Cropping systems with leys

Climate change affects agriculture all over the world and in the Northern hemisphere the change towards warmer temperatures is more rapid than other parts on the planet. As this progresses the need to produce food in a sustainable way and stabilize or increase yields is essential. In Sweden, as well as the rest of the world, the trend in the 20th centaury has been to produce large quantities of food in an intensified large-scale cropping system where a short crop rotation or monoculture has been the norm. One of the fears in agricultural research during the 1950s was what effect these cropping systems would have on soil properties and yield over time. In order to evaluate these effects, a number of long-term field experiments (LTEs) were established during the 1950-1960s. LTEs gives important information about what is beneficial for the soil and crops over time and in that way, what is beneficial for our food production. For a sustainable food production, it is crucial to know what an agricultural system should include to be resilient and sustainable over time. In this thesis an LTE in northern Sweden, established in the 1950s with 4 different cropping systems and different 6-year crop rotations, was analysed for the effects on barley and ley yield. The results suggest that having an animal-based cropping system with longer ley-years, 5 years, reduces the depletion of soil organic carbon and produce a significantly higher yield trend for barley yield over time compared to cropping systems with 0–2 years of ley in the rotation. The results also suggest that cropping systems with shorter ley-years, 2-3 years, result in significantly higher first year ley yield trends over time, compared to a cropping system with 5 years of ley

Stråförkortningsmedel i jordbruket

Syftet med det här arbetet är att undersöka effekterna av stråförkortningsmedel för uppkomst från frö och tillväxt av plantor för en- och tvåhjärtbladiga grödor i relation till växthormonet gibberellin. Stråförkortningsmedel med den aktiva substansen klormekvatklorid (CCC), som hämmar syntesen av växthormonet gibberellin, användes här för att undersöka effekterna på uppkomst och tillväxt hos vete, raps och korn. Resultaten visar att CCC har signifikant positiv effekt på uppkomst vid behandling av vete- och rapsfrön. CCC har signifikant hämmande effekt på tillväxt vid behandling av vete- och rapsplantor och har signifikant ökande effekt på veteplantors bestockning. CCC har inga signifikanta effekter vid behandling av kornplantor.The aim of this thesis is to study the effects of growth retardants on emergence of seed and growth on mono- and dicot crops in relation to the plant hormone gibberellin. A growth retardant with the active substance chlormequat chloride (CCC), that inhibit the synthesis of gibberellins, was used to study the effects on emergence of seed and growth in wheat, rapeseed and barley. The results show that CCC has significant positive effects on the emergence of wheat and rape seeds. CCC significantly reduces stem elongation on wheat and enhances the number of tillers on wheat. Likewise, CCC also has reducing effects on growth on rapeseed plants. In contrast CCC has no effect on emergence from seed, stem elongation or tillers on barley

Circum-Arctic distribution of chemical anti-herbivore compounds suggests biome-wide trade-off in defence strategies in Arctic shrubs

Spatial variation in plant chemical defence towards herbivores can help us understand variation in herbivore top-down control of shrubs in the Arctic and possibly also shrub responses to global warming. Less defended, non-resinous shrubs could be more influenced by herbivores than more defended, resinous shrubs. However, sparse field measurements limit our current understanding of how much of the circum-Arctic variation in defence compounds is explained by taxa or defence functional groups (resinous/non-resinous). We measured circum-Arctic chemical defence and leaf digestibility in resinous (Betula glandulosa, B. nana ssp. exilis) and non-resinous (B. nana ssp. nana, B. pumila) shrub birches to see how they vary among and within taxa and functional groups. Using liquid chromatography-mass spectrometry (LC-MS) metabolomic analyses and in vitro leaf digestibility via incubation in cattle rumen fluid, we analysed defence composition and leaf digestibility in 128 samples from 44 tundra locations. We found biogeographical patterns in anti-herbivore defence where mean leaf triterpene concentrations and twig resin gland density were greater in resinous taxa and mean concentrations of condensing tannins were greater in non-resinous taxa. This indicates a biome-wide trade-off between triterpene- or tannin-dominated defences. However, we also found variations in chemical defence composition and resin gland density both within and among functional groups (resinous/non-resinous) and taxa, suggesting these categorisations only partly predict chemical herbivore defence. Complex tannins were the only defence compounds negatively related to in vitro digestibility, identifying this previously neglected tannin group as having a potential key role in birch anti-herbivore defence. We conclude that circum-Arctic variation in birch anti-herbivore defence can be partly derived from biogeographical distributions of birch taxa, although our detailed mapping of plant defence provides more information on this variation and can be used for better predictions of herbivore effects on Arctic vegetation.Peer reviewe

Circum-Arctic distribution of chemical anti-herbivore compounds suggests biome-wide trade-off in defence strategies in Arctic shrubs

Spatial variation in plant chemical defence towards herbivores can help us understand variation in herbivore top?down control of shrubs in the Arctic and possibly also shrub responses to global warming. Less defended, non-resinous shrubs could be more influenced by herbivores than more defended, resinous shrubs. However, sparse field measurements limit our current understanding of how much of the circum-Arctic variation in defence compounds is explained by taxa or defence functional groups (resinous/non-resinous). We measured circum-Arctic chemical defence and leaf digestibility in resinous (Betula glandulosa, B. nana ssp. exilis) and non-resinous (B. nana ssp. nana, B. pumila) shrub birches to see how they vary among and within taxa and functional groups. Using liquid chromatography?mass spectrometry (LC?MS) metabolomic analyses and in vitro leaf digestibility via incubation in cattle rumen fluid, we analysed defence composition and leaf digestibility in 128 samples from 44 tundra locations. We found biogeographical patterns in anti-herbivore defence where mean leaf triterpene concentrations and twig resin gland density were greater in resinous taxa and mean concentrations of condensing tannins were greater in non-resinous taxa. This indicates a biome-wide trade-off between triterpene- or tannin-dominated defences. However, we also found variations in chemical defence composition and resin gland density both within and among functional groups (resinous/non-resinous) and taxa, suggesting these categorisations only partly predict chemical herbivore defence. Complex tannins were the only defence compounds negatively related to in vitro digestibility, identifying this previously neglected tannin group as having a potential key role in birch anti-herbivore defence. We conclude that circum-Arctic variation in birch anti-herbivore defence can be partly derived from biogeographical distributions of birch taxa, although our detailed mapping of plant defence provides more information on this variation and can be used for better predictions of herbivore effects on Arctic vegetation

Miljöarbete inom två företag - En studie om överensstämmelsen mellan prat på strategisk nivå och handling på operativ nivå

Bakgrund och problem: Sedan slutet av 1980-talet har miljö haft en central roll för företag, då medvetenheten kring negativa effekter i miljön orsakade av människan har utvecklats i samhället. För företag har det inneburit att nya begrepp och krav har introducerats. Företags miljöarbete kan beskrivas som en utveckling från ett utifrånperspektiv till ett inifrånperspektiv. Idag innebär miljöproblematiken att även den företagsstrategiska nivån omfattas, då miljö berör kärnan vad företag gör och tror på. Miljöfrågor har i ledningssammanhang på kort tid gått från att vara dolda till att bli öppet strategiska. Vad gäller miljöarbete inom företag finns det en problematik i att gå från teori till praktik, alltså en avsaknad i miljömässigt handlande trots ämnesmässiga fackkunskaper. Uppsatsens problem behandlar graden av överensstämmelsen mellan prat på strategisk nivån och handling på operativ nivå vad gäller miljöarbete inom företag. Syfte: Uppsatsen beskriver graden av överensstämmelse mellan prat på strategisk nivå och handling på operativ vad gäller miljöarbetet inom studerade företag. Vidare syftar uppsatsen till att förklara graden av överensstämmelse. Metod: Uppsatsen bygger på en kvalitativ undersökning. Primärdata utgörs av nio intervjuer vilka har gjorts med representanter från två svenska företag. Vidare har böcker, tidskriftartiklar samt sökning i databaser utgjort uppsatsens sekundärdata. Avgränsningar: De företag vilka uppsatsens undersökning baseras på arbetar med miljö som en integrerad del av deras balanserade styrkort. Val av respondenter har skett efter organisatorisk position inom respektive företag. Resultat och slutsatser: Studerade företag har en god överensstämmelse mellan prat på strategisk nivå och handling på operativ nivå. Vidare arbetar företagen med miljö som en integrerad del av verksamheten och därmed inte från ett utifrånperspektiv. Delaktighet, kommunikation samt samverkan ses som viktiga byggstenar i ett lyckat miljöarbete. Förslag till fortsatt forskning: Uppslag till fortsatt forskning är bland annat att studera företag, utifrån samma frågeställning, vilka inte arbetar med miljö som en integrerad del av det balanserade styrkortet. Vidare kan studier göras på vilken betydelse ett internt belöningssystem har som incitament för att utveckla företags miljöarbete, vilken roll en drivande aktör har i ett företags miljöarbete samt om företag har en önskan om absolut överensstämmelse mellan prat på strategisk nivå och handling på operativ nivå vad gäller miljöarbete

Circumpolar impacts of herbivores on Arctic tundra vegetation

Arctic tundra vegetation provides many ecological services that have implications for the global climate. However, the tundra biome is currently changing in response to increasing temperatures. Herbivores may mitigate some of these responses to warming through their impact on Arctic vegetation. Understanding plant-herbivore interactions is therefore crucial to make better predictions of future Arctic vegetation changes and possible ecological consequences. Most current knowledge on plant-herbivore-interactions in the Arctic comes from local studies that do not allow for large-scale generalisations due to non-comparable methods. Also, existing large-scale studies of herbivory do not cover the tundra biome in a representative way. In this thesis, I used standardised methodology in biome-wide sampling across the Arctic tundra, to uncover how plant-herbivore interactions shape circumpolar vegetation patterns.   I have identified clear biogeographic patterns in plant chemical defence against herbivores that could influence the capacity of herbivores to control warming-driven increases of birch shrubs. I also found that herbivores counteract many effects of climate change on tundra vegetation by reducing vegetation greenness (NDVI), Leaf Area Index (LAI), vegetation density and shrub abundance and thereby mitigate vegetation responses to climate warming. Herbivores also increase species richness across the Arctic by supressing dominant species but not by increasing light availability. In a detailed study, I show that the effects of large and small herbivores are similar between continents although they vary with habitat type. This thesis advances our understanding of top-down control of herbivores on tundra vegetation and provides important tools to better predict future Arctic vegetation changes

Circumpolar variation in anti-browsing defense in tundra dwarf birches

The shrub encroachment (shrubification) currently happening in tundra ecosystems can result in increased greenhouse gas emissions. Shrubification is in turn generally explained to be driven by increased temperature, but there is regional variation in shrub encroachment that cannot be solely explained by climate. Instead, herbivory is proposed as a key factor since browsing has been shown to regulate density of shrubs in the tundra. Furthermore, regional variation in anti-browsing defense, i.e. various deterrent and/or toxic compounds, has been hypothesized to control the herbivory pressure. Dwarf birches are present and often dominant throughout the low arctic. They can be divided into two functional groups based on their anti-browsing defense, i.e. resinous and non-resinous birches. This study investigated the variation in anti-browsing defense within and among different taxa of dwarf birches and the two functional groups. We also examined if these differences in anti-browsing defense affects the level of invertebrate damage in dwarf birch. We found that although there were clear differences in terpenes between resinous and non-resinous shrubs, neither functional groups nor taxa are sufficient to understand the circumpolar variation in defense compounds. Moreover, the variation in chemical anti-browsing defense had no clear effect on the level of invertebrate damage, indicating that many other factors than food quality regulate the abundance and importance of herbivores. This study does, for the first time, reveal the circumpolar variation in anti-browsing defense in dwarf birches, which will be vital for a mechanistic understanding of the greening of the arctic in the future

The development of established shrub seedlings in persistent historical reindeer milking grounds

This study focuses on how established shrub seedlings (Salix myrsinifolia x phycilifolia and Vaccinium vitis-idaea) develop in historical milking grounds. Historical milking grounds are cultural remains from the intensive reindeer herding era when the Sami migrated with closely controlled herds. Although the places were never fenced, the high concentration of reindeer close to the tenting grounds created patches of grass and forb dominated vegetation in areas outherwise dominated by deciduous or ericoid shrubs. Despite about 100 years of abandonment the shrubs have not come back and the milking grounds are still clearly visible in the landscape. One theory why the former milking grounds are so stable is that shrubs cannot establish from seedlings due to unfavorable abiotic conditions, or due to competitive dominance of already established forbs and grasses. I tested this hypothesis by planting shrub seedlings in the milking grounds and in reference areas, with and without neighboring vegetation and investigated seedling survival and growth. The results show that shrub seedlings are able to both survive and develop in milking grounds suggesting that the seedling state is not the limiting factor in shrub encroachment in the milking grounds

Circumpolar impacts of herbivores on Arctic tundra vegetation

Arctic tundra vegetation provides many ecological services that have implications for the global climate. However, the tundra biome is currently changing in response to increasing temperatures. Herbivores may mitigate some of these responses to warming through their impact on Arctic vegetation. Understanding plant-herbivore interactions is therefore crucial to make better predictions of future Arctic vegetation changes and possible ecological consequences. Most current knowledge on plant-herbivore-interactions in the Arctic comes from local studies that do not allow for large-scale generalisations due to non-comparable methods. Also, existing large-scale studies of herbivory do not cover the tundra biome in a representative way. In this thesis, I used standardised methodology in biome-wide sampling across the Arctic tundra, to uncover how plant-herbivore interactions shape circumpolar vegetation patterns.   I have identified clear biogeographic patterns in plant chemical defence against herbivores that could influence the capacity of herbivores to control warming-driven increases of birch shrubs. I also found that herbivores counteract many effects of climate change on tundra vegetation by reducing vegetation greenness (NDVI), Leaf Area Index (LAI), vegetation density and shrub abundance and thereby mitigate vegetation responses to climate warming. Herbivores also increase species richness across the Arctic by supressing dominant species but not by increasing light availability. In a detailed study, I show that the effects of large and small herbivores are similar between continents although they vary with habitat type. This thesis advances our understanding of top-down control of herbivores on tundra vegetation and provides important tools to better predict future Arctic vegetation changes

Stockholms modevecka synad i sömmarna : en undersökning om vad som ligger till grund för aktörernas syn på sin och övriga aktörers medverkan

Background: Over the past few years Swedish fashion has expanded and gained attention, both in Sweden and abroad. Every year fashion weeks take place around the world with the purpose of showcasing fashion designers new collections for the up-coming season. Fashion week in Sweden is arranged in Stockholm four times a year in the end of January, in February, in the turn of June and July and in August. The different occasions have different activities and focus. The main focus of January and June/July are fashion shows and the main focus of February and August are trade fairs for buyers and wholesalers. The fashion shows and trade fairs are closed to the public, but other fashion events directed to the public takes place during these weeks. Seeing as many stakeholders are involved in fashion week they all have some kind of relationship to one another. This makes fashion week in Stockholm an interesting case to study and analyze from a sociological theoretical approach