Search for dissertations about: "Nutrient cycling"

Showing result 1 - 5 of 98 swedish dissertations containing the words Nutrient cycling.

  2. 1. Herbivores influence nutrient cycling and plant nutrient uptake : insights from tundra ecosystems

    Author : Hélène Barthelemy; Olofsson Johan; Ellen Dorrepaal; Ann Milbau; Gough Laura; Umeå universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Reindeer grazing; large herbivores; nutrient cycling; plant nutrient uptake; soil nutrient availability; arctic plant ecology; soil microbial communities; 15N stable isotopes; plant-soil interactions; plant quality; dung and urine.; Environmental Science; miljövetenskap; biology; biologi;

    Abstract : Reindeer appear to have strong positive effects on plant productivity and nutrient cycling in strongly nutrient-limited ecosystems. While the direct effects of grazing on vegetation composition have been intensively studied, much less is known about the indirect effect of grazing on plant-soil interactions. READ MORE

  4. 2. Nutrient cycling in agroecosystems: nitrogen cycling in southern Sweden in the 1850s and two Tanzanian villages in the 1990s

    Author : Lars-Erik Williams; Biologiska institutionen; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; nutrient; nutrient model; nutrient cycling; nitrogen fixation; nitrogen budget; mixed system; miombo; manure; livestock; land use; historical system; food production; efficiency; crops; agroecosystem; carrying capacity; phosphorus; Scania; sustainability; Plant ecology; Växtekologi;

    Abstract : This study presents a general model for analysing nutrient cycling in agroecosystems. The focus is on food production intensity, human carrying capacity, sustainability and efficiency. The model can be used on systems including different kinds of land uses, which makes it applicable for studies on different scales. READ MORE

  5. 3. Silicon cycling in the Baltic Sea : Trends and budget of dissolved silica

    Author : Liana Papush; Åsa Danielsson; Lars Rahm; Petra Tallberg; Linköpings universitet; []
    Keywords : Dissolved silica; trends; nutrient; nutrient ratios; diatoms; Redfield; limitation; eutrophication; riverine load; budget; fluxes; accumulation; retention; optimisation; Baltic Sea; Löst kisel; trender; näringsämne; näringsämnens kvoter; kiselalger; Redfield; tillväxtbegränsning; övergödning; flodtillförsel; budget; flöden; ackumulering; retention; optimering; Östersjön; NATURAL SCIENCES; NATURVETENSKAP;

    Abstract : The dissolved silicon (DSi) has a crucial role for growth of a large group of primary producers – diatoms and, hence, impact on functioning of the aquatic food web. This thesis contributes to an increased understanding of the modifications of the DSi cycling in the Baltic Sea. READ MORE

  6. 4. The Baltic Sea from the present to future : microbial carbon & nutrient cycling in a changing climate

    Author : Laura Seidel; Mark Dopson; Jarone Pinhassi; Ashfaq Ali; Stefan Hulth; Linnéuniversitetet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Climate change; coastal sediments; Baltic Sea; eutrophication; bacterial communities; 16S rRNA; metatranscriptomics; geochemical layers; diversity; nutrient- energy cycling; Klimawandel; Küstensediment; Ostsee; Eutrophierung; Bakterielle Gemeinschaften; 16S rRNA.; Metatranskriptome; Geochemische Schichten; Diversität; Nährstoff- Energiezyklus.; Klimatförändringar; bottensediment; kust; Östersjön; eutrofiering; mikrobiella samhällen; 16S rRNA; metatranskriptomik; geokemiska lager; diversitet; närsalts- och energiflöden; Akvatisk ekologi; Aquatic Ecology; Miljövetenskap; Environmental Science;

    Abstract : Climate Change is caused by the accelerated increase of anthropogenic greenhousegas emissions to the atmosphere and affects all ecosystems on our planet. A resultof higher CO2 uptake by the oceans as well as an increase of heat trapped in theatmosphere leads to, for example acidification, stratification, sea-level rise, oxygenloss, and temperature increase of the earth’s waterbodies. READ MORE

  7. 5. Impacts and drivers of insect herbivory on element cycling in forests globally

    Author : Bernice Hwang; MERGE: ModElling the Regional and Global Earth system; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; biogeochemical cycling; folivory; insect cadavers; insect frass; insect herbivory; litter decomposition; nutrient cycling; carbon; nitrogen; phosphorus; silicon; silica;

    Abstract : The effects of insect herbivores on forest functioning are not well understood even though they can have important impacts on ecosystem processes by intercepting foliage before resorption and depositing nutrient-rich materials to the soil. In this thesis, I investigated the impact and drivers of insect folivores on carbon (C), nitrogen (N), phosphorus (P) and silica (Si) cycling in broadleaf forests, and how this varies with major climate variables. READ MORE