karst. seedlings with mycorrhizas of Cenococcum geophilum Fr., Piceirhiza bicolorata, and Hebeloma crustuliniforme (Bull.) Quel. has any impact on: 1) survival and growth of outplanted seedlings on abandoned agricultural land, and 2) subsequent mycorrhizal community development. For inoculation, the root system of each plant was wrapped in a filter paper containing mycelium, overlaid with damp peat-sand mixture and wrapped in a paper towel. In total, 8,000 pine and 8,000 spruce seedlings were planted on 4-ha of poor sandy soil in randomized blocks. Already after the first year natural mycorrhizal infections prevailed in the inoculated root systems, and introduced mycorrhizas were seldom found. Yet, the seedlings that had been pre-inoculated with C. geophilum and the P. bicolorata during the whole 3-year period showed significantly higher survival and growth as compared to controls. Moreover, the independent colonization of roots by C. geophilum and the P. bicolorata from natural sources was also observed. A diverse mycorrhizal community was detected over two growing seasons in all treatments, showing low impact of inoculation on subsequent fungal community development. A total of 19 additional ectomycorrhizal morphotypes was observed, which clustered into two well-separated groups, according to host tree species (pine and spruce). In conclusion, the results showed limited ability to increase tree survival and growth, and to manipulate the mycorrhizal community even by extensive pre-inoculations, indicating that fungal community formation in root systems is governed mainly by environmental factors.
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- Lundén, K., et al.
(författare)
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Heterologous array analysis in Heterobasidion : Hybridisation of cDNA arrays with probe from mycelium of S, P or F-types
- 2008
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Ingår i: Journal of Microbiological Methods. - : Elsevier BV. - 0167-7012 .- 1872-8359. ; 75:2, s. 219-224
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Tidskriftsartikel (refereegranskat)abstract
- Because of the close relatedness between three species of Heterobasidion annosum (P type), Heterobasidion parviporum (S-type) and Heterobasidion abietinum (F-type). we investigated the possible use of arrays from one species for studies of gene expression in the other. Clones containing partial cDNAs from 94 identifiable genes expressed during spore germination and differentiation in H. parviporum were printed manually in six replications on nylon membranes. The membrane was hybridized with chemifluorescent labelled cDNA from actively growing mycelia of H. parviporum, H. annosum or H. abietinum, cultivated on a non-selective substrate. Product-moment correlation coefficient varied between 0.81 and 0.49. Due to the level of correlation, in the gene expression among the intersterility groups, we concluded that the cDNA array of one can be used to study gene expression in the others.
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- Valiente-Dobon, JJ, et al.
(författare)
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High-spin rotational structures in Kr-76
- 2005
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Ingår i: Physical Review C (Nuclear Physics). - 0556-2813. ; 71:3
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Tidskriftsartikel (refereegranskat)abstract
- High-spin states in Kr-76(36)40 have been populated in the Ca-40(Ca-40,4p)Kr-76 fusion-evaporation reaction at abeam energy of 165 MeV and studied using the Gammasphere and Microball multidetector arrays. The ground-state band and two signature-split negative parity bands of Kr-76 have been extended to similar to 30 (h) over bar. Lifetime measurements. using the Doppler-shift attenuation method show that the transition quadrupole moment of these three bands decrease as they approach their maximum-spin states. Two signatures of a new rotational structure with remarkably rigid rotational behavior have been identified. The high-spin properties of these rotational bands are analyzed within the framework of configuration-dependent cranked Nilsson-Strutinsky calculations.
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- Valiente-Dobon, JJ, et al.
(författare)
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Lifetimes of high-spin states in Kr-76
- 2005
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Ingår i: Acta Physica Polonica. Series B: Elementary Particle Physics, Nuclear Physics, Statistical Physics, Theory of Relativity, Field Theory. - 0587-4254. ; 36:4, s. 1339-1342
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Tidskriftsartikel (refereegranskat)abstract
- High-spin states in Kr-76(36)40 have been populated in the Ca-40 (Ca-40,4p) Kr-76 fusion-evaporation reaction at a beam energy of 165 MeV, and studied using the GAMMASPHERE and MICROBALL multi-detector arrays. The ground-state band and two signature-split negative-parity bands of Kr-76 have been extended to similar to 30h. Lifetime measurements using the Doppler-shift attenuation method indicate that the transition quadrupole moment of these three bands decrease as they approach their maximum-spin states.
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- van Hees, Patrick A. W., et al.
(författare)
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The biogeochemical impact of ectomycorrhizal conifers on major soil elements (Al, Fe, K and Si)
- 2006
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Ingår i: Geoderma. - : Elsevier BV. - 0016-7061 .- 1872-6259. ; 136:1-2, s. 364-377
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Tidskriftsartikel (refereegranskat)abstract
- Mobilisation of nutrients and dissolution of minerals are of key importance for plant growth and soil formation, as well as long term ecosystem sustainability. The effects of Pinus sylvestris seedlings, ectomycorrhizal colonisation and potassium supply on the mobilisation of Al, Fe, K and Si were studied in a soil column experiment. Budgets were constructed considering amounts in drainage water, accumulation in plants and changes in the pools of exchangeable ions (BaCl2 extractions). Drainage was the most important sink under the experimental conditions imposed, but the other two pools were also of quantitative significance. Plants had a significant positive effect on the total quantities of all elements mobilized. Mycorrhizal colonisation had limited quantitative impact on the mobilization, probably because the chosen mycorrhizal fungi did not cause any growth promotion in this experiment. Despite this, a multivariate analysis (PCA) showed a clear separate grouping of mycorrhizal, non-mycorrhizal and no-plant treatments, and in particular Si and K mobilization was related to soil biological variables which in turn were affected by the presence of mycorrhiza. When K was omitted from the watering solution, plants were able to mobilise significantly more K, which was reflected in plant uptake and a potential replenishment of the exchangeable pool. Up-scaling of total Al, K and Si mobilization to field conditions resulted in rates between equal to and up to 10 times higher than the average historical weathering rate.
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- Van Hees, P, et al.
(författare)
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The carbon we do not see : The impact of low molecular weight compounds on carbon dynamics and respiration in forest soils - A review
- 2005
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Ingår i: Soil Biology and Biochemistry. - : Elsevier BV. - 0038-0717 .- 1879-3428. ; 37:1, s. 1-13
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Tidskriftsartikel (refereegranskat)abstract
- Dissolved organic matter (DOM), typically quantified as dissolved organic carbon (DOC), has been hypothesized to play many roles in pedogenesis and soil biogeochemical cycles, however, most research to date concerning forest soils has focussed on the high molecular weight (HMW) components of this DOM. This review aims to assess the role of low molecular weight (LMW) DOM compounds in the C dynamics of temperate and boreal forest soils focussing in particular on organic acids, amino acids and sugars. The current knowledge of concentrations, mineralization kinetics and production rates and sources in soil are summarised. We conclude that although these LMW compounds are typically maintained at very low concentrations in the soil solution (<50 muM), the flux through this pool is extremely rapid (mean residence time 1-10 h) due to continued microbial removal. Due to this rapid flux through the soil solution pool and mineralization to CO2, we calculate that the turnover of these LMW compounds may contribute substantially to the total CO2 efflux from the soil. Moreover, the production rates of these soluble transitory compounds could exceed HMW DOM production. The possible impact of climate change on the behaviour of LMW compounds in soil is also discussed.
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