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51.
Hanna Haikka Timo Knürr Outi Manninen Leena Pietilä Mika Isolahti Esa Teperi Esa A. Mäntysaari Ismo Strandén 《Plant Breeding》2020,139(3):550-561
Genomic selection has been adopted in many plant breeding programmes. In this paper, we cover some aspects of information necessary before starting genomic selection. Spring oat and barley breeding data sets from commercial breeding programmes were studied using single, multitrait and trait-assisted models for predicting grain yield. Heritabilities were higher when estimated using multitrait models compared to single-trait models. However, no corresponding increase in prediction accuracy was observed in a cross-validation scenario. On the other hand, forward prediction showed a slight, but not significant, increase in accuracy of genomic estimated breeding values for breeding cohorts when a multitrait model was applied. When a correlated trait was used in a trait-assisted model, on average the accuracies increased by 9%–14% for oat and by 11%–28% for barley compared with a single-trait model. Overall, accuracies in forward validation varied between breeding cohorts and years for grain yield. Forward prediction accuracies for multiple cohorts and multiple years’ data are reported for oat for the first time. 相似文献
52.
Mikko T. Niemi Mikko Vastaranta Jari Vauhkonen Timo Melkas Markus Holopainen 《Scandinavian Journal of Forest Research》2017,32(8):762-773
Heavy off-road traffic causes soil compaction and rutting, which can significantly reduce the yield of forest stands. Reliable information on terrain trafficability, that is, the ability of terrain to support the passage of vehicles, would enable significant enhancement of wood procurement planning and reduction of soil damage. The objective here was to determine the feasibility of airborne scanning light detection and ranging (LiDAR)-derived digital terrain models (DTM) in terrain trafficability mapping. Soil damage was inventoried from a total of 13?km of forwarding trails, and a logistic regression model was fitted for predicting the event of soil damage. DTM-derived soil wetness indices performed well as predictor variables, and DTM-derived local binary patterns also proved useful in terrain trafficability mapping. A prediction accuracy of 83.6% (Cohen’s kappa of 0.38) was observed for soil damage probability modelling, using only DTM-derived predictors, and a corresponding accuracy of 85.0% (kappa of 0.45) was achieved when an existing soil map was used as well. In addition to the topography-related features, soil stoniness proved to be a critical factor affecting soil resistance to rutting. Our results indicate that the utilisation of LiDAR-derived elevation data for terrain trafficability mapping is a feasible method in sustainable forest management. 相似文献
53.
This study developed growth models for Eucalyptus saligna Sm., E. camaldulensis Dehnh., E. macarthurii H.Deane & Maiden, E. resinifera Sm., E. siderophloia Benth. and E. grandis Hill ex. Maiden, for the central highlands of Angola, and used these models to simulate the development of stand characteristics. The obtained model set included dominant height, diameter increment, tree height and self-thinning models. The study was based on 10 499 radial increment observations measured on cores taken from about 700 trees growing in 22 plots located in seven sites in the Angolan highlands. The model set makes it possible to simulate stand development on an individual tree basis. Comparison of simulated stand development and measurements indicated good performance of the models. A non-linear fixed-effects diameter increment model performed best for most species, but a non-calibrated linear mixed-effects model used with the Snowdon correction was better for E. saligna and E. macarthurii. This study showed a similar dominant height development of young stands as found in most previous studies done for southern Africa. Some differences emerged at older ages. 相似文献
54.
Prevalence of antibodies against feline panleukopenia virus in client-owned cats in Southern Germany
Katherina Mende Bianca Stuetzer Carola Sauter-Louis Timo Homeier Uwe Truyen Katrin Hartmann 《Veterinary journal (London, England : 1997)》2014,199(3):419-423
Feline panleukopenia is a frequent and commonly fatal disease of cats. Recent published studies have raised suspicions that some cats fail to develop antibodies after vaccination. The purpose of this study was to assess the prevalence of antibodies against feline panleukopenia virus (FPV) in cats in Southern Germany, and to identify factors that are associated with a lack of antibodies. In total, 350 cats presented to the Clinic of Small Animal Medicine, Ludwig-Maximilians-Universitaet were randomly included in the study. Information regarding signalment, origin, environment, lifestyle, housing conditions, health status, chronic diseases, glucocorticoid therapy, and vaccination status were collected. Antibodies were detected by haemagglutination inhibition test. Asymptomatic chi-squared tests and univariable logistic regression were used to investigate associations between a lack of antibodies and the different variables. Associations determined to be statistically significant at P < 0.1 were verified by a multivariable logistic regression analysis.Of the 350 cats, 103 (29.4%) had no antibodies against FPV. Chronic kidney disease, neoplasia, glucocorticoid therapy, and vaccination status were significantly associated with a lack of antibodies. The cats with no antibodies were likely to have inadequate immunity against panleukopenia and those with chronic diseases or receiving glucocorticoids were less likely to be protected. 相似文献
55.
Management of a Norway spruce stand planted on a site infected by Heterobasidion coll. is problematic because the fungus spreads vegetatively from the colonized stumps of the previous generation to the new seedlings. Growing of mixed stand with more resistant tree species has been suggested to decrease the economic losses caused by butt rot in Norway spruce trees. The mechanistic simulation model Rotstand describing the spread of Heterobasidion coll. in coniferous stands of southern Finland was used to study the effect of planting Scots pines around colonized clear‐felling stumps of Norway spruce of the previous generation. Planting of Scots pines in clusters around colonized stumps markedly decreased the butt rot of Norway spruce trees at the age of 20 years and at clear felling. If the same number of Scots pines were planted randomly, the effect was weak. When the average diameter of colonized clear‐felling stumps was 30 cm, a Scots pine circle with a radius of 3 m resulted in the highest soil expectation value (SEV) at 2% discounting rate, whereas with 40‐cm stump diameter, a 4‐m radius produced the highest SEV. When the proportion of Heterobasidion parviporum in the old colonized stumps was 50% instead of 95%, planting pines around colonized stumps still clearly decreased the butt rot at the age of 20 years and in final felling. 相似文献
56.
Llu??s Coll Jos?? Ram??n Gonz??lez-Olabarria Blas Mola-Yudego Timo Pukkala Christian Messier 《European Journal of Forest Research》2011,130(1):55-65
In some areas of the Mediterranean basin where the understory stratum represents a critical fire hazard, managing the canopy cover to control the understory shrubby vegetation is an ecological alternative to the current mechanical management techniques. In this study, we determine the relationship between the overstory basal area and the cover of the understory shrubby vegetation for different dominant canopy species (Pinaceae and Fagaceae species) along a wide altitudinal gradient in the province of Catalonia (Spain). Analyses were conducted using data from the Spanish National Forest Inventory. At the regional scale, when all stands are analysed together, a strong negative relationship between mean shrub cover and site elevation was found. Among the Pinaceae species, we found fairly good relationships between stand basal area and the maximum development of the shrub stratum for species located at intermediate elevations (Pinus nigra, Pinus sylvestris). However, at the extremes of the elevation-climatic gradient (Pinus halepensis and Pinus uncinata stands), stand basal area explained very little of the shrub cover variation probably because microsite and topographic factors override its effect. Among the Fagaceae species, a negative relationship between basal area and the maximum development of the shrub stratum was found in Quercus humilis and Fagus sylvatica dominated stands but not in Quercus ilex. This can be due to the particular canopy structure and management history of Q. ilex stands. In conclusion, our study revealed a marked effect of the tree layer composition and the environment on the relationship between the development of the understory and overstory tree structure. More fine-grained studies are needed to provide forest managers with more detailed information about the relationship between these two forest strata. 相似文献
57.
Zuheir Shater Sergio de-Miguel Bassel Kraid Timo Pukkala Marc Palahí 《Annals of Forest Science》2011,68(1):149-157
Pinus brutia Ten. subspecies brutia, which occurs in the Eastern Mediterranean region, is the main forest species in Syria and important for multi-purpose forestry.
In this study, 6,631 10-year past growth diameter increment measurements were taken in 83 temporary sample plots. The current
breast height diameter of all trees was measured and a sample of trees was measured for height and age. The plots were placed
so as to capture the whole range of variation in site quality, stand age and stand density. The data were used to develop
the following models:
| • |
Dominant height model: the guide curve method was used to fit an anamorphic site index model between stand age and dominant
height. 相似文献
58.
Samuli Launiainen Gabriel G. KatulPasi Kolari Timo VesalaPertti Hari 《Agricultural and Forest Meteorology》2011,151(12):1672-1689
Linkage between the leaf-level stomatal conductance (gs) response to environmental stimuli and canopy-level mass exchange processes remains an important research problem to be confronted. How various formulations of gs influence canopy-scale mean scalar concentration and flux profiles of CO2 and H2O within the canopy and how to derive ‘effective’ properties of a ‘big-leaf’ that represents the eco-system mass exchange rates starting from leaf-level parameters were explored. Four widely used formulations for leaf-level gs were combined with a leaf-level photosynthetic demand function, a layer-resolving light attenuation model, and a turbulent closure scheme for scalar fluxes within the canopy air space. The four gs models were the widely used semi-empirical Ball-Berry approach, and its modification, and two solutions to the stomatal optimization theory for autonomous leaves. One of the two solutions to the optimization theory is based on a linearized CO2-demand function while the other does not invoke such simplification. The four stomatal control models were then parameterized against the same shoot-scale gas exchange data collected in a Scots pine forest located at the SMEAR II-station in Hyytiälä, Southern Finland. The predicted CO2 (Fc) and H2O fluxes (Fe) and mean concentration profiles were compared against multi-level eddy-covariance measurements and mean scalar concentration data within and above the canopy. It was shown that Fc comparisons agreed to within 10% and Fe comparisons to within 25%. The optimality approach derived from a linearized photosynthetic demand function predicted the largest CO2 uptake and transpiration rates when compared to eddy-covariance measurements and the other three models. Moreover, within each gs model, the CO2 fluxes were insensitive to gs model parameter variability whereas the transpiration rate estimates were notably more affected. Vertical integration of the layer-averaged results as derived from each gs model was carried out. The sensitivities of the up-scaled bulk canopy conductances were compared against the eddy-covariance derived canopy conductance counterpart. It was shown that canopy level gs appear more sensitive to vapor-pressure deficit than shoot-level gs. 相似文献
59.
Lauri V. Punto MD ScD DVM PhD Timo O. Nevalainen DVM MS Sirkka A. Wiljasalo MD ScD Ilkka V. O. Alitalo DVM PhD 《Veterinary radiology & ultrasound》1984,25(1):43-45
A dog with aspiration pneumonia was examined by computed tomography (CT) with 8-mm continuous scans of the chest. The results demonstrated that CT is a useful procedure for evaluating pneumonia, although high cost prevents its routine use. A normal littermate was examined, and normal structures of the chest and chest wall were compared. 相似文献
60.
Timo Kautza Frank Ellmer Cristina López-Fando Enn Leedu Wolfgang Köhn 《Archives of Agronomy and Soil Science》2013,59(5):513-520
Soil micro-arthropods play an important role in the nutrient cycle of agro-ecosystems and are considered to have a strong impact on microbial activity. The occurance of soil microarthropods was investigated in the International Organic Long-Term Field Experiment (IOSDV). The investigation took place in the experimental fields of Berlin/Germany, Madrid/Spain and Tartu/Estonia. Field plots "without organic fertisation", "farmyard manure" and "straw-beet-leaves-green manure" without mineral N-fertilisation and with 120kg/ha mineral N-fertilisation respectively have been investigated. Data shows that the effects of organic manure and mineral N-fertilisation are considerably influenced by specific site characteristics. The highest abundances were found in the experimental field of Madrid. In the two nothern sites soil microarthropods were found only in very low quantities. Data indicates that not only organic manure but also mineral N-fertilisation may influence the abundance of soil micro-arthropods positively. 相似文献
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