No description available.

No description available.

Det finns en stark koppling mellan historisk markanvändning och biologisk mångfald. Flera ängs- och betesmarksarter gynnas eller är beroende av traditionell hävd såsom slåtter och bete. Syftet med studien är att undersöka om olikheterna i den historiska markanvändningen har påverkat den biologiska mångfalden. Genom att studera kartor från olika tidsperioder kan förändringar i landskapet tydas. Arkivstudier kan sedan kopplas till kartor och komplettera de historieluckor som kartorna inte visar. Fältarbetet bestod av tre växtinventeringstillfällen: 23 maj, 23 juni och 14 juli 2013. Fyra storytor (á 100 m2) placerades ut i Tjörnedalas strandbetesmark som år 1841 var strandäng. Kartanalysen visar att åkerns utbredning har tagit strandängsmark i anspråk under 1900-talet. Växtinventeringarna tillsammans med arkivstudierna visar att områden med högst biologisk mångfald är de som hävdats traditionsenligt och med beteskontinuitet. Den här studien visar likaså att kvävegynnade arter dominerar i områden som tidigare varit åker. Både arkivstudier och växtinventeringar behövs för att få en rättvis beskrivning av hur ett område har brukats. Den biologiska mångfalden är därmed ett arv av den historiska markanvändningen. / There is a strong connection between historical land use and biodiversity. Several grassland species are advantaged or relied to mowing and grazing. The purpose of this study is to investigate if changes in the historical land use have affected the biodiversity. By studying maps from different time periods, changes in the landscape can be interpreted. Archival studies can then fill in historical gaps that the maps doesn’t show. The field work consisted of three plant inventory occasions: may 23, june 23 and july 14 in 2013. Four major surfaces, of 100 m2 each, were placed in the shore meadow of Tjörnedala. Analysis of maps shows that arable land expansion has taken meadow land space during the 20th century. The plant inventories along with archival studies shows that areas with the highest biodiversity are those that are used with traditional methods and with continuity of grazing. This study also shows that nitrogen favored species dominate in areas of former arable land. Both archival studies and plant inventories are needed to get a fair description of how an area has been used. The biodiversity is thus a legacy of the historical land use.

No description available.

Semi-natural grasslands are one of the most threatened habitats in Scandinavia. The grassland in this study is situated in the northern part of the nature preserve of Haväng och Vitemölla strandbackar in the province of Skåne and consists of grey dunes and a pasture which partly consists of calcareous grassland and the vegetation type sand steppe which is very rare in Sweden. There are several threatened plants in the area and during the summer of 2017 their distribution was registered to be able to protect them during conservation management. The results showed that most of the area contained important species and the most important areas to protect were the sand steppe areas. This is probably due to the dry, sandy, calcareous and nutrient poor conditions in these areas which many of the threatened plants are connected to. Most of the threatened plants were found in abundance in the area but have a limited distribution in Sweden. The population of Eryngium maritimum however was very small and is threatened by extinction. The plants in the area are threatened by a long-term process of nutrient enrichment and continuous leakage of calcium which may lead to lower pH and a more nutrient rich soil which leads to a higher availability of phosphorous. This may lead to a change in species composition and loss of species richness. Continuous grazing, soil disturbance to expose lime-rich sand and also removal of litter to minimize the nutrient levels are needed to maintain favorable conditions in the area. However, the number of important species requires attention and careful planning, especially in the sand steppe areas. / Ängs-och hagmarker är några av de mest hotade och viktiga habitattyperna i Skandinavien. Gräsmarken som studerades i detta projekt ligger i norra delarna av naturreservatet Haväng och Vitemölla strandbackar i Skåne och består av gräsbevuxna sanddyner och en hage med inslag av kalkgräsmark och marktypen sandstäpp som är väldigt sällsynt i Sverige. I reservatet finns flera skyddsvärda kärlväxter och under sommaren 2017 kartlades deras utbredning för att bättre kunna skydda dem vid skötsel- och restaureringsåtgärder. Resultatet visade att större delen av området innehåller skyddsvärda arter och att de mest skyddsvärda områdena var de delar av området där det fanns inslag av sandstäpp. Detta beror med stor sannolikhet på att de flesta skyddsvärda arterna i området var knutna till de torra, sandiga, kalkhaltiga och näringsfattiga förhållanden som rådde där. De flesta skyddsvärda arter fanns i stora antal i det undersökta området men har en begränsad utbredning i Sverige. Populationen av Eryngium maritimum var dock så litet att det hotas av utrotning. I övrigt hotas växterna i området på längre sikt av ökad tillsättning av näringsämnen och långvarig urlakning av kalk. Detta kan leda till lägre pH och mer näringsrik mark och gör att den nuvarande artsammansättningen kan försvinna och ersättas. För att området ska fortsätta ha en gynnsam status kommer det krävas fortsatt bete, skapande av sandblottor för att röra upp kalkrik sand samt åtgärder så som avlägsnande av förna och ytskikt för att hålla nere näringshalten. Det stora antalet rödlistade och skyddsvärda arter i området gör dock att det krävs varsamhet och noggrann planering vid en åtgärd, framför allt i sandstäppsområdena.

Skyddsvärda träd, speciellt ekar (Quercus spp.), är betydelsefulla både ur ett kulturellt och biologiskt perspektiv. Flera rödlistade arter som finns i Sverige är kopplade till gamla, grova ekar och tyvärr är detta ett habitat som har minskat i Sverige. Fragmentering av ekhabitat har påverkat den biologiska mångfalden hos ek-habitaten negativt. Förändrad markanvändning är en faktor som haft stor betydelse för ekbeståndens förekomst och åldersstruktur. Studier visar att beteshävd främjar utvecklingen av större ekar genom att hålla borta omgivande träd som annars skuggar ekarna. I den här studien har förekomsten av värdefulla ekar i Kalmar kommun återinventerats efter 10-20år. Syftet är att undersöka omsättningen av ekar, och vilka faktorer som påverkar rekryteringen av värdefulla ekar. Värdefulla ekar avser här stora träd med en diameter på minst 1 meter, och deras efterträdare, med en diameter på ³80 cm i brösthöjd. Resultatet visar en nettotillökningen av värdefulla ekar i Kalmar kommun under tidsperioden mellan inventeringarna. Sammanlagt påträffades 133 nya ekar. Av de totalt 222 ekar som noterats i den föregående inventeringen återfanns 215. Av de återfunna hade 24 ekar dött under perioden mellan inventeringarna. En analys av sambandet mellan ljuskonkurrens, mätt som krontäckning, och antalet döda träd visar att dödligheten av ekar ökade med en ökande täckningsgrad i trädskiktet, vilket stödjer att eken är en skuggkänslig art. Dock var ekarnas tillväxt, mätt som ökning av omkretsen, inte störst i de lägsta täckningsgraderna, vilket innebär att fler faktorer har betydelse för trädens tillväxtframgång. / Protected trees, especially oak trees (Quercus spp.), are important from a cultural and biological perspective. Several red listed species found in Sweden are linked to old oaks and unfortunately this is a habitat that has decreased in Sweden. Fragmentation of oak habitat has adversely affected the biodiversity of oak habitat. Changed land use is a factor that has had a major impact on the occurrence and age structure of oak stocks. Studies show that grazing promotes the development of larger oaks by keeping away surrounding trees that might otherwise shade the oaks. In this study, the occurrence of valuable oaks in Kalmar municipality was re-invented after 10-20 years. The purpose is to investigate the turnover of oaks, and what factors affect the recruitment of valuable oaks. Valuable oaks here refer to large trees with a diameter of at least 1 meter, and their successors, with a diameter of ³80 cm in chest height. The result shows a net increase in valuable oaks in the municipality of Kalmar during the time period between the inventories. A total of 133 new oaks were found. Of the total 222 oaks recorded in the previous inventory, 215 were found. Of the recovered, 24 oaks had died during the period between the inventories. An analysis of the relationship between light competition, measured as crown coverage, and the number of dead trees shows that the mortality of oaks increased with an increasing degree of coverage in the tree layer, which supports that the oak is a shade-sensitive species. However, the growth of the oaks, measured as an increase in the perimeter, was not greatest in the lowest coverage ratios, which means that several factors have a bearing on the tree's growth success.

Actinorhizal plants are in symbiosis with the nitrogen-fixating soil bacterium Frankia, which forms nodules in the plant root. However, several studies also report other endophytic bacteria appearing in the nodules, but their function and interaction with the host plant or Frankia is not yet understood. This thesis used a bioinformatic approach to investigate the metagenomes of eighteen actinorhizal nodule samples to find out which bacteria are present, how the microbiomes differed from each other, and if the genomes of non-Frankia inhabitants could give indications of any functions. The results showed that the bacterial composition, richness, and diversity differed among the samples, especially between the samples sequenced from the field versus those primarily cultivated in a greenhouse. All samples had a substantial number of sequencing reads belonging to potential endophytes, such as strains of Enterobacteria, Pseudomonas, Streptomyces, Micromonospora, Mycobacteria and Pseudonocardia. There seemed to be a common microbial community shared among the plants on a family level, since no significant difference was found in the core microbiomes between the field and greenhouse groups. Some sequences found in the metagenomes were annotated as potential functions of the fellow travellers, such as antibiotic synthesis, proteins involved in regulating abiotic stresses, but also probable plant damaging compounds rather associated with pathogens than symbionts.

The evolutionary relevance of homeotic alterations for the origin of new taxonomic entities is still a controversial objective in plant sciences. In this context, the discovery of a floral homeotic variant of Capsella bursa-pastoris in natural populations offers the unique opportunity to elucidate the evolutionary significance of homeotic mutants in the wild. Since all petals are transformed into additional stamens, the variant was termed Stamenoid petals (Spe). In this thesis, a combination of ecological and molecular characterisation of the variant was performed, to improve the understanding of evolutionary processes in plant populations. Molecular markers were used to analyze genetic differentiation among known provenances and also within a large sympatric population of wild-type and homeotic mutant. The results clearly suggest a repeated evolution of the novel flower morphology. Furthermore, genetic analyses provided substantial evidence, that the two floral variants are well-defined into flower-type dependent sub-samples within one population. The evaluation of phenotypic traits elucidated that the homeotic variant is not hampered in fitness. In greenhouse and field experiments, a significant ecological differentiation in the onset of flowering was detected among variants. Finally, the novel floral phenotype shows a co-dominant inheritance, and a marker-assisted mapping approach exposed a single locus in a genetic map. In conclusion, the comprehensive study of ecological and molecular aspects indicates that the floral homeotic variant may be treated as an established taxonomic entity and proved the predicted role as model for evolutionary objectives. Since morphological alterations like Spe are discussed as a result of macroevolution, the homeotic variant of C. bursa-pastoris provides the opportunity to survey a (macro)evolutionary novelty in association with continuous micro-evolutionary adaptation

Mozambique is to fifty percent covered by forest, most of which belongs to the biodiverse miombo woodlands. The last decades, Mozambique has been suffering from rapid deforestation. The once continuous forest cover has turned into a mosaic of forest patches, farmland, settlements etc. The remaining forest patches are in many cases very isolated. These forests have distinct edges towards the neighbouring land, which means that the edge zones have different environmental conditions (more light, higher temperatures etc.) and tree species composition than the interior. In order to examine how the forests of Mozambique are affected by edge effects, the highly isolated Nhamacoa forest was studied. An additional aim of the project was to make a floristic inventory of the forest in order to further assess its conservation status. Specimens were collected, pressed and photographed for identification. Edge effects were studied in plots at the edge and in the interior of the forest in a paired design. Trees inside the plots were identified, counted and measured (dbh (diameter at breast height) and height) to search for differences in species richness, diversity, biomass and height-to-dbh ratios. Environmental parameters (air temp., soil temp., light and slope) were also measured. In total, 76 species of trees were sampled and 44 (35 in the interior and 32 at the edge) of these were found inside the plots. The interior plots harboured significantly more individuals and species of trees than their paired edge plots. Additionally, biomass and height-to-dbh ratios were higher in the interior plots than in the edge plots. These differences strongly suggest that the Nhamacoa forest is affected by edge effects, although none of the measured environmental parameters could explain why. That the Nhamacoa forest is affected by edge effects goes in line with the research hypothesis and shows that it is important to maintain large and intact pieces of forest in order to preserve the Mozambican miombo forests. For future studies, additional environmental parameters (wind speed, humidity etc.) could be examined in order to better explain the presence of edge effects in the Nhamacoa forest.

Rhizomania, caused by beet necrotic yellow vein virus (BNYVV), has been considered as an economically important disease around the world because of the extreme reduction in sugar beet yield and sugar content in affected plants. The spread of rhizomania all over the world, including the emergence of resistance- breaking virus isolates, have been become a major concern for the plant pathologists and plant breeders aiming at improving sugar beet resistance to   BNYVV as well as better understanding sugar beet-virus interactions during disease development. The main focus of this project is to elucidate the role of P25-interacting partner, the VIP1 transcription factor, in activation of transcription.  The isolation of the gene-of-interest (VIP1) was performed by RT-PCR on total RNA preparations extracted from root tissue of sugar beet (Beta vulgaris ssp. vulgaris).  The isolated gene of interest was cloned using gateway system into a binary expression vector and the obtained construct was then transformed into Agrobacterium tumefaciens for analysing transient expression in the experimental host (Nicotinana benthamiana).  Dual-luciferase promoter activity assay was performed on isolated leaf discs co-expressing P25 and VIP1 and compared to appropriate controls.  Six promoter constructs were tested. However, we observed an increase in luciferase activity (1.8-4.2-fold) upon co-expression of P25 and VIP1 only for two constructs tested, although the increase was not supported by Student’s t-test at 0.05 significance level. Nevertheless, the luciferase activity assay data for these two constructs were consistent with RNA-seq and RT-qPCR data obtained previously showing upregulation of the expression of these two specific sugar beet genes during BNYVV infection in sugar beets.     Thus, the results support our hypothesis that the interaction of the virus virulence factor P25 with VIP1 transcription factor is needed to activate transcription of certain genes in the nucleus for the virus benefit.