A coat protein transgene from a Scottish isolate of potato mop-top virus mediates strong resistance against Scandinavian isolates which have similar coat protein genes

Resistance tests were made on seedlings of transformed lines of Nicotiana benthamiana which contain a transgene encoding the coat protein (CP) gene of a Scottish isolate of potato mop-top virus (PMTV). This transgene has been reported to confer strong resistance to the PMTV isolate from which the transgene sequence was derived and also to a second Scottish isolate. Plants of lines of the transgenic N. benthamiana were as resistant to two Swedish and two Danish PMTV isolates as to a Scottish isolate, and of five lines tested, greater than 93.5% of transgenic plants were immune. The coat protein gene sequences of these four Scandinavian isolates were very similar to those of the two Scottish isolates. The greatest divergence between the isolates was three amino acid changes and there was less than 2% change in CP gene nucleotide sequence. It is concluded that the PMTV CP transgene used in these experiments could confer resistance against isolates from different geographical areas because it is becoming apparent that the CP genes of PMTV isolates are highly conserved.     

Changing stock of biomass carbon in a boreal forest over 93 years

The growing stock more than doubled from 1.6 to 3.4 million m³ between 1912 and 2005 in forests on an area of 387 km² in southern Finland. The stock expansion continued for 93 years noting interim results, which were available for 1959, 1982, 1994 and 1999. Forested area in the region hardly changed. Carbon sequestration was mainly a result of a long-term recovery from forest degradation, a legacy of land use in the 18th and 19th centuries. Tree demography responded to management change especially of mature stands: Average tree size and stocking density of stands increased. On average the expanding biomass stock sequestered 18 tons C annually per km² (18 g C per m²). In comparison, the emissions of fossil carbon in the region were estimated at 12 tons C per km² (12 g C per m²) on average. However, fossil CO₂ emissions exceeded biomass sequestration in recent decades. The powerful and persistent expansion of the carbon stock was an unintended co-benefit of forestry, which was motivated by the intention to improve timber yield. On the more negative side the change in management introduced clear-cuts, and a loss of diverse elements of the pre-industrial biota.     

Crystallinity of wood and the size of cellulose crystallites in Norway spruce (<Emphasis Type="Italic">Picea abies</Emphasis>)

X-ray diffraction was used to study variations in the crystallinity of wood and the average thickness and length of the crystallites of cellulose as a function of the number of the year ring in Norway spruce [Picea abies (L.) Karst.]. The crystallinity increased from ring 4 to ring 10 from the pith and was constant after ring 10. The crystallinity of mature wood was about 30% ± 5%. The average thickness and average length of the crystallites were 3.2 ± 0.1nm and 28 ± 2nm, respectively; and no systematic variation of these values with the number of the year ring was observed. The mean microfibril angle decreased near the pith but was constant in the mature wood.     

Effect of temperature and compression on the mechanical behavior of steam-treated wood

The mechanical behavior of steamed spruce wood changes dramatically with compression along the grain, the change being much more moderate perpendicular to the grain. The stiffness decrement due to increased temperature is greatest in the tangential material direction. The stiffness decrement due to compression is greatest along the grain. Compression to 80% compressive strain at 131°C inverts the order of the material directions regarding stiffness, the stiffness being the least along the grain. Plastic strain due to compression is greater at higher temperatures. The compression-induced decrement of stiffness along the grain is greater at higher temperatures, but the off-axis decrement of stiffness is less at higher temperatures.     

Mixing methods – assessment of potential benefits for natural resources planning

Multi-objective forest planning is a multi-methodological endeavor whose success largely depends on how well the combined use of different methods contributes to the goals of the planning. This review assessed the benefits of mixing methods in natural resources planning. A sample of 30 peer-reviewed research articles was analyzed using an evaluation framework, designed based on democracy and planning theories, and participatory planning literature, including four dimensions: transparency, flexibility, consensus building, and operability. According to analyses, mixing different types (i.e. qualitative and quantitative) of methods generally yields greater benefits than the combination of similar methods. The subsample of 12 planning cases that utilized simulation-optimization software (SOS) appeared operable and moderately transparent, whereas flexibility and consensus building were often lacking. In comparison to the wide scholarly discussion on multi-methodology and mixing methods, it was observed that successful mixing examples in natural resource planning are still scarce and there are weaknesses in bridging the methods together. There is an evident need to pursue and to better communicate the benefits of mixing. Some good mixing examples utilizing SOS provided evidence that forest planning processes would make an excellent venue for studying the benefits and caveats of using mixed methods.     

Bioenergetic calculation of mercury accumulation in fish

A numerical model was developed for the bioaccumulation of mercury (Hg) in fish. The model is based on the bioenergetic calculation of fish growth, food consumption, respiration, specific dynamic action and waste losses (egestion/excretion) using the program of Hewett and Johnson (1992). Based on the predation and food results obtained, the accumulation of Hg in fish is calculated taking into account the concentrations of methyl mercury (MeHg) in food and water, its intake and accumulation from food and from water, and the removal of Hg from the body. Some species at various levels of food web are considered in the multistep model applications. The model is used to compute the changes of Hg contents in perch (as prey) and pike (as predator) caused by the release of Hg from the bottom sediments when the Kokemäki River in Western Finland was dredged. The model results were not far from the observed results even though the forcing conditions had been described only roughly.     

Effects of Supplementation of a Grass Silage and Barley Diet with Urea,Rapeseed Meal and Heat-moisture-treated Rapeseed Cake on Omasal Digesta Flow and Milk Production in Lactating Dairy Cows

Four multiparous dairy cows, fitted with rumen and duodenal cannulas, were fed grass silage and one of four concentrates of barley (B), barley+urea (BU), barley+solvent-extracted rapeseed meal (BRM) or barley+heat-moisture-treated rapeseed cake (BRC). Despite marginal N deficiencies for the control diet (B), BU did not affect milk yield, ruminal fibre digestion or omasal total non-ammonia-N (NAN) or microbial NAN flow. In contrast, BRM and BRC diets significantly increased milk and milk protein yields and omasal dietary NAN flows. Effects of rapeseed meal (RSM) and rapeseed cake (RSC) on milk yield and omasal NAN flow were similar. The diets had no effect on rumen microbial protein synthesis. In general, non-protein N and soluble true protein comprised 0.20 of omasal total NAN flow, for all diets. Supplementary AAT from rapeseed feeds appeared to escape from the rumen as insoluble feed particles.     

Assessing physical surrogates for biodiversity: Do tributary and stream type classifications reflect macroinvertebrate assemblage diversity in running waters?

Landscape classifications are increasingly being used in conservation planning and biodiversity management, although there is a dearth of studies actually showing concordant patterns between such classifications and biodiversity. We studied the utility of tributary and stream type classifications in accounting for the variability of invertebrate biodiversity in a boreal drainage system. We found that only weak, although significant, differences existed between the studied three tributaries and four stream types in macroinvertebrate assemblage structure, species distributions, and taxonomic richness. Further, the classification strengths, calculated as mean within-group-similarity minus mean between-group-similarity of assemblage structure, were rather low, suggesting that the a priori physical classifications did not effectively describe variability in macroinvertebrate assemblage structure. The low classification strengths likely resulted from the facts that: (i) most stream macroinvertebrate taxa show individualistic responses to environmental gradients; (ii) many taxa occur either across all stream types; or (iii) only sporadically in a given stream type; and (iv) only a few species show high fidelity to a given stream type. However, the significance of the differences in macroinvertebrate assemblage structure and taxonomic richness, as well as a bunch of effective indicator species for different stream types, suggest that such classifications could be used as a preliminary scheme for the conservation planning of running waters. This reasoning is also supported by the evidence from other studies that have found stream size and the distance to upstream lakes to shape considerably the biodiversity of various groups of stream organisms, although no single organism group is likely to show a perfect match with any classification scheme.     

Absorption of ozone onBetula pendula Roth leaf surface

Leaf cuticular surface absorption of O₃ was investigated inBetula pendula Roth leaves which have no stomata on their adaxial surface. A two-component absorption model was assumed to approximate experimental data. The first component, having second order kinetics, decreased exponentially during ozonation, the second or residual component remained constant. The residual ozone conductance of the leaf cuticle was about an order of magnitude higher than the leaf cuticular conductance to water vapour. It is concluded that leaf surface absorption must be taken into consideration during short term experiments and in those with low ozone concentrations.