Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2020
Authors
Hyung Sik Choi Torbjörn Jansson Alan Matthews Klaus MittenzweiAbstract
No abstract has been registered
Authors
Nobertas Uselis Jonas Viškelis Juozas Lanauskas Mindaugas Liaudanskas Valdimaras Janulis Darius KviklysAbstract
A study on the influence of planting distances on the growth, productivity and fruit quality of dwarf apple trees in a 15- to 18-year-old orchard was carried out at the Institute of Horticulture, Lithuanian Research Centre for Agriculture and Forestry. Trees of the apple (Malus × domestica Borkh) cultivar ‘Auksis’ on rootstock P 60 were planted at distances of 3 × 1.5, 3 × 1.25, 3 × 1.00 m and 3 × 0.75 m. With increasing density of fruit trees, single-tree growth, generative development and yield were significantly reduced. The opposite results were obtained when these parameters were evaluated per unit area. Yield and fruit quality measurements were made at two canopy heights: 0–1.5 and 1.5–2.5 m. In the upper part of the fruit tree canopy, fruit average weight and diameter were higher, while the colour was more intense and less dependent on the planting density of fruit trees. In the lower part of the canopy, fruit quality was inferior and with increasing fruit tree density it further deteriorated. Planting distances had a significant effect on the accumulation of sugar, soluble solids and dry matter content: greater planting distances resulted in increased sugar content from 10.97% to 11.90%, soluble solids – from 12.30% to 13.17% and dry matter content – from 13.80% to 14.80%. Conversely, higher accumulation of phenolic and triterpenic compounds in apple fruits was found with decreasing planting distances. A significant increase of phenolic compounds from 2.91 up to 4.03 mg g-1 DW (dry weight) was recorded at the upper part of the canopy, while an increase of triterpens from 12.9 up to 16.07 mg g-1 DW – at the lower part of the canopy. The best productivity and fruit quality of ‘Auksis’ apple trees on P 60 rootstock at the full bearing stage were obtained, when fruit trees had been spaced at 3 × 1.25 m. Key words: fruit biochemical composition, fruit colour, Malus × domestica, planting system.
Authors
Hermine Mitter Anja-K. Techen Franz Sinabell Katharina Helming Erwin Schmid Benjamin Leon Bodirsky Ian Holman Kasper Kok Heikki Lehtonen Adrian Leip Chantal Le Mouel Erik Mathijs Bano Mehdi Klaus Mittenzwei Olivier Mora Knut Øistad Lillian Øygarden Jörg A. Priess Pytrik Reidsma Rüdiger Schaldach Martin SchönhartAbstract
No abstract has been registered
Authors
Magda Chudzinska Yoko L. Dupont Jacob Nabe-Nielsen Kate P. Maia Marie Vestergaard Henriksen Claus Rasmussen W. Daniel Kissling Melanie Hagen Kristian TrøjelsgaardAbstract
Understanding interactions between individual animals and their resources is fundamental to ecology. Agent-Based Models (ABMs) offer an opportunity to study how individuals move given the spatial distribution and characteristics of their resources. When contrasted with empirical individual-resource network data, ABMs can be a powerful method to detect the processes behind observed movement patterns, as they allow for a complete and quantitative analysis of the agent-to-environment relationships. Here we use the small-scale, within-patch movement of bumblebees (Bombus pascuorum) as a case study to demonstrate how ABMs can be combined with network statistics to provide a deeper understanding of the mechanisms behind the interactions between individuals and their resources. We build an ABM that explicitly simulates the influence of distance to the nearest flowering plant (allowing minimal energy expenditure and maximum time spent foraging), plant height and number of flower heads (as a proxy of food availability) on local foraging decisions of bumblebees. The relative importance of these three elements is determined using pattern-oriented modelling (POM), where we confront the network statistics (number of visited plants, number of interactions, nestedness and modularity) of a real B. pascuorum individual-resource network with the emergent patterns of our ABM. We also explore the model results using spatial analysis. The model is able to reproduce the observed network statistics. Despite the complex behaviour of bumblebees, our results show a surprisingly precise match between the structure of the simulated and empirical networks after adjusting a single model parameter controlling the importance of distance to the next plant visited. Our study illustrates the potential of combining field data, ABMs and individual-resource networks for evaluating small-scale, within-patch movement decisions to better understand animal movements in natural habitats. We discuss the benefits of our approach when compared to more classical statistical methods, and its ability to test various scenarios in a new or altered environment.
Authors
Jamie N. Orr Roy Neilson Thomas E. Freitag David M. Roberts Keith Davies Vivian C. Blok Peter J. A. CockAbstract
No abstract has been registered
Authors
Ahto Agan Rein Drenkhan Kalev Adamson Leho Tedersoo Halvor Solheim Isabella Børja Iryna Matsiakh Volkmar Timmermann Nina Elisabeth Nagy Ari HietalaAbstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Bente FøreidAbstract
No abstract has been registered
Authors
Andreas BrilkeAbstract
Plastics in terrestrial ecosystems negatively affect their functioning by altering physical properties and disturbing soil microorganisms. The same could be true for biodegradable plastics entering nature through incomplete degradation in composting plants, and their subsequent application to soil in fertilizer substrate. So far, no standard analysis protocol for biodegradable plastic degradation exist. This Master's thesis has focused on developing methods for the analysis of biodegradable plastic degradation in a compost matrix and lays a foundation which later research can be built upon. Fenton's reagent and hydrogen peroxide were tested as a sample up-concentrating pre-treatment of an organic matter matrix containing biodegradable microplastics. The degradation of four different biodegradable plastics in nylon bags in a compost tumbler and a compost oven incubation were assessed. Samples for pH and phospholipid fatty acids (PLFA) of different treatments were collected to compare their development and interchangeability. Fenton's reagent was the better suited up-concentrating pre-treatment for samples with some uncertainty remaining. Assessing the biodegradable plastic degradation indicated an incomplete process in home composts and (Norwegian) composting plants. pH values coarsely reflected the composting conditions and suggested interchangeability of most treatments. Analysis of pH together with PLFA results would have been optimal, but could not be accomplished as the COVID-19 epidemic hindered the PLFA analysis. While some uncertainties in the developed methods remain, it can be concluded that a basis for establishing biodegradable plastic degradation analysis was created. Subsequent research should continue their development to assess whether biodegradable plastic remains from composting plants contribute to the accumulation of plastics in terrestrial ecosystems.
Abstract
No abstract has been registered