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910 Uppsatser om Species conservation - Sida 23 av 61
The effect of domestication on insect resistance in cotton : bioassays with the insect herbivores Spodoptera littoralis and Agriotes spp.
A plant's defensive ability against herbivore attack can be influenced by many different factors, one of them being domestication. During human selection to improve the yield of plants, the resistance against herbivore attack can have been lowered, due to a trade-off for use of resources between these traits in the plants.
In this thesis I investigated the effect of domestication on resistance against herbivorous insects in cotton plants. I used different varieties and species of wild and domesticated cotton in three different experiments. A feeding assay was conducted, the mortality, development
time and pupal weight of larvae of the Egyptian cotton leaf worm Spodoptera littoralis was studied. In a second experiment the preference of the root-feeding beetle Agriotes spp.
Validation of realtime-PCR of Fusarium avenaceum for detection in wheat
Mould is a common contamination in cereals. The growth of mould can stimulate mycotoxins production andsome of which at critical concentrations cause health problems in humans and animals. Fusarium is one of thefungus species that has been found in crops and can cause major problems for farmers such as reduced harvestand economic losses. A group of Fusarium species, Fusarium avenaceum, Fusarium poae and Fusariumtricinctum express a mycotoxin, enniatin. The limited information available today about enniatin-forming fungiis that they grow out on fields of wheat in colder climates.
Personarkiv på Kungliga biblioteket -ordningar, kopplingar och krockar på ett nationalbibliotek
The departure point of this thesis is the context of the institution and the processes surrounding the handling of personal archives at the National Library of Sweden. These processes are examined using Actor Network Theory. Around the personal archive a network is constructed and contained by actors ? the archive itself, the librarian, the conservator, the researcher, organizational structures and others. Within this network choices are made of what is significant.
Genomgång av kemikalieförteckning som exempel på uppströmsarbete : en identifiering av utfasningsämnen i spillvattnet
Benthic invertebrates play important roles as feeding resources for many organisms in different food webs. Shifts in predation of these organisms can generate cascading effects and potentially lead to the disappearance of one or more species from a site. Cascading effects can bring impacts to organisms who aren?t even directly involved, why studies in this field are important for understanding sudden changes in ecosystems. I examined the predation from fish and waterfowl on benthic invertebrates in the shallow and eutrophic Lake Tåkern in the plains of Östergötland County, southern Sweden.
Spridningsmönster och potentiella spridningsytor hos invasionsarten stor bockrot (Pimpinella major) i Tullgarns naturvårdsområde : ett framtida problem för områdets diversitet?
An organism that is transferred from one place to another, causing major problems to the native species is termed invasive. Its natural dispersal across barriers may have been prevented but as man has turned able to rapidly travel all over the world organisms are brought to sites where they were never before observed. Adding the increasing global warming organisms may find it necessary to move around even further. This might cause major disturbance to the biological diversity, and hybridization and homogenization is one of many scenarios that could disturb the native diversity. In Sweden more that 2/3 of all alien plant species have been introduced to disturbed areas and the major introduction mechanism is gardening.
Betydelse av lövinslag, död ved och variation i träddiameter för artrikedomen hos småfåglar
Forest management contributes to the changes in forest structure by turning heterogenous forests of varied age into homogenous forests of similar age and thus affect bird species depending on different structures or habitats which are lost during forestry. In this report, a study was made to investigate how the amount of decidious trees, dead wood and variation in tree diameter affect bird diversity. The purpose of this study was to be able to give forest management guidelines to increase bird diversity. This study was conducted by investigating 65 transects in forests of different structure south of Linköping, Sweden. Along the 65 transects, birds were inventoried as well as the vegetation.
Analys av hemområdesstorlek hos mellansvenska vildsvin (Sus scrofa scrofa)
The wild boar population grows rapidly in number in Sweden, and it has been predicted that the annual number of shot wild boar will soon exceed the cull of moose. According to estimates, the Swedish population encompassed some 150 000 individuals in 2010. The mean annual harvest has increased by 30% since 1990, indicating that the wild boar is a species we must learn to manage sustainably. A successful management of the boars aims for a population in balance with agriculture and traffic, and also provides good hunting opportunities. For this to be possible, understandings of several aspects of the ecology of wild boar is needed.
The sows in this study had an average homerange of 707 hectares during summer, and 659 hectares in winter.
Skyddet av arter: en jämförelse mellan amerikanska Endangered Species Act och den svenska fridlysningslagstiftningen
I dagens samhälle är skyddet av hotade och utrotningshotade arter väldigt aktuellt och kontroversiellt. Den problematik som uppstår när man vill skydda arter återfinns i alla länder, därför är det intressant att se hur andra länder valt att genomföra sitt skydd. Ett land med en omtalad och långtgående lagstiftning i detta fall är USA. Därför valde jag att genomföra en jämförelse mellan USA:s Endagered Species Act (ESA) och den Svenska fridlysningslagstiftningen. Den svenska fridlysningslagstiftningen är ingen enhetlig lagstiftning såtillvida att den har samlats upp enbart i miljöbalken (MB).
Föryngringsplan för en svårt stormskadad fastighet i Kronobergs län :
In January 2005 large forest areas in south Sweden were severely damaged by storm. This final thesis describes the work with creating an ecological and landscape-adapted regeneration plan for a severely storm damaged property in Kronobergs region in south Sweden.
This regeneration plan, in difference to more regular plans, are focusing more on the owner?s use and goal?s for the property and seeing the property from a more comprehensive view in the regeneration process. Beside production and environmental values the plan also take in consideration other values as aesthetic, culture history, landscape picture and recreation values.
Den licensierade vargjaktens betydelse för vargstammen
In October 2009, a new decision was made concerning the administration of predators which resulted in a new wolf policy in Sweden. This meant that the wolf population now should be limited to 210 individuals by harvest. The new policy also recognized that the public acceptance of this species must increase and the genetic status improved. In the 17th of December a decision was taken by the Swedish parliament that it should become legal to hunt wolves in Sweden. The wolf hunt resulted in debate on a large scale amongst people, some thought of it as a good decision while others thought it was wrong.
Evaluating six crop mixes used for game fields in southwest Sweden : biomass production, fallow deer preference and species diversity
Game fields are one way to divert animals away from sensitive areas, create shelter and forage, and also to increase the biological diversity. In this study I investigated how the plant composition in six different crop mixes used for game fields affected the biomass production, biomass consumption and biological diversity at the Koberg estate in southwestern Sweden. Six experimental fields were used and each field contained six plots, approximately 1500 m2 each, that was sown with a different crop mix. The crop mixes ranged from a pure grass mix (A), 70 % grass and 30 % leguminous plants (B), 53 % grass, 21 % leguminous plants and 26 % other herbs (C), 100 % leguminous plants (D) to the most complex mixes constituting of 91 % leguminous plants and 9 % other herbs (E) and 87 % leguminous plants and 13 % other herbs (F). The fields were cut weekly during the summer in 2010, to estimate weekly biomass production.
Hur påverkas dvärghamstrar av att vistas i hamsterbollar?
Lately the popularity to keep different species of dwarf hamsters has increased in Sweden.
The requirements of the Swedish legislation to keep hamsters as pets are low which could be a reason for the increasing popularity. Hamsters are in nature generally nocturnal and can travel far distances to find food sources during their active part of the day. Their eyesight is poor, but is compensated by their well-developed hearing and olfaction. ?Run about balls? are made of plastic and the hamster is placed inside it where after the ball is placed on the floor and the hamster can then run protected outside the cage.
Användning av satellitdata för lokalisering av skogsområden där lövröjning bedöms angelägen : en analys av användbarheten med fjärranalys som hjälpmedel till röjningsrådgivning
This master thesis project is a part of a project called ?Järboprojektet? at the regional board of forestry, the district of Gästrikland. The project will give answers to questions regarding if an analysis of satellite images can be used to contact and inform landowners of the located areas where precommercial thinning is useful. The whole project is a part of the National Board of Forestrys IT-stake where the analysis of satellite images will, at the latitudes possible, be adapted to each district in purpose to identify these areas in need of precommercial thinning. This master thesis project is based on a field inventory of identified objects where precommercial thinning is useful.
Ekosystemstödjande och multifunktionella växtval i urban miljö : En fallstudie med utgångspunkt i Nacka stadsbildning
This study has investigated how urban vegetation can be used in a multifunctional way to support ecosystem services in urban environments. Nacka municipality is in the start-up phase of building what is to become Nacka city. This provides a unique possibility to study and analyse what role the vegetation play in making the city a healthy living environment and how it needs to be adapted in order to be resilient against changing climate conditions and how the effects of those changes can be regulated. The study further investigates how airborne pollution, caused by urbanization processes, can be regulated or reduced by vegetation or species selection. Methods used in this study were a combination of qualitative interviews and literature studies, seeking to answer the questions: Which specific ecosystem functions are needed in the urban environment and which aspects will influence the ecosystems ability to deliver the functions in demand? And which plant species have the right mechanisms needed to deliver those functions? These questions have been studied and analysed in a local based context where the local conditions ands site specific needs of Nacka define criteria for plant selection.
Klimatförändringars påverkan på kulturmiljöer i Uppsala stad ur ett geovetenskapligt perspektiv
Cultural heritages are environments created by humans that are considered to have a conservation value for the posterity. They can be seen as one of society's non renewable resources. It is important to have knowledge of how cultural heritages are affected by future climate changes.The water flow in Uppsala is estimated to increase during winter and decrease during spring and summer. Precipitation will gradually increase as well as the intense short period precipitation. The average temperature is estimated to increase as well.