Specialerapporter og -abstracts

Does alcohol consumption increase reproductive fitness of virgin males of drosophila melanogaster?

Shoshan, Anna Brødsgaard, 15.08.2017

Abstract:
Ethanol is a naturally occurring dietary supplement, containing a high content of energy, while being capable of causing behavioral changes. The species Drosophila melanogaster is well adapted to ethanol, and the intake of ethanol has been linked with increases in fitness. However, it is possible that we have not yet revealed all fitness gains that flies have from ethanol intake. Here I investigated if virgin males of D. melanogaster increase reproductive fitness, by taking in ethanol. I tested this, by comparing fitness traits between males fed with lab medium only, and males offered an ethanol solution as a supplement. Besides this, I investigated if fitness gains are due to ethanol’s content of energy or an effect on their behavior. This I tested by additionally observing the behavior of the males before introduction of a female, and adding a treatment with a sucrose solution as a supplement, with the same amount of calories as in the ethanol treatment. The days the supplements were offered, and the number of males pr. vial during the treatment period, were varied, to test for consistency across circumstances. The results showed that the percentages
of virgin males that failed to mate decreased, if ethanol or sugar was taken in, while the males were in groups, prior to introduction of a female. If the intake period additionally was limited to one day, the copulation latency decreased. Both increases in fitness were primarily caused by the energy content in ethanol. My data suggests that competition for food resources might have been a key factor, driving the
adaptation of male D. melanogaster, toward taking in ethanol as a supplement to their diet.

Expression of Genetic Variance and Environment Dependent Evolutionary Potential

Friborg, Magnus Lak, 24.07.2017

Abstract:
Distribution and abundance of ectothermic organisms is highly influenced by their tolerance to environmental variables, such as temperature and humidity. Studies have shown that the evolutionary potential to increase tolerance to such factors may be limited due to physiological constraints and lack of genetic variation. As the global climate faces vast increases in both mean temperature and frequency of extreme temperatures, adaptive potential to increase thermal tolerance becomes increasingly important. It has long been known that phenotypic variance of traits depends on the environmental context, which in turn affects the heritability of traits. However, an increasing number of studies show that in morphological and life history traits, additive genetic variance may also be affected by environment through decanalization under stress or increased expression in novel environments. Using a paternal half-sib full-sib breeding design, I examine how the additive genetic variance and heritability of thermal tolerance is affected by three different environmental conditions: 1) thermal hardening, 2) desiccation hardening and 3) random temperature fluctuations. I show that additive genetic variance for thermal tolerance can either in- or decrease with environmental stresses and that heritability can be affected through changes in both additive and environmental variance. In addition, significant amounts of additive genetic variance were detected under near all conditions. These results, suggest that genetic adaptation to increased thermal tolerance is possible, though much depends on the environment.

Long-term crop rotation and crop management effect on leaching of dissolved organic nitrogen and total nitrogen in arable cropping systems

Lau-Jeppesen, Mads Alexander, 30.06.2017

Abstract:
Nitrogen leaching is an important topic in Europe. Various regulations and rules have been implied to reduce leaching of nitrogen from agricultural lands. Also in Denmark, has nitrogen leaching been a concern for many decades. The contributor to nitrogen leaching is nitrate leaching. That is why most studies have focused on nitrate leaching. However, some of the leached nitrogen also comes from dissolved organic nitrogen (DON). DON concentration and leaching, have mostly been studied in grasslands or terrestrial ecosystems. DON concentration and leaching is affected by various biological and physical factors, and mechanisms are complex. 2 different models were considered regarding leached DON, the continual stripping model and dynamic exchange model. One way to reduce nitrogen leaching have been to incorporate crop management solutions, crop rotation solutions and different farming practices. Crop management, crop rotation and farming systems have shown to reduce nitrate leaching from agricultural soils. This study aims investigate different crop management solutions (cover crops and fertilizer), crop rotations (OGL, OGC and C) and location effect on concentration of DON, leached DON, total leached N and contribution of leached DON on the total leached N. 3 different study sites was also investigated to investigate the effect of soil texture. Temporal variation was also investigated. This study was conducted over winter in 2015 and 2008. Results show that there was no impact of cover crops and fertilizer on concentration of DON, leached DON, total leached DON and the contribution of leached DON to total leached N. Suggesting that cover crops and fertilizer didn’t reduce DON concentration and leaching of DON over winter. Results showed that OGL had significantly higher concentration of DON and amount of leached DON compared to OGC. Suggesting that a legume based crop rotation would increase concentration of DON and increase leaching of DON. Soil texture did also have an impact on the concentration of DON, leaching of DON and total leached N. Result showed highest values in Jyndevad (coarse sand) compared to Flakkebjerg (sandy loam). Highest concentrations of DON and highest amount of leached DON was found in early winter, with a decline towards spring.

Keywords: Dissolved organic nitrogen (DON), concentration of DON, leach amount of DON, total leached N, crop management, crop rotations, organic and conventional farming practices, temporal variation and soil texture.

Airborne Bacterial and Archaeal communities in farm and urban environments – A comparative study

Vestergaard, Ditte Viereck, 30.06.2017

Abstract:
This study investigated the airborne bacterial and archaeal community in urban homes, pigsties and their associating farmers’ homes. The dust was collected from the air using a passive airborne dust collection method referred to as an electrostatic dust fall collector (EDC). The bacterial and archaeal communities were determined by 16S rRNA gene sequencing using next generation sequencing. The community analysis was conducted on the basis of operational taxonomic units (OTUs) and analysis such as Bray Curtis and Jaccard distance matrix and Shannon and Simpson indices was used to illustrate the OUT distribution and the OUT diversity, respectively. As a result, the bacterial communities was different between each environment, however the farmers’ homes and pigsties contained a more similar bacterial community compared to the urban homes. The season did not show an impact on the bacterial diversity and distribution. Each environment was dominated by the same four phyla (­­~93%) both in summer and winter: Firmicutes, Actinobacteria, Proteobacteria and Bacteroidetes. Clostridia were found to be the most dominating order especially in the pigsties and farmers’ homes and included high numbers of Lachnospiraceae, Peptococcaceae and Ruminoccocaceae that were found in significantly higher abundances in the farm environment compared to the urban environments.

Competition between honeybees and wild Danish bees in an urban area

Blindbæk, Thomas, 30.06.2017, speciale

Metabolism and nutrient uptake of macrophytes and the associated biofilm i small lowland streams. - Implication of frequent weed-cutting

Thiemer, Kirstine, 30.06.2017

Abstract:
Submerged macrophytes are abundant in many lowland streams in areas with agricultural land use. Macrophytes influence physical, chemical and biological characteristics of lowland streams and management in form of removal (i.e. weed-cutting), is therefore of great interest since it can alter the ecological functions of streams. The effect of weed-cutting is often evaluated to address changes in species diversity, but the derived effects, such as impact on macrophyte functioning have so far received little attention. The objective of this study was therefore twofold. Firstly, the aim was to examine the functional traits; nutrient uptake and metabolism, of macrophytes with different morphology and how their associated biofilm affect these. Secondly, the aim was to evaluate whether frequent weed-cutting events, will affect the functional traits of macrophytes and their associated biofilm. 
This study was conducted as a controlled replicated experiment where three macrophytes species (Callitriche sp, Elodea canadensis (Rich.) and Potamogeton perfoliatus (L.)) were grown in 12 flumes, simulating small lowland streams, with different weed-cutting scenarios; no cutting, one cut and two cuts over a three-month period. Following regrowth after the last weed-cutting event, short time measurements (<24 h) of nutrient uptake and metabolism were performed on macrophytes with different ages and with or without biofilm.
I found that both rates of metabolism and nutrient uptake were different among macrophytes species. Furthermore, biofilm was found to have no effect on these functional traits of macrophytes, which was probably due to the low densities of biofilm found in this study. 
Finally, weed-cutting was found to have effect on metabolism and partly on nutrient uptake in all examined macrophytes. Young macrophytes’ biomass had higher photosynthetic capacities and higher uptake rates of ammonium compared to old macrophytes’ biomass.
In summary, this study gives unique insight in a derived effect of weed-cutting, since it is the first study to examine the response of frequent weed-cutting to functional trait of macrophytes. In order to address the finding to whole stream level, which can influence future managements strategies further studies are needed, as the methods used to measure functional trait in this study, did not allow a direct scaling to whole stream level.

Microbial activity in the deep subsurface sediments of the Guaymas Basin, Gulf of California

Møller, Elise Marie Okholm, 30.06.2017

Abstract:
The the microbial activity and the organic matter quality was investigated in Holocene marine sediments (~3°C) at two stations from the Guaymas Basin, Gulf of California. The microbial activity was investigated with the D:L amino acid model, which estimates the turnover times of microbial necromass (i.e. dead microorganisms) and biomass, as well as the amino acid carbon oxidation rates. The source of the amino acids and amino sugars was suggested to be of microbial origin, by the source indicators, the glycine and serine ratio and the glucosamine and galactosamine ratio. The quality of the sedimentary organic matter decreased with depth of the sediment, which was shown by a decrease in the ratio between aspartic acid and its non-protein degradation product β-alanine and the ratio between glutamic acid its degradation product
γ-amino butyric acid. The necromass turnover times were in the range of 2079 - 6315 years, while the biomass turnover times were in the range of 14 - 253 years. The amino acid carbon oxidation rates were in the range of 22 - 157 nmol gdw-1 yr-1.

This study demonstrates that the quality of the organic material in the cold sediment in the Guaymas Basin decreases with the depth, and that the microbial activity is consistent with other Holocene sediments such as the Bay of Aarhus, Denmark and the Labrador Sea, Canada.

Documentation of the Aalborg method as an alternative method of weed cutting

Henriksen, Lisbeth Dalsgaard, 30.06.2017

Abstract:
Hydromorphological alterations have negative impacts on macrophyte communities in lowland streams. This study provides a comparison of different methods of weed cutting. The Aalborg method is compared to methods of weed cutting conventionally practiced in stream management in Denmark. Specifically, this study investigates (i) if streams cut with the Aalborg method have a different community structure of machrophytes compared to weed cutting using scythe, boat and to that found in uncut streams and (ii) if good ecological status can be achieved with the Aalborg method using DVPI (Danish Water Plant Index). The data represents 55 stations scattered across 28 streams in Eastern Jutland (figure 4). The results suggest that macrophyte communities in streams cut with the Aalborg method are more severely affected by disturbance according to the functional trait composition compared to weed cutting by scythe, boat and the uncut streams. Especially, ‘single basal meristem’ and a negative relationship with ‘rooted heterophylly’ indicate a severe impact of disturbance and homogeneous habitat condition. Also, species- and substratum composition indicate disturbance. Streams cut by the Aalborg method have a markedly higher coverage of Sparganium and mud compared to the other groups. Weed cutting by the Aalborg method, scythe and boat achieve good ecological status in the range of 14-17%, while the uncut streams have 50% with good ecological status.

Grødeskærings effekt på de fysiske forhold i vandløb med fokus på Aalborgmetoden

Kallestrup, Helena, 30.06.2017, Speciale

Environmental and ecological factors determining sett site selection by two meso-carnivores: the Red fox, Vulpes vulpes, and the European badger, Meles meles, in mosaic landscapes in Denmark

Larsen, Stine Lindberg, 29.06.2017

Abstract:
Sett site selection of two meso-carnivores, the Red fox, Vulpes vulpes, and the European badger, Meles meles, was analyzed in six study areas in Jutland, Denmark (9.600 ha). The study areas were separated in two groups: more intensively cultivated (n=3) and more extensively cultivated (n=3) areas. Five hundred setts were recorded in the six areas, from this 125 main setts were compared with 3000 random points. In order to examine the factors affecting sett choice, 27 land cover and topographical variables were considered, including the effect of each study area and the specific resident species relative to main setts found. The aim of this study was to identify: 1) which environmental and ecological parameters were associated with the presence of fox and badger setts, 2) if the distribution of setts was equally common in intensively cultural areas and extensively cultural areas, 3) how the coexistence of the two meso-carnivores affected their choice of habitat. Analyses by a logistic regression model showed that main setts were equally distributed between the two groups of areas. Contrary to the expected, fox and badger setts were localized in more intensively cultivated areas than by chance. In both intensively and extensively cultivated areas, main setts were located most predominantly in woodland (> 40 %), on sloping ground near crop fields and meadows compared to random points. Additionally, marginal habitats as hedgerows and coverts close to grass fields were chosen as sett site and disturbance sources such as urban areas and boundary marks were avoided. Furthermore, the present study shows a positive coexistence of the two species, potentially reflecting spatial and temporal segregation. In conclusion, the two meso-carnivores have adapted to the Danish mosaic landscape, also intensively managed areas. Especially, woodlots, hedgerows and coverts hold more setts. In extensively managed and more forested areas setts are typically established in the interior of the forest, whereas in more intensively cultivated areas, the two species utilize the small biotopes in the fragmented landscape as sett sites.

Recruitment patterns and early growth of benthic flora and fauna in a subarctic glacial fjord system, SW Greenland

Ørberg, Sarah Bachmann, 29.06.2017

Abstract:
Atmospheric warming has accelerated the mass loss of glacial ice in the Arctic, increasing the risk of changes in the physico-chemical environment within glacial fjord systems, which may affect the persistence, connectivity and distribution of marine organisms. Especially, marine benthos is susceptible to an increase in ice scour events and changes in surface temperatures, salinity and light conditions. These communities depend highly on recruitment (addition of juveniles to the population), as most of the species are immobile or slow moving as adults, limiting the ability to escape immediate changes in the surrounding environment. Hence, understanding what drives recruitment and early growth of Arctic benthos is important, as physical exposure is considered a key driver in the Arctic compared to milder environments.

In my thesis, I studied potential abiotic and biotic drivers of benthic recruitment and early growth in a subarctic glacial fjord system in SW Greenland, the Godthåbsfjord system. In the first experiment, settling plates were deployed in the subtidal at 3 spatial scales (fjord system, fjord, site) and 3 temporal scales (summer, winter, 1 year), to study how benthic recruitment varies in space and time and in relation to abiotic factors. Here, I found that variation in benthic recruitment and growth was likely influenced by the large-scale variation in physical parameters, such as temperature and salinity, created by glacial meltwater and ice. In addition, I observed that substrate modification by the macroalga Demarestia aculeata likely affects recruitment of barnacles negatively and mussels positively, indicating that timing in disturbance and settlement of different species is important in structuring these communities. Moreover, I found that kelp recruitment was highly variable in time and space, while showing a high growth potential once recruitment occurred. In a second experiment, intertidal canopy cover of the macroalga, Ascophyllum nodosum, was manipulated to test the hypothesis that canopy-forming algae facilitate faunal recruitment. Here, I found that canopy-forming macroalgae facilitate faunal recruitment to the understory, likely by dampening extreme air temperatures locally but not dampening ice scour. In addition, A. nodosum recruitment increased with higher substrate roughness and full recovery of the canopy was estimated to take ca. 15 years, presupposing a large supply of spores.

Overall, these results indicate that benthic recruitment and growth patterns in subarctic fjords are likely impacted by changes in glacial discharge of meltwater and ice. Moreover, biotic interactions, such as facilitation by modification of habitat structure and physical stressors, are important structural parameters of subarctic benthic communities and their recovery after physical disturbance. Finally, this study emphasizes that it is important to understand both abiotic and biotic drivers in Arctic benthic communities, to be able to target the relevant scale of biological communities when predicting impacts of climate change on benthic communities and future species distribution.

Does contraceptive rods affect the behaviour of African lions (Panthera leo) in captivity?

Jansen, Anne Lucia Nørgaard, 29.06.2017

Abstract:
The last couple of years there have been a great debate on how to solve the problem with surplus animals in zoos and wildlife parks. Some use the “Breed and Cull”-method where an animal gets to reproduce, but if there are no room or a takers for the offspring, the offspring will be culled when it reaches a certain age. Others sterilize the animals or inject them with contraceptive rods to prevent reproduction. The rods work through hormones, which prevents the ggs, in females, and sperm cells, in males, from maturation. Naturally secreted hormones affect both behaviour and morphology, but what about the hormones injected with the contraceptive rods? In this study the effect of contraceptive rods on behaviour of female African lionesses in captivity is investigated. The study is an observational study and was made in 8 different zoos in Denmark, Germany, Belgium and The Netherlands. The results showed no significant differences between the two treatments (with and without rods), with regard to behaviour, indicating that there was no effect of contraceptive rods. However, this result can be due to factors like sample size, pride composition, age and weather. Further studies should increase the sample size and include physiological measurements to get a more reliable result.

Nitrous Oxide Emission and the Gut Induction Hypothesis Described in the Aquacultured Shrimp Litopenaeus vannamei

Moeslund, Sara, 29.06.2017

Abstract:
The aim of this study was to determine whether the gut induction hypothesis for denitrification was true, and to measure the whole body N2O emission rate of the shrimp Litopenaeus vannamei, it’s stomach and gut, as well as it’s feed, all measured under nearly in situ conditions. The mean N2O emission rate from whole shrimps incubated under simulated in situ conditions were 26.88 nmol ind-1 h-1. This is the highest measured emission rate recorded to date for any aquatic invertebrate. This is almost negligible compared to the emission rate from the entire aquacultural plant as this was 679.84 mmol day-1. Incubations of dissected guts revealed DNRN to be the most active nitrogen turnover process with a mean cell specific turnover rate of 4.11*10-5 nmol h-1 cell-1. This is as much as a 100 higher than N2O production which had a mean cell specific production rate of 3.01*10-7 nmol h-1 cell-1. The gut induction hypothesis was to some extent confirmed as OTUs were activated when they were ingested by the shrimp, and passed from the oxic environment in the feed, to the anoxic environment in the gut. One of the activated OTUs were classified as Shewanella known to include denitrifying species, and this along with a large group of unclassified, activated OTUs may be able to explain the N2O emisison and DNRN turnover rates.

Investigation of behaviors related to mental disorders in genetically modified mice by the use of behavioral tests

Christensen, Louise Rask, 28.06.2017

Abstract:
Copy number variation (CNV) 22q11.2 and 15.q13.3 have been strongly associated with different mental disorders such as schizophrenia, autism, depression, and anxiety disorders in humans. Mouse models of the CNVs have successfully proven to show a schizophrenia-like phenotype. However, autism, depression, and anxiety have been little investigated and reflected in the mice models of the deletions. Therefore, we want to make an extended behavioral analysis on two mice models of the CNV 22q11.2 and 15q13.3 deletion to screen for other mental disorders in the mice. For this study the mouse models Df(h22q11)/+ and Df(h15q13)/+ that represent the 22q11.2 and 15q13.3 deletion respectively were used. The mice were screened for autism, depression, aggression and anxiety-related behavior. Our results indicate that both Df(h22q11)/+ and Df(h15q13)/+ mice have a tendency toward an autism related phenotype. Furthermore, the Df(h22q11)/+ animals also show a depression-related phenotype. The findings give us a better understanding of CNV 22q11.2 and 15q13.3 role in psychiatric illness. In the future it may be possible to screen peoples DNA for the deletions to see if they are particularly susceptible for the mental disorders the CNV 22q11.2 and 15q13.3 are correlated with.

Investigation of nectar resources for the marsh fritillary butterfly, Euphydras aurinia, from digital images

Langhein-Winther, Sidsel, 28.06.2017

Abstract:
Nutrition is a key factor for reproduction. This also applies to the holometabolic insects, the butterflies, where nutrition obtained during the larval and adult stages has an important effect on the reproduction success. Fragmentation and homogenization of the landscape has affected the number of flowers and hence the nectar resources for the adult butterflies. This is one of the reasons for the decline in the numbers of butterfly species in Denmark and the rest of Europe. One of the butterfly species with a severe decline in Denmark is the red-listed marsh fritillary butterfly, Euphydryas aurinia. One method to gain knowledge about the amount of available nectar resources is by using automated counting of flowers from digital images. Therefore, in this thesis, the amount of nectar resources as the number of flowers from ten sites with the marsh fritillary butterfly is examined by using automated counting of flowers from images. The automated counting of flowers is performed with a custom built script that identifies flowers by using color codes. The method's uncertainty is examined against manual counts in a sensitivity analysis, and it is tested whether the script can find a specific flower species. In addition, it is investigated whether there is a difference in the number of flowers from the ten sites as well as whether there is a correlation between the numbers of flowers and the factors vegetation height and humidity in soil.
A significant difference is found in the number of flowers from the different sites, and it is found that the vegetation height, humidity in soil and the site affect the numbers of flowers in different ways. There are still improvements to be made both in regard to the scripts and in the collection of images in the field, but the method of automated flower counting gives results close to reality.
Even though there is not collected data about the flowers' content and quality of nectar, data about the number of flowers or host plants can still gain knowledge about the butterfly population and food situation, as well as being able to asses new habitats.
There are other areas about the nectar resources that would be interesting to investigate, and these show that there are many possible ways in which automated flower counting can have a role in future studies.

Immunogenetic variation in small populations: β-defensins in the Cape Verde warbler

Jakobsen, Tenna Marie Hertel Jacobsen, 27.06.2017

Abstract:
β-defensin are a vital part of the innate immune system that provides the host with defense against microbial organisms making them highly important to the fitness of the individual. The Cape Verde warbler is an endemic passerine that has been classified as endangered. Here variation in the beta-defensin genes AvBD4, AvBD7 and AvBD11 is examined in order to assess the current genetic composition of β-defensin genes in the populations of the Cape Verde warbler and by comparing β-defensin data to that of genetically neutral data establish if this variation has been caused by selective forces or demographic factors. The results showed that two of the three β-defensin genes contained polymorphism. There was no sign of diversifying selection found in the Cape Verde warbler species itself or between it and its closest relatives. Evidence for balancing selection was generally found in all populations for all β-defensins examined. And patterns of differentiation between populations showed no sign of strong selection having occurred. A surprising result was that some populations showed signs of selection towards homozygotes, which does not comply with current theory of selection on immune genes. It is concluded that the Cape Verde warbler due to the current genetic composition of β-defensin has evolutionary potential to adapt to environmental changes in pathogen composition. Moreover it is assessed that from the results of this project, translocation of individuals between populations can be a viable way of maintaining genetic variation. 

Air convection requirement in mice (Mus musculus): The effect of tem-perature and gestational status

Bjerregaard, Patrick Rolighed, 27.06.2017

Abstract:
The air convection requirement (ACR), the ratio between ventilation and metabolic rate, is a value which have been overlooked in previous studies. Some studies have measured ventilation and metabolic rate, at the same time, but there have been no studies which were fully dedicated to investigate the nature of this value.
Therefore, this study investigated the topic by measuring ACR on mice (Mus musculus), which is one of the most important animal models, and therefore is needed to be better understood. The mice in this study were exposed to different treatments, which should raise the metabolic rate to see if this would affect the ACR. The treatments were temperature, food intake and pregnancy. To do all the above, a new setup had to be developed. Intermittent closed respirometry which can measure metabolic rate was combined with the barometric method which can measure ventilation. This combination allows for prolonged measurements, and the subject need no physical restrictions nor stress. Furthermore, a method capable of determining resting metabolic rate (RMR) entirely objectively was desired.
The ACR varied a lot. Looking at individuals at seemed like deeper breaths made the ACR decrease, while it did not seem like the different treatments had any effect on the ACR.
Finding a way to objectively determine RMR was made possible, by using a method which were recently developed to find standard metabolic rate in fish.

Vegetation analysis of the composition of woodland plant species and their relation to the environmental development in the forests of Kalø, Denmark

Olesen, Diana, Klynge, 27.06.2017

Abstract:
Old, varied and heterogeneous forests often show a high species richness compared to recent or highly managed forests. These forests are important biotopes and their heterogeneity and variation provide ecological habitats for many vulnerable and specialised plant species.
In this study, plant species richness and composition in the Hestehave and Ringelmose forests of Kalø were examined throughout an investigation period of 23 years. The registrations of the plant species were carried out in 1993, 1998, 2005 and 2016. The forests are at least 300 years old and have been managed as high forestry until the 1990s, where it was changed to close-to-nature forestry.
During the 23 years an increase in the species richness was registered and species composition was identified, showing changes throughout the period. The species composition was used to calculate the forest nature value per plot, which increased during the period. The main focus was on the ancient forest species, which generally showed progress. The graminoids, ferns and seedlings mainly showed an increase in their presence, which is expected to be a result of the decreased herbivory in the forests caused by the decreasing deer population.
Furthermore, the changes in the species diversity were assessed in relation to the environmental conditions, where the frequency of the open forest type showed a strong decreasing tendency. The investigation of the biotic homogeneity showed an increase throughout the period. As a result of this increase the ecological habitat for plant species becomes narrower in 2016 compared 1993.
The species composition also showed changes in Ellenberg indicator values, which especially revealed a significant decrease in light and temperature, while the soil moisture showed increasing tendencies.
It can therefore be concluded that the changes in the species composition in the forests of Kalø moved towards more light- and water-stress and less disturbance. However, the biotic similarity in the species composition was particularly a result of decreased light intensity to the understory vegetation, which showed effects in both temperature and soil moisture.
Preservation of forest habitats with heterogeneous and various environmental ranges ensures an overall high species richness. The conservation of nature should particularly be prioritised in forests, because the habitats contain many native species which are otherwise rare and vulnerable in the Danish landscape. These forest plant species are attached to the unusual structural and environmental conditions the stands create within the forest floor. Due to maintenance of the high species richness in the Kalø forests it is important to make initiatives, which promote variation and heterogeneity in the forests to establish diverse habitats, which accommodate the needs of different forest plant species.

Carbohydrate feeding in ants: Advantages and challenges in relation to biological pest control

Nielsen, Maria Wejersø Rosenlund, 27.06.2017

Abstract:
The main findings of the first paper was that the wood ant Formica polyctena generally demonstrated preference for high-concentration sugar baits while there appeared to be some restraints to the intake of a more solid sugar source, highlighting the importance of viscosity. Moreover, workers demonstrated a marked preference for melezitose indicating, that this attractant may be a successful asset in the attraction of ants to sugar baits rather than aphids. Trehalose and, surprisingly, peptone was disregarded, indicating that more information of amino acid preference and perhaps colony nutritional status might be needed when using protein as an attractant. Finally, there were some differences among the two test sites (natural habitat VS organic apple orchard) indicating that it might be easier to distract ants from aphid tending in crops than in their natural habitat. It is suggested, that laboratory- and field trials involving F. polyctena and aphids should be conducted in order to directly assess the potential of optimized sugar baits as an distractor from aphid tending.
The main finding of the other paper was that colonies of Asian weaver ant Oecophylla smaragdina increased their activity level substantially during carbohydrate starvation. Changes in activity parameters were detectable within the first 24 hours of the starvation period with a higher number of workers participating in what was assumed to be resource search activity. Moreover, workers readily accepted offered prey items even when subjected to serious starvation stress; these prey items were in fact discovered and retrieved faster than when the colony was well-provided of carbohydrate. These results suggest a high usability of strategic removal of sugar resources when using ants as biological control agents since it may effectively increase the speed and area of pest reduction. It is further suggested, that a similar experiment involving the choice between a carbohydrate source and a prey item is offered, thus more closely resembling a situation in the field where prey and honeydew-producers may be encountered in the same area.
The overall take-away from these experimental studies is, that the field of biological pest control could benefit greatly from handling the provision of sugar sources for ant pest agents more strategically; with the right timing of utilization and the right composition these sugar baits may highly optimize the biological control potential of ants and may even mediate the direction of control to specific sites of particular pest control interest. 

The antimicrobial activities of Oecophylla smaragdina

Zhang, Yang, 27.06.2017, Speciale

Using LiDAR for describing ecologically relevant aspects of forest structure

Lyck, Tenna, 27.06.2017

Abstract:
The factors determining species composition is of interest to ecology. In forests the structure of the canopy affects the microclimate which is essential for the understorey species composition. Light Detection And Ranging (LiDAR) has proven an effective way to quantify structure. The utility of LiDAR for describing ecologically relevant aspects of forest structure is examined based on vegetation surveys of 325 plots in the forests at Kalø, Denmark. LiDAR-derived forest structure variables and a number of non-structure variables relative importance for species composition and habitat conditions evaluated through average Ellenberg values is examined. Structural classes defined by LiDAR-derived variables and biological differences between these are also investigated. We find that species composition is better explained by forest structure variables compared to non-forest structure variables, while the opposite is found for average Ellenberg values though both variable groups contribute considerable to the explained variance. The structural classes differ in species composition, Ellenberg values and soil Ca, K and Mg, though some of these differences are eliminated if the effect of moisture is removed.

Ecology and conservation of island interactions

Villumsen, Caroline Vester, 26.06.2017, speciale

Cable bacteria in freshwater sediments: potential implications on the sulfur cycle

Sandfeld, Tobias, 26.06.2017

Abstract:
The newly discovered cable bacteria (Desulfobulbaceae) oxidize sulfide with oxygen or nitrate over centimeter distances in marine sediment  (Pfeffer et al. 2012; Marzocchi et al. 2014).  This have profound implications on the sulfur cycle in these sediments (Malkin et al. 2014; Risgaard-Petersen et al. 2012). Recently, cable bacteria were found in freshwater sediment (Risgaard-Petersen et al. 2015) which potentially have important effects on the sulfur cycle, as freshwater sediments are viewed as low-sulfur environments (Holmer and Storkholm 2001). In particular, this could affect the sulfate reduction as sulfate is scarce and the concentration is considered too low to maintain sulfate reduction over time (Pester et al. 2012). This is the first-time, that consequences of cable bacteria presence on the sulfur cycle in freshwater sediments have been investigated. This study demonstrates, that presence of cable bacteria enhances the sulfate availability in freshwater sediment, leading to higher sulfate reduction rates (SRR). The investigated sediments with cable bacteria regenerated sulfate from sulfide, by electrogenic sulfide oxidation (e-SOx), and hence produced sulfate. The same sediments significantly increased the sulfate reduction rate (SRR) by, on average, a factor 4,5 compared to sediments absent of cable bacteria. However, cable bacteria rely on acid volatile sulfides (AVS), including iron sulfide (Risgaard-Petersen et al. 2012), and their population dynamics is proposed to be closely tied to the dynamics of the iron sulfide pool (Seitaj et al. 2015). Thus, the presence of cable bacteria and their implications on the sulfur cycle are not a steady-state regime but a temporary regime. Suggesting that cable bacteria only under specific environmental conditions flourish. In conclusion, this study offers new insight on sulfide oxidation in freshwater sediments, showing that cable bacteria driven sulfide oxidation temporarily fuel sulfate reduction. Hereby, this study adds another piece to the puzzling sulfur cycle in freshwater sediments.  

Forest dynamic in young urban forest: the effect of forest origin on forest structure and plant species composition

Skjærlund, Kasper Keun, 26.06.2017

Abstract:
In Denmark, forests have a long history of overexploitation and conversion for agricultural purposes which threaten forest biodiversity. However, in recent years’ a largescale forest restoration has happened. This study investigated differences in forest environment and forest structure between spontaneous and planted forests. In Denmark, vegetation surveys were carried out in 23 deciduous forests. Results showed that forest environment and plant species composition differed between forest origin. Concerning forest structure, only understorey vegetation height, median tree stem diameter, and tree and shrub density differed between spontaneous and planted forests when the effect of forest identity and municipality were removed. Overall, variation in few of the investigated variables differed between forest origin. These results suggest that forest origin does not a sufficiently explain differences in forest structure. Local environmental conditions and plant dispersal abilities is expected to be more important predictors of forest structure in the early successional stages. Future investigations should consider the effect of forest origin on forest structure in later successional stages, and if the recovery of forest species differ between planted and spontaneous forests.

The effects of antioxidants on the renal function

Juulsager, Maja B., 26.06.2017

Abstract:
Flavonoids are known for their ability to act as antioxidants and scavengers of free radicals. This also applies to quercetin, that is the most abundant flavonoid found in nature. Unilateral ureteral obstruction (UUO) is a severe condition, which may occur due to many different reasons. As the UUO persist, the progression of damage will evolve and could, at worst, lead to tubular atrophy, inflammation, interstitial fibrosis and permanent renal damage. Increasing amounts of reactive oxygen species is one of the first events to occur after the onset of UUO. The aim of this study was to investigate the effect quercetin on the renal function and damage after three days UUO.Rats were subjected to three days UUO and treated with 50mg quercetin*kg-1*day-1 administrated as subcutaneous injection. The results of the study showed that quercetin did affect the production of extra cellular matrix, which was suspected to be related to an increase in heme-oxygenase 1. Also, IHC-staining of aquaporin 2 did reveal promising results on the effect of quercetin, that calls for further investigation.

Heart Function in Pythons

Kristensen, Ditte Lind, 26.06.2017,

Abstract:
The pulse of the reptilian heart is approximately ten-fold slower than that of their endothermic relatives, birds and mammals, and the undivided reptile heart appears to lack a specialised conduction system in the form of His and Purkinje fibers. Nevertheless, electrographic recordings clearly reveal a coordinated activation of the cardiac chambers, such that the sinus venosus contracts before the atria followed by the ventricle. It is also well established that both rate and force of cardiac contractions are under autonomic nervous regulation, but little is known about the influence of behaviour and environmental abiotic factors on the timing of the electrical activation of the cardiac chambers in reptiles.
In this master’s thesis, I investigated the electrocardiograms (ECGs) in pythons under different circumstances. The purpose was to alter the pulse with a variety of methods, in order to determine whether or not there is a difference in the manner, in which the cardiac events behave. To provide this knowledge, I placed stainless steel electrodes in a lead II formation in ball pythons (Python regius) under anaesthesia. Once the animals had recovered, ECGs were measured during rest, exercise, fasting, digestion and at different temperatures, to un-derstand the normal cardiac function in pythons. Then, I investigated the underling mechanisms by measuring the ECG upon injection of adrenergic and cholinergic agonists and antagonists. Furthermore, the relationship between heart rate (HR) and ECG time intervals to body mass (BM) was investigated in Burmese pythons (Python molurus bivittatus).
All the ECG intervals, PR, QT and TP, were found significantly altered with each condition. Temperature had a direct effect on HR, while exercise and digestion showed signs of a dromotropic effect due to sympathetic innervation. This was confirmed by β-adrenergic stimulation, which caused similar elevation of HR and short-ening of the ECG intervals, as exercise did. Interestingly, the same response could also be created by parasym-pathetic inhibition by the cholinergic antagonist. The shortening of the absolute PR interval in response to adrenaline and isoproterenol demonstrates that β-adrenergic stimulation exerts a positive dromotropic influ-ence on the reptile heart that could be fully abolished by propranolol. The absolute QT interval was reduced during adrenergic activation as well as during cholinergic inhibition. As propranolol injection did not alter QT in the resting snake, this suggest that the ventricular repolarisation is mainly influenced by a parasympathetic tone, and that the resting python heart is mainly influenced by cholinergic innervation.
BM had significant influence on all ECG segments, as all cardiac events were prolonged in large individuals, and thus scaled with BM: RR: BM0.38, P: BM0.19, PR: BM0.24, QRS: BM0.19, QT: BM0.16, TP: BM0.72. However, during exercise, the effect of BM was weakened, due to increased sympathetic tone. I found that even though HR was altered with these diverse conditions, the ECG intervals appeared to correlate with HR in a predetermined exponential way. Thus, no matter the type of influence, the interval durations seem to be altered in the same way – in relation and in response to HR.

ldentifying Sperm Whale lndividuals and Clans Through Patterns of Vocal Variation

Bøttcher, Anne, 23.06.2017

Abstract:
In the Pacific, sperm whales live in a multi-leveled society where stable social units only socialize with units with whom they share a substantial part of their coda repertoire. Codas are stereotyped patterns of clicks and is their primary form of communication. Due to the overlaying pattern of social segregation and coda repertoires, codas have been suggested to mark social affiliation. However, whether this pattern of distinct coda repertoires exist in the North Atlantic has yet to be tested. Here, we compare daily coda repertoires from nine regions in the North Atlantic using similarity measures obtained using both a Euclidean and dynamic time warping distance metrics. Furthermore, we correlate the similarities between repertoires with the geographical distance between the recording sites to evaluate evolutionary mechanisms driving patterns of similarity in coda repertoires. We find that there are significantly distinct coda repertoires in the North Atlantic, and that repertoires within the same region are significantly more similar than repertoires from different regions. However, the correlations of distances and similarities show contradicting results. We suggest that this can be explained by several factors playing important roles in shaping the repertoires, including cultural drift for example emerging from learning errors and selection to recognize cultural group members.

A Study on a possible Effect of S-nitrosyl-ated Myoglobin on Mitochondrial Respi-ration Rate and ROS Production Rate

Christensen, Mads Mogens, 23.06.2017

Abstract:
In rainbow trout (Oncorhynchus mykiss) myoglobin can be S-nitrosylated on one of its two cysteines. More-over, this S-nitrosylation is reversible as the degree of S-nitrosylation decreases as it gets deoxygenized. This led to the idea that as Mb-SNO gets denitrosylated, nitric oxide might become bioavailable for other cell compartments e.g. mitochondria. In the mitochondria NO is known to inhibit mitochondrial respiration and increase ROS production. We hypothesized that if NO became bioavailable in the presence of Mb-SNO it would affect mitochondrial respiration and/or ROS production in a similar manner, as in the presence of Cys-SNO, a known NO donor. We found that Mb-SNO did not affect respiration rate or ROS production. However, in the presence of just myoglobin, ROS production increased in state III and this increase was not observed in the presence of Mb-SNO.

The role of submerged plants in constructed wetlands Nutrient uptake, biomass production and denitrification potential in mono- and polycultures

Olesen, Annica, 22.06.2017

Abstract:
Excess nitrogen and phosphorus are released from agricultural drainage to freshwater and marine ecosystems, where the nutrients can cause eutrophication. Constructed wetlands are therefore created with the purpose of minimizing the release of nutrients from agriculture to aquatic environments by creating a filter zone for nutrients before they reach aquatic systems. The role of submerged species in constructed wetlands was assessed in this study with focus on nutrient uptake, biomass production and denitrification potential in mono- and polycultures of one to four submerged freshwater species. The objectives of this study were to investigate whether, and how much, habitats with submerged plants could contribute to nutrient retention in an aquatic environment and whether niche complementarity occur in polycultures versus monocultures of submerged plants. Nutrient uptake of PO4-P, NH4-N and NO3-N was assessed in two nutrient depletion experiments with start concentrations of 1 mg PO4-P L-1, 1 mg NH4-N L-1 and 3 mg NO3-N L-1. The two experiments were 1) an outdoor mesocosm experiment with habitats of mono- and polycultures of Ranunculus aquatilis, Potamogeton perfoliatus, Potamogeton obtusifolius and Elodea canadensis and a habitat without plants, and 2) a small-scale indoor experiment where the individual nutrient uptake of shoots from the four species was tested without influence from biofilm and sediment. The biomass production after eight weeks and denitrification potential (DEA) in the sediment in mono- and polycultures was measured in the mesocosm experiment. This study showed that habitats with submerged plant species have roughly five times higher nutrient efficiency of N and three times higher nutrient efficiency of P than habitats without plants. However, neither nutrient uptake rates, biomass production or denitrification potential increased significantly with increasing species richness. There were nevertheless indications of polycultures in general being more effective in terms of nutrient uptake than monocultures, which could be due to niche complementarity. Furthermore, niche complementarity in biomass production was found in more than half of the polycultures. The highest nutrient uptake and biomass production was however achieved by R. aquatilis in monoculture, which indicates that R. aquatilis is a good species for planting in constructed wetlands to achieve a higher water purification in constructed wetlands.

Nutrient uptake by wetland plants: Microcosm study in the period from summer to autumn

Nielsen, Emil, 22.06.2017

Abstract:
Mini-wetlands are a promising technology for treating nutrient-rich agricultural drainage water and thereby mitigating nutrient pollution of aquatic environments. Plants facilitate the retention of nitrogen (N) and phosphorus (P) in mini-wetlands by uptake in the plants as well as by positively influencing many other physical-, biological- and chemical processes in the wetlands that act to retain and transform N and P. Several studies have indicated species-specific differences in the plants’ effect on N and P retention in wetlands, thus suggesting some species might be more beneficial to establish in mini-wetlands than others. The aim of this study was to characterize the uptake of ammonium (NH4-N), nitrate (NO3-N) and phosphorus (PO4-P) of 19 different wetland plant species of both emergent and submergent growth forms in a NO3-N dominated environment, as well as to examine the positive association between the species’ nutrient uptake capacity (Vmax) and their relative growth rate (RGR). Furthermore, seasonal changes in the nutrient uptake in the period from summer (June) to autumn (October) was examined. Species differed in their Vmax for NH4-N, NO3-N and PO4-P. Submerged species exhibited a high preference for NH4-N, while emergent species to a greater extent simultaneously utilized NH4-N and NO3-N. The minimum concentration at which species were able to exhibit a positive net uptake of nutrients (Cmin) also appeared to differ between species. A positive association between RGR and Vmax NH4-N and Vmax NO3-N was found for the emergent species. Vmax exhibited seasonal changes, and in general appeared to be highest in summer and lowest in autumn, though the seasonal changes in Vmax differed between species.

Phylogeography and Mitogenome Variation in Arctic Char (Salvelinus alpinus)

Jensen, Nana Gry Wirenfeldt, 22.06.2017

Abstract:
Udbredelsen af arter, som vi kender den i dag, er formet af geologiske begivenheder. Sådanne begivenheder er bl.a. istider, hvor nordlige arter blev presset sydpå af et stigende isdække. Dette resulterede ofte i, at arter blev isolerede i såkaldte refugier og den genetiske diversitet faldt pga. manglende gen-flow. Da isen smeltede, kunne disse arter genkolonisere de nu isfri områder. Dette mønster kan oftest ses i generne (fylogenien af en art) og bliver kaldet fylogeografi. I dette studie undersøges fjeldørreden (Salvelinus alpinus), som er den nordligst levende ferskvandsfisk på kloden. Den er kendetegnet ved at være anadrom - migrerer fra ferskvand til saltvand og omvendt – og den har desuden en vigtig status i forhold til fiskeri. Vi fokuserede her på de Grønlandske fjeldørreder, idet vi mener, at de er overset i tidligere studier. Tidligere studier har vist tilstedeværelsen af fem glaciale linier – Arktisk, Atlantisk, Acadia, Beringia og Siberisk. Vi ekstraherede mitokondrielt DNA (mtDNA) fra adipose finnerne og benyttede ’nextgeneration sequencing’, til sekvensering af hele mitogenomer. Vi kombinerede to markører; 1) mitogenomer og 2) d-loop, en markør der er kontrolregionen i mtDNA. Desuden undersøgte vi om eventuel positiv selektion, da dette kan have en indflydelse på mtDNA, som bliver betragtet som neutralt for dette. Vi ønskede at teste følgende hypoteser: 1) at Grønland repræsenterede den Arktiske linie, den Atlantiske eller om der var tale om et miks af disse. 2) Muligheden for kryptiske refugier, ved at identificere unikke haplotyper. 3) at divergens tiden mellem clades og evolutionære
slægter (linier) afspejler allopatriske processer, f.eks. istider og mellem-istider.
Vores resultater viste, at de Grønlandske fjeldørreder overordnet tilhører to geografiske linier, nemlig den Arktiske og Atlantiske, som begge er identificeret i tidligere studier. Generelt tilhørte individer fra lokaliteter øst for Grønlands sydlige spids den Arktiske slægt, mens et mere interessant billede tegnede sig for den Atlantiske. Idet den Atlantiske ser ud til at bestå af to clader, hvori den ene – sub-clade 1- kun blev fundet på den østlige side af Grønland. D-loop analyserne understøttede samme overordnede mønster. Vores sekvenser blev desuden fundet fri for positiv selektion og der blev fundet en klar differentiering mellem Vest Grønland vs. Øst Grønland, Island og Norge. Vi konkluderer, at fjeldørreden viser et klart fylogeografisk mønster, i overensstemmelse med istider og mellem-istider. Vi fandt en mulig genkolonisering fra et europæisk refugie (den Atlantiske linie), samt et nordligt refugie fra det Arktiske øhav og/eller fra Beringia (den Arktiske linie). Et muligt kryptisk refugie blev fundet, selvom placeringen af denne ikke kunne bestemmes med det
tilgængelige data. Endeligt er dette studie med til at illustrere den øgede opløsning, som brugen af af
mitogenomer giver.

Habitat selection of giraffes (Giraffa camelopardalis tippelskirchi) and elephants (Loxodonta africana) in Maasai Mara, Kenya – a comparative study

Warming, Marie Kristine, 22.06.2017

Abstract:
A major decline in wildlife population in Maasai Mara demands an urgent need for wildlife conservation. Even though the area is being preserved, human impact has taken its toll. This paper investigates the effect of anthropogenic disturbances and ecological factors on the vulnerable species Maasai giraffe (G. c. tippelskirchi) and African savanna elephant (L. a. Africana) in Mara North Conservancy, Kenya. Species occurrence data has been gathered from mid-September till mid-December 2016 with a handheld GPS. 207 GPS points was collected, 121 of Maasai giraffe and 86 of African savanna elephant. The analysis was carried out in ArcMap 10.4.1. The species habitat selection is determined by both anthropogenic disturbances and ecological factors. However, the effect of anthropogenic disturbances is found to be twice as large as the ecological factors. The results provide knowledge of the species useful for creating sustainable conservation and management plans in Mara North Conservancy.
Key words: Habitat selection, G. c. tippelskirchi, L. Africana, Mara North Conservancy, conservation

Hvor meget næring kan fjernes fra randzonen via planteoptag

Larsen, Trine Bork, 22.06.2017

Abstract:
Eutrofiering af vandløb, søer og fjorde er et voksende problem globalt og det er derfor nødvendigt at finde nogle metoder til at reducere udledningen af næringsstoffer fra de diffuse kilder, på en mere økonomisk og bæredygtig måde. Randzoner har længe været et brugt værktøj til at mindske den diffuse udledning af næringsstoffer fra landbruget, men i januar 2017 blev det, i Danmark, bestemt at randzoner ikke var obligatoriske længere. Det er derfor vigtigt at der bliver udarbejdet en måde, at forvalte randzonen på, så landmændene kan se nogle umiddelbare fordele såvel som en miljømæssig gevinst i at have randzoner. En måde dette kan gøres på er ved at høste og fjerne biomassen i randzonen. Biomassen vil kunne bruges til foder og vil potentielt kunne fjerne en stor mængde af de næringsstoffer der bliver tilført.
I dette studie blev der undersøgt hvor meget næring der kunne fjernes fra randzonen ved at afhøste vegetationen, især i plantesamfund der er meget produktive; ved hvilken høstfrekvens der kan fjernes den største mængde næringsstoffer og foderkvaliteten af det afhøstede materiale. 
Overordnet viste resultaterne at der blev fjernet en større mængde næringsstoffer ved at afhøste biomassen fire gange om året end henholdsvis en og to gange. Resultaterne viste også at foderkvaliteten var højest når biomassen blev afhøstet mere end en gang om året. 
På baggrund af mine resultater fandt jeg, at selvom der blev fjernet en større mængde næringsstoffer og at foderkvaliteten var højere når biomassen blev afhøstet ved fire høslæt om året, er det ikke nødvendigvis den mest ideelle løsning for landmanden. Dertil kommer der at man i Danmark anbefaler at biomassen først afhøstes fra midt-juni og indtil slut-september, hvilket begrænser antallet af afhøstninger om året. Baseret på dette konkludere jeg at biomassen i randzonen skal afhøstes en til to gange om året.

Circadian rhythm gene variation in Arctic char (Salvelinus alpinus)

Madsen, Rikke Pechüle Arndt, 20.06.2017

Abstract:
Climate change generates increasing temperatures resulting in earlier onset of spring and longer growing seasons causing shifting trends in phenology of living organisms. Especially the Arctic region is influenced by climate change. One species inhabiting the Arctic is Arctic char (Salvelinus alpinus) with an anadromous life-history encompassing seasonal events of migration and spawning. Seasonal activities are rhythmic and synchronized by an endogenous clock of 24-hours or one year stimulated by environmental factors (e.g. photoperiods and temperature). These circadian rhythms are formed and regulated by a core set of genes that have been shown to significantly affect phenology-related traits in salmonids. Allelic variation at one of the genes Clock has been found to be correlated with latitude in some salmonid species. Therefore, the aim of this study was to investigate a possible relation between allele variation and latitude in Arctic char and detect possible selection on the phenology-related genes. This was addressed using 53 neutral single nucleotide polymorphisms (SNPs) and four circadian rhythm genes in 18 anadromous and landlocked populations from Greenland, Iceland and Norway. Population structure analyses revealed high genetic differentiation and a strong isolation-by-distance pattern, suggesting geographical distance to play a major role in the genetic divergence of populations. An FST based outlier test showed no loci to be under selection and a landscape genomic analysis associated with sea-surface temperature, latitude and longitude revealed no evidence of selection, thus not providing evidence for selection acting on phenology-related genes in this species. The results contradict the evidence of selection maintaining allele variation found in several previous studies, but confirm results by others showing no selection acting on these genes. Even if the loci are not currently under selection, the finding of allelic variation in the phenology-related genes could mean that there is a potential for Arctic char to adapt to future climate change through microevolution, in case variation at the loci that has previously been effectively neutral becomes adaptively important.

Spatiotemporal genetic structure of arctic char (Salvelinus alpinus) populations subject to climate change

Christensen, Camilla, 20.06.2017

Abstract:
We examined spatio-temporal genetic variation at 53 single nucleotide polymorphisms (SNPs) in Arctic char (Salvelinus Alpinus) populations from Western Greenland. Samples collected at eight locations consisted of historical otoliths and scales collected in the 1950s, along with contemporary DNA samples and were used to assess spatio-temporal genetic population structure. We aimed to investigate whether population structure has been temporally stable and furthermore to estimate the effective population sizes (Ne) to evaluate the adaptive potential of the analyzed populations. Estimates of pairwise genetic differentiation (FST), a hierarchical analysis of molecular variance (AMOVA) and a multidimensional scaling analysis of pairwise FST all revealed that genetic differentiation between temporal samples from populations was lower than the differentiation among geographically different samples. In total, the analysis of genetic structure showed high temporal stability. Ne estimated using a temporal method revealed Ne>500 in two of four populations and all four populations for which historical samples were available with sample sizes > 20 showed Ne > 50. By assuming a framework for assessing the potential for local adaptation and assuming Ne and migration values (m) comparable to our findings, we concluded that on the scale of individual populations, selection needs to be strong for local adaptation to occur. However, on the scale of regions, involving populations subject to similar selection regimes, local adaptation is possible even if selection is weak. This evolutionary potential is important, as populations of Arctic char in Western Greenland are currently facing significant climate change.

 

Færdslens effekter på vegetationen i Nationalpark Mols Bjerge

Møller, Irene Svanborg, 19.06.2017, speciale

Aktivitetsstudie af lille skovmyre Formica polyctena i en økologisk æbleplantage

Pedersen, Nanna Søndergard, 13.06.2017

Abstract:
Biologisk bekæmpelse er blevet mere populært indenfor skadedyrsbekæmpelse i Danmark, da dette er et alternativ til pesticidbrug. I dette observationsstudie undersøges om lille frostmåler Operophtera brumata Linnaeus (Geometridae, Lepidoptera) og lille skovmyrer Formica polyctena Förster (Formicidae, Hymenoptera) har overlappende aktivitet i æbletræerne på en økologisk æbleplantage. Der blev lavet to indsamlinger; en stor indsamling forår til midt sommer og en mindre indsamling midt efterår til start vinter. Larver af lille frostmåler blev første gang registreret i plantagen den 09. maj 2016, samme dato som løvudspring. Registreringerne toppede den 16. maj 2016, efter den 01. juni 2016 blev der i observationsperioden ikke registreret flere larver af lille frostmåler. Æbletræsblomstringen var i perioden den 16. maj til 01. juni 2016.  Lille skovmyre blev registreret på tuerne, i græsset og i æbletræerne inden løvudsprang og derved inden registreringerne af lille frostmåler. Myrerne var proteinsultne næsten en måned før larverne blev registreret. Der var en lineærkorrelation mellem overfladetemperaturen og tuedække på én af myretuerne. T-test gav at overfaldetemperature over 7,5 °C medførte tilstedeværelse af lille skovmyre på tuens overflade. Den længste fouragerende afstand i græsset blev registreret samme dato, som de første registreringer af larverne. Der var signifikant flere myrer i æbletræer med sukkerautomater end almindelige æbletræer, hvilket betyder, at der var flere æbletræer med sukkerautomater, som havde tilstedeværelse af lille skovmyre, end almindelige æbletræer. Forskellen mellem to plots af æbletræer og deres tilstedeværelse af lille skovmyre var signifikant på alle undersøgelser. Der var derfor en højere tilstedeværelse af lille skovmyre i ene plot fremfor det andet plot på både æbletræer med sukkerautomater, men også almindelige æbletræer. Der blev observeret stor fugleaktivitet på én af myretuerne i perioden 25. marts til 21. maj 2016, om tuerne har medført øget fugleaktivitet i plantagen vides ikke. Lille skovmyres sidste sæsonaktivitet på tuerne blev registreret den 22. august 2016, mens aktiviteten i æbletræerne blev registreret frem til den 31. oktober 2016. Imagostadiet af lille frostmåler blev registreret i observationsperioden fra den 31. oktober til 05. december 2016. Disse resultater viser, at lille skovmyre har overlappende aktivitet med lille frostmåler i målernes larvestadie, men ikke i imagostadiet. 

Effekter af dødt ved på diversiteten og densiteten af makroinvertebrater – Med perspektivering til restaurering af vandløbssystemer

Anchersen, Christian, 07.06.2017, speciale

Feasibility of determining Zoonotic Bacteria in Polar Bear Liver Tissue by using 16S Next Generation Sequencing

Nielsen, Maria, 30.05.2017

Abstract:
Zoonoses are diseases transferable from animals to humans and include viruses, parasites and bacteria. 60% of known pathogens are zoonotic, and among emerging infectious diseases, zoonoses represent 60.3%, 71.8% of these stem from wildlife. The importance of zoonoses in Greenland has yet to be determined. Few previous studies have investigated parasites in Greenland, while most of the Arctic studies have been focused on Canada and Alaska. The purpose of this dissertation was to determine the possibility of using 16S next generation sequencing (NGS) for the determination of zoonotic bacteria in polar bear liver tissue. This being a meaningful contribution to the current knowledge of zoonoses in the European Arctic as part of the ongoing ZORRO (Infectious Zoonotic Diseases Transmissible from Harvested Wildlife to the Humans in the European Arctic). For the sample matrix of this thesis, polar bear livers, the best extraction method and PCR conditions of the investigated were determined. These were the DNeasy Blood & Tissue kit (Qiagen) for DNA extractions and the enzyme AccuPrimeTM Supermix II for the polymerase chain reactions (PCRs). The preliminary results from the PCR analysis revealed whether bacterial DNA was present in the liver tissues, and this was the case for 62% of the samples tested. Female polar bears had a higher prevalence of bacterial DNA than males (71% and 57% respectively), and among the females, East Greenlandic polar bears had a higher prevalence (73%) than Western Greenland females (40%). That females had a greater prevalence of bacterial DNA than males could have something to do with immunosuppression during pregnancy, in order to avoid rejection of the fetus. In addition, the female bears have a higher burden of contaminants, due to exposure of long-range transported and biomagnified environmental contaminants such as mercury (Hg) and polychlorinated biphenyls (PCBs), which could explain the results in addition to sex-related feeding habits and behavior. These preliminary results show that it is possible to amplify bacterial DNA in polar bear liver samples and the subsequent sequencing of the samples will reveal the genus of the bacterium, the relative amount and further explain the differences between age groups, sex and geographical location. The preliminary results from the PCR analysis seem promising, however, the completion of the 16S NGS analysis was not possible within the frame of this dissertation. The samples are sequenced while finishing off this thesis, and the results, if reliable, will make a significant contribution to the ZORRO project.

Potential Determinants of Functional Diversity in Carnivorous Mammals on a Global Scale

Berg, Klaus, 29.05.2017

Abstract:
Human kind are altering and transforming our ecosystems as fast as never before. In order to know where to spend our limited resources, trying to rescue species from extinction, we need to know where we can do the most. Functional diversity (FD) has been greatly studied throughout the last decades as it is important to have an index to compare the different areas around the world. Functional diversity can be divided into three subunits, namely functional evenness, functional divergence and functional richness (FRic). Different variables affect the FD and hence also the species richness (SR) as these are tightly correlated. Here we try to find which variables are ecological relevant and important for explaining FRic for Carnivora at a global scale. We seek to answer three questions; we want to see if there are more diversity where productivity is higher, we want to see if the diversity is higher where environmental variability is higher, and last we want to see if there are any geographical differences across the globe. We obtained data on 268 carnivores and merged these with a set of environmental variables. Using linear regression and correlation statistics, we found that SR is the most important variable describing FRic for carnivores. We found a clear pattern of the FRic increasing towards the tropics, as predicted by the productivity hypothesis. We did not find any pattern towards environmental variability, and the geographical differences were mainly due to latitudinal effects and therefore not longitudinal. We conclude that SR is the most important variable due to a high correlation with FRic, but also our climatic variables explain a lot. Conclusively we conclude that these results may vary from species to species and from area to area.
Key words: Functional diversity, Carnivores, Global scale, Species richness

Effects of bioactive pharmaceuticals on aquatic and terrestrial invertebrates

Nielsen, Maria Sandbjerg, 03.04.2017

Abstract:
Human pharmaceuticals are found in increasing amounts in aquatic and terrestrial environments. They are discharged via wastewater and sludge, where they are often found in complex mixtures. The concentrations found for single substances in nature are typically in the ng/L - µg/L range. Previously, pharmaceuticals were not considered as possible toxicants that could exert an adverse effect in line with other xenobiotics. However, this has changed in recent years. Despite this, the knowledge about effects on non-target organisms caused by pharmaceuticals is still limited, and because of their bioactive nature they are suspected of exerting a potent effect.
Pharmaceuticals acting on the human nervous system are suspected of exerting an effect on the behaviour of aquatic organisms. In this study it was investigated whether it was possible to develop an acute test that could detect effects on sublethal concentrations of pharmaceuticals. In a videotracking test the freshwater shrimp Gammarus pulex was exposed to increasing concentrations of the pharmaceuticals carbamazepine, citalopram, diclofenac, fluoxetine and ibuprofen to investigate the effect of pharmaceuticals on the activity level. Fluoxetine and ibuprofen was discarded for further testing since high concentrations were needed to exert an effect. The three remaining pharmaceuticals were tested as single substances and in a mixture test. A 28 day chronic reproduction test was also performed on the springtail Folsomia candida to examine the effect of the pharmaceuticals carbamazepine, citalopram and diclofenac on a soil dwelling organism. This was done for single substances and a mixture as well.
The results from the videotracking showed a significant decrease in the overall activity level for all substances as the concentrations increased. They also showed a significant difference between control treatments and treatments with pharmaceuticals in concentrations of 8, 8 and 50 mg/L for carbamazepine, diclofenac and citalopram respectively. The mixture test showed that the model did follow the principle of concentration addition, even though the expected EC50 showed a much higher activity level than expected. The videotracking also showed that the activity level of G. pulex decreased significantly from trial 1-5 and that the activity level in trial 5 in general decreased from August to December, as the winter approached. Furthermore, it was observed that the activity level was significantly higher in trial 1 than any of the following trials throughout the whole testing period.
The reproduction test showed that the reproduction decreased significantly for all substances as the concentration of pharmaceuticals increased. For carbamazepine, diclofenac and citalopram a significant difference in reproduction was found for concentrations of 25, 100 and 50 mg/kg respectively. For the mixture test, it was found that the model followed concentration addition. Testing at environmentally relevant concentrations did not reveal any effect for either the videotracking- or reproduction test.
Based on the findings, it cannot be concluded that the videotracking test can be used as an alternative for the classic acute tests at low environmentally relevant concentrations. It is therefore not considered likely that carbamazepine, diclofenac or citalopram will exert an effect on the activity level of G. pulex or the reproduction of F. candida in nature. The same applies to mixtures of the three pharmaceuticals. But because of the additive response showed by the mixture test, the possibility of a negative effect cannot be excluded, if several pharmaceuticals occur at the same time in low concentrations. Since pharmaceuticals often co-occur in nature, this should be investigated further.      

Anvendelse af GIS til analyse af vedanatomi i Calluna vulgaris

Hjorth, Hanne, 22.03.2017

Abstract:
I specialeprojektet undersøges muligheden for at anvende Geografiske Informationssystemer (GIS), som en effektiv metode til at registrere vedanatomiske ændringer i forbindelse med dendroøkologiske undersøgelser. Et pilotprojekt blev gennemført med henblik på at teste metodens evne til at afsløre effekterne af græsning på vedstrukturen hos Hedelyng, herunder ændringer i de dele af i plantens ledningsvæv, som er bestemmende for dens vand ledningsevne. Som udgangspunkt regnede vi med det kunne lade sig gøre at detektere disse ændringer ved hjælp af en 2D raster model i GIS. Hedelyng, Calluna vulgaris, er en almindeligt forekommende dværgbusk og udgør et dominerende element på heder som Danmark er forpligtiget til at vedligeholde. Vind Hede i Vestjylland blev udvalgt som undersøgelsesområde, fordi lyngen i visse områder bliver græsset hårdt af kronvildt, mens den i andre områder tættere på bebyggelse ligger næsten ugræsset hen. Digitale billeder af anatomiske snit blev underkastet en billedanalyse i ArcGIS®.  Relativt få signifikante forskelle blev fundet mellem henh. græsset og ugræsset lyng, hvilket kan skyldes at på lyngen Vind Hede havde været hårdt angrebet og afløvet af Lyngens Bladbille Lochmaea suturalis få år forinden. På trods af dette fravær af klare resultater viser afslører pilotprojektet med al tydelighed at GIS 2D raster er anvendelig til dendroøkologiske undersøgelser og der er mange muligheder for at udvikle metoden yderligere.

The effect of changing water level in streams on plant communities in riparian areas

Andersen, Chris Jesper, 09.03.2017

Abstract:
During the last 200 years rich fens in Denmark have experienced a massive decline, making it a threatened habitat due to various human activities, such as changes in the hydrology. Rich fens are classified as a particular valuable type of nature because of high species richness and many rare habitat specific species, and therefore the Danish government is committed by EU to protect and improve the current unfavourable conservation status of rich fens.
The objective of this master thesis was to examine three hypotheses stated as: 1) the hydrology and the nature quality will be different between rich fens, wet meadows, and reed beds; 2) a lowering of the stream water table resulting from either dredge cutting or deepening of streams will affect the hydrology in the adjacent riparian area; and 3) the parameters which define nature quality in rich fens will be negatively affected by a lowering of he stream water table.
Plant species coverage data from 51 plots divided into 191 sub-plots on riparian areas along 10 medium sized stream reaches were available for this study. Additionally, stream water level and groundwater level in the riparian areas was measured on a monthly basis during one year (2010-2011). The nature type of the riparian plots was characterized as rich fen, wet meadow or reed bed. Models describing the behaviour of a range of vegetation parameters to changes in in ground water level were developed from this data set. Hydrologic models were used to describe the correlation between stream water level and riparian ground water level. Scenarios on the effect of dredge cutting and deepening of streams were calculated by linking the hydrological models to the vegetation models.
The results from this study showed differences in both hydrology and nature quality between the three nature types, with highest water levels and species richness, and lowest nutrient levels in rich fens. Hydrologic scenarios showed that lowering the stream water table from both dredge cutting and deepening, resulted in significant lowering of the riparian water table. Using the specific size of changes in riparian water levels, the established vegetation models confirmed negative effects on all of the nature types from both dredge cutting and deepening of streams.
Linkages of hydrologic interactions between streams and riparian areas and specific effect on riparian vegetation from changing stream water table have not been examined earlier. As stream hydrology is manipulated in many Danish streams, and water levels are lowered from dredge cutting and deepening, understanding the hydrologic interactions can be essential for the future conservation of rich fens. 

Are temporal changes in ringed seal (Pusa hispida) blubber thickness related to climate change and hunting?

Jensen, Lærke Najbjerg, 27.02.2017

Abstract:
The sea ice extent in the Arctic is decreasing dramatically due to anthropogenic climate change, and it has severe implications for the ringed seal (Pusa hispida), which depends on the sea ice for prey and reproduction. Changes in prey abundances, loss of food sources and increased competition with other species, are all expected effects of global climate change (GCC) and may lead to changes in blubber thickness maintenance. The present study aimed to determine if temporal trends could be detected in blubber thickness, and if these were related to GCC, for three different regions in Greenland; Thule (Avanersuaq) in Northwest Greenland, Disko Island (Qeqertarsuaq) on the West coast and Scoresbysund (Ittoqqortoormiit) on the East coast. Three GCC predictor variables were used; sea ice extent, sea surface temperatures and the Arctic Oscillation Index. Additionally, human hunting pressure was used as another predictor variable, because climate change also negatively impacts this. Significantly increasing linear temporal trends were found for the ringed seal populations of Disko Island and Thule in the periods 1994-2012 and 1998-2014, respectively, while there was no significant linear temporal trend for the Scoresbysund ringed seal population between 1986 and 2016. Akaike's Information Criterion (AIC) model selection highlighted the importance of regional variability, but sea ice extent seemed to be the overall most important variable for blubber thickness, while AO seemed to be the least important one. No direct relationship between hunting pressure and blubber thickness could be discerned. Why the blubber thickness has been increasing on the West coast and remained stagnant on the East coast, is being discussed in the present study, but no clear explanation was evident. Potential theories involve an increased prey base and possibly reproductive failure, both as a consequence of significant sea ice declines happening within the same period. The present study emphasises the need for population density estimates, as declines in ringed seal populations will have consequences for the Arctic food webs, the indigenous people, and the polar bears, who all depend on ringed seals.

Laboratory natural selection for heat tolerance in dry and humid environments in Drosophila

Hilmar, Emma S., 13.02.2017, Speciale

Innovation in teaching high school biology – using design-based research to investigate the field between goals in science education and innovation skills in a biomimicry learning activity.

Aude, Nanna Johanne, 24.01.2017

Abstract:
Despite the demand for integration of innovation in science education in high school, quite few examples are seen in practice, especially regarding biology education. The result being that it is still unknown how the field between goals in science education and innovational skills is formed when an instructional design is developed. This paper explains how an instructional program combining education in biology and innovation skills was developed, using the design-discipline biomimicry as a framework and design-based research to measure students engagement and academic achievement. The paper shows that it is possible to combine goals in biology education and innovation skills in the class program, yet the practical execution poses a number of challenges. The paper shows that there is a challenge with displacement between goals in science education and innovation skills. It also shows that the evaluation of a program in innovation should be of a formative nature.

Narrow-band high-frequency click communication in wild harbour porpoise

Sørensen, Pernille Meyer, 19.01.2017

Abstract:
Highly social delphinids employ a rich vocal repertoire of clicks, burst pulses and tonal sounds for echolocation and communication. Conversely, harbour porpoises (Phocoena phocoena), seen as largely solitary animals, only produce narrow-band high-frequency (NBHF) clicks with properties that appear poorly suited for communication. Nevertheless, it is likely that these small toothed whales, like other cetaceans, mediate critical social interactions such as mate choice and mother-calf contact with sound. Therefore, we tested the hypothesis that stereotyped NBHF click trains are used for communication via their repetition rate by deploying stereo sound and movement tags (DTAG3) on six wild porpoises in Danish waters for a total of 96 hours. The tagged animals produced frequent (up to 27min-1), high-repetition rate click train calls (N = 3,792) at high apparent output levels and in dense bouts with high redundancy. The calls can, based on their developing click rate, be classified in distinct categories similar to those observed from studies on acoustic communication in captive porpoises. Thus, wild porpoises may be much more social than previously assumed and their frequent social interactions are mediated by calls made of short, high rate click trains that likely encode information via the repetition rate of their stereotyped NBHF clicks.

Keywords: communication, narrow-band high-frequency clicks, harbour porpoise, Phocoena Phocoena call rate, high repetition rate click trains, mother-calf

 

 

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