Sökning: "Lars Tranvik"

Visar resultat 1 - 5 av 19 avhandlingar innehållade orden Lars Tranvik.

  1. 1. Organic Phosphorus Compounds in Aquatic Sediments : Analysis, Abundance and Effects

    Författare :Joakim Ahlgren; Emil Rydin; Monica Waldebäck; Lars Tranvik; Karin Markides; Sven Blomqvist; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Environmental chemistry; Organic phosphorus; aquatic sediment; eutrophication; NMR; internal loading; sample preparation; extraction; degradation; Miljökemi; Environmental chemistry; Miljökemi;

    Sammanfattning : Phosphorus (P) is often the limiting nutrient in lacustrine and brackish eco-systems, and enhanced input of P into an aquatic system might therefore negatively impact the environment. Because modern waste water manage-ment have reduced external P input to surface waters, internal P loading from the sediment has become one of the main P sources to aquatic ecosys-tems, in which relatively unknown organic P compounds seem to be more active in P recycling than previously thought. LÄS MER

  2. 2. Ecology across Boundaries : Food web coupling among and within ecosystems

    Författare :Pia Bartels; Peter Eklöv; Lars J. Tranvik; Daniel E. Schindler; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; cross-ecosystem; food web; habitat coupling; terrestrial-aquatic linkages; subsidy; allochthonous; lake ecosystem; population divergence; trait variation; Terrestrial; freshwater and marine ecology; Terrestrisk; limnisk och marin ekologi; Freshwater ecology; Limnisk ekologi; Biology; Biologi; Biology with specialization in Limnology; Biologi med inriktning mot limnologi;

    Sammanfattning : Cross-boundary movements of energy and material are ubiquitous. Freshwater ecosystems receive nutrients, dissolved, and particulate organic matter from adjacent terrestrial ecosystems, whereas terrestrial ecosystems mainly receive prey organisms and detritus deposited by physical processes such as floods from freshwater ecosystems. LÄS MER

  3. 3. Coarse detritus in oligotrophic lake littoral zones : utilization by intervertebrates and contribution to carbon flow

    Författare :Irene Bohman; Jan Herrman; Lars Tranvik; Jan Stenson; Mark O. Gessner; Högskolan i Kalmar; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Shredders; Biodiversity; Ecosystem; Limnology; Nattsländor; Sjöar; Kol; Biologisk nedbrytning; Freshwater ecology; Limnisk ekologi; Akvatisk ekologi; Aquatic Ecology;

    Sammanfattning : Syftet med denna avhandling är att öka förståelsen av hur grovt organiskt material, sk grovdetritus, tex löv och makrofytrester, bryts ner i sjöars strandzoner. Motivet bakom intresset för detta är att små näringsfattiga sjöar i skogsrika områden ofta är beroende av tillförsel av energi utifrån och att nedbrytningen av grovdetritus är relativt lite undersökt i sjöar. LÄS MER

  4. 4. Bottom-up and top-down regulation of heterogeneous lake food webs

    Författare :Fernando Chaguaceda; Peter Eklöv; Kristin Scharnweber; Lars Tranvik; Blake Matthews; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; food webs; resource coupling; ontogenetic diet shifts; resource specialization; bottom-up; top-down; browning; eutrophication; lake; mesocosms; fatty acids; apparent competition; Biology with specialization in Limnology; Biologi med inriktning mot limnologi;

    Sammanfattning : Food webs are networks of organisms linked by trophic interactions that regulate the responses of ecosystems to environmental change. Such regulation is a result of the effects of resources on the abundance of their consumers (i.e. bottom-up effects) and/or the influence of consumers on the abundance of their resources (i. LÄS MER

  5. 5. The Niches of Bacterial Populations in Productive Waters : Examples from Coastal Waters and Four Eutrophic Lakes

    Författare :Alexander Eiler; Stefan Bertilsson; Lars J. Tranvik; Janet Jansson; Katherine McMahon; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Ecology; diversity; 16S rRNA; phytoplankton; bloom; pathogen; carbon cycle; Ekologi;

    Sammanfattning : Recent research in microbial ecology has focused on how aquatic bacterial communities are assembled. Only a few of these studies follow a “Gleasonian” approach where the roles of single bacterial populations are in focus. LÄS MER