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Displaying theses 1-10 of 233 total
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F.J.W. Vlaar
Master programme: Geo-ecological Dynamics May 21st, 2018
Institute: IBED Research group: Ecosystem & Landscape Dynamics Graduation thesis Supervisor: Dr. L.H. Cammeraat
Soil water repellency along a lime poor and lime rich chronosequence in the Luchterduinen, the Netherlands
Soil water repellency (SWR) and how it is influenced by vegetation succession and lime content is studied in the Luchterduinen. This area contains a lime rich and lime poor soil-vegetation chronosequence as a result of dune blowouts that have been stabilized randomly over the past 100 years. Soil samples were taken at 0-5 and 5-15 cm depth and SWR was measured using the water drop penetration time (WDPT) test, sessile drop (SD) test and molarity of an ethanol droplet (MED) test. The main conclusion of this study is that SWR increases with vegetation succession but it does not significantly differ between the lime poor and lime rich chronosequence. The WDPT and MED method also indicate a decrease in SWR over depth. Another finding is that the results of the three SWR methods are comparable. Furthermore, pH, soil organic matter, lime content and plant species and cover were included to have a more detailed understanding of SWR development. All soil properties correlate significantly (weak to very strong) to the three SWR methods and soils underneath Dicranum scoparium, mosses, lichen, grasses, herbs and plants with a symbiotic relationship with Vesicular Arbuscular Mycorrhizal (VAM) fungi correlate significantly with SWR.
picture that illustrates the research done
Scientific abstract (pdf 2K)     For more info or full text, mail to: l.h.cammeraat@uva.nl

J. Steenvoorden
Master programme: Geo-ecological Dynamics April 9th, 2018
Institute: IBED Research group: Computational Geo-Ecology Graduation thesis Supervisor: Daniel Kissling
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Assessing the Ecological Importance of Unburned Islands in the Conservation and Management of Wildlife Species: a Case Study on Greater Sage-Grouse Populations in the Sagebrush Ecosystems of South-Eastern Oregon
In this thesis, I assessed the effect of unburned islands (wildfire refugia) on the population dynamics of the greater sage-grouse, a bird of conservation concern in the Great Basin of North America. First, I assessed the effect of unburned islands on sage-grouse population dynamics after fire in comparison to burned areas using yearly male counts on mating locations (leks). Second, I evaluated the effect of post-fire habitat composition on the population recovery and persistence of these populations, to find out if certain habitat characteristics could explain patterns in population dynamics after fire.
picture that illustrates the research done
Scientific abstract (pdf 5K)     For more info or full text, mail to: W.D.Kissling@uva.nl

A.W.R. Luikink
Master programme: Geo-ecological Dynamics March 30th, 2018
Institute: IBED Research group: Ecosystem & Landscape Dynamics Graduation thesis Supervisor: William Gosling
The onset of regional and local vegetation during the Last Glacial Maximum in Bergvennen Twente, the Netherlands
The master thesis focuses on comparing pollen and phytoliths to determine the onset of regional and local vegetation during the LGM in Twente, the Netherlands. Multiple studies in the Netherlands focus on analysing pollen to reconstruct the vegetation, but almost no studies have focused on phytoliths solely or even together. This research tried to close this gap and show that analysing pollen and phytoliths are a viable method to reconstruct regional and local vegetation and can even be compared to determine the timing of vegetation onset. The results of this research have shown that it is indeed a viable method to compare pollen and phytoliths and that the results show that the delay between regional and local is often underestimated. The delay is ca. 2100 years while estimates are often between 500-1000 years.
picture that illustrates the research done
Scientific abstract (pdf 2K)     For more info or full text, mail to: W.D.Gosling@uva.nl

M. van Dusseldorp
Master programme: Geo-ecological Dynamics February 22nd, 2018
Institute: IBED Research group: Earth Surface Science Graduation thesis Supervisor: Albert Tietema
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Disentangling climatic drivers of 15N and 13C plant data in a standardized phytometer setup.
In this research, a phytometer experiment was done to test the influence of a European climatic gradient on 13C and 15N in a plant community including Dactylis glomerata, Plantago lanceolata and Trifolium pratense. Initial conditions in the greenhouses at different sites turned out to have a significant influence on the isotopes values in the plant seedlings. After the seedlings grew in the local climates for 50-days, correlations were found for the changes in 13C and 15N and climatic parameters. The short-term changes in these isotopes in plant material from seeds to seedlings and due to local climatic conditions in the field show that these isotopes are sensitive enough be used as common metrics in climate change manipulation experiments.
picture that illustrates the research done
Scientific abstract (pdf 62K)     For more info or full text, mail to: a.tietema@uva.nl

K. Wartęga
Master programme: Geo-ecological Dynamics January 29th, 2018
Institute: IBED Research group: Earth Surface Science Graduation thesis Supervisor: Erik Cammeraat
Determination of the added value of high-resolution satellite soil moisture in the WOFOST crop model
The changing climate and decreasing precipitation in the last decades have put strain on agriculture in Morocco and caused unpredictable crop yields that affect the country's food security. This situation encourages the use of additional tools, such as crop simulation models, to improve yield predictability. This study uses WOFOST model and satellite soil moisture data to attempt to improve crop modelling and to investigate whether satellite soil moisture has the potential to become an indicator of Morocco’s crop yields. Modelled crop yields, modelled soil moisture data as well as reported crop yields and satellite soil moisture data were used in this research. Modelled and reported yields were compared using statistical tools. Similarly, modelled and satellite soil moisture values were compared in the same manner. This study has not found significant links between the areas of weak model performance and low soil moisture correlations. Additionally, no links were found between yields and soil moisture level during the sensitive growth stage of the plant. This study was a first step, but more research is needed to further analyse the sensitivity of winter wheat to water availability in Morocco.
picture that illustrates the research done
Scientific abstract (pdf 3K)     For more info or full text, mail to: L.H.Cammeraat@uva.nl

K.M. Michalska
Master programme: Environmental Management November 30th, 2017
Institute: IBED Research group: Earth Surface Science Graduation thesis Supervisor: Erik Cammeraat
Development of a modelling framework for a quick overview of a flood damage estimation.
The goal of the thesis was to develop a dynamically integrated flood damage model that would rapidly estimate flood losses. The developed model is based on two existing models, namely inundation (HEC-RAS) and damage (Damage Scanner). Both models are simplified and integrated in the NetLogo software. The new inundation-damage model allows to model any magnitude of the inundation extent, computation of damage estimation as Expected Annual Damage or for specific return periods, and incorporation of mitigation measures. Later, the model was used to calculate flood damages for the City of Calgary, Canada. Obtained results were examined in regards to the effectiveness of damage reducing measures, and compared with pre-existing flood damages calculated for the City of Calgary.
picture that illustrates the research done
Scientific abstract (pdf 2K)     For more info or full text, mail to: l.h.cammeraat@uva.nl

M.J.M. Verploegen
Master programme: Environmental Management October 31st, 2017
Institute: IBED Research group: Paleo-ecology and Landscape Ecology Graduation thesis Supervisor: John van Boxel
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The Relationship Between Rossby Wave Activity And Climate Change
In this thesis Rossby waves are defined quantitatively and linked to climate change. Due to increasing temperatures all over the world, pressure levels in the troposphere are changing. Because the Arctic is heating faster than the tropics, the difference in pressure between these areas is slowly decreasing at the pressure level of 500 hPa (approximately 5.4 km altitude). This changes naturally occurring meandering flows in the jetstream, known as Rossby waves. These Rossby waves play a role in the movement of high and low pressure systems, which in turn influence daily weather. A decrease in Rossby Wave Activity (RWA) results in more frequently occurring dry spells, heat waves, cold spells or periods of rainfall. Using Matlab to calculate trends and correlations in climatological variables, a relationship between RWA and climatological trends is found. However, since there is no statistically significant trend in RWA, it is yet to be confirmed that this correlation is influencing trends in climate change.
picture that illustrates the research done
Scientific abstract (docx 13K)   Data file (docx 14K)   Full text (pdf 2288K)

P.A. Zitman
Master programme: Geo-ecological Dynamics August 31st, 2017
Institute: IBED Research group: Computational Geo-Ecology Graduation thesis Supervisor: Dhr. Dr. A.C. Seijmonsbergen
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Automated detection, delineation, and classification of gypsum dolines with OBIA and LiDAR
An automatic method for classification of gypsum dolines in Vorarlberg is proposed. A combination of Object-Based Image Analysis (OBIA) and Light Detection and Ranging (LIDAR) technology is applied to segment dolines using an ISODATA clustering method. A k-Nearest Neighbour (k-NN), Random Forest (RF), and Genetic Algorithm-based Random Forest (GARF) have been trained and tested with data from two case study areas in the Gampbach Valley and near the village of Lech. The models were also tested for their transferability using an independent study area, which is located near the Davenna summit in Montafon, in the SW of Vorarlberg. The dolines depth and gypsum lowering rates were used to make an age-depth age estimation, which was used to refine landscape development in the study areas.
picture that illustrates the research done
Scientific abstract (pdf 2K)     For more info or full text, mail to: a.c.seijmonsbergen@uva.nl

A.G. Romeo-Hall
Master programme: Environmental Management August 17th, 2017
Institute: HIMS Research group: Synthetic Organic Chemistry Graduation thesis Supervisor: Marissa de Boer
A Viable Pathway for Realizing a Circular Dutch Nutrient Economy
This thesis project assesses the potential for phosphorus (P) recovery from Dutch water boards and their municipal wastewater treatment plants (WWTPs), in The Netherlands.
picture that illustrates the research done
Scientific abstract (pdf 2K)     For more info or full text, mail to: m.a.deboer@uva.nl

C.Y. Man
Master programme: Environmental Management July 10th, 2017
Institute: IBED Research group: Earth Surface Science Graduation thesis Supervisor: Elly Morrien
photo of the author
Do late-successional root exudates initiate fungal root colonization?
Fungal functional activities dominate throughout the transition in secondary succession and the major initiator of the fungal channel is plant root exudates. The influences of plant root exudates on fungal development were studied to investigate whether late-successional root exudates would initiate fungal root zone colonization. Three types of root exudates were incubated with the abundant fast- and slow-growing fungal species from the Veluwe, NL. The results showed that the synthetic exudate compound, Strigolactone rac-GR24, stimulate the fast-growing fungi in low concentration and slow-growing fungi in low to high concentrations. No positive growth results were found for the synthetic compound, Fumaric acids. Besides, root exudates from seed-grown mid- and late-successional plant communities, collected by a hydroponic method, stimulate fast-growing fungi significantly. And, late-successional exudates from two common field-grown successional plant species, Plantago lanceolata and Senecio jacobea, collected by a flushing method, stimulate slight fungal growth. The discoveries suggest that late-successional exudate is a key initiator in fungal functions and Strigolactones are a potential substance. Future studies are required to verify the effect on a wider range of plant and fungal species and the presence of Strigolactones or other potential exudate substances in late-successional exudate.
picture that illustrates the research done
Scientific abstract (pdf 2K)     For more info or full text, mail to: W.E.Morrien@uva.nl

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